An investigation of the factors affecting the output of a transformer Essay Example

An investigation of the factors affecting the output of a transformer Essay Transformers are used in everyday life. They work on the principle of Electromagnetic field induction. Current (electrons) has an electromagnetic field. This field can manipulate the field of magnets. Also the field of magnets can manipulate the field of electrons in a similar way to how magnets interact. Transformers work by using the fields to transfer energy through the field lines: Wire induces a magnetic field in the iron core. Iron core. The field lines Are cut causing We will write a custom essay sample on An investigation of the factors affecting the output of a transformer specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on An investigation of the factors affecting the output of a transformer specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on An investigation of the factors affecting the output of a transformer specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Wire an induced current. Causing a voltage in the first wire, causes a current. Around the current is a magnetic field, this induced a field in the iron core, the field lines of the core are then cut by a conductor (the second wire) and so a voltage is induced, in the reverse of how a voltage was induced in the transformer. In this way energy is transferred from electrical energy, to magnetic energy, back to electrical energy. The field lines must be continually moving in order to induce a current in the second coil (because a voltage is only induced when the field lines are being cut). The only way to do this is make the field lines change directions continually, in order to do that the electrons in the primary coil must be changing direction continually, and so we have to use alternating current. In order to make this more efficient the wires are coiled around the core. The point being that the more contact the wire is the more energy is put into the core and the more comes out, making the process more efficient. In theory the amount of energy going into the transformer should equal the amount of energy going out, no matter what the coil numbers but because of the nature of the coils and magnetic field lines, 100% efficiency is near impossible. Variables affect the system in many ways: The number of coils- There three general scenarios: Both primary and secondary coils are the same in number. In this case the more coils the more efficient the experiment, the increased coils mean that there is a larger, stronger field induced. These stronger fields are then cut by the increased number of coils, inducing more current, therefore making the whole process more efficient. The number of coils in the primary coil is greater than the number in the secondary. In this case because the electrons in the secondary coil are in less contact with the field lines they therefore receive less energy. However because all the energy must go through to the second coil and so the number of electrons (the current) increases. ( Power = current x time) So the voltage and current are inversely proportional. (see graph below) This is called a step down transformer because the voltage decreases. The number of coils in the secondary is greater than the number of coils in the primary. In this because the electrons in the secondary coil are in more contact with the field lines they therefore receive more energy. However because energy is constant the number of electrons (the current) decreases. ( Power = current x time) So the voltage and current are inversely proportional. (see graph below) This is called a step up transformer because the voltage increases despite the fact that the current decreases. voltage (v) Current (a) A graph to show the relationship between voltage and current. The distance between the coils. The further magnetic fields are from their source the weaker they are. If the coils are close together and close to the core then the lines dont have to go as far, therefore they are stronger. Therefore if the coils are closer together then they effect the core better and the core effects them better, resulting in a more efficient transformer. If they are further apart then energy is lost resulting in a less efficient transformer. Voltage in primary coil The higher the voltage the more energy an electron has, if the electrons have a higher energy then they have stronger fields, so they then cause stronger fields in the core, which causes a higher voltage in the secondary coil. The graph should look like this: Voltage in Primary coil Voltage in secondary coil. A graph to show the theoretical relationship between voltage in the primary and secondary coils. Method Apparatus 1. A power supply that allows the output voltage to be varied. 2. An iron core 3. Wires. 4. A ruler 5. Voltmeters 6. Crocodile clips 7. Insulation tape. 8. Wires for the coils 9. Wire strippers and clippers. Diagram: Primary coil Secondary coil Iron core I will set up the circuit as shown. I will use a power supply and connect it to the coil around the core, using crocodile clips and stripping the insulation from the ends of the core. I will have a voltmeter in parallel to the coil. The coil will be around an iron core. The core is basically an iron rod. There will be the secondary core further up along the rod, which will be attached using crocodile clips to a voltmeter. Using this set-up I can then vary the distance between the coils by using the ruler. The power supply will draw power form the mains. It will be set to AC for the reasons explained beforehand. I will vary the voltage by turning off the power supply and changing it, then turning it back on. I will vary the number of coils by turning the whole thing off and then removing or adding coils to either coil. For voltage I will use a voltage between 0 and 8 volts so as not to have any problems with heat. I will use nominal voltage jumps of 1V but because of the inefficiency of the power box they most probably wont be 1V. I will have 45 coils in the primary coil and keep that number fixed. But I will change the number of coils in the secondary coil in fixed jumps from 15 to 75. To keep the test fair I will: 1. Keep all variables constant except the one that I am changing. 2. Make sure the distance between the coils is 1CM at all times, if it is not being changed. 3. Keep the number of turns on the primary core the same. 4. I will use the same core throughout the whole experiment. 5. Allow the rod to cool if hot. 6. I will do repetitions to make sure that the result I have gotten is not a freak result. I think that this is a good way of doing the experiment because it is fair, and versatile. It is simple so there is less chance of something going wrong, More than one variable is being changed so there is more chance of a pattern emerging. The variables are easy to change. Safety 1. I will make sure the experiment is properly wired and that the wires are not touching, so as not to cause the power box to fuse. 2. I will determine a safe level of voltage in the preliminary and not go higher than it. 3. I will allow the experiment to cool if it is hot, so nothing has a chance of catching fire. 4. I will make sure there is no current going into the core by checking that no connectors are touching the core. 5. I will make sure there is no water present near the experiment to prevent an electric shock. 6. I will not touch the rod if it is hot (I will use the wire coating condition to see if it is hot) 7. I will keep the experiment away from anything flammable so as not to start a fire. 8. I will turn off the experiment if the wire coating melts or sparks appear. 9. I will make sure to turn off the power supply before changing the voltage so the power supply does not fuse. 10. I will turn the experiment off before changing the no of coils or the wire configuration, to prevent electric shock. I have chosen to vary the no of coils and the voltage in the primary coil. I plan to use a voltage range between 1 and 8 volts, which should give eight results, this ought to be enough to draw a conclusion. Also I want to vary the coil by having 45 turns in the first coil, but use varying turns in the secondary, starting at 15 turns and going up in jumps of 15 turns, to 75. This should give six results, which ought to be enough to determine a pattern. Based on the results of the preliminary, I think that the experiment will be very inefficient, but trends should show up in the results. Prediction I think that as voltage in the primary coil increases then the voltage in the secondary coil will increase and the increase will be directly proportionate: Voltage in Primary coil Voltage in secondary coil. A graph to show the theoretical relationship between voltage in the primary and secondary coils. This is because the higher the voltage the more energy an electron has, if the electrons have a higher energy then they have stronger fields. A higher voltage in the primary will cause stronger fields in the core, which causes a higher voltage in the secondary coil. And doubling the primary voltage should double the effect, therefore doubling the secondary voltage. I also think that there will be some loss in efficiency meaning that the transformer is about 80% efficient. 