Aztec and Inca DBQ free essay sample

Both the Aztecs and the Incas demonstrated outstanding cultural, intellectual, and religious developments in their societies. These Empires maintained a high level of cultural development due to their social, architectural, and religious aspects. The social effects of the Aztec and Incan Empires clearly emphasized the amazing cultural development that occurred there. The Mendoza Codex (Document 1) is an example that shows the daily activities and customs of the Aztec society. It shows the type of work done by people depending on their gender. The men were taught how to fish and hunt while the women were taught how to work with crafts. The point of view is the author(s) that wrote the Mendoza Codex and believed what was right for each gender. The page from the Codex Mendoza (Document 6) shows how advanced the Aztec marketplace was because of the great variety of goods they contained. The point of view was probably from the author(s) that wrote the Codex Mendoza and saw the items that were being sold there. We will write a custom essay sample on Aztec and Inca DBQ or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page In the memoirs of the conquistador Bernal Diaz del Castillo, he describes the quality and vast amounts of goods sold at the Aztec marketplace (Document 7). He states how the items were displayed and the policies that enforced order throughout the marketplace. Bernal Diaz is the author of this document and does show bias because he compared the Aztec marketplace to the marketplace of Portugal, and is truly only interested in gold, silver, and slaves, rather than everything else that is offered in the marketplace. The picture of the Chinampa system shows the importance of the agricultural method of the Aztecs as well as how the geography of the area promoted its use (Document 8). Much force needed to be exerted by the workers in order to harvest the crops because of the soil-dredged islands. Although it required a lot of labor, it resulted in great benefits since they produced many crops. The author’s POV is most likely a historian who studied the agricultural aspects of the Aztec society. The picture of the Incan Bridge shows the intercommunication between people from different parts of the area to do so with ease (Document 10). The bridges not only encouraged communication between people, but also aided them to gather crops from one side of the area to the other, and the increase trade between the two parts of the Incan Empire. The POV is most likely an artist who liked the fact of a bridge to connect the two parts. The picture from the First New Chronicle and Good Government, illustrated by Felipe Guanan Poma de Ayala, depicts how  the ruler had servants to assist him whether it be in his duties or his palace (Document 11).The POV is a writer, Felipe Guaman Poma de Ayala who wrote this manuscript to and included this picture to show how the ruler was depicted in the society. Architecture also contributed to the development of culture in the Mesoamerican societies. The picture of the carved glyph on the Tenayuca Pyramid in Mexico City exhibits the skill and precision that architects had in constructing a building (Document 2). Although all these sculptors had were rocks to carve into the rock, they did so in a way that was very proficient and showed their expertise in architecture. The POV is a historian/photographer who was interested in the architectural developments in the Aztec society. The twelve cornered stone, shows the great amount of skill and effort the Incan architects had and needed in order to make such reliable and dependable walls (Document 9). This picture shows how precise the aligning is of the carved rocks that a knife blade cannot even fit between them. The POV is a photographer who was interested in the rock formations constructed in the palace. Apart from architecture, the Incan engineers built reliable bridges, just like the one that still stands today (Document 10). This shows the expertise in bridge making as well as how the bridge could have helped architects build their structures, by using the bridge to cross over the chasm and retrieve rocks that could be used as carving rocks or as building materials. The photograph of Machu Picchu shows the great amount of effort and skill required to create a society that could be depended on and maintained in the mountains (Document 13). The POV is a photographer that was probably astonished at how well Machu Pichu was surviving even though it was in the mountains. It consisted of about two hundred buildings, mostly being residences, and the rest being temples, storage structures, and other public buildings. This photograph also shows how the builders of this city had to create a way for the city to not fall down, which also took much thought and skill. A good additional document would be an explanation from an architect or constructor that described some of the obstacles they needed to surpass in order to erect the magnificent buildings and temples. Religion was also a great supporter for the cultural development in the Aztec and Incan Empires. The civil calendar used by the Aztecs shows the sophistication and complexity of activities throughout the course of the year, and how they paid close attention to religious  ceremonies and the agricultural cycle (Document 3). In this society the gods needed to be worshipped in order to produce great and bountiful harvests, so the veneration of gods was a necessity. The POV is the constructor of the calendar and how he was very religious to contract this picture. The chart (Document 4) describes the rituals that were associated for each month of the year and how it coincided with the Aztec calendar. The chart shows the intense religious devotion of many gods through ways of sacrificing people of certain age groups for each month. The POV is probably a calendar constructor who followed the religious duties of the gods and constructed this calendar to inform the people on the months of sacrificing’s. The photograph from the Florentine Codex by Friar Bernadino, exhibits the great sacrificial society of the people (Document 5). The picture depicts a human sacrifice. This document shows bias because to the people of Central America because human sacrifice is part of their religion and the way of worshiping their gods and giving their offerings to them, while to someone else not from this society and not familiar with the religious sacrifices, these ways are seen as heretic and the people are considered savages. The First New Chronicle and Good Government by Felipe Guaman Poma de Ayala exhibits the great devotion of Incas and their leaders to their sun god (doc. 12). They were strictly believers of the Sun God and many other gods. Since the document was written by someone who is of Incan descent, it shows bias. The author sees the Kings rejection to the Christian missionary Fray Vincente, as an act of great courage, loyalty, and devotion to his god, and is seen as a religious figure to other followers of the Sun God.

