Wind Power Essay Example | Topics and Well Written Essays - 750 words

Wind Power - Essay Example History of Wind Power The term windmill came from the invention of early machines used by farmers for milling grain. Wind was the main source of power for the machines hence the name windmill. These machines were first used in Persia and China around 500 AD according to Ollholf (6). Windmills were also used in Netherlands for pumping water from the ground. The United States in 1870’s had its farmers using the power of the wind through windmills in pumping water. In the 1980’s electricity could be generated through the use of windmills. The first individual to use wind turbine in the generation of electricity was Charles Brush according to Sharman (10). However the invention of the power grid which used fossil fuels overcame the use of windmills in generating electricity. In 1931, the first commercial power plant using the wind turbines in generation of electricity was established in Russia. In the 1970’s with the rise in the price of oil, wind turbines which were stronger and lighter were invented as a source of power. The largest wind power farm established in the United States was built at Altamont pass, California. The Use of Wind Power Today With the many challenges facing the use of fossil fuels such as increased globalization, wind power is regaining its importance as source of energy. Wind power today is regarded as the most rapidly growing source of renewable energy. The wind power produces about one percent of the United States energy with Europe producing and using more than this. Wind power in Denmark produces around twenty percent of the countries electricity. More developed windmills have been established which are made up of three parts; the tower, blades and the box. These windmills have equipment used for converting wind motion into electricity according to Ollholf (8). The modern wind power through wind pumps is used in different ways. For instance it is used in pumping underground water which used for various purposes such as drinking, watering crops, and cooking. The windmills are still used today in grinding grains into flour. The use of wind power today has improved the lives of people living in dry and hot areas as it ensures water is pumped from underground to the surface or places of need. Small wind turbines which are capable of running generators help create electricity for powering televisions, lights and radios in areas where there in rural areas. The wind turbines sometimes form part of a hybrid system for generating power together with solar energy which is reliable and affordable for villagers not connected to the national grid. Floating wind turbines have been established today which are more economical in shipping and installation activities. Wind power turbines which possess contra-rotating rotors have been used today in aircrafts, marines for improving propulsion. The contra-rotating rotor is also used in offsetting of system reactive torques. How Wind Power can be used To Impact the Society As the use of wind power as source of energy continues to grow, more developed and newer applications are appearing in the society. Wind turbines which are able to ride offshore have been envisioned. The use of wind powered electric cars has also been envisioned to apply in the future as suggested by Gipe (390). With the increased global warming due to the use of fossil fuels, a future where communities are powered by the use of wind turbines has been envisioned. Another development that could improve the use of wind power in future is integration of the current windmill with installation. This will involve selling and installing of windmills in the homes like any other appliance used in the house. The enhancements of wind power machines will make

Risk Management Within an Enterprise

Risk Management Within an Enterprise Introduction Risk management is a identification process of upcoming threats and danger to an organisation. In an organisation risk can enter through many ways, it can come from project failure, financial market, an accident in organisation such as flood, earthquake, cyclone, power failure, public health and safety and legal risk etc. Risk can be low to medium, or medium to high. It is difficult to say that an organisation can solve all the upcoming risks to the organisation like earthquake, we can just assume that earthquake can damage the business, but we cannot say how much, but there are some alternatives of upcoming threats like in power failure we can use generator to keep running the business. 1) Purpose of risk management within an enterprise-  The purpose of risk management in an organisation to identify problems before they enter and create problems in the organisation, so that risk management handling process may be planed. It is a continuous looking ahead process so it is an important part of a business. Early detection of risk is important because it is easier, not much expensive, and changes can made easily in the planned process. It is easy to maintain a strategy and solve the risks when they are in early stage. A successful manager can monitor risks before they create problems in a business. The lack of information can is dangerous in a business so the staff of the organisation should be well training so that they can assume the risk when it is in early stage and report to the management as soon as possible. 