100% efficient results should look like this: Primary voltage (v) Secondary Voltage (v) No. of primary turns No. of secondary turns 1.00 1.00 30 30 2.00 2.00 30 30 3.00 3.00 30 30 4.00 4.00 30 30 5.00 5.00 30 30 6.00 6.00 30 30 7.00 7.00 30 30 A table showing the predicted relationship between voltage in the primary and secondary coils. Using this we can see that: So higher voltage input causes higher voltage output. Also I think that the ratio will have an effect on the secondary voltage: If both primary and secondary coils are the same in number: In this case the more coils the more efficient the experiment, the increased coils mean that there is a larger, stronger field induced. These stronger fields are then cut by the increased number of coils, inducing more current, therefore making the whole process more efficient. If the number of coils in the primary coil is greater than the number in the secondary: In this case because the electrons in the secondary coil are in less contact with the field lines they therefore receive less energy. However because all the energy must go through to the second coil and so the number of electrons (the current) increases. ( Power = current x time) So the voltage and current are inversely proportional. (see graph below) This is called a step down transformer because the voltage decreases. If the number of coils in the secondary is greater than the number of coils in the primary: In this because the electrons in the secondary coil are in more contact with the field lines they therefore receive more energy. However because energy is constant the number of electrons (the current) decreases. ( Power = current x time) So the voltage and current are inversely proportional. (see graph below) This is called a step up transformer because the voltage increases despite the fact that the current decreases. voltage (v) Current (a) A graph to show the relationship between voltage and current. A table to show the predicted relationship seen when the number of coils on the secondary changes. Primary voltage (v) No of turns in primary coil No. of turns in secondary coil Secondary voltage (v) 10.00 45 15 3.33 10.00 45 30 6.67 10.00 45 45 10.00 10.00 45 60 13.32 10.00 45 75 16.65 10.00 45 90 20.00 This works in that if you double the amount of time an electron influences the magnetic field or the field influences the electron you double the energy resulting in directly proportionate relationship between the number of turns in the secondary coil and the secondary voltage: No of coils in secondary Secondary voltage (v) Based on this I predict that : and that: secondary voltage x no of primary turns = primary voltage x no of secondary turns Preliminary I decided to do the preliminary experiment and investigate the variables before I decided what to investigate, as some variables may not have been worth investigating in depth. I used the method and set up described above except there were thirty turns in both coils. Distance between the coils (cm) Voltage in primary coil (v) Voltage in secondary coil (v) 0 (the coils were intertwined) 3 0.286 1 3 0.248 2 3 0.192 3 3 0.087 As you can see the voltage is highest when the coils are intertwined together, so the transformer is most efficient then. Based on this I decided to intertwine the coils in order to get the best voltage possible, however, because of time restraints I was easiest to keep the coils 1 cm apart. Primary voltage (nominally) Secondary voltage (v) 1 0.042 2 0.091 3 0.149 4 0.209 5 0.251 6 0.315 7 0.354 8 0.371 9 0.392 10 Reset switch popped 11 Reset switch popped 12 Reset switch popped 13 Reset switch popped 14 Reset switch popped 15 Reset switch popped 16 Reset switch popped 17 Did not attempt 18 Did not attempt 19 Did not attempt 20 Did not attempt The fuse tripped because too much current was drawn. So I decided to use current between 0 and 8. Obtaining evidence I had planned to do three repetitions of each experiment but I ended up with the same result anyway, so I decided not to waste time on it. Instead I decided to find the average of the different voltages, and use the averages to see how the ratio of turns affects the secondary voltage. Experiment No.of Primary coils No. of Secondary coils Ratio of coils Primary voltage (v) Secondary voltage (v) Secondary perfect voltage (v) Efficiency 1 45 15 3 to 1 0.67 0.048 0.223 21.568 1 45 15 3 to 1 0.67 0.048 0.223 21.568 1 45 15 3 to 1 0.67 0.048 0.223 21.568 2 45 15 3 to 1 1.17 0.083 0.391 21.137 2 45 15 3 to 1 1.17 0.083 0.391 21.137 2 45 15 3 to 1 1.17 0.083 0.391 21.137 3 45 15 3 to 1 1.96 0.149 0.653 22.828 3 45 15 3 to 1 1.96 0.149 0.653 22.828 3 45 15 3 to 1 1.96 0.149 0.653 22.828 4 45 15 3 to 1 2.98 0.214 0.992 21.572 4 45 15 3 to 1 2.98 0.214 0.992 21.572 4 45 15 3 to 1 2.98 0.214 0.992 21.572 5 45 15 3 to 1 3.69 0.345 1.230 28.044 5 45 15 3 to 1 3.69 0.345 1.230 28.044 5 45 15 3 to 1 3.69 0.345 1.230 28.044 6 45 15 3 to 1 4.43 0.472 1.476 31.970 6 45 15 3 to 1 4.43 0.472 1.476 31.970 6 45 15 3 to 1 4.43 0.472 1.476 31.970 7 45 15 3 to 1 5.05 0.496 1.683 29.444 7 45 15 3 to 1 5.05 0.496 1.683 29.444 7 45 15 3 to 1 5.05 0.496 1.683 29.444 8 45 15 3 to 1 5.65 0.509 1.885 27.030 8 45 15 3 to 1 5.65 0.509 1.885 27.030 8 45 15 3 to 1 5.65 0.509 1.885 27.030 Average 45 15 3 to 1 3.20 0.289 1.067 25.449 1 45 30 3 to 2 0.67 0.066 0.447 14.857 1 45 30 3 to 2 0.67 0.066 0.447 14.857 1 45 30 3 to 2 0.67 0.066 0.447 14.587 2 45 30 3 to 2 1.17 0.125 0.782 16.046 2 45 30 3 to 2 1.17 0.125 0.782 16.046 2 45 30 3 to 2 1.17 0.125 0.078 16.046 3 45 30 3 to 2 1.96 0.241 1.305 18.452 3 45 30 3 to 2 1.96 0.241 1.305 18.452 3 45 30 3 to 2 1.96 0.241 1.305 18.452 4 45 30 3 to 2 2.98 0.346 1.984 17.438 4 45 30 3 to 2 2.98 0.346 1.984 17.438 4 45 30 3 to 2 2.98 0.346 1.984 17.438 5 45 30 3 to 2 3.69 0.411 2.460 16.705 5 45 30 3 to 2 3.69 0.411 2.460 16.705 5 45 30 3 to 2 3.69 0.411 2.460 16.705 6 45 30 3 to 2 4.43 0.463 2.952 15.669 6 45 30 3 to 2 4.43 0.463 2.952 15.699 6 45 30 3 to 2 4.43 0.463 2.952 15.699 7 45 30 3 to 2 5.05 0.486 3.366 14.432 7 45 30 3 to 2 5.05 0.468 3.366 14.432 7 45 30 3 to 2 5.05 0.468 3.366 14.432 8 45 30 3 to 2 5.65 0.499 3.770 13.248 8 45 30 3 to 2 5.65 0.499 3.770 13.248 8 45 30 3 to 2 5.65 0.499 3.770 13.248 Average 45 30 3 to 2 3.20 0.330 2.133 15.856 1 45 45 1 to 1 0.61 0.079 0.610 12.959 1 45 45 1 to 1 1 45 45 1 to 1 2 45 45 1 to 1 1.07 0.126 1.068 11.793 2 45 45 1 to 1 2 45 45 1 to 1 3 45 45 1 to 1 1.78 0.238 1.783 13.326 3 45 45 1 to 1 3 45 45 1 to 1 4 45 45 1 to 1 2.71 0.352 2.710 12.993 4 45 45 1 to 1 4 45 45 1 to 1 5 45 45 1 to 1 3.36 0.418 3.360 12.447 5 45 45 1 to 1 5 45 45 1 to 1 6 45 45 1 to 1 4.03 0.497 4.032 12.322 6 45 45 1 to 1 6 45 45 1 to 1 7 45 45 1 to 1 4.60 0.522 4.597 11.349 7 45 45 1 to 1 7 45 45 1 to 1 8 45 45 1 to 1 5.15 0.536 5.148 10.418 8 45 45 1 to 1 8 45 45 1 to 1 Average 45 45 1 to 1 2.91 0.346 2.913 12.201 1 45 60 3 to 4 0.75 0.096 1.000 9.565 1 45 60 3 to 4 1 45 60 3 to 4 2 45 60 3 to 4 1.31 0.174 1.750 9.948 2 45 60 3 to 4 2 45 60 3 to 4 3 45 60 3 to 4 2.19 0.343 2.923 11.738 3 45 60 3 to 4 3 45 60 3 to 4 4 45 60 3 to 4 3.33 0.428 4.442 9.625 4 45 60 3 to 4 4 45 60 3 to 4 5 45 60 3 to 4 4.13 0.508 5.508 9.221 5 45 60 3 to 4 5 45 60 3 to 4 6 45 60 3 to 4 4.96 0.572 6.610 8.649 6 45 60 3 to 4 6 45 60 3 to 4 7 45 60 3 to 4 5.65 0.730 7.535 9.687 7 45 60 3 to 4 7 45 60 3 to 4 8 45 60 3 to 4 6.33 0.751 8.440 8.893 8 45 60 3 to 4 8 45 60 3 to 4 Average 45 60 3 to 4 3.58 0.450 4.776 9.666 1 45 75 3 to 5 0.58 0.099 0.967 10.204 1 45 75 3 to 5 1 45 75 3 to 5 2 45 75 3 to 5 1.02 0.154 1.692 9.082 2 45 75 3 to 5 2 45 75 3 to 5 3 45 75 3 to 5 1.70 0.262 2.825 9.263 3 45 75 3 to 5 3 45 75 3 to 5 4 45 75 3 to 5 2.58 0.388 4.294 9.032 4 45 75 3 to 5 4 45 75 3 to 5 5 45 75 3 to 5 3.19 0.457 5.325 8.580 5 45 75 3 to 5 5 45 75 3 to 5 6 45 75 3 to 5 3.83 0.514 6.390 8.048 6 45 75 3 to 5 6 45 75 3 to 5 7 45 75 3 to 5 4.37 0.579 7.284 7.943 7 45 75 3 to 5 7 45 75 3 to 5 8 45 75 3 to 5 4.89 0.611 8.158 7.491 8 45 75 3 to 5 8 45 75 3 to 5 Average 45 75 3 to 5 2.77 0.383 4.617 8.705 Analysis All anomalous results were circled on the graphs. All graphs were checked for direct proportion and if they were it was written in the bottom right corner, and the point, which it became untrue, was also written down. For example in the experiment of 45 coils to 45 coils, this was untrue at 3.4 V. Also if a string of results in a pattern was seen then a curve or line of best fit was drawn for them. As the results show that primary voltage and secondary voltage are directly, positively proportionate. As one doubles so does the other. E.G in the graph of 45 coils to 45 coils at 1 primary volt the secondary voltage was 0.13V and at 2 primary volts the secondary voltage was 2.6V, showing that if you double the primary voltage you double the secondary voltage. This is because the higher the voltage the more current, more current causes a stronger field in the core, these then get cut by the secondary coil more, resulting in the electrons induced having more energy (voltage). So higher voltage input causes higher voltage output. This is what I predicted. However the secondary voltage would be about 80% efficient, however it was much lower than this. The average efficiency overall was about 15%, a fraction to what I predicted. This is because much more energy was lost than I expected. The experiment works well up to a point but then the efficiency decreases and this is because the current limiting switch popped before the full current, and thus full voltage could be achieved. This caused the graph to slope off. Also the coil ratio and efficiency are inversely proportionate. This is because the higher the ratio the more inefficient the result. This is the opposite to what to I predicted. I think this is caused by the inefficiency of the experiment as a whole. I think that at higher coil ratios the factors that caused a loss of energy were amplified. Meaning that there was more energy lost due to the number of turns etc. No. of Primary coils No. of Secondary coils Primary voltage (v) Secondary voltage (v) Secondary perfect voltage (v) Vs = Vp x (Ns/Np) Efficiency 45 15 3.199 0.289 1.066 25.448 45 30 3.199 0.329 2.133 15.855 45 45 2.913 0.345 2.913 12.200 45 60 3.582 0.450 4.776 9.665 45 75 2.770 0.382 4.616 8.705 As you can see the efficiency was tiny and the secondary voltage never even came close to the perfect voltage. The reasons energy was lost were: 1. Resistance in the wire and increasing current. As the voltage increased so did the current to correspond with it. An increased current has more resistance (V/I = R) and coupled with the thin wire, lots of energy was lost to resistance. Most of this energy became heat and the heat was lost to the air and the coil. 2. Eddy currents occurred in the core. A current was induced in the core (because it is made of a conductor) the current had nowhere to go so it swirled in the core, in an eddie. 