Leadership and Hero Essay Example | Topics and Well Written Essays - 500 words

Leadership and Hero - Essay Example In some ways, using my own hopes and romantic ideals, I had created an America that was, perhaps, more mythical than real. I imagined, for instance, a country and a system without serious problems or difficulties. I imagined a country with perfect education and tolerance of other peoples and other cultures. I was, in effect, defining America through my own preconceptions, without having ever truly experienced the country and her culture. Once I arrived in the United States, however, this mirror was removed; to be sure, as stated by Ronald Heifetz, the realities were much different than my original impressions. I learned that America was not all that much different from other countries. To be sure, there were wonderful opportunities for education and employment; on the other hand, there was fierce competition and expensive costs. There was, contrary to my initial beliefs, a very real possibility of failure. I have also learned that one needs to experience people, places, and things first-hand in order to truly understand. We need to remove the mirror, to peel away romantic mythologies, and look at things objectively. In sum, I have learned the value of true experience and the need to be careful about relying on second-hand information. In this essay, I will describe Prometheus and why his character is such a popular hero.

Coporate Accounting Research Paper Example | Topics and Well Written Essays - 1000 words

Coporate Accounting - Research Paper Example There are instances in which the subsidiary and the holding company prepare their financial statements using conflicting policies and principles. In these cases, the parent company has the responsibility of making the necessary adjustments in order to have the subsidiary statements restated to become uniform to that of the holding company. This has to be done before the line-by-line consolidation of summing the respective asset and liabilities are done to arrive at the consolidated figure (Deegan, 2010). A breach of this accounting requirement will mean that the financial statements are inconsistent with the set principles, hence making them unreliable and untrue. Consolidation of inventory will be used to show how the adjustments should be done. AASB 102 demands that inventory be measured using the lower of cost and net realizable value to ensure that the financial statements are not over or under valued. The cost here includes the purchase price, import costs and any cost incurred to bring the stock to its current state. Inventory should also be tested for impairment in order to avoid possible overstatement in the financial statement. In case the subsidiary accounts for stock by violating this requirement, the holding company will have to do the necessary adjustment to ensure that the value posted in the financial statements are uniform. ... The second financial statement asset that is susceptible to errors during consolidation is property, plant, and equipment. The property, plant, and equipment are the long-term assets of the business that are utilized in the production of goods or delivery of services in order to earn revenue to the business. Accounting standard requires that in reporting the value of this item in the balance sheet, depreciation be subtracted from the purchase price to arrive at the net value (Deegan, 2010). Similarly, companies should test the property for impairment and expense any impairment losses in the income statement. The impairment value will also be used to reduce the value of the asset in the statement of financial position. It must, however, be noted that in calculating the depreciation amount, the holding company and its subsidiary might use different measurement bases. Depreciation can either be calculated using the straight-line basis or the reducing balance method. The holding company will, therefore, have to make adjustment to have the depreciation value determined using same method. For example, if the holding company calculates its depreciation using the straight-line method while the subsidiary does the same by the use of reducing balance, the parent company will have to adjust the depreciation values according to the straight-line method. The final consolidated value will then be determined by summing the net values of the property, plant, and equipment. In summary, adding the asset values that are arrived at by use of different measurement bases is inappropriate and violates the accounting rules and standards. The preparers of the financial statements must, therefore, make the necessary measurement adjustments before summing the respective assets and

Management Change Excercise Research Paper Example | Topics and Well Written Essays - 750 words

Management Change Excercise - Research Paper Example The steps include creation of urgency, development of powerful coalition, creation of a change vision, communication of the change vision, eradication of obstacles, creation of short-term success goals, building on the change, and integration of change into the corporate culture of the organization (Mind Tools, 2012).The first step in the process of change management requires the organizational leaders to convince the organizational personnel that a certain change needs to be there on urgent basis because of certain reasons (Coutts, 2000). If this action is not taken, people would underestimate the need of change. In the second step, the organizational leaders need to develop a team which facilitates gaining of people’s consent for change implementation. If this action is not taken, much more effort would be required to convince individuals because they would be scattered and not members of the same team. In the third step, the leader needs to develop a relation between change and a big vision in order to make it easier for the followers to realize what is happening. If this action is not taken, followers would have subjective idea of what is happening. In the fourth step, measures need to be taken to quickly communicate the change and spread the vision. If this action is not taken, there would not be uniformity of approach due to lack of information in certain followers. In the fifth step, the leader needs to recognize the barriers in the