How Did My Girlfriend Run Away with My Best Friend

Last summer my girlfriend ran away with someone else. To make things worse it was my best friend with whom she ran away. Relationship seems perfect until something like this happens to you. I was in the 9th grade when I met my ex. She was in the same section with me. To me she was the cutest girl I could ever imagine. On the first sight I had a crush on her. I had the first chance to talk to her in a lab class. I was assigned as her lab partner. Slowly we came closer to each other. One day I proposed her in front of her friends. She accepted. That’s how it all started. Things were going too well. We used to date at least four times a week. We had a perfect relationship for more than two years. But things started to fall apart from the beginning of last year. And it all ended in a single month. The first thing that happened, we had a date in KFC. I reached there in time. But for the first time she was late. So I waited. But she didn’t come. I waited for a whole hour but there was no sign of her. Then I called her. But her number was busy. So I failed to contact her. After waiting for two hours I returned home. The following night I tried to call her again. But she wasn’t picking up. I signed in to face book and I found her online. So I send a message why she didn’t come. After a while I got a message saying I am the one who didn’t come. I was shocked. I thought it was a misunderstanding. So I tried explained everything. But I got no more reply from her that night. Next day I found her in the class. I saw her talking to my best friend Rifat. I went to them and shockingly she ignored me. I asked Rifat what was happening. But I didn’t get any clear answer. Then it was the Valentine’s Day. I planned to resolve everything between us. I knew where to find her on that day. So I went there in time. And in that particular time what I saw I wish I hadn’t seen. I saw Rifat proposing her and she accepted. Later I understood that the whole thing was a lie. From the very beginning she had a crush on Rifat. She just used me to get close enough to Rifat. I am never going to forgive her for using me like this I thought this first. But life will not stand still for me. I know I have to move on without her. Whatever she thought my feeling for her was real. I wish for her welfare wherever she is, whoever she’s with.