3. Flux leakages occurred. This basically means that not all the field lines were cut. This is because the coils didnt completely cover the core, so field lines were wasted. Also the ends of the core lost a lot of lines. So the energy was lost. A circular or doughnut shaped core would remedy this. 4. Also a humming sound was heard this was because of the iron core. In a magnet all the magnetic domains are in one direction, so the particle field lines are all in the same direction, causing one big field line set. Because an alternating current was used, the magnetic domains had to realign every 50th of a second; this caused them to scrape against each other. The friction caused by this caused heat to build up and caused the core to hum at a frequency of 50Hz (the same frequency of the mains) 5. The coil ratio was not a big a factor as predicted. This was because the coils did not cover the entire magnet so the field lines lost a lot of energy anyway. Also the more the coils the further the current has to move, causing more resistance. So the longer the coil the more energy was lost. This is why the coil ratio and the efficiency were inversely proportional. Evaluation The experiment worked quite well despite the low efficiency. It showed the trend and gave sufficient evidence for conclusions. The results were much more accurate than I expected and (excluding the anomalous results at the end) they rarely came off the line of best fit. All the results that did were circled. The method was quite good in theory but in practice fell somewhat, because the efficiency was tiny. The basic method of varying input and checking output is the only way of doing the experiment so it is by default the best. It was fairly good, but with adjustment could be much better. If I were to do the experiment again, I would: 1. Use a laminated core to keep the heat from leaking into the core. 2. Use a core that is circular, so no energy is lost in the ends of the core by uncut field lines. 3. Use thicker wire, so there is less resistance giving more efficiency. 4. Use more voltages to get more accurate results. 5. Use the coils intertwined instead of 1 cm apart, so as not to have any exposed core. 6. Use a pure core, or an alloy of magnetic metals. 7. Use more wires 8. Use more voltages, in order to get a more accurate mapping of the curve. 9. Use a fixed amount of current to get more accurate results 10. Check the amount of energy in joules going in and the amount coming out, in order to get a better idea of efficiency. 11. Use more numbers of coils 12. Use a power box with a dial so exact inputs can be checked 13. Have better heat insulation on the wires so energy is not lost 14. Have better connections that dont give as much resistance. The results were reliable enough for conclusions to be drawn but are not very reliable, even though they correlated well and the trend they show is solid. Because the trend is only visible up to about 3.5V (input) before it starts to fall in efficiency very dramatically. This was because the secondary current never reached its full potential, the current limiter always popped because too much current was being drawn. This was because each voltage corresponds to current and if there is resistance then more current is drawn. Other experiments I would like to do are: 1. A repeat of this experiment changing the coil ratios and the input voltages, keeping the number of turns on the primary coil constant. I predict the same result. But I would like to use more voltages, from 0V to 10V. 2. Investigating other metals like nickel, steel and copper as cores to see how they affect the experiment, I predict that the larger the atom the stronger the fields. 3. The separation of the coils, I predict that the larger the separation the more energy is lost. I want to see how these effect the experiment varying the distance from intertwined, to 10 cm. 4. Larger of smaller core. I predict that the larger the core the more efficient the output because of a larger amount of iron atoms, therefore more magnetic fields therefore more field lines, therefore more field lines cut.

The plight of a child Essay Example

The plight of a child Essay Example The plight of a child Essay The plight of a child Essay Helping Homeless Youth A. What is the problem? A. There are homeless youth without supervision on the streets of America b. They are abusing substances and that may be the cause of them being homeless c. Their family does not accept their lifestyle (LIGHT) B. What is being done to fix the problem? A. Shelters are being built specifically for them b. People are getting the word out c. Giving kids hope d. Foundations are being created C. What is not done? A. More shelters need to be built b. Awareness not raised enough c. Safety regulations need to be changed d. Acknowledgement of their accomplishment D. How can we/you help? A. Volunteer b. Be there for someone c. Give all that you can d. Help raise awareness Is it not to share your bread with the hungry and bring the homeless poor into your house; when you see the naked, to cover him, and not to hide yourself from your own flesh? (Isaiah 58:7) What is the problem? It is so easy to Just live your daily life without noticing the people you pass by on your way home from work. It is easy to Just turn the music up and keep your eyes forward but, how, at the same time, is it so hard? You cannot bear to look into the eyes of that a Day ten sloe AT ten street, out you cannot stop staring Into tenet soul. Many Kilos on the street can feel helpless, but they are not hopeless. A lack of guidance and ignorance cause these youth to be without shelter. While there are efforts to help the youth, there is still more that can be done and those who are concerned can help, There are many reasons that a child could be on the streets of America tonight. They could be on substances, their parents could have lost their Job and then their house, their parents might not accept their lifestyle, or a myriad of other reasons. In any case, they should be helped. We must be able to show Chrisms love to everyone, ND most of all, the homeless. Jesus replied, Foxes have holes and birds of the air have nests, but the Son of Man has no place to lay his head. (Matthew 8:20) Christ, himself, was homeless and he says to you who help the least of these because that is helping him. These homeless youth in the United States is estimated to be 1. 6 million, and that is one in every forty children (Mantra). One in forty-five of Americas future adults and leaders are on the streets hiding or begging for food. It is Just breath taking to think that that many children are on our streets while we are bundled up in our warm, cozy beds. The population of America has surged passed 300 million people, so that is . 53% of America. That may not seem like much, but that is still 1. 6 million people. Wicked it be easier to not look passed that if they were part of your family or someone you knew? Most of the kids are not looking for a handout either. They Just want help to get by, food to live, and a warm enough place to sleep. Many of these youth are homeless because of their parents. They do not accept the life-style that the youth wishes to lead. Even on the streets, their life-style might not be accept, which leads to homophobic violence. Almost half of Chicago homeless youth identify as LIGHT, Lesbian, Gay, Bi-sexual, Transgender, or Queer (Franco). I find it quite deplorable that parents will throw their child out on the street because they do not agree with them. How is that showing Chrisms love? Christ loved everyone, no matter the fault. So, why do we, as Christians, put labels on people and not help them because their sin is different than ours? Granted, not every parent that kicks out his or her child is Christian, but about 80% of America is Christian (Wonky). So, it is safe to assume that most of the parents tossing out their youth are Christian. In this recession, youth homelessness has increased incredibly. There are 28% more homeless youth now than there was in 2007. Chrisms followers should have heartache for these youth. Do not be slothful in zeal, be fervent in spirit, and serve the Lord. (Romans 12:11) . As Christians, we should not be apathetic to Gods word and these helpless youth. We are called to help in any way possible the poor. Christians should not let an opportunity to share Christ pass. Youth have a very acute ear when they are being helped. Some of these youth are with parents that cannot feed them. They do not get food often, maybe but once a day. Soup kitchens are increasing getting better at providing quality food, but they cannot provide for everyone (Rating). What is being done to fix the problem? Homeless youth are not helpless or hopeless. Some are getting the help they need, wanly Is amazing, out some are not. Many organizations are getting ten word out and are trying to help the best they can. Sadly, funding is a major issue. It is essential that these youth be helped. They, along with every other youth, are the future leaders of America. They can accomplish great things, with help. For instance, Isis, a reciprocity student became a contestant on Americas Next Top Model. Isis was kicked out on the street because her parents did not accept that she was a transgender. (Homeless) It is breath taking to think that Isis, with a little help, accomplished so much. In another instance of someone helping, the True Colors foundation is helping the LIGHT youth. The recently had a benefit concert and all the profits went straight to helping the youth. Because of their great strides and selflessness, enough money was raised to erect a 30-apartment residence for the LIGHT youth in New York. Peters) It is that kind of effort that pays off. The foundation put something to their minds and they got something done. These youth do not want a handout either. Some of them are self-sufficient and all they want is a safe place to lay their head. They try so hard to Just find a safe place to stay and they end up with the wrong person they picked up at a bar cuddling for a night and are out on the street then next morning. (Franco) Many do not agree with their lifestyle and that is okay, but Jesus loved the rich, poor, sick, well, the thief, and the tax collector. Who are some people to say that they are above loving someone because of their lifestyle? It is okay to disagree, but that does not mean a person should not do everything possible to help a person out, no matter their orientation. Most of these youth are Just trying to get by. They do not want a hand out, and do not want their hand held and guided along. The youth Just want a helping hand to get back on their feet. The reciprocity foundation takes this a step further though. They put these children in a situation that is comforting and productive. It is pitiful that a person who does not profess to be of any religion helps the LIGHT out more than most Christians would even think to do. Tara Banks partnered with the Reciprocity Foundation to create an episode of Americas Next Top Model to educate teens about youth homelessness. (Homeless) She used her show, which reaches millions every week, to educate teens. We are called to love all, even our enemies. While they should not be seen as enemies, the principle still applies. Love all, care for all, and help all. After reading this, you may feel compelled to help, and you may ask how can I