way of implementation of change and do whatever is required to remove them. If this action is not taken, the change process is likely to be interrupted along the way. In the sixth step, the leader should appreciate together with the followers the achievement of intermediary goals. If this action is not taken, followers might lose interest as there is little realization of achievement of preliminary goals. In the seventh step, the leader should emphasize upon a need for the followers to continue working in the same dire ction so that the achievement of preliminary goals leads to the attainment of the ultimate goal. If this action is not taken, followers might become over-confident and not do the needful. In the eighth step, the followers need to be motivated to constantly review the change process and keep modifying it to attain optimal results. If this action is not taken, the change may not bring the desired results. Each of the eight steps included in the Kotter’s model is essentially an action that requires a complete strategy to be taken effectively. Implementation of change and its management as suggested by Kotter requires sound management skills in an individual. As a manager, I have good oratory skills and thus, can convince people or for the least, present my opinion in an apprehensible manner. I am good at taking actions pertaining to all the steps of Kotter’s eight step model generally. However, I need a little improvement in the fourth, seventh and eighth step. This is be cause of the fact that I am a little careless due to which, I might not be able to make sure that the process of change is communicated to all of the organizational personnel. This requires a bit of organization on my part. I find it difficult to recollect myself if the continuity in a process is broken. So after the sixth step, in which I as a manager would celebrate preliminary goals with the organizational personnel, it might be difficult for me to develop the focus again to make sure that

The Reader and Hughes Essay Example for Free

The Reader and Hughes Essay The first statement is an irony because young Langston said he was saved when in actual fact he was not saved . He only pretended to be saved so that he could save more trouble. The purpose of writing â€Å"Salvation† is to show the difference in the way of thinking between the young and old generation. Also to clarify the misconception of the older generation that the younger generation can easily comprehend and read in depth meaning to what they are told. This is shown when Hughes and his aunt have different thought about what is expected of â€Å"Salvation† . †And I kept waiting serenely for Jesus, waiting ,waiting waiting but he did not come†. Literally Hughes was expecting to see Jesus and he was expecting him to come to him. On the other hand his aunt (the older generation) thought Hughes was crying because he saw God. Another purpose is to show the irony of life, when others believe you have done something because you have experience the feeling when in actual fact you did it to save the day. † So I decided that maybe to save further trouble, Id better lie, too, and say that Jesus had come, and get up and be saved . So I got up†. Langston loses his faith because of Auntie Reed. She tells him that when you were saved you saw a light, and something happened to your insides! Langston took this literally, expecting to actually see a light and to feel something happening in his body. When he doesnt see or feel anything after hes saved, Langston gives up on believing in Jesus because he believed his aunts descriptions of salvation. His confusion worsens when Westley gets saved because he knows Westley didnt experience anything such as a light and is lying. Abdulwahab 2 Langston goes up to be saved only because he doesnt want to disappoint the adults, and they are all telling him to come up and be saved. That night, Langston cries because he lied, showing he is a good Christian because he believes the commandment about lying. His aunt misreads his tears and tells her husband hes crying because hes experienced the Holy Ghost and seen Jesus. The story reflects how adults dont realize or understand how children think, especially when it concerns a concept as difficult as faith. Auntie Reed expects Langston to accept what she says because shes the adult, and hes a child. She never explains that Biblical stories are a useful guide for how to live ones life . Langston assumes that all his readers are familiar and well acquainted with a charismatic church . † preaching, singing, praying, and shouting†. Hughes chose narration because it was his way of really putting down his feelings and emotions just the way he experienced them . This added to the credibility of the story and the effect that it would have on the reader ,based on criticism coupled with the act that this dealt with a very argumentative topic â€Å"religion†. Hughes also applies the use signal transitions ,:going on thirteen† â€Å"for weeks† ,†then just before†,† for days ahead† and many others . This signal transition are used through out the essay mainly at the time of â€Å"Salvation†. Irony is the only thing that keeps life interesting. The process analysis of the understanding of how a revival meeting works is critical to the essay. Without this piece of information a reader who is not known with such things would not be able to connect with Hughes due to the lack of knowledge of such an event. The reader has to be acquainted with the material that he is reading to gain a sort of relationship with the author. The fact that Hughes did lay out the process set a ground for the reader to connect to the story. Hughes’s language shows that he was writing the essay as if he were still a child holding on to the feelings and thoughts of that time. The effect of the sentences and the beginnings of the sentence with the word â€Å"And†, emphasize Abdulwahab 3 the idea of this being a child . this allows the reader to truly feel as if the child were telling the story. The dialogue and the details of the sound recreate the story of the event in the readers mind . This way the reader is able to put himself in Hughes shoes and get to feel the pressure that was being put into the situation. Works cited : 1 http://www. enotes. com/revolt-mother 2 AMYCARRILLI’S BLOG.