Study of Electromagnetic Clutch

ACKNOWLEDGEMENT It gives us great pleasure when a certain task is accomplished with great zeal and enthusiasm. We would like to extend our heartfelt thanks and deep sense of gratitude to all those who helped us in completing this project. First and foremost, we feel greatly indebted to Mr. D. M. SINGH and Mr. UBAID AHMAD KHAN, from the core of our heart for their constant support and valuable guidance time to time, because they encouraged and persuaded us to complete the project. We are also thankful to entire faculty members for their support.In order to complete the project we have taken help from various sites, books, study material etc. INTRODCTION A clutch is a mechanism for transmitting rotation, which can be engaged and disengaged. Clutches are useful in devices that have two rotating shafts. In these devices, one shaft is typically driven by motor or pulley, and other shaft drives another device. The clutch connects the two shafts so that they can either be locked together an d spin at the same speed (engaged), or be decoupled and spin at different speeds (disengaged). The clutch disc (centre) spins with the flywheel (left).To disengage, the lever is pulled (black arrow), causing a white pressure plate (right) to disengage the green clutch disc from turning the drive shaft, which turns within the thrust-bearing ring of the lever. Never will all 3 rings connect, with any gaps. TYPES OF CLUTCH DOG CLUTCH A dog clutch is a type of clutch that couples two rotating shafts or other rotating components not by friction but by interference. The two parts of the clutch are designed such that one will push the other, causing both to rotate at the same speed and will never slip.Dog clutches are used where slip is undesirable and/or the clutch is not used to control torque. Without slippage, dog clutches are not affected by wear in the same way that friction clutches are. Dog clutches are used inside manual automotive transmissions to lock different gears to the rota ting input and output shafts. A synchromesh arrangement ensures smooth engagement by matching the shaft speeds before the dog clutch is allowed to engage. Wet and dry A ‘wet clutch' is immersed in a cooling lubricating fluid, which also keeps the surfaces clean and gives smoother performance and longer life.Wet clutches; however, tend to lose some energy to the liquid. A ‘dry clutch', as the name implies, is not bathed in fluid. Since the surfaces of a wet clutch can be slippery (as with a motorcycle clutch bathed in engine oil), stacking multiple clutch disks can compensate for the lower coefficient of friction and so eliminate slippage under power when fully engaged. Cone clutch A cone clutch serves the same purpose as a disk or plate clutch. However, instead of mating two spinning disks, the cone clutch uses two conical surfaces to transmit torque by friction.The cone clutch transfers a higher torque than plate or disk clutches of the same size due to the wedging acti on and increased surface area. Cone clutches are generally now only used in low peripheral speed applications although they were once common in automobiles and other combustion engine transmissions. They are usually now confined to very specialist transmissions in racing, rallying, or in extreme off-road vehicles, although they are common in power boats. This is because the clutch doesn't have to be pushed in all the way and the gears will be changed quicker. Centrifugal clutchA centrifugal clutch is a clutch that uses centrifugal force to connect two concentric shafts, with the driving shaft nested inside the driven shaft. Centrifugal clutches are often used in mopeds, lawnmowers, go-karts, chainsaws, and mini bikes. Fluid coupling A fluid coupling is a hydrodynamic device used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch. It also has widespread application in marine and industrial machine drives, where variable speed operation and/or controlled start-up without shock loading of the power transmission system is essential.Torque limiter It is also known as safety clutch. A torque limiter is an automatic device that protects mechanical equipment, or its work, from damage by mechanical overload. A torque limiter may limit the torque by slipping (as in a friction plate slip-clutch), or uncouple the load entirely (as in a shear pin). The action of a torque limiter is especially useful to limit any damage due to crash stops and jams. Torque limiters may be packaged as a shaft coupling or as a hub for sprocket or sheave. A torque limiting device is also known as an overload clutch. Electromagnetism What is an electromagnet?An electromagnet can be made by sending current through a coil of wire wound around an iron core. When current passes through a conductor, magnetic field will be generated around the conductor and the conductor become a magnet. This phenomenon is called electromagnetis m. Since the magnet is produced electric current, it is called the electromagnet. In short, when current flow through a conductor, magnetic field will be generated. When the current ceases, the magnetic field disappear. The direction of the magnetic field formed by a current carrying straight wire can be determined by the Right Hand Grip Rule or the Maxwell Screw Rule.What is magnetic field pattern? A magnetic field pattern can be represented by field lines that show the shape of the field. Magnetic field lines which are closed together represents strong field. Field direction is defined as the direction indicated by a compass needle placed in the magnetic field. Force on current carrying conductor If a current carrying conductor is placed in a magnetic field produced by permanent magnets, then the field due to current carrying conductor and the permanent magnets interact and cause the a force to be exerted on the conductor .The force on the current carrying conductor in a magnetic field depends on:- 1. The flux density of the field, B teslas 2. The strength of current, I amp 3. The length of the conductor perpendicular to the magnetic field 4. The direction of the field and current When the magnetic field, the current and the conductor are mutually perpendicular to each other then force exerted: F=IBL Newton When the conductor and magnetic field are at an angle, then the force exerted: F=IBLsin? Where; I=current, B magnetic field, L=Length of conductor ?-angle between conductor and magnetic field.Right Hand Grip Rule Grip the wire with the right hand, with the thumb pointing along the direction of the current. The other fingers give the direction of the magnetic field around the wire. The Maxwell's Screw Rules The Maxwell Screw Rules sometime is also called the Maxwell's Corkscrew Rule. Imagine a right handed screw being turn so that it bores its way in the direction of the current in the wire. The direction of rotation gives the direction of the magnetic fie ld. Electromagnetic clutch Electromagnetic clutches operate electrically, but transmit torque echanically. This is why they used to be referred to as electro-mechanical clutches. CONSTRUCTION A horseshoe magnet has a north and south pole. If a piece of carbon steel contacts both poles, a magnetic circuit is created. In an electromagnetic clutch, the north and south pole is created by a coil shell and a wound coil. In a clutch, when power is applied, a magnetic field is created in the coil. This field (flux) overcomes an air gap between the clutch rotor and the armature. This magnetic attraction, pulls the armature in contact with the rotor face.The frictional contact, which is being controlled by the strength of the magnetic field, is what causes the rotational motion to start. The torque comes from the magnetic attraction, of the coil and the friction between the steel of the armature and the steel of the clutch rotor. For many industrial clutches, friction material is used between the poles. The material is mainly used to help decrease the wear rate, but different types of material can also be used to change the coefficient of friction (torque for special applications).For example, if the clutch is required to have an extended time to speed or slip time, a low coefficient friction material can be used and if a clutch is required to have a slightly higher torque (mostly for low rpm applications), a high coefficient friction material can be used. In a clutch, the electromagnetic lines of flux have to pass into the rotor, and in turn, attract and pull the armature in contact with it to complete clutch engagement. Most industrial clutches use what is called a single flux, two pole design. Mobile clutches of other specialty electromagnetic clutches can use a double or triple flux rotor.The double or trip flux refers to the number of north/south flux paths, in the rotor and armature. This means that, if the armature is designed properly and has similar banana slot s, what occurs is a leaping of the flux path, which goes north south, north south. By having more points of contact, the torque can be greatly increased. In theory, if there were 2 sets of poles at the same diameter, the torque would double in a clutch. Obviously, that is not possible to do, so the points of contact have to be at a smaller inner diameter.Also, there are magnetic flux losses because of the bridges between the banana slots. But by using a double flux design, a 30%-50% increase in torque, can be achieved, and by using a triple flux design, a 40%-90% in torque can be achieved. This is important in applications where size and weight are critical, such as automotive requirements. The coil shell is made with carbon steel that has a combination of good strength and good magnetic properties. Copper (sometimes aluminium) magnet wire, is used to create the coil, which is held in shell either by a bobbin or by some type of epoxy/adhesive.To help increase life in applications, f riction material is used between the poles on the face of the rotor. This friction material is flush with the steel on the rotor, since if the friction material was not flush, good magnetic traction could not occur between the faces. Some people look at electromagnetic clutches and mistakenly assume that, since the friction material is flush with the steel that the clutch has already worn down but this is not the case. Clutches used in most mobile applications, (automotive, agriculture, construction equipment) do not use friction material.Their cycle requirements tend to be lower than industrial clutches, and their cost is more sensitive. Also, many mobile clutches are exposed to outside elements, so by not having friction material, it eliminates the possibility of swelling (reduced torque), that can happen when friction material absorbs moisture. HOW DOES IT WORKS The clutch has four main parts: field, rotor, armature, and hub (output) . When voltage is applied the stationary magne tic field generates the lines of flux that pass into the rotor. (The rotor is normally connected to the part that is always moving in the machine. The flux (magnetic attraction) pulls the armature in contact with the rotor (the armature is connected to the component that requires the acceleration), as the armature and the output start to accelerate. Slipping between the rotor face and the armature face continues until the input and output speed is the same (100% lockup). The actual time for this is quite short, between 1/200th of a second and 1 second. Disengagement is very simple. Once the field starts to degrade, flux falls rapidly and the armature separates.One or more springs hold the armature away from the rotor at a predetermined air gap. Engagement time There are actually two engagement times to consider in an electromagnetic clutch. The first one is the time that it takes for a coil to develop a magnetic field, strong enough to pull in an armature. Within this, there are two factors to consider. The first one is the amount of ampere turns in a coil, which will determine the strength of a magnetic field. The second one is air gap, which is the space between the armature and the rotor. Magnetic lines of flux diminish quickly in the air..Air gap is an important consideration especially with a fixed armature design because as the unit wears over many cycles of engagement the armature and the rotor will create a larger air gap which will change the engagement time of the clutch. In high cycle applications, where registration is important, even the difference of 10 to 15 milliseconds can make a difference, in registration of a machine. Even in a normal cycle application, this is important because a new machine that has accurate timing can eventually see a â€Å"drift† in its accuracy as the machine gets older.The second factor in figuring out response time of a clutch is actually much more important than the magnet wire or the air gap. It involves cal culating the amount of inertia that the clutch needs to accelerate. This is referred to as â€Å"time to speed†. In reality, this is what the end-user is most concerned with. Once it is known how much inertia is present for the clutch to start then the torque can be calculated and the appropriate size of clutch can be chosen. Most CAD systems can automatically calculate component inertia, but the key to sizing a clutch is calculating how much inertial is reflected back to the clutch or brake.To do this, engineers use the formula: T = (wk2 ? ?N) / (308 ? t) Where T = required torque in lb-ft, WK2 = total inertia in lb-ft2, ? N = change in the rotational speed in rpm, and t = time during which the acceleration or deceleration must take place. There are also online sites that can help confirm how much torque is required to accelerate a given amount of inertia over a specific time. Circuit design and analysis OBJECTIVE A control circuit is to be designed to control the motor and drive unit. The Design specifications are to be fully implemented.An incomplete circuit and equipments are given and once it is understood appropriate values for the different components should be decided. These values should allow the circuit to perform as specified. Design Specification A circuit is to be designed which is 1. Allows the angular speed of the motor to build up to a value of 20 revolutions per minute (rpm), in a time of 2 seconds (s). 2. Maintains the angular speed of 20 rpm for a time of 3s. 3. When clutch pedal is pressed it brings the machine to a halt in a time of 1s. 4.Builds up the angular speed again to 20 rpm, in a time of 2s, except this time in the opposite direction. 5. Maintains the angular speed of 20 rpm for a time of 6s. 6. Brings the machine to a halt in a time of 1s. 7. Repeats the cycle above (1-6) indefinitely when powered on. The motor must not be in dynamic braking mode at the same time as it is being driven. CIRCUIT OPERATION The initial design for the complete circuit is shown below. All references to components refer to this circuit diagram. * ANALOGUE SECTION When power is supplied to the circuit the 555 Timer switches on and its output pulses high.The initial high pulse is longer because the 555 Timer is initially at 0V. The capacitor C3 usually charges from 1/3Vcc to 2/3Vcc. However initially it has to charge from 0V to 2/3Vcc. The duration of this initial high pulse is ta = 1. 1(R6 + R7)*C3 After the initial high pulse a constant charge time is the capacitor charge time is given as tc= 0. 693(R6 + R7)*C3 (1) The output of the timer is brought up to +5V by R5. Pin 3 of the 555 Timer is at +5V when the output is at logic high.TR2 is then forward biased due to the fact that it is a NPN transistor and its collector is grounded. TR2 has a base current limiter R4. TR1 has a base current limiter R2. Transistor TR1 is now reversed bias (i. e. it is open circuited) and C1 now charges up via resistor R1. As a result the motor turns on. If suitable values of resistor R1 and capacitor C1 are used then the required waveform will be obtained for the analogue output. The duration of this low pulse is td= 0. 693(R7)*C3 (2) Pin 3 of the 555 Timer goes to 0V.TR2 is then reverse biased due to the fact that it is a NPN transistor and its collector is at +5V. Transistor TR1 is now forward biased (i. e. it is short-circuited) and C1 now discharges. The motor is now switched off. * Digital Section The voltage at the collector of TR2 provides the input clock pulse for IC2, which is configured so that it is triggered on the rising edge. Both the inputs A1 and A2 are always grounded. When the output from pin 3 of the 555 Timer is high the transistor TR2 forward biased. Therefore the input to IC2 is high. It is seen that when this occurs the output Q is high.This in turn becomes a clock signal for the J-K flip- flop (IC3) and provides Logic 1 on one of the OR-gate inputs of IC4. After IC2 is triggered, it remains high fo r a time determined by the formula tw= C2*R8*ln2 (3) C2 and R8 control the length of time of braking as well as switching the direction of the motor. When IC2 is reset a pulse is sent to the negative edge triggered J-K flip-flop (IC3). From the Data sheet for (IC3) it is seen that with the clear high and both the inputs J and K high the JK toggles.Assuming that the initial state of (IC3) is Q = 1 and Q = 0, A is initially at logic 0 and B is at logic 1. Therefore the motor will rotate to the left in an anti-clockwise direction. When IC 2 is being triggered logic 1 will be applied to both of the OR-Gates of IC4. As a result A and B will be high. The motor will now be in dynamic braking mode. When the IC 2 is reset, Q now is logic zero and Q is logic high. Therefore A will be high and B will now be zero. The motor will now run in a clockwise direction. When the IC 2 is re-triggered it will again be in dynamic braking mode.Circuit Simulation PSpice Before building the circuit that the group had modified and it was necessary to simulate its operation to see if the design we had would work correctly i. e. within the parameters. The simulation was carried out in an electrical simulation package Pspice. Pspice is a useful design tool that allows the testing of electrical circuits without the necessity to build them. It allows designs to be modified quickly and easily so that new ideas and improvements can be incorporated, before the circuit is constructed.This saves time and a considerable part of the effort when de-bugging the wiring and operation of the circuit. There were a number of reasons that the group simulated the circuit before going to the actual building stage. The main advantage was that Pspice allowed us to use theoretical values for components so we could get the timing of the circuit-very important in this case- exactly right. Although this does not mean that ‘ideal’ components may be used in practice it allowed us to narrow the range of available components that were required. This saved time when building and testing the circuit.Another advantage was that the wiring of ICs (Integrated circuit) was made simpler because we could use the Pspice schematics as a visual aid COMPONENTS USED Resistors The resistor's function is to reduce the flow of electric current. This symbol is used to indicate a resistor in a circuit diagram. There are two classes of resistors; fixed resistors and the variable resistors. They are also classified according to the material from which they are made. The typical resistor is made of either carbon film or metal film. There are other types as well, but these are the most common.Fixed ResistorsA fixed resistor is one in which the value of its resistance cannot change. Carbon film resistorsThis is the most general purpose, cheap resistor. Usually the tolerance of the resistance value is  ±5%. Power ratings of 1/8W, 1/4W and 1/2W are frequently used. Carbon film resistors have a disadvantage ; they tend to be electrically noisy. Metal film resistors are recommended for use in analog circuits. The physical size of the different resistors is as follows. METAL FILM RESISTOR| | Metal film resistors are used when a higher tolerance (more accurate value) is needed.They are much more accurate in value than carbon film resistors. They have about  ±0. 