Dream Journal related to Psychology

Dream Journal related to Psychology When a situation becomes dangerous, the mind will figure out a way to make it safer. After the shooting in Platte Valley, many school officials are worried about how the students are handling this event. In "The Windsor Tribune", Chris Casey's article reviews just how chaotic all of these procedures can be. Every single one of the procedures can be a physical and mental strain on the all the school officials and students. The emotional strain was also another big worry that the weld county superintendent had.When a student has lived through that type of traumatic event, many things can be racing through their mind. Their behavior may change completely after this one event; they may feel as if it is better to be shy so that they do not attract too much attention. The student may do the complete opposite and be very outgoing because they feel as if they have nothing to lose anymore, or they feel invincible.English: Alexander Blok's poem 'Noch, ulica, fonar...I believe that the emotiona l strain that is put on everyone at this time will prevail and prepare us all for a very terrible possibility. I also believe that this emotional strain would be much less than that of someone losing a very close friend that was a victim of yet another school shooting.My MemoryI had to memorize "The Dreams," a poem written by Eugene Field, for my competition in speech debate. The first way I tried to memorize it was called "chunking." It is where I would separate the different stanzas so I could learn them separately and then put it all together at the very end. For me, this worked all the way up until I tried to put the entire poem back together. I could not remember what stanza went after the...

I can read reviews dealing with the content and criticism of cultural Essay

I can read reviews dealing with the content and criticism of cultural topics (films, theatre, books, concerts) and summarise the main points - Essay Example Like on other occasions, the entrance to this museum night event is free and with the company of my friends, the self-guided tour around it will be a thrilling experience. Further, some of the friends have intense knowledge on the history of this bank from school and they will serve well in my understanding of most of the exhibitions and the wide variety of souvenirs that exist within the museum. My visit is also motivated by my great urge to criticize and make notes on what I have observed. This will serve as a great source of relevant cultural information and knowledge about a unique element of England’s culture. From the visit, I also intend to confirm some myths like earliest paper money being made of receipt that the goldsmith was left with for safekeeping2. I also want to understand why the bank of England Museum has so much association with gold to the extent that the advertisement of this event includes people lifting a gold bar worth