help? Well, there are many shelters that are need your time and effort. Some shelters Hough, will require you to go throug h stringent tests and evaluations, but they are much needed for the safety of the children. (Franco) The leaders of the shelters Just want what is best for these misunderstood youth. Money is also a big help, and so can opening your home too youth. It may be difficult to take in someone, but Just think of the influence that you could have on that child. The youth you take in may feel helpless and hopeless, but you bringing them into a better environment might be what they need to change the world. To run a single bed with all the amenities needed to make the youth feel secure and safe is bout 40,000 dollars, but taking in a child for a year costs Just a fraction of that at 8,100 collars. (Franco) Effort is a huge thing. It is understandable, especially in the current economy, that you cannot give your money, but your time and effort will be welcomed with open arms. Many scrape every penny they can Just to keep their head above water, and they work two Jobs full time in order Just to put a piece of bread in their childs mouth. They do not have a lot of time to help others, but there is always time. For instance, my father works a full time Job and was going to college at the same mime, but he always found time to spend with me and to do other things necessary for himself and me such as grocery shopping. He maybe got 2-3 hours of sleep a night before he woke up and did the same exact thing again. He made the effort to do what was best for me. While this is not a perfect example because I was neither homeless nor in great need, he made the effort and squeezed as much time as he could out of his schedule to help someone else and you can do the same. It is not necessary to get 2-3 hours of sleep Just to help someone, but there are always days off that you can help instead of staying home and doing nothing. There is always holidays like Thanksgiving that you could work at a soup kitchen and give out a Thanksgiving meal. People are dedicating their lives to this cause of helping the homeless and even more so certain sects of the homeless population such as the LIGHT youth. Bambini Weevil is a prime example of this as she is an activist for gay rights. After a few years out of college, she started an organization called Out Impact to raise concerns when it comes to the LIGHT. She tries to do everything she can to help these youth because according to Weevil, Its important to me because we do need change in this entry, as well as accountability for all citizens, she says. L believe its important to have your voice heard and to speak up for those who feel powerless to do so, or cant. (Kay). As Christians, are we not supposed to fight for those who do not have a voice? We are to fight for the children, widowed, and others that are helpless. Should we disregard these youth because they are homeless or are LIGHT? No, of course we should not. We should treat them equally because we are all equal in the ey es of God. We all sin, Just because their sin is homosexuality does not mean they are worse than we are. In fact, it makes them Just like us, sinful.

Financial Sector in GCC Countries Essay Example | Topics and Well Written Essays - 3750 words

Financial Sector in GCC Countries - Essay Example Nonetheless, current events indicate increasing cooperation among GCC countries on particular trade matters such as customs duties, quality standards, cross-member investment, and intellectual property right protection (USTR 179). An agreement for free trade among the six member countries in 1983 was one of the early achievements of the Gulf Cooperation Council. All of the six member countries were signatories to the United Economic Agreement which provides duty free access to all products manufactured in GCC member countries with compliance to existent origin and ownership laws (Al-Muharrami et.al. 5). With the aim of achieving goals for greater economic integration, member states agreed in 1999 to set external tariffs to a common range by 2005. In January 2003 the six GCC member states put up a Customs Union which in theory implies that member states are to adopt integrated customs laws and regulations, one point-of-entry, with open internal exchange of products and classification of products as national origin inside the GCC. Tariff application, income allocation and quality standards are some of the unresolved issues related to the bylaws of the Customs Union. The council was set to agree in 2005 on convergence criteria for adoption of a single currency in 2010 (USTR 179). Bahrain is one of the most diverse and active financial centers in the Gulf. Much of the financial sector's growth can be credited to the oil boom of the 1970s and the replacement of Beirut as a major banking hub during the 1980s. The financial sector is presently the biggest contributor to GDP at 27.6 per cent. Around 370 offshore banks and representative branches are established in Bahrain (IMF Country Report). . The Bahraini government is planning to draw more foreign banks to the area and is anticipating eliminating impending competition from Dubai and a return of Beirut. The government is assessing the structure that polices commercial banking sector of Bahrain in line with the above objectives. The government implemented new, fortified policies for the insurance sector in 2001 (USTR 33). The Bahrain Stock Exchange (BSE) started operation in 1989 with two responsibilities: playing as a securities controller with management of the capital market and functioning as a securities exchange. Foreign businessmen will be permitted to own 100 percent of listed banks within three years. The BSE has also introduced several information facilities to disseminate real-time values for all listed in real time through satellite TV (IMF Country Report). In July of 2000, the Ahli United Bank (AUB) was established by Bahrain's Al-Ahli Commercial Bank (ACB) and United Kingdom's United Bank of Kuwait (UBK) as an offshore banking unit. Trading began in August 2000 of shares of the AUB. The bank has a capital of $323.5 million which symbolizes an important development in the future of financial sectors in the region (USTR 33). Finance and Banking in Kuwait Kuwait has benefited from considerable budgetary surpluses starting from 1999. The budgetary surplus has risen to 40 per cent of GDP in 2005 and is projected to be in the rate of 43 per cent of GDP in 2006. This has been brought about by remarkably higher oil prices coupled with larger

International Relations Essay Example | Topics and Well Written Essays - 1500 words - 7

International Relations - Essay Example The world community is quite skeptical of this stance taken by the regime as they see the program as a chance for the current regime to make a nuclear weapon. This situation would certainly cause a stir in the region due to the unstable relationship that Iran has with neighboring countries such as Iraq, Saudi Arabia and others (Bruno, Irans Nuclear Program, 2010). Iran’s nuclear program has caused a lot of hue and cry over the few years that it became common knowledge that Tehran was working on the program. Many resent the thought of Tehran having the potential of enriching nuclear material and using it either for energy purposes or for weapons as something unacceptable and dangerous. Even the Arab nations, though in the front portraying a show of support, are in the background somewhat skeptical of the program. In a meeting of the Gulf Cooperation Council in November of 2005 the leaders of several Arab nations, including Saudi Arabia and the United Arab Emirates, made a statement inviting the world nations to prevent he program taking off. The Secretary General in a statement claimed that the program had no justification for it and it was for the better that the Middle East be a weapons free zone with regards to weapons of mass destruction (KHAITOUS, 2008). There are a number of clear cut reasons why there needs to be concern over Iran’s nuclear program over that of France and Great Britain. Those two nations have their nuclear program off the ground and have managed to secure their facilities, as best as one can in this current global situation. Iran’s nuclear facilities are still in the preliminary stages with respect to the other nuclear programs operating in the world. A major concern are the Muslim extremists in the nation who are a threat to the world security. There are serious doubts as to how safe the nuclear material will be in Iran and whether Muslim extremists can get their hands on

Classifications of Snakes and Reptiles

Classifications of Snakes and Reptiles Reptiles are some of the oldest living creatures on the planet and made their first appearance some 300 million years ago. It is believed that the first species of snakes contained limbs which became more and more reduced through great periods of time, this phenomenon can be seen as a clear indicator just how evolution took place within a group of organisms. Today vestigial structures occur in certain serpent families such as Pythonidae and Boidae, and are remnants of structures they once possessed. Spurs which occur in the posterior position opposite the cloacae in Boas and Pythons is a clear example of vestigial structures that formed through time. Snakes are carnivorous reptiles that belong to the order Squamata (Lepidosuaria), which is regarded the most important assemblage, as far as snakes are concerned. Squamates is a very diverse group of ectothermic (organisms that rely on their external environment to obtain the energy needed to facilitate metabolic and other processes crucial for life), amniote vertebrates which contain the distinct characteristic of being elongated and covered in overlapping scales. Squamata is subdivided into three distinct suborders: Ophidia or Serpentes, containing snakes, Sauria containing lizards and Amphisbaenia containing worm- lizards. The suborder Ophidia contains 15 families which are subdivided into 456 genera that consist of more than 2900 species. Snakes have one of the widest distributional ranges in the animal kingdom, covering the whole planet except Antarctica (Figure 1.1). In South Africa alone there occurs 166 species and subspecies of snakes, 101 of these species have enlarged fangs to deliver venom of which only 15 are regarded as very dangerous and potentially fatal to man. This means that of all our snake species only 8.5% are classified as dangerous, where administration of antivenin is deemed