05% tolerance. They have about  ±0. 05% tolerance. Resistors that are about  ±1% are more than sufficient. Ni-Cr (Nichrome) seems to be used for the material of resistor. The metal film resistor is used for bridge circuits, filter circuits, and low-noise analog signal circuits. From the top of the photograph 1/8W (tolerance  ±1%) 1/4W (tolerance  ±1%) 1W (tolerance  ±5%) 2W (tolerance  ±5%)| Rough size| Rating power (W)| Thickness (mm)| Length (mm)| | | 3| 1/4| 2| 6| 1| 3. 5| 12| 2| 5| 15| |VARIABLE RESISTORThere are two general ways in which variable resistors are used. One is the variable resistor which value is eas ily changed, like the volume adjustment of Radio. The other is semi-fixed resistor that is not meant to be adjusted by anyone but a technician. It is used to adjust the operating condition of the circuit. Capacitors The capacitor's function is to store electricity, or electrical energy. The capacitor also functions as a filter, passing alternating current (AC), and blocking direct current (DC). This symbol is used to indicate a capacitor in a circuit diagram.The capacitor is constructed with two electrode plates facing each other, but separated by an insulator. When DC voltage is applied to the capacitor, an electric charge is stored on each electrode. While the capacitor is charging up, current flows. The current will stop flowing when the capacitor has fully charged. Electrolytic Capacitors (Electrochemical type capacitors) The most important characteristic of electrolytic capacitors is that they have polarity. They have a positive and a negative electrode. [Polarised] This means that it is very important which way round they are connected.If the capacitor is subjected to voltage exceeding its working voltage, or if it is connected with incorrect polarity, it may burst. It is extremely dangerous, because it can quite literally explode. Make absolutely no mistakes. Generally, in the circuit diagram, the positive side is indicated by a â€Å"+† (plus) symbol. Electrolytic capacitors range in value from about 1 µF to thousands of  µF. Ceramic capacitors Ceramic capacitors are constructed with materials such as titanium acid barium used as the dielectric. Internally, these capacitors are not constructed as a coil, so they can be used in high frequency applications.Typically, they are used in circuits which bypass high frequency signals to ground. These capacitors have the shape of a disk. Their capacitance is comparatively small. TRANSISTORSThe transistor's function is to amplify an electric current. Many different kinds of transistors are used in ana log circuits, for different reasons. This is not the case for digital circuits. In a digital circuit, only two values matter; on or off. The amplification abilitiy of a transistor is not relevant in a digital circuit. In many cases, a circuit is built with integrated circuits(ICs). Transistors are often used in digital circuits as buffers to protect ICs.For example, when powering an electromagnetic switch (called a ‘relay'), or when controlling a light emitting diode. (In my case. ) Two different symbols are used for the transistor. PNP type and NPN type INTEGRATED CIRCUITSAn integrated circuit contains transistors, capacitors, resistors and other parts packed in high density on one chip. Although the function is similar to a circuit made with separate components, the internal structure of the components are different in an integrated circuit. The transistors, resistors, and capacitors are formed very small, and in high density on a foundation of silicon.They are formed by a v ariation of printing technology. There are many kind of ICs, including special use ICs. DIODEA diode is a semiconductor device which allows current to flow through it in only one direction. Although a transistor is also a semiconductor device, it does not operate the way a diode does. A diode is specifically made to allow current to flow through it in only one direction. Some ways in which the diode can be used are listed here. A diode can be used as a rectifier that converts AC (Alternating Current) to DC (Direct Current) for a power supply device.Diodes can be used to separate the signal from radio frequencies. Diodes can be used as an on/off switch that controls current. This symbol is used to indicate a diode in a circuit diagram. The meaning of the symbol is (Anode)(Cathode). Current flows from the anode side to the cathode side. RELAYThe relay takes advantage of the fact that when electricity flows through a coil, it becomes an electromagnet. The electromagnetic coil attracts a steel plate, which is attached to a switch. So the switch's motion (ON and OFF) is controled by the current flowing to the coil, or not, respectively.A very useful feature of a relay is that it can be used to electrically isolate different parts of a circuit. It will allow a low voltage circuit (e. g. 5VDC) to switch the power in a high voltage circuit (e. g. 100 VAC or more). The relay operates mechanically, so it can not operate at high speed. | WIRING MATERIALWire is used to electrically connect circuit parts, devices, equipment etc. There are various kinds of wiring materials The different types of wire can be divided largely into two categories: single wire and twisted strand wire, single wire is used to connect devices (resistors, capacitors etc. together on the PWB. It is also used for jumper wiring. Twisted strand wire can bend freely, so it can be used for wiring on the PWB, and also to connect discrete pieces of equipment. If single wire is used to connect separate equip ment, it will break soon, as it is not very flexible. It is convenient to use the single tin coated wire of the diameter 0. 32 mm for the wiring of PWB. If the diameter is larger, soldering becomes a little bit difficult. And if the diameter is too thin, it becomes difficult to bend the wire the way you want it to stay.DiscussionsElectro-Magnetic CompatibilityElectromagnetic compatibility is a field which is becoming ever more important in the modern world as the use of electronic devices becomes even more widespread. It refers to the effect of electromagnetic waves on an electrical device and the degree to which this device affects other devices in the neighbourhood. This interference can act in a number of ways. Conduction – the interference occurs because of a current flow into the circuit from an external source or from one part of the circuit to another via an unintended path. e. g. a loose wire.Inductive coupling – the interference is caused by a magnetic field i n the neighbourhood of the device. This can affect the electrons flowing in the wires of the device. Capacitive coupling – the interference is caused by an electric field in the vicinity of the device. This also affects the current flowing in the device. Radiation – this type of interference is caused by waves in the electromagnetic spectrum. One example of this is radio waves being affected by radiation from a nearby mobile phoneIn the control circuit for the de-burring machine there were very few sources of EM interference.The voltage levels used meant that any waves generated would probably not be of sufficient power to affect external devices. The time was not available to measure the interference being generated by the control circuit but if a real company was planning to develop this product they would have to test it thoroughly to ensure that no compatibility problems would exist under normal operating conditions. For example in a factory environment it is possi ble that the circuit could be placed near sensitive devices such as computers.The reverse is also true the manufacturer must check to ensure that the circuit is not adversely affected by the other forms of EM interference generated in the workplace by devices such as robots, air conditioning systems and motors. One advantage of the control circuit for the de-burring machine is that it is very compact so it would therefore not be too expensive to construct a case which would shield the device from external sources of EM waves and also contain any emissions generated by the device. It would also be possible to put a filter on the analogue output from the circuit to remove any noise being picked up by the circuit.This would ensure that the analogue output was not seriously affected; however it is not really necessary. The analogue output level for the device was chosen to be 1. 2V because this gives a relatively low RPM however it could be raised so that any noise picked up would only alter the analogue output by a very small percentage. The gearing could then be adjusted to give the correct speed. The largest source of EM emissions from the de-burring machine would probably be the motor itself. This is because of the magnetic fields generated by the rotor and stator coils.As stated on the motor data sheet no testing has been carried out on the EMC of the motor but no effect has been noticed on the circuit. The simplest solution to any problems caused by the motor would be to place some form of shielding around the motor or to place the motor a distance away from the control circuit. GearingThe motor and control unit used in the construction of the circuit was not suitable for operation at the low RPM required for the drum of the de-burring machine. The lowest voltage possible speed input to the control unit was 500 rpm when the input voltage was 1V.In order to scale down the speed of the drum it was decided to use a gearing unit. In order to meet the specificati ons of the design brief it is required to drop the speed of the motor to 20rpm. Given the current design of the circuit the output voltage of 1. 2V gives a speed of 800rpm. This means that a gear ratio of 800:20 or 40:1 is required. This can be achieved by using two gear wheels with diameters in the ratio 40:1 but this would not be practical as it would require one wheel to be a great deal larger than the other. Using 2 gear wheels would also result in the drum turning in the opposite direction and this is undesirable.Gear TrainsAnother possible gear combination to achieve the required reduction in speed would be to use three cogs. The first two would be in the ratio 8:1 and then the second two in the ratio 5:1. To achieve this a ‘gear train’ would have to be formed as shown in figure 5. 1. This would save space and also correct the problem of the drum rotating in the wrong direction as the second cog would reverse the direction then the third would return it to normal. Planetary GearingAn even more compact method of gearing would be to use what is known as a planetary gear.In this type of gearing mechanism the smaller cogs are fitted inside the larger cogs as shown in figure 5. 2 below. The red cogs are held stationary and the yellow gear is connected to the input. This saves space by having the input and output on the same axis and also makes the mechanism more robust by using three central gears instead of one. This would reduce the servicing required by the machine which is an important consideration in industry. The red and yellow gears would be in the ratio of 5:1 and the blue and red gears would have to be in the ratio 8:1 to give the required 40:1 reduction.Worm GearsThe final type of gear to be considered is the worm gear (figure 5. 3). In this system the reduction factor can be very large which would allow one cog to make the 40:1 reduction? Worm gears also have the useful property of being one way. The angle between the worm and the gea r teeth is such that the worm can turn the gear but the gear cannot be used to turn the worm. This would be particularly useful as an additional form of braking for the drum of the de-burring machine however the circuit would have tobe re-designed to slow the analogue output from its full voltage to zero gradually.If this were not done the gears would lock when the motor stopped and the sudden jerk would place a great stress on the components. If the circuit was to be re-designed as suggested the dynamic braking of the motor would be redundant. Improvements to DesignAfter completion of the circuit it was evident that a number of improvements could be made to the design that would make the circuit more versatile or better suited to its task. These will be covered in this section with the aim of showing possible routes for further development of the circuit. Had time permitted some of these could have been tried in the laboratory.Perhaps the simplest of the possible routes for improvi ng the circuit is the replacement of resistors R6 and R6 with variable resistors. This would allow the forward and reverse times for the drum spinning to be altered. In this way the most suitable length of time for the parts to be de-burred can be found without the need to re-build the circuit. It would also mean that different components, requiring different lengths of time, could be de-burred in the same machine, although not at the same time. This would allow the machine to be more flexible and save the company money.By using variable resistors the times could also be fine tuned to compensate for any errors in the timing caused by the tolerances of the components used and also any extra resistance caused by the non-ideal nature of the components. Another improvement to the design would be to eliminate the extended first pulse from the 555 timer which causes the drum to rotate longer on its first cycle. Because the pulse is part of the operation of the 555 timer it is hard to alte r before it affects the analogue out so one solution would be to have some form of clutch system between the drum and motor.This would disengage the drum from the motor at start-up and not allow the drum to be turned until after the first cycle. Some form of circuit could be designed to control the clutch and only engage the motor after the first cycle has passed. Another alternative would be to have the clutch only engage after a set time equal to the duration of the first cycle. This could either be a mechanical or electrical timer and would be required to engage the clutch after 7. 746†¦ +1+8=16. 75sec. Some form of switch could also be incorporated into the circuit to reset the JK flip-flop each time the circuit is switched on.This ensures that the flip-flop always starts in the correct state and that the motor is always turning in the right direction for its first rotations. This switch would also allow the cycle to be restarted without turning the power off. Such a functi on could be simply implemented by connecting the reset pin to +5V via a switch. A final consideration when improving the circuit would be to alter the switching circuit for R6 in such a way that one resistor is always connected and connecting a second resistor in parallel with it alters the total resistance as shown in figure A.A-Alternative Switching CircuitPractical ConsiderationsWhile the motor circuit worked as required in the laboratory test, a number of other factors must be brought into consideration when the circuit is being designed for use in industry. One of the major factors has already been discussed in the section on EMC but there are many more will be briefly covered in this section. One of the most obvious differences between the test equipment and an industrial system is the motor being driven.For safety reasons the motor connected to the circuit was a low power motor but to drive a large drum a larger motor with a higher torque would be required. While the controll er card used can only support motors with an operating voltage up to 30V, a similar controller could be designed to operate at much higher output voltages while still being run off of the same circuit. Another possibility would be to run a number of motors off of on control circuit. This would allow a much greater number of parts to be de-burred without the need for an exceptionally large drum. This would introduce the problem of fan-out however.The relatively low analogue output voltage of 1. 2V would have to be increased if a large number of controller cards were to be driven. The same is true of the voltages from the OR gates controlling direction. This is problem is easily rectified by using op-amps to boost the voltage. When the system is being used in a factory environment there are also a number of environmental issues to be deal with. There could be a great deal of dust or fine particles of metal in the air from the de-burring process, it is also possible that in an automate d process the factory may not be heated.Placing the control circuit in a sealed container can resolve some of these issues, as this will prevent dust from affecting its operation. It would also be possible to incorporate shielding into this casing to improve EMC. The temperature issue is not very important, as it is unlikely that the operating ranges of the IC would be exceeded. For 74 series chips this is in the region of 0-70? C and 54 series chips have an operating range of about –50-120? C. The final consideration when constructing a system for industry would be ease of manufacture.If a large number of these machines were required the circuit would have to be laid out in such a way that it could be easily constructed on printed circuit boards. There are computer programs available to aid the designer in this process and it would be unlikely to cause a major problem. ConclusionsHaving designed and constructed the circuit it was felt that it met all of the given specificati ons although there were still a number of improvements that could have been made. These improvements have been covered briefly in the discussion section and given more time they could have been implemented in the circuit.As already mentioned the only specifications not met were that on start-up the machine should rotate for 3 seconds in one direction before braking and reversing. Using the clutch method mentioned in the discussions could solve this but the design brief given did not extend to cover the drum so has not been included in the final design. During the course of the project a number of other points became evident which greatly ease the process of designing an electronic circuit. Simulation using a computer package such as Pspice saves a considerable amount of time by allowing the circuit to be easily laid out and tested.Any changes required can be made easily without disturbing the rest of the circuit. Another advantage of Pspice is the ability to produce graphs of the ou tputs from the circuit, which can then be scaled, formatted and printed as required. To do this for the actual circuit requires very specialised and expensive equipment. In conclusion, the group felt that all objectives had been met and that the final circuit was successful in fulfilling its role. A number of important lessons were learned about the problems involved in designing a circuit to meet a real-world need and ways of overcoming these problems were found.BILL OF MATERIALS S. NO. | ITEMS| Quantity| PRICE | 1. | motor| 1| | 2. | Diode | | | 3. | capacitor| | | 4. | 555 timer| | | 5. | Relay switch| | | 6. | Coils| | | 7. | resistances| | | 8. | transformer| | | 9. | Wiring materials| | | 10. | Integrated circuit| | | 11. | Wiring board| | | References[1] Schematic Capture with Microsim Pspice Herniter Prentice Hall 3 Ed. Rd P250-252[2] http://www. emclab. umr. edu/An Introduction to EMCUniversity of Missouri-Rolla EMC laboratory[3] http://reality. sgi. com/csp/scvemc/emcdef. tmlEnsuring Compatibility Between the Electromagnetic Environment and Electric and Electrical Devices Kimball William, Chairman, IEEE EMC Education Committee[4] http://www. howstuffworks. com/gears. htmHow gears Work[5]www. scribd . com[6]www. mechanicalprojects. comBackground Reading * Digital Fundamentals Floyd Prentice Hall 7 Edition t h. * Introductory Circuit Analysis Boylestad Prentice Hall 9 Edition t h. * Machine Design – R. K. Rajput. * Kinematics Of Machine – R. S. khurmi. * Automobile Engineering – R. K. Rajput | | |