2) Benefits of risk management within an enterprise-  An effective risk management program can help the organisations to manage their risks and maximise success opportunities .There are too many benefits of risk management to an organisation, like less time consuming, less costly, less labour. The managers of an organisation should train the staff that they can discuss the risks with the management when it is in early stage. Communication is a beneficial way for an organisation it helps to understand the most important risk areas. Staff can provide information in written or discuss with the management. So it can be early identification for the management and an alert to the management about the upcoming threats. The potential risk management benefits are ; supporting business planning, use of resources in effective ways, continuous improvement in the business, fewer dangers and threats, increase of new opportunities, increasing communication between staff and management, helps and focus internal audit programme etc. 3) A Reviewing of activities and internal environment-  By reviewing the internal environment of a organisation we can assume that how we can identify the risks and found risk in the organisation is acceptable or unacceptable, if it is unacceptable then how can we manage that risk to avoid an upcoming danger or threat. It can be found by an audit committee or by a group. Risk can affect the internal environment of the organisation .It depends on the organisations staff that how well they are trained by the management, it depends on the skills of the staff that how they will handle it or will they handle it themselves or will report to management of the organisation. The staff and management should perform their duties with responsibilities and complete their assignments on the given time frame by the management. There should be a continuous monitoring of activities in the organisation and the management should do something for the development of the staff and give them a proper and continuous training so they can be perfect in performing their duties. B. Setting objectives-  All the organisations face the risks from internal and external environments. Objectives should be exist before the management can identify risks affecting the achievements of the organisation. An agency should develop related objectives. There are three broad categories of objectives †operations, reporting, and compliance. In operations the company should do all the operations and work very effectively and in a progressive way, there should not be the minor faults in the formulations of the products and services of the company. If there are any risks around the operation the management should make a report and find the solutions of the involved risks. If they will avoid the so there will not be compliance risks for the company, and the company can achieve their target successfully. There are some questions that what risks should a company not accept for example quality compromises and environmental and rules and regulations set by the government. They must not accept the legal risks. All the product and services should be a standard quality. Always worst outcomes should be assessed for the development of the company. C. Event identification-  An event is a incident arising from external and internal sources that can affect implementation of strategy. There are some external and internal factors through which we can identify events. Economic changes can affect the company financially. Ups and down in the currency of the country can affect the import and export of the company. Natural environments can also affect the company. Environmental damage can cause by failure in the rules and regulations set by law. Loss of funds through frauds can be a serious problem for the company. Failure to measurement of product can be another deficit for the company. Project delay can affect the company, s reputation. Failure of contractors and partners can be another bad situation for the company. Technical faults can also be costly for the company, It can be time consuming and affect the company, s target and reputation. D. Risk assessment with particular reference to the impact and likelihood of risk-  In an organisation it is possible that an event can occur and affect the achievements of the objectives. It can decrease the value of the goods and services, so that risk should analysed because of their impacts. Management should consider the future events, expected or unexpected. They should always finding that what is worst that can happen or damage the reputation of the organisation. Considering the risk appetite the amount of risk is acceptable or not, most likely the government entities risk is low than the private organisations. Tolerance level is high in the private organisations. Risk assessment can use quantitative and qualitative methods. If the management already miss to give notification to the controller and it can be failure to recover the funds. Lack of notification can result in investigation. E. Risk response-  Management determines that how can be respond to the risk, reviewing and impact, evaluating costs and benefits and selecting options within the entity, s risk tolerance. Management should keep trying to avoid the risk if there are other alternatives in front of company. By doing that the risk management we can find out what is good for the company. If the risk occurs the specific actions should taken by the management