necessary. The remainder of venomous species is of no medical importance to man, in fact in some species the toxicity of their venom is less than that found in bees and wasps. There are a few morphological characteristics of Ophidia which distinguishes them from the other two suborders e.g. the lack of eyelids, external ears, the lack of limbs and the occurrence of a single row of ventral scales, whereas lizards and amphisbaenas differ in the sense that they have various patterns of scales that do not occur in specific rows. Amphisbaenians scale formation is atypical in the sense that scales are arranged in rows around the body of the animal thus supposedly mimicking the resemblance of an earthworm. The skulls of Serpents are very unique in the sense that their upper jaw bones arent united/interconnected at snout of the animal, this enables the two jaw bones to act separate form one another and enables the snake to swallow large prey items. In contrary to popular belief snakes can however not dislocate or unhinge their jaws to swallow large prey items, the two upper jaws are simply connected to each other through connective tissue which is highly elastic a nd serves as the binding factor between the jaws. Snakes fulfill a crucial role/function in nature and can be seen as an integral aspect of our environment both as key predators and as prey. They assist in regulating rodent numbers and are good indicators of the natural balance of the environment (bio-indicators). In addition to this, research and development is being done on the properties of venom in the medical field. Research is being conducted on the applications of venom in fields such as high blood pressure, mental disorders and diseases of the central nervous system to mention but a few. Such is the complexity of venom that further studies, beneficial to man, are essential. It is there for imperative that we conserve our snakes not only for the preservation of our environment, but also for the wellbeing of mankind. Evolution that took place within the Class Reptilia Reptiles evolved from prehistoric amphibians called Labrynthodonts (Flank, 1997), and according to paleontologists made their first appearance in the Pennsylvanian era some 300 million years ago. They were also the first vertebrates to escape dependency on water. The earliest forms of reptiles suggested a mixture of both amphibian and reptilian characteristics, and diversified greatly over the next 200 million years. Reptiles were the dominant animal group on earth during the Mesozoic period, and were represented by 15 major groups. Only 4 of these orders survive today. Extinct are the fishlike Ichtyosaurus, sail-backed Pelycosaurs, flying Pterosaurs, Mosasaurs, plesiosaurs, well-known dinosaurs like Brachiosaurs and many others. The dinosaurs included the largest animals ever to walk on earth-the Sauropods, some of them reaching lengths of nearly 27 meters long. Many of the less familiar dinosaurs were no longer than chickens. (Carr,1963) Several basic advances made possible the rise and wide distribution of reptiles on land. Most important was the amniote egg, with its tough outer covering and protective membranes, and a cornified skin that protected the animals from drying out. The positioning of the limbs also made it possible for reptiles to move more easily on land, and an improved circulatory system ensured that oxygen rich blood reached the animals. In their Mesozoic heyday, Reptiles dominated the land, seas and air, and the reason for their dramatic decline during this period is still not clear, although there are some speculation by biologists that the decline was probably caused by a meteor shower which altered a dramatic change in climate and giving rise to the so called Ice Age. Warm blooded vertebrates (Birds and Mammals) began to expand by the end of the Mesozoic period. By the time the Cenozoic period arose only 4 orders of reptiles still existed, and these same four have persisted to this day. The order Rhynchocephalia is represented by only one species, the lizzardlike, granular scaled Tuatara (Sphenodon punctatus) confined to New Zealand where its survival is now threatened. The remaining 3 orders have representatives throughout the world. The order Testudines (turtles) is the most ancient, appearing about 250 million years ago and remaining virtually unchanged for the past 200 million years. The order Crocodylia (cro codilians) is slightly less ancient and is traceable to the Permian thecodonts. The order Squamata refers to scaled reptiles that include lizards, amphisbaenids and snakes. This is the most recent order and was not common until the late Cretaceous times about 65 million years ago. In order to classify snakes or other organisms it is necessary to understand the origin and evolution of the species and place them into specific genera and families (Figure 1.2) Scientists believe that modern day snakes evolved from the family Varanidae, a group of lizards that belong to the genus Veranus. The fossils of Lapparentophis defrennei (Figure 1.3) was found in North Africa as we know it today, and it represents the earliest member of the suborder Ophidia. This species however shows no direct link between earlier snake like reptiles, and its origin continues to boggle biologists. Lapparentophis defrennei appeared on the earth around 100 million years ago during the Cretaceous period and were around for about 35 million years, were after it got extinct by the end of the Cretaceous period. Boidae was one of the seven families of snakes that arose after the Cretaceous period and was at its peak of speciation during this time. Colubridae in modern day times is the family that contains the largest amount of different snake species, and first emerged some 36 million years ago during the late Eocene, and the beginning of the Oligocene period. During this time Colubrids started to diversify at an immense rate and eventually gave rise to more new species during the Miocene period. This diversification led to the disappearance of some of the more primitive lineages of snakes because they could no longer compete with the better adapted species that was starting to evolve. Viperidae (vipers, rattle snakes and adders) and Elapidae (front fixed fang snakes generally cobras and mambas and their relatives) originated during the Miocene period and belongs to the infraorder Alethinophidia. The family Viperidae is by far the most advanced evolved species of snake in the world and contains highly specialized structures that enable them to be a very successful hunters e.g. heat- sensitive pits that developed on the upper labial and a brightly colored tail tip that occur in Agkistrodon sp. This is just one example of how specialized this family of serpents is to survive. Distinguising features of the suborder Ophidia All snakes are elongated, lack eyelids, external ears and osteoderms. Snakes poses a forked tongue which can be retracted into a sheath (Figure 2.1) All have along backbone. (Some have in excess of 400 vertebrae), with many articulated ribs used predominantly for locomotion and maintaining body shape. The lower jaw is not fused, which allows the snake to engulf large items. They do however not dislocate their jaw. Prey is subdued either by constriction or by the injection of venom. In the case of venomous snakes small prey items are bitten and held in the mouth until paralysis or death occurs, whereas large prey items are bitten and released to ensure that damage do not occur to the snake. The majority of species have only the right lung but more primitive species such as Pythonidae and Boidae also contains a rudimentary left lung. Unlike lizards the tail cannot be regenerated. All snakes shed their skin. All snakes hatch from eggs, some are Oviparous (eggs hatch outside the females body), and some are ovoviviparous (eggs hatch inside the mothers body thus giving birth to live young). Classification of snakes Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Reptilia Order: Squamata Suborder: Ophidia (Serpentes) Infraorders: -Alethinophidia -Scolecophidia The classification of snakes are based on different morphological structures The general morphology of snakes is a crucial factor used in their Taxonomy. Factors such as the arrangement of bones in the skull and other parts of the skeleton, especially the presence or absence of a pelvic girdle are used to distinguish between separate and subspecies of snakes. The hypapohyses (vertebrae with downward pointing spike like projections), the coronoid bone (a small bone that occur in the lower jaw), structures of the hemipenes (Figure 2.2, Jadin, 2000) and microscopic and biochemical material such as chromosome arrangement and protein analyses are also used in classification of snakes. The presence or absence hypapohyses, especially in the lumbar region of the spine, is used as one of many diagnostic characters when classifying snakes. The hypapohyses is very prominent in the genus Dasypeltis which use them too saw trough egg shells. There occurs much variation in the shape and size of the coronoid bone. It is particularly large in primitive snakes such as Typhlopidae, Leptotyphlopidae and Anomalepididae. The coronoid bone is very small or absent altogether in advanced snake species. A hemipenis is the sex organ of male Squamates. Male snakes has two hemipenes probably for the reason that when one is damaged or injured, it still left with a spare one which can remain to work and carry out its normal function during copulation. This ensures that the males genes dont get lost and can still be carried over through copulation with females. Hemipenes, under normal conditions are used in an alternating fashion when copulation occurs with female individuals. Sperm is carr ied through the sulcus spermaticus (which is the line running through the middle of a males hmipenis) to the female during copulation. By examining the tail of an individual we are able to distinguish its sex. Males usually have a long tail which contains prominent bulges of where the hemipenes are situated and females usually have very short tails without the occurrence of any prominent bulges. The shapes of hemipenes differ greatly from species to species and contain different cranial structures thus forming a very important method for taxonomists to classify snakes into different species and subspecies. Relationships that occur between different species of Squamates as a result of evolution is best explained through the examination hemipenal characteristics of the different