A Message Without Words Essay

Select one (1) of the picture ads from the Benetton advertisement images document, located in the online course shell. Assume you are the project lead at Benetton. You and your team are tasked with revitalizing a social conscious campaign to address a world issue Benetton wants to draw attention to. Craft a message for this image and its appeal to the public on behalf of Benetton. The message selected for revitalizing a social conscious campaign to address a world issue that Benetton wants to draw attention to is, adoption and racial tolerance. Benetton wants people to realize that many children go without a real home or parents to love them and never get a real chance at childhood. They may have to live in orphanages, group homes or even worst, be placed from home to home in foster homes, because they never get adopted. The message is that love has no color, it is colorblind. It does not matter, what color the parents or the child are or what part of the world they come from, anyone can give the gift of love, by giving a child a home of their own. Define the goal of this campaign and the targeted audience with supporting rationale. The goal of Benetton’s communication and advertising is to target the global consumer and create a brand image and lifestyle. In past campaigns, Benetton has sought to create both a global dialogue about specific issues and make this part of its corporate culture. Benetton has used its advertising to champion social causes. Therefore, the goal of this campaign is to make people aware of the need for adoptions, the ease of adoption, bring attention to the beauty of adoption while combining racial tolerance, to promote colorless adoption. We want to shine the light on the colorblindness of adoption and that race, culture or creed should not matter, it is all about giving love. TARGET AUDIENCE – The target audience will be global consumers, men and women between the ages of 18 and 44, because according to J. Jones, PhD. with the National Center of Health Statistics, â€Å"†¦ about 2 percent of the adult population aged 18-44, or nearly 2 million persons, [have] adopted children (4). More than twice the percentage of men (2.3) had adopted a child compared with women (1.1). These percentages represent approximately 1.3 million men and 613,000 women. Higher percentages of people over age 30, who are currently or formerly married, who have given birth or fathered a child, or who have ever used infertility services have adopted children compared with people who are aged 18-29, never married, without biological children, or who have never used infertility services†. This audience was chosen because it represents the majority of the American adopting population and also follows the demographic of Benetton shoppers. Develop a model for the advertisement strategy you will use and briefly discuss each stage of the model. â€Å"Most adoption companies use an advertisement strategy that employs marketing techniques like advertising in local or national magazines. They may write articles, place personal ads or use advertorials in magazines† (Adoption Marketing, n.d.). â€Å"An advertorial is an advertisement in the form of an editorial† (Merriam-Webster Dictionary, n.d.). This method is used because when used in printed publications, the advertisement is usually written in the form of an objective article and designed to look like a legitimate and independent news story. This method has gotten much attention for adoptions, but can be very costly. Other methods that are generally used for marketing adoption are running ads in newspapers or in the Yellow Pages. Because most adoption agencies are non-profit, a non-profit business cannot spend a whole lot of money on marketing. Even though some of these methods are inexpensive, these traditional methods are not very effective and really cost adoption agencies more money than the results, they receive. The reason for such poor results if the fact that newspaper and telephone book use are in decline. Personal ads though, are still somewhat effective. For these reasons, Benetton has decided to support this cause and use their bold, controversial ad campaign and social media network tools, to draw attention to such a worthy cause. Benetton also likes to stir controversy and believes that through this campaign they can address that adoption should be colorblind. This is the reason for this particular image to be used. It is strong and quite an attention getter. We want to use marketing techniques to reach single, young men and women, as well as, couples. The marketing campaign will need to work well and be effective enough to reach singles and couples, who want a baby and are unable to have one or want to add to their existing families. Because this campaign is for a nonprofit, instead of selling a product, we will be trying to get people to take action. We must translate the concepts of for-profit marketing for financial reward to nonprofit marketing or â€Å"social marketing†. â€Å"Social marketing is defined as using marketing concepts and techniques to achieve specific behavioral goals for social good† (Miller, 2010). This researcher believes that a marketing plan really is a set of questions that once answered reveal the actual integrated marketing communications package. The marketing plan is a made up of topics and then the questions to address each topic. The elements of our marketing plan are as follows: 1. Marketing Goals – in this phase we define what we need to do or want to accomplish. As stated above, through Benetton’s bold ads and their existing social media network, our goal is to bring awareness to adoption and that giving love is colorblind and we will do this by targeting the global shopper. We need to make people aware of the ease of adoption and how adoption makes the world better for all parties involved. We have to examine our existing advertising network, to determine if this message a proper fit for our current methods of advertising. Will this message work in our in the current magazines, billboard network (buildings, Times Square, etc., in transit stations, on trains and buses), in our stores and within our established social media network, already in place; which has been used in our other social cause promotions? Should this campaign be just domestic or global and include our international advertisi ng? 2. Environmental Analysis – the conditions under which we will operate. During this stage, a SWOT analysis will be performed, to determine the strengths, weaknesses, opportunities and threats associated with matching adoption and the Benetton corporate image. Because we are operating within the framework of a retailer promoting their stores and products, as well as, this social cause, we will address each of the following conditions: a) What are the internal and external conditions under which this marketing program must operate? Internally, what is Benetton’s corporate governance policy and how have they handled their promotion of social causes in the past? Because much of Benetton’s social promotion has been so controversial, we will need to investigate this question carefully, because adoption involves children and is not strictly an adult issue. Also, are there any adverse corporate public relations issues of record which could arise, that would relate to the company supporting and endorsing adoption? Since Benetton is a global organization where will this promotion appear, in the United States, only or in international markets? Throughout our global market, what are the legal regulations and cultural differences regarding adoption,? Finally, what resources are available to promote this cause within the organization? Does Benetton already have resources in place to promote adoption or will there be the need for partnerships with others? If partnerships are necessary, which ones should be selected. b) What skills will we need to promote this cause and what ones do we have on staff now? c) What systems do we need in place for this IMC plan to succeed? Do we have the proper exposure and audience in place, to make the social media elements of the promotion successful? 3. Audience and Segmentation – Who must we reach and convince and what are their interests and values. (see Target Audience, p. 3 of this document). 4. Messaging – the specific message that will move the audience to action. The message is simple: Adopt!!! Love Is Colorblind. By showing the hand of a child of one race and the adult hand of another race, we wish to communicate that adopting any child is a great gift of love and race should not matter, racial tolerance. The message’s goal is to show that we can all love and share love with any child and make the world a better place, trough racial tolerance and coexistence. 5. Marketing Tactics – how will we deliver the messages? Because of the demographic of the Benetton shopper and the company’s past advertising for social causes, this researcher believes that that they have in place the distribution channels for this message. The methods selected are photographic ads in their current magazine relationships, open air billboards; and billboards in transit stations, on buses and trains and in their retail outlets. Benetton’s existing social media network channels will also be used as a part of this IMC mix. This will include the company website, an email banner and Twitter. 6. Budget and Staffing – the resources to implement the plan. In this phase, we outline the financial and staffing resources required to implement the plan. Questions that must be answered include: What will be the budget for this promotion? Do we have the skills, time, and talent on staff to produce this promotion? For this IMC program to succeed, do we have adequate knowledge about adoption, in house or do we need the support of partner? 7. Strategy Metrics – how will we measure progress against our goals? In a for-profit IMC program this is an extremely important step, but in promoting a social cause, this step is very different and very difficult to measure. Although we want more people to adopt, this is tangible. Getting people to look at others through colorblind eyes, becoming more loving and caring toward others and to increase racial tolerance, is not. Therefore, promoting this message and stirring up publicity and social consciousness about adoption, race issues and tolerance, are one way to measure the success of this social cause IMC program. Formulate an integrated marketing communications plan that communicates the message to the targeted groups. Within this plan, be sure to address: The technologies used along with expected benefits of each. How the message and goals will be promoted. The process of marketing occurs in five steps: Understanding the market and the company’s marketing strengths and weaknesses, developing a marketing strategy, building a marketing plan, implementing the plan, and monitoring the success of the plan. Now that we have formulated our integrated marketing communications plan, and identified our targeted group, we will address the technologies we intend to implement, as part of this IMC program. The technological methods we will use, will be the company website, an email banner and Twitter. The Internet offers innovative and cost effective methods for adoption marketing. Using the Benetton website, we will be able to focus on reaching more people, telling people what adopting means, to a child and to society as a whole. We will take the mystery out of the adoption process. An excellent method of using the website for social cause internet marketing is having a website blog chronicling true stories of happy events surrounding adoptio n, and the fact that this can be interactive and done in a matter of moments, will give Benetton an opportunity to gather consumer data. A good use of the email banner is pay-per-click advertising, this will lower the overall cost and give interested consumers a way to contact an actual adoption agency. It will give the agencies more traffic to their websites and help increase greater awareness. The use of Twitter to promote this cause, is an excellent choice, because the Benetton customer is young, international and upwardly mobile. Benetton has a reputation for being modern, young and on the edge, so this is a perfect fit. Twitter is mobile and â€Å"gives [the user] the ability to share 140-character thoughts in a split second, [Benetton] can easily share links to PR releases, [adoption success stories, positive race messages] and stories about [their] business†¦Ã¢â‚¬  (Lacey, 2010). Twitter can also be used to branch out into other social causes, keeping an eye on trending topics and using it to tweet, about more than just Benetton business. â€Å"Twitter gives [Benetton] the ability to take a single thought [or cause] and share it with millions of people. And [their] customer evangelists can spread [their] message, as well as their opinions about [the] company’s greatness to as many people as possible† (Lacy, 2010). Since Benetton has such a reputation for their involvement in social causes, this element of the IMC, is a perfect fit for the company and the cause. In fact, all three of these technologies fit perfectly with the Benetton consumer demographic and the company’s corporate image and culture. They will be effective, not only to bring attention to this campaign on adoption, but will work well with future social cause promotions. These internet marketing methods will even include search engine optimization, viral marketing and article marketing as well. Decipher and select at least two (2) types of individuals, groups, companies, etc., that you reach out to gain support for the campaign. Be sure to discuss the expected benefits that accompany each external partner you identified. Benetton wants to enhance its reputation and drive sales; and the nonprofit cause wishes to generate awareness of their mission. In this promotion we are drawing awareness to the Benetton brand, adoption and race tolerance. The first group that we will reach out to partner with and gain support for the campaign; will be adoption agencies and orphanages. Benetton has the brand name and the reputation that will get the public’s attention. They want to use and share this with the cause to promote adoption. This a great combination but, the company lacks the knowledge on adoption regulations, laws and the process. Adoption agencies and orphanages have this expertise. An adoption agency or orphanage must be well-versed in laws and regulations regarding adoption, because this industry is so strongly regulated. Each country and even within a country, each state may have a different set of rules, regulation and laws to follow. Adoption agencies and orphanages are also heavily licensed. Because of the stringent regulating and the involvement of children it is necessary to have a partner with this knowledge, to be successful in promoting this cause. For this reason, these organizations are obvious choices to be major partners in this ad campaign. To support the â€Å"colorblindness†/racial tolerance piece of this campaign, Benetton will partner with The Southern Poverty Law Center. This partner was selected because this organization â€Å"is a nonprofit civil rights organization dedicated to fighting hate and bigotry, and to seeking justice for the most vulnerable members of society†(Who We Are, 2012). The Southern Poverty Law Center was founded by civil rights lawyers Morris Dees and Joseph Levin Jr. and is internationally known for tracking and exposing the activities of hate groups. This partnership was selected because of the organization’s international reputation and their dedication to fighting race bigotry. Also, their attention to seeking justice for the most vulnerable members of society, one of which is children. They were also selected because they have a specific program aimed toward children of the world, which distributes, free of charge, documentary films, books, lesson plans and other mat erials that promote racial tolerance and respect. Once this IMC plan is implemented with these partners, Benetton will not only have a successful campaign on adoption and racial tolerance but, this IMC foundation can be used for future social cause promotions. References Adoption Marketing | Advertising Strategies for Agencies & Childrens Homes. (n.d.). Search Engine Positioning | Advertising, Marketing & Optimization. Retrieved December 9, 2012, from http://www.customermagnetism.com/adoption-marketing/ Advertorial – Definition and More from the Free Merriam-Webster Dictionary. (n.d.). Dictionary and Thesaurus – Merriam-Webster Online. Retrieved December 10, 2012, from http://www.merriam-webster.com/dictionary/advertorial Jones J. (2009). Who adopts? Characteristics of women and men who have adopted children. NCHS data brief, no 12. Hyattsville, MD: National Center for Health Statistics. Lacy, K. (2011). Twitter marketing. (2nd ed.). Hoboken, NJ: Wiley Pub.. Miller, K. (2010). The nonprofit marketing guide: high-impact, low-cost ways to build support for your good cause. San Francisco, CA: Jossey-Bass. Who We Are | Southern Poverty Law Center. (n.d.). Southern Poverty Law Center. Retrieved December 17, 2012, from http://www.splcenter.or g/who-we-are