Women Liberation Is Still a Fiction Research Paper

Women Liberation Is Still a Fiction - Research Paper Example Women are considered more responsible and hence even the domestic front has to be looked after by women of the houses. The paper argues on the fact that women liberation is still a fiction. The indicators which give the impression of women liberation are in fact illusions. Most of the offices in the world today give the statistics of women employees. The figure is encouraging. Ii indicates that so many women have come out from the domestic front and are engaging themselves in the economic activities. In reality, the picture is completely different. It is true that women participate in economic activities but how much they are a part of the economy remains a big question. In most cases, women work as hard as men rather more than men but her contribution is not seen as a worthy one in society. The belief is such that her income is mainly for satisfying unimportant desires and hence do not have an importance that is equal to that of a man. Women today put on bold attire. This is because they are liberated from the clutches of conservatism. Through their dress, they try to show the world that they can express their desires in modern society. Unfortunately, it does not remain so easy for women. A study has proved that men were of the opinion that women should pay attention to the kind of dresses that they wear. They should not put on something which will catch the attention of men because that may cause rape and other sexual offences. (Campbell and Norris, 39). â€Å"Only through eradication of outward ornament can women atone for the vices of their sex†. (Coon, 32). Through this, it can be understood that the existing belief was that female sexuality was a vice and it can only be controlled if women control their appearances. It was expected that the proper norm for women was to put on drab dresses in order to prevent sexual exploitation.  

Interim Assessment Report Research Proposal Example | Topics and Well Written Essays - 1500 words

Interim Assessment Report - Research Proposal Example Research objective Research objectives are the most important elements of a study. It is often regarded as the foundation of a research work (Babbie, 2012; Kumar, 2005). Moreover, the scope of the research is also established on the basis of the objectives of the study. This study principally aims to examine the impact of mobile search &social media on brand awareness, marketing and liberalization in Saudi Arabia. However, the study also has other objectives as well. The different objectives are presented below: - To identify the influence of mobile search & social media on brand awareness, marketing and liberalization in Saudi Arabia. To recognize how social media can drive customers towards a business and how it can help companies to embrace loyal customers. To identify the best or the most popular social media in Saudi Arabia. To explore how the indentified social media is helpful for the common people and business houses of Saudi Arabia. To identify how mobile search & social med ia can be used by business houses to investigate the business environment and simultaneously bring innovation to the business. To create an independent model to survey the business environment by employing mobile search & social media. ... In the similar context, O'Leary (2004) put emphasis on the fact that what used to be defined with ease 30-40 years back has now become exceedingly complex in the recent times. One of the obvious reasons is the rapidly changing business scenario and arrival of different type of research methods. Thus, which used to hold true 30-40 years back, not hold fully acceptable or not at all acceptable in the present days. In general, there are two broad research paradigms namely positivism and interpretivism. Positivism is often referred to as a scientific method of doing a research. A researcher believing in this philosophy considers realism as true and can be expressed from the viewpoint of an objective (Tobin &Joseph, 2006). Another significant differentiating factor between the two philosophies is that positivists considers quantitative analysis as the more reasonable and helps to draw a logical solution of the subject of concern. Researches believing in this philosophy often consider ques tionnaire survey, online polls, surveys as the best way of collecting data (Blaxter, Hughes & Tight, 2006; Scharff, 2002). The interpretivism philosophy on the other hand believes in anti-positivism concept. They do not consider reality to be stable or reality is articulated from the objective viewpoint. On the contrary, they regard reality is not stable and is constantly changing (Creswell, 2003). Furthermore, they also believe that the behavior of human being is constantly changing as the surrounding in which they exist, strongly impacts them. The researchers belonging to this category also tries to unearth the perception of people about the circumstances in which they exists (Mukherji & Albon, 2009). The differentiating