to reduce the risk level. Reducing risk by sharing the impact of the risk can be beneficial for the organisation. If the organisation will accept the risk without doing anything then the results can be dangers. It is easy to analyse the cost side in spite of benefit side. Management should first find the risks in each division or in each business unit. A view of risk can be depicted in several ways focusing on major risks and event categories across divisions. If the risk is in the program unit can be tolerated but it depends of the level of the risk. F. Control activities-   there is a major role of effectiveness and efficiency in control activities. Control activities should be tested to ensure that there is not material weakness or difficulties. Management also should ensure that control activities are carried out in a timely manner. Internal auditor can also support management by providing assurance on the effectiveness and efficiency of control activities. In an organisation they must provide the receipt to customers, cash should be handle with care, information system and data processing system should be strong enough, financial reporting, accounts receivable , and investments should handle with care. Misuse of company, s assets, corruption and fraudulent reports should be should be probe properly. The management should focus on the core areas like information system, contracts, purchasing, grants and other programs, services provided to the community, revenue collection, salaries of employees, and property. Risk with large and moderate impacts should be addressed with control activities. G. information communication-  Information is major source to identify risks, and respond them in a appropriate way even is external or internal. Information should available for widespread use, all the transactions should recorded and tracked in actual timing, management should have immediate access to operating and financial information more effectively. If the risk is in tolerance than that, s all right otherwise an action should take immediately. Data reliability in information system should assessed carefully, poor assessment or bad management decisions can affect the targets. Communication is another way to be safe from risks, managers and staff needs to discuss the matters with each other, and tries to find the solutions for the problems. If necessary they should take actions immediately. H. Monitoring- In an organisation ongoing monitoring activities should be continuous process. Ongoing monitoring activities will occur through management activities. Division head, Line manager, controller, senior management, internal auditor, and external auditor can evaluate the monitoring process. A variety of evaluation techniques are available like checklist, questionnaire, flowchart techniques, performance steps etc. Reporting to the management about the risks is a good way to keep an eye in the organisation it will be far seeing process which can keep safe the organisation from unwanted danger and threats. Conclusion:  Savoury aroma coffee shopee should identify threats coming in the way of achieving objectives and start creating hazards. They should do proper assessment and need to find solution. This solution should be bigger than problem. They have to be very competent and efficient.

Christopher Columbus Should Not be Considered a Hero :: Christopher Columbus Essays

Christopher Columbus was a man who much credit was given to for a very small deed. In fact he discovered a new world, but that world was only new to him and the men of his previous generations. What about the many Native Americans whose fathers and father’s fathers shed their blood for the land in which they had lived for so many years. How could one such as Christopher Columbus who was looking for freedom and hope cause so much bondage and destruction? One man’s victory turned out to be devastation for millions. When you think of historical greats like Mother Theresa and Martin Luther King Jr. Columbus is not a name that I would use in association with theirs. Now on the other hand I see similarities between Columbus and Hitler. When we remember Hitlerwe look back on all the devastation that he caused and have nothing but empathy and admiration for the Jews and their endurance. Why not the same for the Indians of these great lands, whose tears and blood where shed for nothing more than mere greed. Christopher Columbus can in no way, shape, or form should be considered a hero. A hero is someone who performs good deeds for the sake of others and not for their own benefit. Christopher Columbus did not do a single good deed in any of his four voyages in the late 1400's. 1492, proved to be a good year for Spain and Columbus , but it would become known as the year of hell for the Indians who occupied the land. Columbus and his crew basically enslaved a whole race of men, women, and children. The Natives were plagued by disease and forced into labor for the sole benefit of finding gold. How can one who is suppose to stand for such democracy assume the position of such a horrible dictator? We as Americans should look at the facts before we celebrate this so-called founder. For far too long we have praised and celebrated a tyrant instead of giving glory to the Native Americans whose land this rightfully is, we read in history books how victorious he was but as the story goes on it reveals a history of rape, murder and deception.