Has the increase in trade in developing countries increased wage Essay

Has the increase in trade in developing countries increased wage inequality between skilled and unskilled workers in the develop - Essay Example inequality and unemployment can be observed in developed countries leading many to think that a connection between the two developments exists. The Increasing Trade in Developing Countries Table 1 shows a comparative illustration of the growth rates in export between developed and developing economies between the periods 1980 to 1990 and 1990 to 1999. Note that the start of the rise in world trade, especially in developing countries, is not shown and instead started two decades later. The growth rate in export rose by more than twice for developing countries and almost doubled that in import rate. On the other hand, the rates for both export and import decreased in the second period for the developed countries. There are two explanations of the current rapid trade growth: technological and political. Technocrats believed that advances in transportation and communication made the world smaller and trade and easier, whilst political scientists believed that political factors such as th e GATT and efforts of developing countries at self-liberalisation in trade explain the growth. Krugman contends, however, that the current rise in global trade is simply a self-correction after it went down during the two world wars implying that the current level is comparable to that prior to said wars. 3 Table 1 Comparative Export/Import Growth, 1980-90, 1990-994 Growing Wage Inequality in Developing Countries Parallel to the rise in global trade particularly involving in developing countries is an observable growing wage inequality between skilled and unskilled workers in developed countries. In a data compiled by OECD, some highly industrialised countries showed a rising wage inequality from 1980 to 2005. Figure 1 shows the comparative rise of income inequality in the USA, the UK, Australia and Canada. The USA income data particularly shows a steep rise in income inequality. The UK, Canada and Australia also revealed a rising pattern but not as pronounced as that of the US. The re are developed countries, however, that do not exhibit this phenomenon such as in the cases of Nordic countries like Norway, Sweden, Finland and Denmark and some continental countries such as France, Italy, Germany and Netherlands. Figure 1 Income Inequality in Continental and Anglo Countries5 Income Inequality as a Consequence of Trade Growth in Developing Countries Some quarter hold the view that the rising income inequality in developed countries is underpinned by the trade growth in developing countries. This is purportedly because the rapid movement of goods and capital in the global market favour those who are in a position to use such opportunity whilst undermined those who are not. The expanding global trade has presented high capital entrepreneurs a wider field with which to expand their business whilst low income group who cannot compete are left behind.6 Relative to this, two theories are used to explain the impact of trade liberalisation on wage inequality in the indus trialised world. The Heckscher-Ohlin theory suggests that

Perform a task analysis Assignment Example | Topics and Well Written Essays - 500 words

Perform a task analysis - Assignment Example One can get information about task identification by observing people using the product (or recalling how the person uses the product) or from the product’s technical documentation (especially user manual). This is followed by task classification into initial setup, product use, troubleshooting and maintenance, which is followed by task prioritization. The final part of task analysis is the development of task scenarios or task sequence, which arranges product tasks into the way they operate (Fain, 2006). This paper develops task analysis for a mobile phone. The primary goal of using a mobile phone is to communicate with other people having mobile phones by calling them, receiving calls from them, texting or receiving text messages from them. A mobile phone also stores date and time and it helps a person to know date and time. Other functions of the mobile phone include reminding a person about important activities, such as meeting, acting as an alarm to help someone to wake up as desired or perform a desired task at a given time and listening to songs stored in the mobile phone. Task prioritization is based on the importance of the task. For instance, communicating is considered the primary goal of the mobile phone, and it is, therefore given first priority. Second priority tasks are secondary tasks while third priority tasks are tertiary and are not necessary. Fain, W. B. (2006). Georgia Tech Research Institute Accessibility Monograph Series: A Study of Accessibility Issues and Potential Design Solutions for Designers, Procurement Officials, and Consumers. Georgia Tech Research

Critical analysis of the process of deconstructing an organisation in Essay

Critical analysis of the process of deconstructing an organisation in such a way as to be able to identify the organisations strategy and policy - Essay Example In the first one, the literature published by the organization in the form of reports and analysis is deconstructed to find out the emphasis and to interpret what it excludes. In addition to the texts of the organization, the symbols can also be deconstructed to find the inner meaning. The second approach is that the deconstruction enables us to write the organizational analysis. The main motive is to understand the theme of the context and how these are employed to understand the inner meanings of the texts. The texts interpret what the organizations do not want to talk about. The deconstruction process helps in the evaluation of the motives of the company. The process of deconstruction has not assumed popularity because it puts in question the integrity of the management and its publications. (Thorpe & Holt, 2008; Pp 71-72) However, the efficiency of the process cannot be questioned in the analysis of the company. The paper will discuss the process of deconstruction in the understa nding of the strategy and policy of the organization. As stated earlier, deconstruction as a process or an analytical tool has not assumed the popularity like the other analytical tools. This is because the deconstruction process emphasizes on the analysis of the inner meanings. Deconstruction as a process is based on the texts and the symbols of the organization. The texts and the symbols are analyzed to reveal the inner meaning. The deconstruction analysis is based on the observation of the organizations as bodies of texts. The organizations are not viewed as static entities and they are viewed as some structure, which have some inherent meaning. True to the deconstruction theory of philosophy, the texts of the organizations have inner meaning that reveals some important information about the organizations. The base of the deconstruction process is based on the observation of the texts of the

Research project (body scanning technology) Paper

Project (body scanning technology) - Research Paper Example These body imaging scanners can be found in several areas of the security industry, including in commercial loss prevention and in government buildings that require an extra level of security. However, one of the most popularly discussed usages of the technology is in airports, and in 2010 it was announced that these would be put into use at 28 airports in the United States, including New Yorks JFK and Fort Lauderdale International. The use of these has been defended by the US Homeland Security Secretary, who says that these will severely reduce incidences of smuggling, terrorism and on-flight crime. The following essay will discuss the technology in detail, including full details on the benefits that these machines can bring to the security industry. Following this, the privacy concerns which have been raised will be covered, as will the health issues that have been linked to the machines. Particular focus will be on the privacy concerns that have been dominating the media with rega rds to this technology, as it is a particularly pressing issue for those who feel we may be lapsing into a Big Brother state, as well as those who feel uncomfortable with the use and possible storage of these images. Body scanning technology is based on the principle of the millimeter wave. Most materials used for clothing are transparent when viewed under this frequency of radio band, and images taken by these scanners will therefore show any concealed objects that may not be evident to the naked eye. The scanners come in two forms, known as active and passive. The passive form is one that uses the natural energy emitted from objects, and is generally considered to be as safe as a digital camera for the person being photographed. The active scanners rely on directing these millimeter radio waves at the object and then reading the energy which has been directed back (Laskey, 2010). This

Living Peacefully in a World Free of Global Warming or Living with All Research Paper