The role of culture in human society

The role of culture in human society Culture is the essential part of the humans society. Every person is spending his or her life within a certain cultural community. It frequently defines what kinds of person a man or woman is and what values will they have. Does the cultural environment have a direct effect on the values within a community for anthropology, psychology and sociology? Let us discuss this topic step by step. To understand it better, we can at first define what the cultural environment is and what influence it has on people within it. The very nature of the cultural environment is cultural and social aspects. It is could also be called a social context and sometimes milieu. It is a culture of a society or a group where a certain person is living or getting an education; it is institutions and people who interact with a certain human. By interaction we can mean not only different types of personal communication (like on a workplace, in class, with neighbors etc.); people could also communicate with each other by means of different communicational media (like phone, internet, newspapers, television etc). In spite of non personal type of the communication, people whom a man or a woman meets in internet can have an influence on his or her values and point of view. Also television and other mass media form our perception of life and other people little by little. This type of interaction we c an call one way or anonymous. It does not always imply the equality of the social status. Thus, the concept of a social environment is wider that the concept of a social circle or a social class. Nevertheless, it is common that those people who have the same social environment start having a sense of solidarity. They easily help and trust each other; also they tend to create a social group. As a result, those people will always have a similar way of thinking and similar patterns even if they make different conclusions. It shows us that people depend on society and culture around them very much whether they recognize this fact or not. Let us briefly define what culture itself is. It is going to help us understand what kind of effect it has on the values within a community for anthropology, psychology and sociology. There is plenty of information about culture and different consequences of it. It is impossible to transmit a culture through genealogy. Culture is not something innate; culture is something that everybody should learn. Different facets of it are interrelated; a culture is spread by those people within a group. Nowadays different cultures could easily exist within a country side by side (like it commonly happens in African countries). According to Hoebel (1960), the definition of a culture is following: The integrated sum total of learned behavioral traits that are manifest and shared by members of society. According Lawton (1975), culture includes age grading, religious rituals and athletic sport. According to Frow (1995) there are traditional differences in task and doing business were breaking down and this meant that standardization rather than adaptation is becoming increasingly prevalent. Probably, a culture is one of the most significant environmental variables that should be considered within a global marketing. Often a culture could not be freely overlooked; it often hiding from a view. Culture consists of some elements; they are language, aesthetics, religion, values and attitudes, education, social organization and material culture. It is necessary to discuss briefly every element of it. Material culture includes communications, power, transportations and others. Language is the next aspect of culture. It is a reflection of the values and nature of a certain society group. It could be sub-cultural languages, for example, dialects; in some countries it could be two or even more languages. Aesthetics includes art, dancing, arts-music. It concerns good taste, beauty, form and color of it. Education, as it is easy to see, includes the transmission of ideas, attitudes, skills and training in certain disciplines as well. Moreover, education serves as a transmitter of cultural and social values. Sometimes a child was introduced to the cultural value by school or later by university. Religion gives the humans behavior the best insight and as well it helps us to answer different questions, for example, why people behave n this way and not in another. We can see that culture is a complicate conception; it includes different aspects. What can we say about values conception? What is commonly meant by values? Shortly, by values a person may mean something that is really matter to him or her. It is beliefs and ideas somebody holds as special. Social and cultural environment forms ones values. Home, church school there are just some places where people could study values that are common for everybody within their cultural environment. Teachers, friends, parents are forming our personal system of values from day to day. As a result we have personal values. Arts et al. (2003) summarized that they consist of something that we accepted from people around as and that part that came with our own life experience. It is too compulsory to accept everything a person is hearing around him or her; nevertheless, values