Diffusion Coefficient of 2m NACL in Water

Diffusion Coefficient of 2m NACL in Water This experiment aims to determine the diffusion coefficient of a liquid mixture, sodium chloride solution, in de-ionized water. This is done through the use of a honeycomb diffusion cell which consists of 121 vertical capillaries which are 5mm long and 1mm in diameter. Ficks Law of Diffusion is used in this experiment to calculate the diffusion coefficient of sodium chloride solution in de-ionized water. The change in concentration of the sodium chloride in the de-ionized water is measured by using the conductivity meter, since sodium chloride dissociates in water. The calculated value of diffusion coefficient was compared with the literature value derived from Eletrochemistry textbook, and the difference in values will be discussed. Some assumptions are being made to make the calculations much simpler. The concentration at the lower end of the diffusion cell is assumed to be equal to 2M, which is the molarity of the sodium chloride solution. The concentration at the upper end of the diffusion cell is taken to be effectively zero. Certain factors that affect diffusion and the calculation of the diffusion coefficient are also discussed to understand more about their effects on diffusion. However, this experiment did not place emphasis on these factors, and these factors are assumed to be negligible in the experiment as steps have been taken to minimise their presence in this experiment. Objective The objective of this experiment is to determine the diffusion coefficient of 2M Sodium Chloride solution in de-ionised water. Principles 1. Diffusion Molecular diffusion, or simply known as diffusion, is a spontaneous process that results in the net transport of molecules from a region of higher concentration to another region of lower concentration. This net transport is a result of the intrinsic thermal energy present in all molecules at temperatures above absolute zero. The phenomenon of diffusion can be mathematically described using Ficks Law (or Ficks 1st Law), which states that for a two component system consisting of A and B, the molar flux, Ni , of the individual component (i = A, B) is defined as: (1) where D is the diffusion coefficient , Ci is the concentration of component i, and is the concentration gradient in the z-direction. The negative sign indicates the flow of transport is from region of higher concentration to region of lower concentration. In the context of this experiment, Ficks law in one-dimension is considered, and there is no mean flow of mixture in the experimental set-up. Therefore, Equation (1) for the molar flux is valid for this experiment. 2. Experimental Set-up A diffusion cell is an instrument that is used to study the diffusion of liquid or gaseous mixtures. The diffusion cell used in this experiment consists of a honeycomb of 121 accurately dimensioned vertical capillaries that are 5mm long and 1mm wide in diameter. This is to restrict the diffusion to a one -dimensional diffusion. To prepare the diffusion cell for use, a small volume of concentrated solution is first placed on one side of the honeycomb, whilst the other side consists of a large volume of pure solvent (de-ionized water). The concentration within the larger volume will increase gradually as diffusion of the solute occurs. This change in concentration is monitored closely with a conductivity sensor and meter. To ensure a uniform concentration within the larger volume, the mixture is continuously stirred with a magnetic stirrer. (Figure 1) The concentration at the lower end of the tube is in fact constant and is equal to the molarity of the solution. The concentration at the upper end of the tube is effectively zero (Figure 2). Honeycomb structure with capillaries Concentration of solution outside tube is zero Concentration of solution inside tube is 2M NaCl Therefore it can be said that: (2) where M is the molarity of the solution and L is the length of the tube. The amount of sodium chloride diffusing per unit time from the capillary is approximately: (3) where d is the diameter of the capillary, n is the number of capillaries and L is the length of the capillary. Outside the tube, since sodium chloride is able to dissociate in water into sodium and chloride ions, the accumulation of the sodium chloride salt in the de-ionized water can be easily calculated by the measurement of change in the conductivity k of the solution with respect to time t. The amount of sodium chloride accumulating per unit time outside the vessel is approximately: (4) where V is the volume of water in outer vessel and CM is the conductivity