Living Peacefully in a World Free of Global Warming or Living with All the Riches in a World Affected with Global Warming - Research Paper Example Contributing to the increasing levels of GHGs are various activities in which cars and power plants are recorded to be the main sources (Mohr, 2005). Indeed, human beings also have contributions to the levels of GHGs. In accordance to what is stated, developments in different countries lead to the heating up of the planet Earth. More and more buildings are set up and used as factories in order to gain wealth. Despite the campaigns that vehicles are emitting GHGs, people do not care. The present has been seen as the moment for development even though it is believed by some, as a destruction of the environment. Research Question: Which is better, living peacefully in a world free of global warming or living with all the riches in a world affected with global warming? Scope of Limitation: Findings of this research will be limited only to the responses of ten (10) environmental experts. Results from this study will only be based from their views and opinions. Significance of the Study: F indings shall educate individuals on the phenomenon of global warming. The conduct of this research will give indications on how individuals should protect their planet. Moreover, this investigation will also supplement the existing research in this field. Objectives of the Study: This research investigation aims to study how the global warming affects the entire world. Specifically, it also aims at knowing and identifying the effects of the said phenomenon through taking a special look on the life on earth as well as the atmosphere. Theoretical Framework: The theory of global warming will be the framework of this research. Global warming, as defined by James Hansen (2000), is mainly because of the occurrence of high levels of GHGs in the atmosphere in which is triggered by the activities of man. For Hansen (2000), the effect of these gases from burning of fossil fuel is climate change. Hypothesis: The increasing rate of greenhouse gases is threatening the life on earth, the negativ e effects being on the life of human beings and the atmosphere. II. Review of Related Literature Various views exist when people talk about global warming. Some are in agreement but some are opposing the other conceptualizations of the phenomenon of global warming. For Thakur (2009), emission of gases is just the contributor to the phenomenon but clearly not the origin. United Nations Environment Programme (2003) has acknowledged global warming is responsible for the climate changes. Some among the mentioned outcomes are more intense rain, severe flood and storms, more extreme heat waves, and the melting of glaciers. With the rapid changes, it is expected that all the fundamental Earth systems would also alter leading to the disturbance in all the aspects of environment. This disruption would then affect the lives of human beings because of the possible effect to food security. These changes, in effect, will inflict harm on human health. Eipsten (2000) added that with the rise of te mperature comes along the rise of many health diseases. This perspective fears the fact that it may not be possible for the human kind to have its next generation due to the effects it may cause the people. However, the contextualization of carbon causes global warming has been opposed. In Happer’s (2011) article, he claimed that the current warming that the planet currently

Object Essay Example | Topics and Well Written Essays - 750 words

Object - Essay Example The cup seemed to follow three geometrical figures, of a cone, a circle and a triangle. The main portion of the cup reminded me of an inverted cone though unfinished towards the cup’s base, thanks to the circular shape that is needed to balance its weight. The handle of the cup stood out from usual designs, by its triangular shape. The size of the cup made me apprehensive of its practical use, of holding it filled with tea, as it was just 10 centimeters tall and 7 centimeters in diameter. However, I was willing to buy it even as a showpiece, and the prize was not exorbitant. I just made sure in the shop that my two fingers can be inserted in the handle and that the cup does not tilt when I hold it. When I reached home, I tried using it as a teacup and was glad to find out that even with tea filled to its rim, the cup does not tilt, and the shape of the handle distanced my fingers from direct contact with the surface of the cup immediately near the hot content inside. The design is proportionate and pragmatic. The small base and expanding mouth of the cup is complemented by its triangular handle, expanding with the shape of the cup towards the tip. The color design is also in accordance with the shape of the cup. The predominant color, yellow, makes the cup look bigger than it is and the circles among the yellow surface and the border at the top in bright red color gives it the grand look that can be achieved only with the judicious bland of colors and shapes. To emphasize the handle, the yellow and red combination does not apply to its base and is instead painted white. The outer portion of the handle is yellow in color, while its inner portion is white. The bright red border extends to a very small portion of the inner surface of the cup, decorating its rim. The inner portion is a pure, spotless white. One functional aspect that I discovered about the extension of the red border

Perceptions of RN associated with screening for PPD Dissertation

Perceptions of RN associated with screening for PPD - Dissertation Example It has been found that postpartum depression not only has both short- and long-term consequences for the mother but also for her newborn child and thus its timely recognition, diagnosis and treatment is vital (Field, 2010). Statistics reveal that each year, approximately 400,000 infants are born to depressed mothers who are thus, at a risk of having adverse emotional, behavioral and physical health outcomes (Joy, 2011). As stated by Beck (2002), postpartum depression is â€Å"a dangerous thief that robs mothers of the love and happiness they expected to feel toward their newborn babies (Beck, 2002, p. 453)†. Studies have revealed that in short term, the mothering practices that become compromised due to the detrimental effects of PPD on the mother’s attitude towards the child include breastfeeding practices, sleep routines, visits to the well child clinic and follow-ups for vaccinations, and overall safety practices (Field, 2010). Moreover, in long-term, PPD impairs con ducive interactions between the mother and the child, negatively impacts nurturance and leads to poor parenting all of which contribute towards negative outcomes for the child, including and not limited to, poorer cognitive development, greater incidence of behavioral issues (such as antisocial and risk taking behaviors) and constrained social interactions on the part of the child such as less sociability (Beck, 2002; Field, 2010). Since this disorder is so common and has such serious and long lasting consequences, it is imperative that appropriate interventions be undertaken in a timely manner in order to prevent the occurrence of the aforementioned negative outcomes. Moreover, as pointed out before, since culture is an important determinant in the etiology of PPD, and postpartum depression has been defined as a â€Å"culture-bound syndrome† (Zubaran, Schumacher, Roxo, & Foresti, 2010) it is important for health care professionals to be aware of the role of culture in the ca usation of PPD and the management, including both diagnosis and treatment, of this disorder should be tailored using a transcultural approach. It has been elucidated that nurses play a significant role in the management of PPD, since they are involved in both screening the women for PPD and also in its treatment, including the provision of counseling services and appropriate referral services when required (Driscoll, 2006). In order to facilitate the provision of these services, nurses need to be culturally sensitive and should approach each woman keeping in mind her cultural, racial and ethnic background and offer culturally appropriate solutions accordingly (Callister, Beckstrand, & Corbett, 2010). Till date most of the literature centered around postpartum depression is predominantly quantitative in nature and the few qualitative studies that do exist focus on elucidating the role of culture in the etiology and causation of PPD. There is a paucity of studies focusing on determini ng the nurses’ experiences and perceptions in providing care for women suffering from postpartum depression, which is pertinent in this setting as nurses are the primary caregivers for patients suffering from postpartum depression. Moreover, there is also an acute shortage of studies examining the different culture appropriate solut

Hawthorne effect Essay Example | Topics and Well Written Essays - 750 words

Hawthorne effect - Essay Example n at Hawthorne, I would define the Hawthorne Effect as the confounding that occurs if experimenters fail to realize how the consequences of subjects performance affect what subjects do". In a Design industry environment consisting of around 150 draftsmen as workforce it was found that the productivity dropped suddenly in the recent six months’ time. Although the workers were given good wages and incentive packages, the productivity didn’t increase. In spite of repeated meetings and re-fixing of targets, there was no improvement in the productivity. The management was confused and tried to study the cause of the situation. After much thought, the Hawthorne studies were taken for experimenting with the situation. The entire workforce was working on a 5 day week, on a general shift of 8Â ½ hours a day, i.e. between 09:00 to 17:30 hours, including 30 minutes break for lunch. Each worker in the entire workforce of 150 draftsmen currently designed 5 AutoCAD drawings per day. The workforce was grouped into two – the formal group and the informal group. At first, both the groups were put on specific targets of 6 AutoCAD drawings per worker per day over a period of 12 weeks. The formal group was made to work on the existing timing. The informal group was given a rest break of 10 minutes twice in the day over a period of 4 weeks. Observations showed that the output of informal group went up. As the next step, the rest breaks for the informal group were lengthened to four 10 minutes rest breaks. The workers complained that the pace of their work was getting disturbed. As a result, their productivity decreased. Then, the rest breaks of informal group were returned to the two rest breaks, the first one with a supply of tea by the Company free of cost. As a result, the productivity increased. Then as the next step, the week was extended to six day working week for the informal group over a period of 4 weeks. The productivity decreased. Finally, the rest breaks

Student Council Essay Example for Free

Student Council Essay To our honorable principal, Mrs. Dianne Derla Atlas, to our hardworking school administrator, Mr. Raymond Go, to our lovable Student Council Adviser, Mrs. Christine Campana Go, to our faculty and staff and to my fellow collegians, a pleasant afternoon to all of you. I’m Marichelle Lubigan, a III- St. Luke student, under the supervision of Ms. Marjorie Aspuria, and I’m running for the position of secretary under VOICE Party. I First started as the English Club secretary. Being new to this campus, I didn’t even know how to start writing the minutes of the meeting. But through the help of our Club President, I survived. When the year was about to end, my sister encouraged me to join the leadership training. Luckily, I passed the screenings and made it ‘till the Leadership training. When the announcement came, I wasn’t hoping that my name will be called. I knew that there are lots of students who are deserving for that positions. It was already summer vacation when Kuya Ron texted me to go to school. When I went to school, I was surprised when I was asked to replace the Filipino Club President. I’ve learned a lot from my experiences during my first year as an SC Officer. I found myself undergoing the leadership training again. I tried my best to prove myself again. Luckily I passed, but this time, I was included to the new batch of SC Officers. I ran as the Business Manager. I wasn’t competitive enough that i will win that time because my opponent is more popular than me, Marc Ryan Clamor. When the results came, I was surprised when I won, i told myself that i won’t waste the trust you’ve given to me and for my last year as a leadership trainee, I was quite nervous for Ms. Tin told us at the screening that there are lots of first year students who are really trying their best. Many of them spoke straight English and want the position of President. When the training came, i actively participated during lectures and group discussions. During the announcement, I felt really nervous because all of the trainees were really deserving to be chosen, that is why I didn’t go to school that day. When my sister told me that I was chosen to have another chance to be an SC Officer, I was really surprised and thankful. I’m actually running for the position of treasurer, but due to the encouragement of my party mates, I’ve decided to run for secretary. The secretary is the one responsible in keeping accurate records of meetings and student activities, programs, and sessions. The secretary also writes the minutes, and takes ideas from students during a meeting. Again, I’m Marichelle Lubigan, running for the position of Secretary under VOICE party. Im hoping that I convinced you to vote for me. Vote wisely. Vote straight, VOICE Party! A pleasant afternoon to all of you. Thank you. :D.