of cultural environment around us has its strong influence on our own system of values. Now, when we recognize what values, culture and cultural environment commonly mean we can examine the direct effect that the cultural environment has on the values within a community for anthropology, psychology and sociology. Before discussing the influence of a cultural environment on a person according to anthropology let us briefly mention the definition of the science. Saying shortly anthropology is the inquiry of humanity. Its origins throw back in the social sciences, natural science and humanities. The term itself is taken from the ancient Greek language and has two parts: man and study or discourse. The matters of anthropology are how do people behave, what are their physical traits, why we can see differences and variations between groups of people, and finally who was the ancestor of the modern humans. Anthropology is commonly divided in to four fields; they are cultural, or social, anthropology, linguistic anthropology, archaeology and biological, or physical, anthropology. We can see that anthropology itself is the science that studies social and cultural values, differences, origins, roots etc. Thus, it is important to talk about the influence of culture environment according to this certain science. According to anthropology, a culture could be seated deeply; unprepared person could take some type of a culture like something senseless, strange and even cruel. Let us give an example. According to the Muslim culture a woman must cover her face with yashmak and hide herself from any alien. Nilaweera Wijetunga (2005) emphasized that this custom could appear strange and senseless to any person from Europe, United States or numeral other countries where people flaunt a womans form openly. Here is another example of the opposite culture. In some African countries (like Congo, Kenya etc) women do not wear top cloths. Oyeshile (2004) explained this fact that according to their culture, their traditions and according to their hot climate they do not consider the top of the female body something that they should cover or hide. There are many other different examples of things and customs that are unacceptable and even criminal in one part of the world; at the same time at another part of it people consider it the culture and commonly do it. Summarizing this short extract we can see that cultural environment have a direct effect on the values within a community for anthropology. Continue the two examples above, a woman from the African country where there is not common or compulsory to cover her body with upper wear have values that are different from the values that are precious for a woman from a Muslim country. If those women could try to explain themselves their culture, values and reasons why they are keeping those culture values they would hardly understand each other. It is common that Muslim people condemn women from Europe and America. For them even the most modest and restrained American female seems to be a woman without culture values because she shows certain part of her body What can we say about the influence of the social environment on personal values for psychology? What is psychology? It is the science of the humans behavior and mind. This science is an attempt to understand humanity by exploring certain specific cases and by discovering some general principles as well. One of the main goals of psychology is to benefit the society. Scientists who involved in it we can divide in to some groups: cognitive scientists, social scientists and behavioral scientists. Among others, social behavior is among different subjects of psychology. The science of psychology explores following concepts: emotion, cognition, phenomenology, perception, attention, brain functioning, behavior, motivation, personality, unconscious mind and interpersonal relationships. As anthropology, the science of psychology is a social science and it has a strong connection with social environment. According to psychology, some type of behavior could be considered normal and other type c ould be considered abnormal. Commonly, humanity has the same nature. For example, murdering and cruelty is considered abnormal in every social group and community. Nevertheless, within some cultures the conception of cruelty may vary. Let us give an example. In American and European countries violation in any form is unacceptable even within a family. Thus people who keep doing it to others would consider psychologically abnormal. According to the culture of some eastern countries, especially countries with Muslim culture, a husband can beat his wife or punish her or in any other way if she does not satisfy him. What kind of misdeed could a wife do? She may cook a food that her husband does not like; she may say a word that her husband could consider unacceptable. People within the community with such culture are considered psychologically normal even if they commit violence every day. According to their culture cruelty is acceptable. A woman is expecting for it and she has no even right to complain. According to the example above we can see that psychological situation within a community could have a strong negative effect on personal values of a human. A person can look at low