Compare and contrast these two newspaper articles Essay

The tabloid and broadsheet articles have the same topic but are written in extremely different styles. They are both in the same place within the two papers and are not on the front page. This shows they are not major stories. The lexis and syntax are different as is the graphology. The tabloids aim for target readers in social groups C2, D and E while the broadshhet papers aim for target readers in social groups A, B and C1. The tabloid paper uses the pyramid formation to lay out the pages. The headline is made the biggest piece of writting to grab attention. A pun is put in to get you to then read on. For Prince Harry they use ‘ His Royal Styness’ which is a play on words were they involve the story and how he is being punished by having to work on a farm. The tabloid then focuses mainly on the pictures which have been manipulated by adding in people that aren’t there to make Harry look worse so more people will want to read the rest of the story. The picture was superimposed and this sets you up for the following text. The writting its self isn’t very informative and uses a basic lexis and syntax ‘for wearing a Nazi uniform to a pal’s fancy dress party. ‘ this uses a more Colloquial language. The style is informal and the writer uses a semantic field of ‘Nazis and pig farming’. The tabloid also has small side stories and links that lead of in another direction, they have a story still involved with the royal family but moves of Prince Harry and on to the whole royal family when they have a survey about them. The writer makes the overall register quite playful and slightly mocking towards the Prince making him look less respectable † Weed the plants (not that weed Harry)† is put into embarasses him as he had been acused of doing cannabis before. The writting is more opinion based â€Å"The rowdy royal† than factual based and it doesn’t state who the quotes are from in name †a security resource revealed†. Unlike the broadsheet paper so it shows that the tabloid paper is more factual. In the broadsheet paper the quotes seem more reliable because it says exactly who is saying it and it gives a short amount of information about who the quote is from †Ian Davidson, the MP for Glasgow†. This article doesn’t exploit the story and use it as an excuse to mock Prince Harry. The writer Andrew Pierce puts in his opinion subtly. The writer makes fewer puns and uses fewer pictures and focuses more on the actual text. Pierce uses a more intellectual syntax and using a wider and more polysyllabic words †recomendations, combination and commemorate†. Pierce uses longer more complex scentences using more clauses † the hearings, which will be televised, begin on February 7†. The target readership is for people who generally enjoy reading, like those in social groups A, B and C1. Pierce took a different perspective on this story and didn’t focus on Harry so much but spread the story wider to cover the whole of the royal family questioning them politaclly and morally. â€Å"Plans by German politicians †¦.. could cause further embarrassment for the Royal Family† This shows that the braodsheet paper is taking things into more depth. The graphology is plainer with just the headline, the text and a small picture making you focus more on the actual text. The overal register is more serious and truthful. The broadsheet paper and tabloid papers are on two very different levels. The broadsheet is more in depth and formal, while the tabloid is more informal and uses a more colloquial language. This shows the different styles of writting used and the different layouts.

Photosynthesis

The leaves are the part of a plant where most photosynthesis takes place. If you cut a leaf in half and look at the cut end, it would look like this: Key: 1. Waxy cuticle: this gives the leaf a waterproof layer, which lets in light. 2. Upper epidermis: provides an upper surface. 3. Palisade cells: contain chloroplasts. 4. Spongy mesophyll: collection of damp, loosely packed cells. 5. Lower epidermis: layer of cells on the lower surface. 6. Air space inside the leaf: allows contact between air and moist cell surfaces. 7. Stoma: a hole in the leaf through which gases diffuse. . Guard cells: change shape to close the stoma. One unique feature of leaves is that they have tiny holes in them to let carbon dioxide and oxygen enter and exit. The hole formed between these cells is called a stoma. A stoma is just a hole. It is controlled by two guard cells, which change shape to either open or close the hole. Something makes water enter the cells by osmosis and so they swell up and change shap e, but no one is quite sure of the trigger. The stomata (air holes) on plants are normally open during the day and closed at night.These stomata are found on the undersides of leaves. This is because if they faced the sunlight, some of the plant's precious water could evaporate out of them. [IMAGE] Guard cells Hole Open stoma Closed stoma Photosynthesis is the way that plants make their food using energy from sunlight. This is the word equation: [IMAGE] Plants use the green dye (or pigment) called chlorophyll to pick up the energy from the sunlight. Plants make sugar and use some of it for energy to keep them alive (respiration) but they also use some for growth and repair by making fats and proteins.However, it is not always sunny so plants need to be able to store some of the sugar they make, so they convert it to a storage carbohydrate (starch). Plants could use starch or glucose. Starch is insoluble (it does not dissolve in water) while