Theories for the Evolution of Alarm Calls

Theories for the Evolution of Alarm Calls Alarm Call Evolution: Altruism or Kin Selection? Taylor Rystrom Introduction Humans have always been fascinated by animal communication. One important manifestation of animal communication is alarm calls. Alarm calls, even functionally referential alarm calls, can be observed across many different species. Prairie dogs give alarm calls specific even to the shirt color that a nearby human is wearing (Slobodchikoff 2009). Male blue monkeys give alarm calls that are specific to predator type, distance, and location (Murphy et al. 2013). Even African elephants, who have relatively few predators, give alarm calls when they hear the sound of bees (King et al. 2010). But why did these alarm calls, a seemingly altruistic act, evolve in so many different animal groups? How did some get so specific? Sherman lays out six interesting theories of the evolution of alarm calls. Alarm calls could have evolved to divert the attention of the predator, discourage the predator, alert relatives of the caller, help the group which the caller resides in, reduce the later return of the predator, or warn others who will reciprocating at a later time (Sherman 1977). The main findings have suggested that alarm calls have either evolved as an altruistic act, possibly with reciprocity among the group, or as a mechanism to protect kin (Trivers 1971, Sherman 1977). As for functionally referential alarm calls, meaning that the alarm calls encode specific information about the predator, evolution has been suggested as a response to the need for different escape methods from different predators due to the habitat of the group (Furrer and Manser 2009). Altruism Theory Although Koenig (1988) points out that there is no commonly accepted definition of altruism in behavioral ecology (Koenig 1988), it can be explained for the purposes of this review as an act that has a cost to the individual and a benefit for others. Reciprocal altruism, which Trivers argues to be present in alarm-calling birds (Trivers 1971), would be a type of altruism which benefits the individual only when another party reciprocates the act toward the first individual (Koenig 1988). Trivers suggests that alarm calling in birds is reciprocal altruism because alarm calling keeps predators from specializing on the location and species of the caller (Trivers 1971). However, Koenig points out that reciprocal altruism is still speculative in birds (Koenig 1988). Furthermore, it is unlikely; if alarm calling is altruistic and natural selection acted on the individual that had the novel gene for alarm calling, the animal would have no increase in fitness, the gene would not spread, and t he trait would not evolve (Charnov and Krebs 1975). This being said, if alarm calling is an altruistic behavior, it must have evolved because of some benefit to the caller (Charnov and Krebs 1975). One speculation is that an alarm call could encode the presence of a predator but leave out the location of the predator, thus causing confusion of the dispersal of the flock while the caller knew exactly how to escape the predator (Charnov and Krebs 1975). However, it has been found that male blue monkeys can in fact encode the predator distance and location, thereby giving all immediate information to their conspecifics (Murphy 2013). Problems arise in this theory when specific species of birds are studied more closely. The alarm calls of one species of jay, the Siberian jay, were closely analyzed due to the nature of the groups of this species of jay. In this species, the jays live in social groups comprised of one dominant breeding pair, their offspring, and sometimes non-related immigrant birds (Griesser and Ekman 2004). If alarm calling is altruistic in this species, the dominant breeding pair would call whenever a predator is nearby, regardless of whether they were with immigrants or kin (Griesser and Ekman 2004). However, the results showed that females called only during the breeding season while their kin was present, while males called indiscriminately (Griesser and Ekman 2004). This raises further questions about the intentions of males; do they call indiscriminately to selfishly protect future mates or to dilute a predator attack by providing benefits to immigrants in the group to reduce the caller†™s chance of being attacked? Willow tits also give alarm calls, but Hogstad (1995) suggests that this is a form of mate investment and evolved for this purpose. Males are dominant and breeding pairs last for several years, so if a female dies, especially during the winter, the male partner will likely be unpaired the following breeding season (Hogstad 1995). Adult willow tit males gave alarm calls more frequently when they could see their mates than when they could not; this implies that alarm calling for this species is primarily a form of mate investment (Hogstad 1995). Since the benefit of having a mate the following season is fairly large for a male willow tit, this is not an altruistic act. Studies regarding animals other than birds suggest that alarm calling is not an altruistic act. Alarm calling would only be categorized as altruistic if the calling was costly to the caller in some way (Koenig 1988). Round-tailed squirrels only give alarm calls when they are already retreating, thus not endangering themselves (Dunford 1977). Marmots do not reduce their own chances of survival because they rarely call when exposed to predators, and their calls are acoustically difficult to detect by predators (Barash 1975). There is no real threat to either of these species when they give alarm call, thus destroying the option of alarm calling being altruistic. Furthermore, yellow-bellied marmots can identify who produced an alarm call and will ignore calls after many false alarms (Blumstein and Daniel 2004). Although this seems to support the hypothesis for reciprocal altruism since identification of false callers is important for the reciprocity, there are no known cases of which ro dents take turns calling. Kin Selection Theory The kin selection theory requires that kin be nearby when alarm calls are given for the function of alerting kin of danger. Kin selection is not altruistic because protecting offspring and other kin is a way to protect the future of one’s own genes. The evolution of alarm calls due to kin selection is definitely dependent on the social system of the species. Belding’s ground squirrels have a social system where females generally stay in their natal territory their whole lives and males are polygynous, do not defend any mates or offspring, and emigrate from their natal territory alone, constantly moving after they mate (Sherman 1977). Sherman (1977) found through an extensive observational study that females call frequently when relatives are nearby and do not call at all when they have no living kin; meanwhile, males rarely call. In another study regarding ground squirrels, Dunford (1977) found that males do sometimes call – but this is only when they are juvenil es and their mother and siblings are near. Sherman (1977) hypothesized that the function of alarm calling is nepotism, and that the evolution of this behavior is due to kin selection. Similar results are found with Gunnison’s prairie dogs (Hoogland 1996). Females with kin in the same territory called more often than females who did not have nearby kin. This species has a slightly different social system than Belding’s ground squirrels. Males guard 3-4 females and move between adjacent territories, and it was observed that males give alarm calls regardless of whether or not they had kin in the territory (Hoogland 1996). It is likely that the males had kin in adjacent territory, so these kin could theoretically be close enough to benefit from an alarm calls. These prairie dogs assess their own personal safety before calling, as they are more likely to call if they are farther from the danger (Hoogland 1996). Previously it had been found that male Black-tailed prairie dogs only give alarm calls only after they sire offspring in the territory (Hoogland 1983). These studies show extreme support for the hypothesis that alarm calls evolved as a form of sele cting for kin. A study on chipmunk alarm call behavior offers support that there could be a reciprocal altruism component to the maintenance of alarm calling in the species (Smith 1978). This is because they are one of few species in which all members of the group can and do give alarm calls (Smith 1978). Although kin selection was most likely the basis for the evolution of the behavior since older females with many nearby daughters give the most alarm calls (Smith 1978), it is interesting that both seemingly opposing hypotheses can work together. When yellow-bellied marmots call, the spotted predators almost always leave. However, not all of these marmots call. Blumstein and Armitage (1975) found that the calling is generally a safe activity for these marmots so there is not much cost associated with alarm calls. Their hypothesis is that some individuals do not call because they are trying to reduce reproductive competition (Blumstein and Armitage 1975). Females are the most likely to call, and only when they have vulnerable young. So if another female refrains from calling when she spots a threat, she will reduce the competition for her young since the most vulnerable are the young which are ignorant to the threat (Blumstein and Armitage 1975). Further Extensions and Conclusions There are also factors which affect the complexity of alarm calls, including the level of sociality and habitat composition of species. Sociality and communicative complexity were compared across three different sciurid rodents, and only in marmots did communicative complexity increase with sociality; there was no correlation for prairie dogs or squirrels (Blumstein and Armitage 1997). This implies that alarm repertoire size has many factors, such as facial and laryngeal morphology and habitat acoustics (Blumstein and Armitage 1997). Habitat could influence the evolution of functionally referential alarm calls because if different escape routes are needed for different predators due to the physical nature of the habitat, then it would be beneficial to your survival to have different alarm calls for each type of predator to streamline the escape (Furrer and Manser 2009). However, this hypothesis is not completely supported by data. In Gunnison’s prairie dogs, the habitat does i nfluence the alarm calls; they have been found to change their alarm call dialects for different levels of vegetation cover (Perla and Slobodchikoff 2002). However, meerkats and Cape ground squirrels live in the same habitat yet only meerkats have functionally referential alarm calls; thus habitat does not have a profound influence on the evolution of functionally referential alarm calls (Furrer and Manser 2009). The continuing evolution of alarm calls into more complex communication like functionally referential alarm calls is an important angle of study. How much of alarm call behavior is learned? Female Campbell’s monkeys produce three alarm calls in the wild but only two in captivity, one of which is not observed in the wild (Oattara et al. 2009). This implies that the capacity for alarm calling evolves, but not fully utilized if not needed. This study also suggests that in order for alarm call behavior to be expressed in a population, the threat of predation must be large. Since captive monkeys do not have predators, they have lost vocalizations associated with this danger (Oattara et al. 2009). The evolution of alarm calls is no simple matter. When factoring in the specific ecology of each species studied to give alarm calls, it all comes down to each species’ life history. It makes sense evolutionarily for a species which live in social groups comprised of kin and non-related individuals to call to warn kin, and if only females live near kin, for females to predominantly call. However, if a species lives in a different type of social group, alarm calling does not necessarily have to function as a way to warn kin. Alarm calling in species of many different types of social groups should be studied in regards to the hypotheses offered by Sherman (1977) in order to find support for other evolutionary drivers as well as reciprocal altruism and kin selection. Literature Cited Barash, David P. Marmot Alarm-Calling and the Question of Altruistic Behavior.American Midland Naturalist94.2 (1975): 468. Print. Blumstein, Daniel T. The Evolution of Functionally Referential Alarm Communication: Multiple Adaptations; Multiple Constraints.Evolution of Communication3.2 (1999): 135-47. Print. Blumstein, Daniel T., and Janice C. Daniel. Yellow-bellied Marmots Discriminate between the Alarm Calls of Individuals and Are More Responsive to Calls from Juveniles.Animal Behaviour68.6 (2004): 1257-265. Print. Blumstein, Daniel T., and Kenneth B. Armitage. Does Sociality Drive the Evolution of Communicative Complexity? A Comparative Test with Groundà ¢Ã¢â€š ¬Ã‚ Dwelling Sciurid Alarm Calls.The American Naturalist150.2 (1997): 179-200.JSTOR. Web. 14 Mar. 2014. Blumstein, Daniel T., and Kenneth B. Armitage. Why Do Yellow-bellied Marmots Call?Animal Behaviour56 (1998): 1053-055.JSTOR. Web. 1 Mar. 2014. Charnov, Eric L., and John R. Krebs. The Evolution of Alarm Calls: Altruism or Manipulation?The American Naturalist109.965 (1975): 107-12.JSTOR. Web. 15 Mar. 2014. Dunford, Christopher. Kin Selection for Ground Squirrel Alarm Calls.The American Naturalist111.980 (1977): 782. Print. Furrer, RomanD., and MartaB. Manser. The Evolution of Urgencyà ¢Ã¢â€š ¬Ã‚ Based and Functionally Referential Alarm Calls in Groundà ¢Ã¢â€š ¬Ã‚ Dwelling Species.The American Naturalist173.3 (2009): 400-10. Print. Griesser, Michael, and Jan Ekman. Nepotistic Alarm Calling in the Siberian Jay, Perisoreus Infaustus.Animal Behaviour67 (2004): 933-39.Science Direct. Web. 14 Mar. 2014. Hogstad, Olav. Alarm Calling by Willow Tits, Parus Montanus, as Mate Investment.Animal Behaviour49.1 (1995): 221-25. Print. Hoogland, John L. Nepotism and Alarm Calling in the Black-tailed Prairie Dog (Cynomys Ludovicianus).Animal Behaviour31.2 (1983): 472-79. Print. Hoogland, John L. Why Do Gunnisons Prairie Dogs Give Anti-predator Calls?Animal Behaviour51.4 (1996): 871-80. Print. King, Lucy E., Joseph Soltis, Iain Douglas-Hamilton, Anne Savage, and Fritz Vollrath. Bee Threat Elicits Alarm Call in African Elephants. Ed. Karen Mccomb.PLoS ONE5.4 (2010): E10346. Print. Koenig, Walter D. Reciprocal Altruism in Birds: A Critical Review.Ethology and Sociobiology9.2-4 (1988): 73-84. Print. Murphy, Derek, Stephen E.g. Lea, and Klaus Zuberbà ¼hler. Male Blue Monkey Alarm Calls Encode Predator Type and Distance.Animal Behaviour85.1 (2013): 119-25. Print. Ouattara, Karim, Klaus Zuberbà ¼hler, Eliezer K. Ngoran, Jean-Emile Gombert, and Alban Lemasson. The Alarm Call System of Female Campbells Monkeys.Animal Behaviour78.1 (2009): 35-44. Print. Perla, Bianca S., and C. N. Slobodchikoff. Habitat Structure and Alarm Call Dialects in Gunnison’s Prairie Dog (Cynomys Gunnisoni).Behavioral Ecology13.6 (2002): 844-50.Oxford Journals. Web. 6 Feb. 2014. Sherman, P. W. Nepotism and the Evolution of Alarm Calls.Science197.4310 (1977): 1246-253. Print. Slobodchikoff, C. N., Andrea Paseka, and Jennifer L. Verdolin. Prairie Dog Alarm Calls Encode Labels about Predator Colors.Animal Cognition12.3 (2009): 435-39. Print. Smith, Stephen F. Alarm Calls, Their Origin and Use in Eutamias Sonomae.Journal of Mammalogy59.4 (1978): 888. Print. Trivers, Robert L. The Evolution of Reciprocal Altruism.The Quarterly Review of Biology46.1 (1971): 35. Print.