values of members of the community around him or her and subconsciously this person could understate those values that he or she had before. Psychologically people inclined to depend on society. That is why we can state that the cultural environment have a direct effect on the values within a community for psychology. Sociology is the last science that we are going to discuss. It studies the society using different methods of critical analysis and empirical investigations. This science refines and develops knowledge about the activity of human society. One of the aims of sociology is to achieve the social welfare with the mean of the knowledge. Mancheno-Smoak et al. (2009) stated that the field of interests in sociology varies from the micro level of interaction and agency to the macro level of social structures and systems. It is a very broad conception that is focused traditionally on social class, religion, social stratification, social mobility, secularization, deviance and law. It includes all spheres of peoples activity. It is interesting that sociology studies different types of interactions between people. We are living in the age of the world wide globalization when the whole planet is becoming one big house. Different cultural and social communities are not staying separate from each oth er like it was some hundreds years ago. People are moving, migrating and spreading their culture and different values among other societies. Why can we state that according to sociology, the cultural environment have a direct effect on the values within a community? First reason is that people like to communicate with each other. It means that they getting some new knowledge and values. Roniger (1995) declared that when representatives of different cultures are staying in contact for some time they will get used to new values. It will stop being new for them. New cultural values will become common and according to sociology people will start accepting it in their lives. In some time they would not remember that one or another culture or value was not imparted to them. And it is the second reason why the cultural environment has an effect on values of people for sociology. In other words, when people move from one place to another they create a new social group with mixed culture and values. In conclusion of all factors and aspects that we discussed above we can see that anthropology, sociology and psychology are connected between each other. These three sciences are all about the human nature, culture and community. They are examining interactions and cooperation between different people; we can state that the cultural environment have a direct effect on the values within a community for anthropology, psychology and sociology because according to these sciences it is up to peoples nature to take something new from others. According to religion, human society was created as one big family. Let us agree that this statement is right; thus, we need to accept that people within a social community have a direct effect on each other in the same way in which members within an ordinary family have. Every science that we discussed has one main aim to make our society better. We need to remember that it is up to everybody to help in achievement of this aim.

OPV Cell Fabrication

OPV Cell Fabrication To fabricate the inverted OPV cells with the structure of ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag, the ITO was first coated onto a glass substrate. The ITO coated glass substrate was then cleaned by ultra-sonication in detergent solution, deionized water, acetone and isopropanol sequentially for 10 minutes each. After that, the pre-cleaned and pre-patterned ITO substrate was exposed to a UV-ozone treatment for 10 more minutes. A solution of ZnO was prepared for spin coating onto the ITO coated glass substrate. To prepare the solution, 0.15g of ethanolamine (NH2CH2CH2OH) and 0.6g of zinc acetate dihydrate [Zn(CH3COO)2à ¢Ã‹â€ Ã¢â€ž ¢2H2O] were dissolved in 5 mL of 2-methoxyethanol [CH3OCH2CH2OH] with continuous stirring for 24 hours. After that, 1mL of ammonia (NH3) was added to the solution and stirred for 2 more hours. To remove the inpurities, the solution would need to be filtered through a 0.25mm PVDF filter. With the technique of spin coating at 3500 rpm for 90 s, a ZnO film of about 40 nm would be coated onto the pre-cleaned ITO coated glass substrates. Mild washing would then be performed on the ZnO films with isopropyl alcohol and it was blown dry in air. In the next step, poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) are mixed in the proportion of 10 : 8. The mixture was then dissolved in 1,2-dichlorobenzene solution and to be spin-coated to a thickness of approximately 200nm on the ZnO/ITO layer prepared. Annealing at 120 oC was then carried out to the film for 10 minutes. The hole transport layer of PEDOT:PSS was then spin-coated on the bulk layer of P3HT:PCBM from a commercial solution (Clevios) under the temperature of 120 oC for 10 minutes. In the last step, under a pressure of about 1 milliPascal, the silver electrode of a thickness about 100 nm was coated onto the PEDOT:PSS layer. The devices then needed to be annealed for 10 minutes at around 70 oC under a pressure of about 1 milliPascal. After that, the device was cooled down