glucose is soluble. This means that if sta rch is used, less water is required to keep its food stored. The amounts of water, carbon dioxide, sunlight and temperature can all affect how effectively a plant carries out photosynthesis.The amount of water is effected by how much is taken up through the roots and how much is lost from the leaves. If less water is available in the leaf then photosynthesis will occur more slowly. Similarly, if there is less carbon dioxide around then photosynthesis will occur more slowly. There wont be enough of the fuel (substrate) to get the reaction to work. If there is less sun, which usually means it is cooler too, then there is less energy for photosynthesis and it occurs more slowly. So photosynthesis works best when it is warm and sunny.Aim === The aim of my experiment is to determine whether or not the intensity of light will affect the rate of photosynthesis in a plant. To do this, I am going to observe Canadian pond weed (Elodea) under varying light intensities. The Elodea will be subme rged in water. I will count the amount of oxygen given off in this experiment by counting the number of bubbles produced. I used Canadian pondweed because of its unusual ability to emit bubbles of gas from a cut end, when placed in water. IntroductionPhotosynthesis occurs only in the presence of light, and takes place in the chloroplasts of green plant cells. Photosynthesis can be defined as the production of simple sugars from carbon dioxide and water causing the release of sugar and oxygen. The chemical equation for photosynthesis can be expressed as: sunlight [IMAGE]Carbon dioxide + water sugar (glucose) + oxygen + water CO2 + H2O C6H2O6 + O2 + H2O All plants need light in order to photosynthesise. This has been proven many times in experiments, so it is possible to say that without light, the plant would die.The reason that light intensity does affect the rate of photosynthesis is because as light (and therefore energy) falls on the chloroplasts in a leaf, it is trapped by the c hlorophyll, which then makes the energy available for chemical reactions in the plant. As the amount of sunlight (or in this case light from a bulb) falls on the plant, energy is absorbed. This means that energy is available for the chemical reactions, and so photosynthesis takes place. The more light there is that falls on the leaf in the first place, the quicker the rate that the reaction can take place.There are many factors which will affect the rate of photosynthesis, including light intensity, temperature and carbon dioxide concentration. The maximum rate of photosynthesis will be controlled by a limiting factor. This factor will prevent the rate of photosynthesis from rising above a certain level, even if the other conditions needed for photosynthesis are improved. It will therefore be necessary to control these factors throughout the experiment so as not to let them affect the reliability of my investigation into the effect of light intensity.Predictions ——â₠¬â€Ã¢â‚¬â€œ I predict that as the intensity of light increase, so will the rate of photosynthesis. I also predict that if the light intensity increases, the rate of photosynthesis will increase at a proportional rate until a certain level is reached, and the rate of increase will then go down. Eventually, a level will be reached where an increase in light intensity will have no further effect on the rate of photosynthesis, as there will be another limiting factor, in this case probably temperature. Preliminary work =============== Initially, to determine a suitable range of levels of light intensities at which to record results for my experiment, I did a preliminary investigation in which I recorded the number of bubbles of oxygen given off in a given time at various light intensities. To alter the light intensity, I placed a lamp at various distances from the plant. I also therefore needed a way of accurately measuring the light intensity, and I did this using a light intensity mo nitor. I obtained the following results:Light intensity (%) Number of oxygen bubbles collected 100 38 95 51 90 45 85 36 80 33 75 14 70 7 65 1 60 0 Although this is a very quick, simple and efficient way of obtaining an idea of the trends for the graph, and the boundaries for the measurements, this experiment was not in itself in my opinion accurate enough to be the basis of my main experiment. This lack of accuracy was mainly due to the fact that by simply counting the bubbles, I was relying on each bubble being exactly the same size, which they clearly were not.The preliminary experiment will give me a best fit curve to which I can compare my main graph, and also points at either end of my results at which it is clear to see light intensity has little or no effect. Here, it was in fact at a light intensity of around 95% when it seems that another factor such as temperature or carbon dioxide concentration has become a limiting factor. In my main experiment, it will not be necessary to take readings above this point. It also shows that while my outer limits are justified, it will be better to take more readings between the current light intensity values of around 60 – 95%.I will take readings at 60%, 62. 5%, 65%, 67. 5%, 70%, 72. 