species. The function of the spines and ridges that occurs on hemipenes of different species of male snakes, serves as an adaption to ensure that copulation lasts long enough for egg fertilization to occur. Biology Hearing and Vision Snakes cannot hear airborne sounds due to the fact that they do not posses external ears. Snakes do however have an auditory nerve enabling them to hear sounds travelling through a dense medium. They are extremely sensitive to vibrations and can thus detect someone or something approaching them. For this reason people seldom see snakes whilst walking in the bush, the snake senses the vibrations created by footsteps and beats a hasty retreat for cover. There is however snakes that do not retreat when approached and this is a direct result of the morphological attributes they contain. Bitis arietans, Bitis atropos and, Bitis gabonica, are species of snakes that rather rely on their camouflage to conceal them from potential predators and dangers than to move away, and it is not surprising to find out that Bitis arietans is responsible for 60% of all snake bites in Southern Africa. Contrary to popular believe snakes do have good vision. How else would they safely navigate through the bus h except of course via smell? Their vision however is used mainly for detecting movement. Most snakes have monocular vision (unable to distinguish depth of field) whilst some snakes have binocular vision (able to distinguish depth of field) e.g. Thelotornis capensis and Dispholidus typus. Snakes do not have movable eyelids, instead they possess a fixed transparent shield which covers the eye and is shed during sloughing. Sense of smell For this function the snake uses its tongue. The tongue is flickered; picking up minute airborne particles which when retracted back into the mouth is deposited onto organs situated in the roof of the mouth. These organs are known as the organs of Jacobson. Studies have shown that snakes enjoys a similar sense of smell as we do, the epithelium of the organs of Jacobson works in exactly the same way as the olfactory epithelium we as humans possess. The tongue is forked so that the snake can detect the differences in strength of smell and thus enabling it to locate its prey very accurately. Snakes diet consists of quite a few prey items such as: rats, mice, small mammals, birds, frogs, toads, insects, lizards, fish, small antelope, eggs and other snakes, which is swallowed whole usually head first. Shedding Shedding of skin depends primarily on the growth rate. Juveniles for example shed their skin more often than adults for the simple reason that they are growing faster. Juveniles may shed their skin as often as twelve times a year whereas an adult may only shed its skin three to four times a year. During this process the entire skin is shed from the tip of the snout through to the tail including the eye shields. During this time the snakes eyes become opaque, restricting the snakes vision and therefore making the snake not only more vulnerable, but also more aggressive. A snake may often go into hiding during this period. You may also find snakes basking for longer periods prior to shedding, the reason being higher temperature speeds up the development of new skin, thus reducing the vulnerability period. Cold Blooded (Ectothermic) and Hibernation All members of the order Squamata are so called cold blooded (exothermic) organisms. This simply means that unlike mammals and birds which generate heat internally (endothermic), reptiles obtain their heat externally, usually from the sun. All reptiles will bask in the sun absorbing heat from their environment until their bodies reach the correct optimal temperature (ÂÂ ± 30Â °C) which allows them to function at their maximum potential. The advantage of ectothermy is that it is fuel efficient. Mammals on the other hand convert 90% of what they eat into heat in order to maintain biochemical and muscle efficiency which allows mammals the opportunity to function at colder temperatures. This method demands a constant intake of food. Reptiles however become temporarily dormant at colder temperatures and thus waste no energy. A snake can survive and grow on ten to fifteen meals a year. Reptiles will go into hibernation when their optimal body temperature cannot be achieved from the e nvironment. In areas where there is a significant fluctuation in temperature snakes will go into hibernation. The correct term used is topor. Areas such as the lowveld where there is no significant temperature variations will see reptiles not going into true hibernation but rather into a state of burmation. During hibernation snakes live off the body fat accumulated during the warm periods of the summer, and will exhibit very little signs of activity, thus becoming sluggish. A snake will use anything that will offer it protection against the elements and predation. Sites which are used by Squamates during the winter or cold times of the year for hibernation include deserted termite mounds, hollow logs and rock crevices. Reproduction Sexually active males will approach any snake they come across. The reaction of the approached snake will determine how the encounter develops. If the approached snake is a male and reacts aggressively it may give rise to a battle between the two parties. Battles vary according to species, Vipers and Elapids generally engage in a form of ritualistic wrestling, but refrain themselves from biting each other. Colubrids however react violently and bite each other severely. In some species of snakes several males group together amicably and follow a receptive female. Should there be no reaction from the approached snake the sexually active male uses its Vermonasal organ to chemically determine the species and sex of the snake it has approached. It does so with the use of its tongue interpreting the pheromones emitting from the other snake. Should it be of a different species, the male then seeks out a new mate. All reptiles have internal fertilization. The male places his head on the back of the female and winds his tail around the females and attempts to join their cloacas together. This is seldom achieved at the first attempt. It sometimes takes hours, even days, for successful copulation to take place. The sexual organs of the male consist of two penises, referred to as the hemipenes. Each hemipene is equipped with flexible spines which inflate once penetration has occurred making it difficult for the male and female snakes to become dislodged. Sperm is transferred to the female via a single penis in Crocodilians and Chelonians, and paired penises in lizards and snakes (although only one penis is used at a time). Once mating has taken place the male will often stay with the female for a few days to mate again. Fertilization of the ovule and spermatozoid takes place high in the oviduct, then the egg gradually moves down into the oviduct where the uterine glands secrete a substance which surrounds the egg. The length of the embryonic development depends on the species and also within the species depending on climate (temperature), and ranges from 2-5 months. As stated before all snakes hatch from eggs. The method of incubation however does differ between some species. The majority of snakes lay eggs andleave them to be incubated externally (oviviparous) with no parental care whatsoever. Species such as Python natalensis coils around their eggs throughout incubation. This not only protects the eggs but also regulates the temperature to help assist with incubation. In other species such as Hemachatus haemachatus the female retains the eggs inside her body to produce fully developed live young (viviparous). Between four to eight weeks after mating the female selects a suitable site to deposit her eggs. The site chosen is usually a suitably protected place in the form of rotting vegetation, hollow tree trunks or any other suitable location. The number of eggs deposited depends on a variety of circumstances for example, species, size of the female, habitat (availability of food), age and climate. Eggs laid vary between one and two to as many as 60, sometimes more, depending on factors mentioned above. Eggs usually have soft leathery shells which require a specific amount of heat and humidity in order to ensure that hatch. Once the eggs have been laid there is often no parental care with the exception of a few species. In South Africa the young of Python natalensis may stay with the female for several days after hatching, leaving the burrow by day and returning to the female at night. In most reptiles the sex of hatchlings is determined by temperature, for example outer eggs (cooler) will be female while the inner eggs (warmer) within the nest will be male. The eggs usually hatch between one to three months after the female has deposited them. In the case of some species of chameleons eggs might take up to a year to hatch. The young are equipped with an egg tooth consisting of a sharp ridge on the tip of the snout which allows the young to slit open the eggshell thus freeing itself. The young that emerges are exact replicas of the adults, and the hatchlings of venomous snakes are equipped with fully functional venom glands and fangs, and are thus venomous directly from birth. Egg mortality is quite high. Reasons for egg mortality range from predation to unsuitable nest sites chosen. Giving birth to live young may be an evolutionary process to assure the success of a species, reducing the risk of egg mortality in particularly cold areas where the temperatures wont be adequate enough for incubation. Movement (Locomotion Speed) The ability to function at speed and endurance is directly related to the supply and amount of oxygenated blood to the body. Reptiles, unlike mammals and birds, do not receive as good supply of oxygenated blood. Directly translated, this means that reptiles tire more easily and are incapable of endurance. Based on these facts it is doubtful that the speed of a snake would exceed 20km/h which is much slower than the average human. The two fastest snake species world occur in Southern Africa and belongs to the genus Psammophis and Dendroaspis. There are four basic modes of locomotion in snakes: Sepentine This is the more familiar method of locomotion that most snakes use e.g. the family Elapidae which makes use of this method. The body undulates from side to side while the hind part of the snake makes contact with the surface and the rest of the body is pushed in the direction the snake wishes to go. Caterpillar These are usually