to room temperature. Using a source meter at AM1.5G illumination with a solar simulator, the photovoltaic characteristics of the cell were measured. The photocurrent measurements were done by using a source meter at AM1.5G illumination. This value of photocurrent was used to calibrate the illuminator for measurements later on. The area of the devices was 0.9 cm2. Intro of OPV, normal and inverted geometry In recent years, there has been great interest in organic photovoltaic cells (OPVs) due to various advantages over the conventional silicon solar cells. Some of the prominent advantages include low cost of manufacturing, light cell weight, high power conversion efficiency reaching 10% 1 and being environmentally friendly. The structure of the photoactive layer in these organic photovoltaic cells is usually an amalgamation between a fullerene derivative as an electron acceptor and a p-conjugated polymer as an electron donor. Among different materials, poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) have attracted wide attention for being developed to bulk heterojunction [2]. This is because of their outstanding conductivity for both electrons and holes and good stability in atmospheric conditions [3]. Aside of these advantages, a major challenge in the study of OPV cells is to combine the high power conversion efficiency and operational stability. To tackle this problem, there are two device structure set forth, namely the conventional geometry and inverted geometry. For devices made according to the conventional geometry, as shown in Fig 1, the photoactive layer, which is usually a blend of the P3HT:PCBM, is lodged between two electrodes, such as an aluminum electrode and an indium tin oxide (ITO) electrode. Upon shining of light, the electrons and holes are photo-excited and then separated to be collected at the two electrodes. Electrons are gathered at the aluminum electrode and holes are collected at the ITO electrode. Devices with such geometry usually have relatively high power conversion efficiency. Nevertheless, the stability of such devices is compromised because these devices are easily affected by oxygen and humidity present in the atmosphere. This is due to the fact that the aluminum electrode has a low work function and it is much susceptible to oxidation [4]. Thus, the stability of devices made with the conventional geometry is restricted. However, the oxidation of aluminum electrode is not the only factor responsible for device degradation. Other factors such as: (1) charge carriers being accumulated at the interface between the photoactive layer and the electrode, (2) metal ions diffusing from the electrodes to the photoactive layer [5], (3) the photoactive layer being unstable and degrade in atmospheric conditions [6], (4) the morphology of the photoactive layer varies in the nanoscale [7]. One of the suggested ways to improve the stability of such OPV cells is to add a layer of encaps ulation to prevent the oxygen and moisture from entering the devices [8]. Nevertheless, the encapsulation cannot prevent the degradation reaction from happening within the OPV cells. Therefore, the intrinsic stability of devices needs to be improved. One achievable way is to use the inverted geometry with reversed charge collection. For OPV cells manufactured with the inverted geometry, as shown in Fig 2, the photoactive layer is middled between an electron transport layer (ETL) and a hole transport layer (HTL) which are in turn lodged between two electrodes, which are usually indium tin oxide electrode and a metal with high work function like silver. Upon photo excitation, the electrons generated will go through the ETL and be collected by the ITO electrode; the holes generated will go through the HTL and be gathered by the metal electrode [9]. The high work function of the metal electrode used makes the electrode unreactive to the oxygen and moisture present in the atmosphere, thus, a higher stability of the OPV cells can be maintained in a relatively long time period. However, the power conversion efficiency of OPV cells with inverted geometry is generally lower than those OPV cells made with conventional geometry [10]. Info on ZnO Several materials are commonly used for constructing ETL, some examples are ZnO, LiF[11], and Ca [12]. Currenly, ZnO is most recognized as a good material for ETL because of its high electron mobility, high photo-stability, low work function and optical transparency [10]. Study done by Krebs et al. [2] has shown that inverted OPV cells with ETL made of ZnO exhibit an extended lifetime. In their study, I–V measurements were performed under illuminated conditions in both presence and absence of UV light. Their results showed that there is increased recombination when the oxygen molecules are desorbed from the surface of ZnO layer due to the photoelectrons when the cell is in operation. In the night time when the cell is not in operation, oxygen molecules are adsorbed onto the ZnO layer again from the atmosphere, thus restoring the OPV cells’ performance. This cycle of desorption and re-adsorption of oxygen molecules causes the inflection point in the I-V measurement to di sappear first and re-appear later. Other than the factors affecting the OPV cells in operation, manufacturing factors exert equally