change for unit molarity change and has the value of 0.41ÃŽÂ ©-1M-1 for the solution used in this experiment. Mass balance requires that the amount of sodium chloride going out of the capillaries must be equals to the amount of sodium chloride accumulated in the de-ionized water. (5) Therefore, (6) By rearranging Equation (6), (7) All the terms in equation (7) are constants and known, except for . However, to determine, we can plot a graph of conductivity as a function of time and find the gradient, which is equals to. Thus, by plotting conductivity as a function of time, the value of the diffusion coefficient D for the sodium chloride solution can be determined. Equipment and Materials One litre vessel with cell holder (Figure 3) Magnetic stirrer with variable speed (Figure 3) Magnetic stir bar (Figure 3) Diffusion cell (Figure 4) Conductivity meter (Figure 5) Conductivity leads Stopwatch (Figure 6) A bottle of de-ionized water (Figure 7) 50 ml beaker (Figure 8) 2M sodium chloride solution in a 100ml glass bottle (Figure 9) Experimental Procedure The one litre vessel was filled with de-ionized water up to 1cm below the graduation (black) mark. The magnetic stirrer was set to the lowest setting. The conductivity meter was connected to the electrodes and then switched on. The reading on the conductivity meter was noted to be less than 10-4ÃŽÂ ©-1 (1 ÃŽÂ ©-1 = 1 Siemens). The diffusion cell was completely filled with 2M (molarity) sodium chloride solution (116.9g NaCl/litre). Excess solution on top of the capillaries and on the sides was wiped off gently with a soft tissue. The diffusion cell was clamped in its position with the top of the capillaries lying parallel with the graduation mark on the vessel. The vessel was carefully filled to the graduaton mark with the provided de-ionized water bottle. The nozzle of the bottle was aimed away from the capillaries and towards the wall of the vessel, so as to minimise the turbulence caused. The timer was started immediately when the vessel was filled to the graduation mark. The reading on the conductivity was noted down at the same time. The conductivity readings were noted down every 200 seconds till 3600s. After the end of Run 1, the solution in the vessel and diffusion cell was disposed. Both the vessel and the diffusion were washed thoroughly with de-ionized water. Steps (1) to (10) were repeated to get another set of readings for Run 2. Results The results are tabulated in Table 1. Questions Plot conductivity (k) versus time (t) and determine the slope of the best fit straight line through the points. From the plot, the gradient of slope of the best fit straight line for Run 1 and Run 2 are 4 x 10-8 and 3 x 10-8 respectively. Determine the diffusion coefficient of 2M NaCl using equation (6). To use equation (6), we need the value for . The value for is determined from the graph. We will take the average of the gradient of the 2 slopes we get from the graph. = = 3.5 x 10 -8 Where, V = 1 Litre = 0.001 m3 L = 5mm = 0.005 m CM = 0.41ÃŽÂ ©-1M-1 n = 121 M = 2M d = 1mm = 0.001 m (gradient of slope) = 3.5 x 10^-8 (ÃŽÂ ©s)-1 For = 3.5 x 10^-8 (ÃŽÂ ©s)-1, How does your value(s) compare with literature values? Comment on sources of error. Table 2 is obtained from the literature of an Electrochemistry textbook. The data in the table are obtained by various experimental techniques, such as tracer diffusion determination. The diffusion coefficient of Na+ and Cl- ions in water, extracted from relevant data in Table 2, are found to be 1.33 x 10-5 cm2/s and 2.03 x 10-5 cm2/s respectively. These ionic diffusion coefficients do not take into consideration the effect of solvation of the water molecules on the ionic species. From Table 2, both the sodium ion and chloride ion have different diffusion coefficient from each other. However sodium chloride diffuses with only one coefficient, therefore we need to compute the average diffusion coefficient, DNaCl. From the equation: (8) j1 = j2 = Dc1 = [] c1 The average diffusion coefficient of the electrolyte NaCl , DNaCl = 2 (9) (1/DNa+ + 1/DCl- ) = 2 (1/1.33 + 1/2.03) x 105 = 1.607 x 10-5 cm2/s = 1.607 x 10-9 m2/s Percentage difference between experimental and literature values of diffusion coefficient = (2.246 1.607)/(1.607) x 100% = + 39.8% The experimental diffusion coefficient values of 2.246 x 10-9 m2/s is slightly higher than the literature value of 1.607 x 10-9 m2/s, and this could be due to some possible sources of error (Will be further discussed in the next section). The calculated value (DNaCl) based on Table 2, equation (8) and (9) does not take into consideration the effect of hydration of the water molecules