5% aâ‚ ¬Ã‚ ¦ This way I will obtain more results between an accurate value scale. Here are my results from my preliminary experiment: [IMAGE] Method Input variables Light intensity – This is to be varied by increasing and decreasing the distance from the light source to the plant Output variables Volume of oxygen (rate of photosynthesis) – This is to be measured by finding the number of bubbles of oxygen produced in a 30 seconds. Carbon dioxide concentration – This can affect the rate of photosynthesis, since if there is too little CO2, it can become the limiting factor.In this case, as long as the experiment is done over a short period of time, the amount of carbon dioxide used up by the plant will not b e sufficient enough to cause the carbon dioxide concentration to become the limiting factor. If my experiment were to be performed over a longer period of time, this would become a problem. Water availability – Water is also required in the photosynthesis reaction, and when it is lacking, the plants' stomata close to prevent further water loss. This closing of the stomata cells also leads to little carbon dioxide being able to diffuse through.Clearly, in a water plant, (like the pondweed) as long as the plant is fully submerged in water at all times, this will not be a problem. Temperature – Enzymes are used in the photosynthesis reactions of a plant. Therefore, temperature will increase the rate of photosynthesis, until a point at which the enzymes weaken and work at a slower rate. I am going to perform the experiment at 22 degrees, checking the temperature frequently in case the heat given off from the light should slightly raise the temperature, in which case I shal l simply refill the beaker with more water after each experiment.Apparatus list A § Desk lamp A § Elodea pondweed A § Clamp A § Water A § Thermometer A § Test-tube A § Beaker A § Cold water A § Stopwatch A § Light intensity meter Cut a stem of Canadian pondweed of about 7cm in length. Fill a test-tube with water, and place it in a clamp. Then place the test tube into a beaker of cold water. Insert a thermometer into the beaker, and record the temperature at the beginning and end of each experiment, (as a precaution against a significant unexpected rise in temperature).Set up a lamp at a set distance from the plant, ensuring that this distance is from the filament of the lamp to the actual pondweed, rather than the edge of the beaker. The light intensity must be measured in the same way as described in the preliminary experiment. When bubbles are being produced at a steady rate, start the stopwatch and count how many oxygen bubbles are produced in 30 seconds. Repe at this experiment three times for accuracy. Following the aforementioned method, I obtained these results: Light intensity (%) Number of bubbles counted Test 1 Test 2 Test 3 95 52 0 50 90 47 48 46 85 37 39 39 80 35 32 33 75 12 13 10 70 4 2 3 65 1 0 2 60 1 0 0 From these results, I have worked out one set of average results and drawn a graph to show them. The results are rounded up to integers because the â€Å"number of bubbles counted† is discrete data (ie – â€Å"4 and a half bubbles† would not be appropriate). ===================================================================== Light intensity (%) Average number of bubbles counted 95 51 90 47 85 38 80 33 75 12 70 3 65 1 60 0 *****Analysis***** ================== *****My graph was in the form of a best-fit curve.I drew it as a curve rather than a straight line because of the clear pattern of the points. This meant that the rate of photosynthesis increased as the light intensity increased. This was because ph otosynthesis is a reaction, which needs energy from light to work, so as the amount of energy available from light increased with the rise in light intensity, so did the amount of oxygen produced as a product of photosynthesis. My graphs showed that the relationship between the light intensity and the rate of photosynthesis was non-linear, as both graphs produced a best-fit curve.However, as I expected in my hypothesis, it does appear that for the very first part of the graph, the increase in rate is in fact proportional to the increase in light intensity (i. e. a straight line) and I can show this by taking some readings from the graph: Results from graphaâ‚ ¬Ã‚ ¦ =================== From these results, I am able to say that an increase in light intensity does certainly increase the rate of photosynthesis. The gradual decrease in the rate of increase of the rate of photosynthesis (the shallowing of the curve) can be attributed to the other factors limiting the rate of photosynth esis.As light intensity increases, the photosynthetic rate is being limited by certain factors, such as carbon dioxide and temperature. These factors do not immediately limit the rate of photosynthesis, but rather gradually. As light intensity increases further, so the rate of photosynthesis is being limited by other factors more and more, until the rate of photosynthesis is constant, and so is almost certainly limited in full by another factor. Overall, both graphs and my results support my predictions fully.My idea that the rate of photosynthesis would increase with light intensity was comprehensively backed up by my results. This is because a higher light intensity involves a greater level of light energy, which can then be transferred to a special protein environment designed to convert the energy. Here, the energy of a photon is used to transfer electrons from one chlorophyll pigment to the next. When enough energy has been gathered at a reaction centre, ATP can be synthesised from ADP. The oxygen collected in the experiment is in fact the by-product of this reaction, and so it is lear to see that the more light energy, the more ADP is being converted into ATP and more oxygen is produced as a result. Evaluation ========== Although I feel that my experiment was sound overall, I thought there were many points at which the accuracy was not perfect. As I have already stated, my preliminary experiment was not accurate enough to justify being used as my main experiment. This was mostly due to the fact that I was relying on all the bubbles being the same size, which they clearly weren't, however many of the smaller inaccuracies also apply to my main experiment.Firstly, the distance between the light sources and the Canadian Pondweed were not measured to a very high degree of accuracy, especially when you note the fact that the distance should have been measured exactly from the filament of the light bulb to the centre of the plant. It is possible here to find a percentage error. I estimate that the error could have been up to 0. 