heavy bodied snakes e.g. Bitis arietans. The snake progresses in a primarily straight line using its ventral scales to propel it forward. Concertina This is when a part of the body is anchored whilst pushing forward. The snake may anchor its head and then drags the rest of the body towards the head. This is often seen in arboreal species when negotiating between smooth braches of trees. Snakes that make use of this type of locomotion usually contain the characteristic of keeled ventral scales, and include species of the genus Philothamnus. Sidewinding This method is most seen in desert species. It is the most effective method of locomotion on loose unstable surfaces such as sand. Only one or two sections of the body are in contact with the surface at any given time. A section of the body is thrown sideways and is followed by the next section. This way of locomotion can be seen as a specific adaption for desert species e.g. Bitis peringueyi, to ensure that they dont get burned by the hot desert sand when moving. Scales Most people refer to snakes as being wet or slimy, which is quite the contrary. In fact if you touch a snake you will notice that it is in fact dry. Scales are horny skin that originates from the snakes epidermis. The primary function of scales is to prevent rapid water loss, an evolutionary process which has allowed snakes to move onto land. Scales can be smooth or keeled. Some snakes use their scales as a warning mechanism. By rubbing them together this creates a rasping sound that serves as a warning to would be predators. Dasypeltis scabra is a species of snake that occur in Southern Africa and which use this specific defensive mechanism to ward of predators. The North American rattlesnakes rattle is also an example of modified scales that formed through evolution. Scales also help in the locomotion of snakes. Scale counts remain one of the main methods in the identification and classification between different species of snakes. There are four methods which can be used to correctly identify a species via scale counts: Head scales This is done by counting the upper and lower labials on each side, taking note of which scales are in contact with the eye. Examine the nasal scales (single, semi-divided or fully divided). Count the number of preocular and postocular scales and check whether a loreal shield is present. There should also be taken note of the arrangements of scales that occur on the temples, and the presence of any fused scales. Observe the relative sizes of internasals, prefrontals, frontal and parietals, and also note the proportions and shape of the rostral scales at the front of the nose. Dorsal scales Note whether the scales are smooth or keeled. And one head length away from head and in front of the cloaca Subcaudal scales The first scale is the single or paired scale that meets the lateral scales on both sides. Count back along the tail towards the conical tip. Note whether scales or anal shields are single or divided as this forms a crucial part of the identification between different families of snakes. Internal Anatomy of Snakes A snakes skull is specifically designed to suit their specialized feeding habits. Because a snake cannot chew its food and must swallow it whole it is important that the snake be able to open its mouth very wide. For this reason the fifty odd bones in the skull are not fused together, instead they are loosely connected to each other by ligaments which allows the snake to produce an enlarged gape allowing it to swallow prey much larger than its head. The concept is similar to an elastic band. Often after a snake has eaten it will seem to yawn, this is done simply to relax the ligaments and bones t their original shape. The structure of a snakes brain is very similar to that of a bird, but unlike birds and mammals snakes lack the enlarged cerebral hemispheres. In mammals (and birds) the cerebral is the part of the brain, which acts as the learning center of the organism. For this reason, although snakes are perfectly adapted to the environment, it is correct to say that snakes are not very intelligent. To allow snakes to engulf such large prey whole the stomach has to be very strong and elastic allowing it to expand greatly once prey is engulfed. Powerful digestive juices allow the snake to digest bone and teeth. Because a snake is for the most part long and cylindrical, the shape of the lung must be somewhat different in order to fit inside the snakes body. The right lung is usually the largest and extends for 1/3 of snakes body length. The left lung, in most cases is absent, or very small. Snakes have in effect only one lung. During feeding the snake is able to extend a muscular extension of its windpipe (epiglottis) from the bottom of its mouth allowing it to breathe while prey is being consumed. Most reptiles have a primitive three chambered heart which is not as effective as the four chambered heart found in crocodiles (and mammals). In snakes oxygen depleted blood gets pumped into one of the top chambers while oxygenated blood gets pumped into the other top chamber, both chambers get emptied into the bottom chamber and then circulated through the body. This is the main reason why snakes tire easily. In proportion to their body size snakes have very large kidneys. The left kidney is situated behind the right kidney in the abdominal region. The function of the kidney is to filter the waste products from the bloodstream and pass them on to the cloaca for excretion. Unlike mammals which excrete nitrogen waste in the form of water soluble urea, snakes excrete these body wastes as crystals which forms a dry white paste which is excreted along with the feaces. This allows reptiles to be extremely efficient in their use of water. Mammals have a separate urinary, reproductive and a nal opening. Snakes however do not. Instead they have a common chamber known as the cloaca which performs all these rudimentary functions. Waste material is stored in the cloaca until eliminated. The claoca opens to the outside through a transverse slit at the base of the tail. It is often possible to tell the difference in sexes between species by looking at the length from the cloaca to the tip of the tail. The longer the distance between these points would signify the snake as being male whereas a short distance between these points would indicate the snake as being female. The reason behind this is that during reproduction, as mentioned earlier, the male wraps his tail around the females. Some snakes, like the Pythonidae family, have special glands which also empty into the cloaca, these glands contain a foul musky scent which can be ejected when a snake is threatened, frightened or stressed. Venom There is no easy describing venom. Simply put, snake venom is highly modified saliva which is produced by modified saliva glands. Venom is a combination of different enzymes, or proteins, that act on other chemicals and proteins thus altering them or simply breaking them down. Many of these proteins are harmless, but some are toxins. The makeup of these toxins varies widely from species to species. Snakes venom can therefore be best described as a cocktail of hundreds of different proteins and enzymes, this complexity alone accounts for widely differing effects of snakebite. In essence venom affects the protein and chemicals of the immune system and the blood, transported through the body via the lymphatic system. The venom glands are situated in the skull slightly behind the eyes. In order for venom to be effective it has to be injected into the circulatory system. It is therefore quite safe for a normal healthy person to drink venom without any consequences. Venom cannot be compared to poison, and are totally different entities. Venom has to be injected (circulatory system) Poison has to be ingested (swallowed) The functions of venom are numerous: Prevents the putrification of prey prior to ingestion. Immobilizes prey thus preventing the snake from being injured. Digestive properties within the venom begin the digestive process prior to ingestion. Snake venom is also antibacterial, antiviral, antifungal and antiprotozoal which protects the snake from microbial diseases which it may contract from prey. As a last resort, self defense when the snake is threatened. There are three types of snake venom: Neurotoxic nerve acting venom (Elapidae). Cytotoxic cel destroying venom (Viperidae.) Haemotoxic blood acting venom (Colubridae). Fangs (Dentition) All snakes have teeth, but not all snakes have fangs. Most snakes have teeth on the upper and lower

san jose :: essays research papers

sometimes in each persons life there is a turning point, a point in time when a revelation is reaveled to you. If you cannot see this revelation sometimes your vision may be clouded over by a voice that may or may not be your own. In the novel, many people are telling san jose to stop listening tom his own voice and folow them. But he knows that is wrong. At Polemarchus' house, Socrates discusses old age with Cephalus, Polemarchus' aging father. Cephalus says that old age is really not as bad as people say it is; if you're a moderate and contented person, your virtue makes old age pleasant. Socrates notes that some would say that it is Cephalus' wealth that makes old age bearable for him. Cephalus says that this is not true, wealth can help someone be virtuous, but it isn't the deciding factor. Cephalus defines just behavior as paying one's debts and speaking truthfully, and notes that wealth does help in these things. Socrates questions Cephalus' definition of just behavior, but before they can discuss it Cephalus leaves, leaving his argument to Polemarchus. Polemarchus defends his father's definition, saying that justice is giving each what is owed to him--treating friends well, and enemies badly. Socrates finds numerous problems with this definition. First is that, since people are sometimes mistaken about who their friends are, it appears to endorse treating bad people well and vice versa. Second is that, since injustice breeds injustice, it says that it is the job of the just person to create injustice. Just as Polemarchus agrees that his initial definition is incorrect, Thrasymachus, another guest at the house, roars into the conversation; he announces, with some pomp, that "justice is nothing other than the advantage of the stronger." In all cities, the rulers enact laws that are in their own best interests, and these laws are declared just, and so clearly justice is always at the service of the powerful.