significant influence on the performance of OPV cells. One of such factors is the trap state. In the band gap of ZnO which is a metal oxide semiconductor with nanostructure, there is presence of localized energy states, which are also called trap states. These trap states make the charge transport in ZnO to be different from the bulk material and they exert adverse effect to the charge transport in ZnO [13]. The amount of such trap states increase exponentially from the top of the valence band to the bottom of the conduction band. According to previous research, different amount of trap states can even be present in the band gap of materials which are chemically identical. The different amount of trap states is a result of difference in crystallinity which means the perfectness of the crystal. High electron diffusivity and mobility is usually associated with materials which have higher crystallinity [14]. The crystallinity can be varied by undergone ZnO film through annealing process in different temperature, different density of trap states can thus be achieved. The devices which undergo annealing in higher temperature will have lower depth of trap states, thus consequently exhibiting a better photo-conversion efficiency and greater operational stability. Annealing effect on ZnO, FF, Voc Isc info To further illustrate the effect of annealing on the crystallinity of ZnO layer and consequently the effect on the OPV performance, a study was done by N. K. Elumalai et al.[1] with two devices which have their ZnO thin films annealed at two different temperatures after the ZnO film is coated onto the ITO substrate. As shown in Fig. 3, the current–voltage measurement was done under the illuminated condition of 1 sun for both device A and device B. Device A had its ZnO film annealed at 240 oC, whereas device B had its ZnO film annealed at 160 oC. In the current–voltage measurement, the value of the current when the voltage is zero is called the short circuit current (Isc). In the significance of an OPV cell, Isc is the amount of current going through the cell when the cell is short circuited, which means the voltage across the cell is zero. Hence, the Isc is the maximum current which can be possibly drawn from the OPV cell. The light conversion ability of the OPV cell has a direct influence on the value of Isc. Hence, Isc is useful in characterizing the OPV cell performance. The value of the voltage at the point when the current is zero is called the open circuit voltage (Voc). Voc is the maximum voltage which can be possibly drawn from the OPV cell. In theory, the Voc is dependent either on the work function of the electrodes used or the energy difference between the highest occupied molecular orbital (HOMO) of the electron donor material and the lowest occupied molecular orbital (LOMO) of the electron acceptor material in the OPV cell, depending on whether the contact is non-ohmic or ohmic. With the current–voltage measurement, the fill factor (FF) can be determined. Fill factor is the ratio of maximum power to the product of Voc and Isc. By going through every point on the (I–V) measurement curve, there is such a point with the current (Imax) and voltage (Vmax) values that maximize the fill factor value according to equation, Hence, the fill factor is determined. In addition, the power conversion efficiency (PCE), can be found from the current–voltage measurement. PCE is the ratio of the energy output from the OPV cell to the solar energy the cell received from illumination source. The energy output from the OPV cell is defined as Pcell, the solar energy the cell received is defined as Psun. The PCE can be calculated from the equations shown below. With reference to Fig. 3, it is obviously that device A has a better performance since it shows a higher short circuit current density and a higher open circuit voltage than device B does. With some simple calculation, the fill factor and the power conversion efficiency of both device A and device B can be determined and summarized in Table. 1. From the Isc, Voc and PCE, it is obvious that the device A is superior that device B in terms of photovoltaic performance. Hence, it proved that annealing of ZnO film changes the crystallinity of the nanostructure, reduced trap states density and consequently lead to better photovoltaic performance. In layer ZnO, Voc vs. T in detail examine To examine the effect of trap states of ZnO in more details, the concept of trap depth should be introduced. The trap depth, represented by the symbol , is the depth of the distribution of the trap states in the band gap of ZnO layer. An equation relating the trap depth and Isc is employed [15], as shown below. From this equation, it is obvious that the trap depth is related to the short circuit current which in turn is a function of temperature and illumination intensity. The pre-exponential term Io in the equation summarized factors such as mobility and density of the photo-excited carriers. Researches have been done by N. K. Elumalai et al.