5cm and I will find the percentage error for the largest and smallest reading using this estimate: Percentage error = possible inaccuracy total reading % error distance 10 5cm 1 50cm Percentage error is just how much your guess was off from the actual value. The formula is: |estimate – actual|/actual * 100% [That is: the absolute value of (the estimate minus the actual) all divided by the actual, all multiplied by 100%. ]* It is clear to see that the percentage error is much less for the larger distances. Although I was not actually using the distances as part of my results, I used them as a marker for where the lamp was placed each time, as I assumed that the light intensity would be the same each time at a particular distance. Therefore, any inaccuracies in measuring the distances, i. e. f a distance was slightly different when doing the actual experiment from the distance at which I earlier measured the l ight intensity, an error would ensue. The second major inaccuracy was in measuring the volume of oxygen given off. When reading the syringe there could have been an error of 0. 25mm, and again it is possible to find a percentage error. % error volume 3. 57 7ml 50 0. 5ml For the smallest volumes this is clearly a massive error, and to improve this, it would be necessary to do the readings over a longer period of time, therefore increasing the volumes, and in turn reducing the percentage errors.Another error would have been due to background light in the vicinity. We tried to reduce this error by closing all blinds in the laboratory, but due to practical reasons, we could not all perform the experiment in a separate room, and we therefore experienced light pollution from other student's experiments. This would have had a very marginal effect on my results as a whole, but to eliminate this problem completely, it would have been necessary to perform the experiment in a totally dark room . A further inaccuracy was in the heat generated by the lamp.As I have earlier described, temperature has a very noticeable effect on the rate of photosynthesis, and so any increase in the temperature of the pond water would have had serious effects on the accuracy of my results. To ensure this did not happen, I monitored the temperature of the water before and after every reading, to check that the temperature did in fact not rise. It turned out not to be a problem, as over the short period of time taken by my experimental readings, the temperature did not rise at all.However, if I were to extend the time of my experiment to 5 minutes for each reading for example, which would have the effect of reducing other percentage errors, I would have to find some way of keeping the temperature constant. One way of doing this would be to place a perspex block between the lamp and the plant, which would absorb most of the heat, while allowing the light energy to pass through. As I mentioned in my planning, carbon dioxide concentration could have been an error in the experiment. However, I feel that due to the short period of time taken there is very little chance that the oncentration would ever have been so low as to become the limiting factor. Again if I were to carry out the experiment over a longer time period, it would have been necessary to add sodium hydrogen carbonate to the water to increase the carbon dioxide concentrations. The last inaccuracy, though a small one, was in the time keeping. The main problem here was in when to begin the minute. If for one reading, the minute was started just after one bubble had been produced, and in another reading it was just before, this could have had a negative effect on the accuracy of my results.I therefore ensured that in each case I started the stopwatch just after a bubble had been produced, thus heightening the accuracy. Overall, I felt that due to the small volumes of oxygen involved, my experiment was not as accurat e as it could have been, however I believe it was accurate enough to support and justify my hypotheses. Improvements could have been made as I have stated, mainly by simply increasing the time taken. However, due to practical time constraints in taking the readings for my investigation, and some consequential problems relating to time extension, I could not in fact make these adjustments.The other obvious way of increasing the reliability of my results would be to take many repeat readings and find an average. To extend my enquiries into the rate of photosynthesis, I could perhaps try to link in some of the other limiting factors to the same experiment, as well as investigating them in their own right. It could also be interesting to explore the effects of coloured lights on the rate of photosynthesis, which could lead to the question of whether or not other types of light, such as fluorescent lights or halogen lights, would have a different effect on the rate of photosynthesis.