Structural Biology in Pharmaceutical Research

Structural Biology in Pharmaceutical Research INTRODUCTION Molecular biology plays a key role and contributes a lot in determining the 3D structure of a molecule be it proteins, nucleotides or any other biological macromolecule. It also helps in finding the target sites when it comes to drug designing. Many structural biology techniques are used in the field of pharmaceutical research. These mainly include X-ray crystallography and NMR Spectroscopy. However, structural biology also includes the help of bioinformatics. Structure based drug design plays a major role when it comes to pharmaceutical research and also it has advanced a lot over the years. The remarkable discovery of peptidomimetics and nonpeptides proves this. This was done using techniques like X ray crystallography and NMR spectroscopy as well as other computer based methods. One of the widely used tools in structural biology is X-ray crystallography. This is used to determine the atomic as well as the molecular structure of a crystal where the crystalline atoms cause diffraction of X-rays in many specific directions. It is a form of high resolution microscopy. Using this technique, visualizing protein structures at the atomic level becomes easier and helps in understanding its functions. It also gives information about how proteins react with other molecules and undergo changes in their conformation. As well as the process of catalysis with respect to enzymes. All this knowledge is necessary for designing drugs which are meant to ta rget specific sites or are used for industrial processes. Crystallography, being the most widely used technique may not be successful at all times. With this, NMR comes to the rescue. It helps in elucidating 3D structures of target ligand complexes. With advances in genome sequencing, protein expressions, crystallography and NMR; these have helped in using protein 3D structure for fast discovery of drugs. The role of structural biology and bioinformatics in this is that they help in the manufacturing of drugs that are target specific and well optimized. Also, due to the determination of structure, fragment binding becomes possible. For a drug to work efficiently, it needs to bind to the specific site or the target proteins. Using computer for this is a very good technique which finds and optimizes target proteins that are required. For a substance to bind a target it has be extremely specific like a lock and a key. Structural biology methods and molecular modeling are tools that are used in the developments of such molecules. In the process of drug discovery, computational chemistry proves to be a tool of great help. After the molecule has binded to the desired molecule and the binding properties are known, the suitability of the compound can be improved using the computer. The drug’s binding affinity can be calculated digitally using the computer. Also, using these methods it is also possible to calculate if the changes in the structure would lead to any undesirable or toxic properties. These methods save a lot of time as compared to lab work especially in the early stages of drug designing. Due to this, an increase in the success rates can be observed. Fig 1: Drug Discovery Process Courtesy: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1609333/figure/fig1/ X-RAY CRYSTALLOGRAPHY In order to determine the precise molecular structure of the target protein, X-ray structure analysis is used. In this, the crystal lattice structure of the protein diffracts the X-ray beam in a typical way. The diffraction pattern can be analyzed and due to this, the density of electrons can be read which are present in the parts of the target protein. This in turn, helps in determination of the position of the atoms. Several repetition of this process and refining the image is done till the researchers obtain a 3D structure of the target molecule. Usage on X-ray crystallography in drug discovery has been present since a long time where 30 years ago the 1st three dimensional structure of proteins were determined. However, not all the pharmaceutical companies resort to this technique as it is considered time consuming and too expensive. A total change in drug design has occurred in the past years, thus using 3D structures in the designing processes. For structure that were not available with X-ray crystallography, other methods were used which included comparative models based on homologues. Crystal structures of key drug targets are now available like AIDS drugs such as Agenerase and Viracept were developed using the crystal structure of HIV protease and the influenza drug Relenza was designed using the crystal structure of neuraminidase.Drugs originating from structure based design have entered clinic trials and some of them have even been marketed as drugs now. Knowing the protein structure is a key component in the process of drug design. It is used in lead optimization which is a process that revolves around the usage of structure for guiding chemical modification of the molecule of lead for giving the perfect fit with respect to shape, bonds and other interactions. Protein structure is also used in target selection; this involves homology recognition but with the recent advances in structural genomics this has become easier. X-ray crystallography is also used in the direct screening of chemical fragments. Astex Technology has developed â€Å"Pyramid†, where fragment libraries are screened in cocktails using X-ray crystallography. Fragment hits that are derived from Pyramid are optimized in order to maintain good ligand efficiency. NMR NMR spectroscopy was the first structural technique to be made full use in fragment screening. Target Immobilized NMR Screening (TINS) Usage of NMR spectroscopy on targets that are immobilized helps in binding of small molecules. A process called as Target Immobilized NMR Screening (TINS) has ennumerable advantages; one of them being that a minimum quantity of the non isotopically labeled protein is needed. This method helps in binding in the range of KD values of 100nM to 20mM. If the reference protein is selected carefully, the number of false positive hits that one may get can be avoided. Due to this, maximum valid hits are ensured. These hits can be treated with biological assays. A variety of soluble proteins as well as membrane proteins have been screened. The combination of target immobilization and small screening of fragments using NMR proves to be of immense help in Early Drug discovery. STEPS IN DRUG DISCOVERY PROCESS TARGET IDENTIFICATION FROM SEQUENCE STRUCTURE HOMOLOGY RECOGNITON Structural bioinformatics is a backbone for the identification of new members of supefamilies. Protein structures impart a major information about the families and super families. The proteins that have evolved would be having some common structures or features that they would be exhibiting thus leading to the importance of â€Å"homology recognition†. An example of this was the recognition of HIV proteinase which belonged to be a member of the pepsin/renin superfamily. Recognition of distant homologues can be done using methods like sequence-structure matching that are classified as profile methods or threading. Profile methods involve the sequence comparison algorithms using traditional methods. Computer programs like FUGUE aid in this and helps in the recognition of homologues. Another method used is Threading which fits a probe sequence and evaluates compatibility between the sequenced and the structure that is proposed. This method is powerful for fold recognition. Example of a computer based program is GenTHREADER. After the homologue of the structure is known and identifies, it can be modeled using a variety of procedures. Although structural bioinformatics is helpful, it is necessary to have an accurate experimental structure. Target validation and the identification of ligand binding regions Structures defined by structural genomics programs are mainly of proteins that do not have a known function but they have been identified as proteins only on the basis of their gene sequences. Hence, the need for the development of computerized based methods arises which would identify sites which are involved in the interactions. PROSITE, a sequence motif database identifies the specific residues that have functions. Several attempts have been made to predict the interaction sites using computerized based methods either by identifying high-energy conformations or identifying clefts that can accommodate ligands. LEAD DISCOVERY The trait of a target is based on the number of drug like ligands for a target class. Classification of the targets into families has helped in designing compound libraries for particular families. Screening of a small fragments or molecule is needed and this can be done using biophysical assays. Ligand docking is a method that helps to find the best binding position and orientation. The best docking programmes are successful in dockin 70-80% of ligands in the ligand-protein complexes. A major drawback of this method is that there are difficulties in predicting affinities of different compounds. CONCLUSION Knowledge of the three-dimensional structures of protein targets plays a major role in all stages of drug discovery. Its place in lead optimization is well established with large teams of structural biologists recruited into all major pharmaceutical companies. The success of the method is evident from drugs in use and new ones reaching the market. But structural biology and bioinformatics show that many key targets for drug discovery are multidomain and multiprotein complexes. Such systems pose significant challenges not only for characterization using structural techniques but also because the inter-protein surfaces are usually poor in distinguishing features. BIBLIOGRAPHY RESEARCH PAPERS: Blundell, T., Sibanda, B., Montalvao, R.W., Brewerton, S., Chelliah, V., Worth, C., Harmer, N., Davies, O.,1 and Burke D(2006) Structural biology and bioinformatics in drug design: opportunities and challenges for target identification and lead discovery. Philos Trans R Soc Lond B Biol Sci. 361(1467): 413–423. Congreve, M., Murray CW., and Blundell T(2005) Structural biology and drug discovery. Drug Discov Today. 2005 Jul 1;10(13):895-907. BOOK: Structural Genomics and High Throughput Structural Biology(2006)edited by Michael Sundstrom, Martin Norin, Aled Edwards. WEBSITE: http://www.pharmaceutical-business-review.com/suppliers/zobio/products/nmr-based-structural-biology http://www.bayerpharma.com/en/research-and-development/technologies/research-technologies/computational-chemistry-structural-biology/index.php