[1] to find the effects of different temperature and illumination intensity on the Isc. By a semi-log plot, it is easy to find the trap depth at different condition of temperature and illumination intensity. For this study, it is evident that the trap depth of device A is much lower than device B. This is in line with the theoretical prediction which says that the annealing at higher temperature make the nanostructure have a more perfect crystallinity and thus less trap states distribution. The operational stability of these inverted organic solar cells is influenced by the trap depth and variation of the open circuit voltage. Hence, the effect of temperature and illumination intensity on Voc should be noted. There is on such equation proven to be useful as shown below In this equation, the recombination is assumed to be Langevin type, Eg signifies the effective band gap, which is the energy difference between the highest occupied molecular orbital (HOMO) of the electron donor material and the lowest occupied molecular orbital (LOMO) of the electron acceptor material; the effective density of trap states is represented by Nc; p and n represent the hole density and electron density respectively; e and kB have their usual meaning of elementary electron charge and the Boltzmann constant [16]. From the equation above, when the temperature decreases, the Voc will approach more closely to the effective band gap. Nevertheless, this is only true under the condition that the contacts in the device are all ohmic. When contacts are all ohmic, the barriers for charge carriers are low at the interface. However, in the case which contacts are non-ohmic, charge carriers will stuck and accumulate at the interface due to the higher barrier present. Hence, the Voc will be determined by the difference in the work function of the two electrodes. In Fig 5, the effect of temperature and illumination intensity on the Voc is illustrated. In Fig 5 (a), the ZnO layer in the device is annealed at a higher temperature, the Voc decreases almost linearly when the temperature increases for different illumination intensity. This observation can be explained by an increase in the phonon scattering in the photoactive layer and the ZnO interlayer when the temperature increases. In Fig 5 (b), Voc remains relatively constant when temperature is below 180 K for various illumination intensities, but the linear decrease of Voc is observed again when the temperature increases above 180 K; this may be due to the fact that the resistivity of the ZnO layer decreases at lower temperature. By comparing the two figures, the difference in shape can only be associated to the difference of crystallinity which is a result of annealing at different temperature. Hence, it can be suggested that the Voc is affected by the trap states at low temperature. To va lidate this proposition, the plot of Voc in Fig 5 (a) can be extrapolated to a temperature of 0 K, it will yield a value of 0.8 to 0.9 V. Comparing to the work function difference of the two electrodes which is around 0.7 V, this open circuit voltage is much higher, and it is indeed determined by the effective band gap.

Reverend Grandpa in Cold Sassy Tree :: Cold Sassy Tree

Reverend Grandpa in Cold Sassy Tree  Ã‚      Cold Sassy Tree  Ã‚   In life, people look for direction.   Everyone in the world needs a helping hand.   Some people turn to one another while others turn to forces, which are of great power.   People turn to great forces such as God.   There are many people who live according to the rules of God, out of the bible or whatever book they consider holy.   So therefore, these people are directed in leading a better life.   In the brilliant novel Cold Sassy Tree, by Olive Ann Burns, Grandpa is such a person.   Whenever Grandpa faces an obstacle, he turns to God.     Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Grandpa turns to God whenever he needs true help.   Grandpa is a type of person who is mild, witty, and very religious.   Grandpa uses religion to solve many of his problems.   At the beginning of the story, Miss Love was the target of gossip.   The whole entire town viewed her as an outsider and couldn’t understand why she married Grandpa, especially after his wife recently died.   After Grandpa elopes, he comes back to the house and finds a group of people mourning the sad death.   He introduces his new bride and then out of no where, Grandpa says, â€Å"Lord above, afore this gatherin’ assembled, I ask You to bless the memory of Miss Mattie Lou† (Page 99).   Everyone stood in silence as Grandpa continued the prayer.   Then all of the sudden, people also began to pray along with Grandpa.   This is amazing.   Grandpa used the power of God to divert the feelings of the crowd.   It is very sly of G randpa to do that.   Later on, Will is talking to Grandpa about his frightening encounter with the train.   Will asks Grandpa if â€Å"[he is] alive [because] of God’s will† (Page 97).   Obviously, Grandpa responds with wise words.   He tells Will that â€Å"God gave [him] a brain† (Page 97).   This shows that Grandpa believes God doesn’t do everything.   He believes God only does major things.   He isn’t there twenty four hours a day but God gives one certain abilities which help at all times.   Furthermore, Grandpa starts to give Will a sermon.   Grandpa tells him that â€Å"[One] don’t git thangs jest by astin’† (Page 98).   This shows that Grandpa is an well-educated man who understands the importance of God.   He doesn’t even waste his time asking for petty little things because he knows that God would not listen.