Just A Pot Of Basil

At the age of eight one of my favorite things to do was dream about living in a time where gigantic beasts loomed over the earth. Form the gigantasaurus to the brontosaurus I enjoyed anything from the Precambrian period. I grew to appreciate the monstrous creatures even more after I took my first trip to the Carnegie Museum of Pittsburgh. I had never seen such elaborate displays of marvelous full-scale dinosaurs, since I was accustomed to seeing them no larger than the height of a book or television screen. I recall roaming through the many displays pretending that I was one of them. Usually, I pretended to be the Troodon, a species that is thought to have the largest brain in proportion to the rest of its body. Even though I was smaller than the rest of the dinosaurs, I always knew that I could outsmart them if I was a clever Troodon. Of course I would forget that they had been extinct for millions of years, as the plaques in front of the enormous exhibits reminded those who were tall enough to read them. But I carried on in my world of dinosaurs while I was in the museum, free to dream as I cared to. The distance and time between the real dinosaurs and I disappeared when I was in the museum, in my little world. Therein lies the significant difference between seeing and imagining, and being told or influenced, that is, being mystified. Mystification, as the art critic John Berger in Ways of Seeing explains, is the process of explaining away what might otherwise be evident (Berger 112). I was instantly captivated from the moment I saw the tied-together skeletons stretching as high as my own house; should I have cared about the petty details that would have distracted me from my own imagination? Original paintings are silent and still in a sense that information never is (Berger 125). The skeletal remains of ancient beasts strung up give only a portion of what such creatures really were millions of years ago. The color of their skin, the texture of their bodies, or even the size of their internal organs are just a few of the endless questions that remain unanswered, lost over time. But museums give something more than any book could ever tell, and that is the real life experience of seeing what could never be perceived otherwise. When life breathed through the dinosaurs they were never frozen into a perfect stance like they are portrayed in museums. Our imagination allows us to fathom what it really may have been like, but the past remains where it is, and can only at its best be relived in movies or museums or our imagination. Museums have never made me feel awkward or uneasy, they come as second nature to me. I enjoy being enveloped by a different emotion each time I look at the skeleton of a dinosaur, or see a mummified pharaoh, or even a beautiful painting of a landscape. I have always been able to let everything go, and be consumed by a striking or stunning image. The wonderful thing about museums is that every few feet there lies an artist waiting to draw you into their world. Artists and their works contained within a single building span over centuries and continents. All contain different points of view and expresses it to the best of their abilities. Today we see the art of the past as nobody saw it before. We actually perceive it in a different way (Berger 112). History meets in a museum, and constantly forms new accounts through time. Each day that passes we have gained something which may add to our overall perception of the world around us. This is why Berger claims that we see things differently and therefore there exists no definitive account of exactly the way things were at any specific moment in time. It is lost forever, and at best, can only be saved in an altered form. There is something magical about the power of the atmosphere of a museum. The silence is filled with a sea of thoughts running through viewers minds. When I first saw John White Alexander s painting Isabella and the Pot of Basil I was immediately captivated. Even my first glance told me that there was something more to the large pot in the painting than meets the eye. In a painting all its elements are there to be seen simultaneously (Berger 121). What the eye can perceive in an instant may take pages to explain. There lies the beauty of art. One glance at Alexander s work captivated me instantly. There lives some hidden secret inside the woman s soul that lay next to the pot. And sure enough, the small plaque beside the painting described a story that told me that my assumptions were correct. The painting was written as a reflection of a poem written by John Keats. Here, briefly, is the story of Isabella and the Pot of Basil. Isabella had two brothers that expected her to marry a well-endowed man so they could collect a significant dowry from her marriage. But Isabella never married, and fell in love with a carpenter named Lorenzo, who was working for brothers. The two were madly in love, and visited each other frequently whenever they were certain that no one could find them together. Soon though, a brother learned of their secret, and the two brothers took Lorenzo into the woods, killed him, and buried him in a shallow grave. One night while Isabella was wailing in bed over the mysterious disappearance of her supposed runaway love, Lorenzo’s ghost came to her and described the occurrences and location of Lorenzo s body. Isabella went to Lorenzo s grave, cut off his head, and took it back home with her where she put it in a big basil pot and covered it with moss, soil, and basil seeds. She watered the seeds with rose water and her own tears and talked to her basil until it grew incredibly lush. After her brothers stole her basil pot, Isabella died of misery and heartbreak, singing a song about the loss of her basil and love. Alexander was able to condense this entire love story into a single painting. Without having read the 500-line poem or at least having some knowledge of the story, the average viewer would never have guessed that her lover s head was contained in the pot. The emotions contained within Isabella and her sacred pot reach beyond words. The pain that she felt consumed her to the point of her own death, where no words can exist. Depicted in the painting is not just a sad woman, but a woman who is about to die, sick and miserable with heartbreak, love, and loneliness. The meaning of an image is changed according to what one seen immediately beside it or what comes immediately after it. [It] is distributed over the whole context on which it appears (Berger 123). Only after reading the small plaque beside the work and continued research after visiting completed my perception on the almost life sized piece of art. These important clues added to what I could deduce from the painting. Without them I would merely have seen just a pot of basil and a woman lying next to it. History is a mystery that is continually being investigated. Without knowing the past no deductions can be made of the present. Alexander captures Isabella in a moment of perfect stillness. Perhaps she is already dead in the artist s eyes, lying beside her love, their souls reunited. The barren space below the pot could contain the spiritual body of Lorenzo. Alexander seems to have purposefully left the open space on the right side of the painting for his spirit next to her. Isabella has her eyes closed and her hand is gingerly extended. Her two fingertips brush against the side of the pot, as if she s imagining the pot to be his face. Her neck appears slightly extended as if she were giving the curved pot a gentle kiss. The stench that must have emanated from the pot would have been almost unbearable to others, yet somehow the power of love caused Isabella to ignore all reason and sanity as her soul sought for her love and mercy. White flowers contrast with the overall melancholy of the image yet also add just the right touch of beauty, innocence, and peace. There are several of these flowers directly under the pot and another at the base of Isabella s feet. This white represents the purity of their love that was so terribly destroyed by her evil brothers. The tear of her garment on her right shoulder shows her distress and her apathy towards her self-appearance. Isabella s soul can be at ease once she is reunited with her beloved Lorenzo; her physical condition no longer matters. There are of course many other paintings depicting Isabella and the Pot of Basil, but none seemed to capture the emotion as well as Alexander does. His art is powerful, captivating, and entices the viewer to look deeper, to learn more, and to almost feel the emotions raging through the canvas. The moment I saw the painting, I knew that there was more to it. The stillness that Alexander recreates reaches beyond words, and required only the same silence in return. The way we see things is affected by what we know or what we believe When in love, the sight of the beloved has a completeness which no words and no embrace can match (Berger 106). Perhaps my heart goes out to Isabella, for I myself am in love and can reconcile with what she may have felt. Even if Isabella was just a fictional character for both Keats and Alexander the emotional consequence of such a painting is undeniable. The love between a man and a woman knows no end, and its eternity continues through people of all time and nations. Of course we are all granted different perspectives, but there lies a central burning passion about love which can only be depicted as a fraction of its entirety. Thus, love in fact, [closes] the distance between the painting of the picture and one s own looking at it (Berger 125). The research that I completed on Isabella and the Pot of Basil introduced a different and more in depth perspective on the work. Without reading the corresponding poem, I would perhaps have seen only a woman standing next to her favorite pot, and be left to imagine what more was involved. My intuition told me that there was more to the painting than what first met my eye. The observations and assumptions that I made based on the picture and poem are based completely my own deductions and learned assumptions that I have acquired throughout my life. Therefore, if John Berger had looked at this image in the same atmosphere as I did, he could have seen something completely different. Therein lies the truest beauty of art, for art is capable of capturing and recreating a moment lost in time without regard to the opinions of those who will see it. Art is beautiful often because we make it beautiful. Big ugly dinosaurs are certainly not beautiful to most, but to me as an eight-year-old, they most definitely were. Being told what is beautiful and what meaning lies behind a painting is the epitome of mystification. According to Berger this lends [undeserved] authority (121) to the artist. The image now illustrates the sentence (Berger 122). And thus, whatever thoughts a viewer has conjured about a painting or work of art are lost, negated, or skewed, yet it provides a strong basis for interpretation. The painting by Alexander exemplifies the poem by Keats. In many instances, poetry is associated with a visual image, but provides only the framework from which a perception of an image can be formulated. Words help set the tone, yet can never deter from the heart of work. I prefer to say that sentences help to illustrate an image. And John Berger would most certainly agree that there is much more to Alexander s work than just Isabella and a pot of basil.