on the ionic species. The phenomenon of solute-solvent interaction between sodium chloride and water is called hydration. The solute and the solvent both interact to form a new species, which is the actual species diffusing in the solvent Hence, it should be expected that our experiment value will be different from the literature value (DNaCl), as hydration do play a part in the experiment. In addition, the high concentration of the sodium chloride solution (2M) may result in convection, which will also affect the rate of diffusion. (Will be further under Discussions) Possible Sources of Error S/N Possible Sources of Error Solution 1. If thewalls of the capillary tubes arewet, or if the diffusion tube is filled up too slowly or wrongly, air bubbles may form underthe capillariesin the honeycomb structure. The bubbles can significantly impede diffusion through the capillaries, affecting the rate of diffusion. Ensure that no air bubbles are formed in or under the honeycomb structure. This can be achieved by filling the diffusion cell slowly. 2. Evaporation of water from the 1 litre vessel during the experiment could affect thevolume present in the vessel and hence diffusion coefficient would be affected, since the calculation of the diffusion coefficient involves the volume of water present in the vessel. The vessel could be covered with a cover or lid to minimise evaporation of water. 3. The stopwatch should be startedas close as possible to the instant when the water covers the surface of the capillaries. This is because significant changes in concentration can occur at this pointintime due to the steep concentration gradient between the 2 solutions. However, human reaction time will result in some delay. Have one person to fill up the vessel until the honeycomb structure is fully submerged in water, while another person looks from the side and starts the stopwatch once the honeycomb structure is fully submerged. This will minimise the human reaction time. 4. The solution may not be well-stirred enough, thus resulting in a higher concentration at the diffusion surface than the rest of the solution. Have more than one conductivity sensor at various locations or depth along the vessel enables us to get more accurate conductivity readings by averaging the values obtained. 5. The needle was fluctuating at some of the instant when readings were supposed to be taken, making it hard to determine the value to be recorded. By the time the needle stabilised, it has already exceeded the stipulated time (e.g. 1000s), and the reading obtained from the meter would not reflect the conductivity of the solution at that particular time but instead for another timing. A data logging system should be used where signals from the conductivity meter used for the diffusion cell can be recorded into a computer at fixed regular time interval. This helps to eliminate human error from poor judgment in the reading of results as well as allows for a more accurate reading of the conductivity. 6. The vessel may not be thoroughly cleaned from previous experiment by other students, therefore leaving sodium chloride residue at the wall of the vessel. This may add to the conductivity of the solution during the diffusion experiment when the vessel is filled with de-ionised water and therefore lead to an error when calculating the diffusion coefficient of sodium chloride. Clean the equipments thoroughly once more with de-ionised water to ensure that no residues are present on the equipment. 7. Small air bubbles could have been trapped at the opening of the capillaries of the diffusion cell before the start of the experiment. This would affect the diffusion rate of the sodium chloride solution. A porous plate can be used. It enables the solute and solvent to pass through freely, minimizing the chance where the molecules are stuck at the pores or in the capillaries. 8. Convection occurred in the experiment is a major factor that will affect the accuracy of our experiment. Effort has been made to minimized convection. However, the extent in which convection has affected our experiment values is unknown. The rotation of the magnetic stirrer could introduce convection currents in the water. The addition of dye to the vessel containing watercan be used to determine whether the magnetic stirrer is causing too much convection. This should be done before the commencement of the actual experiment to ensure minimal or no convection are present. The dye should never be used during the commencement of the experiment as it might interfere with the diffusion rate of sodium chloride solution. 9. The changes in the conductivity may be so small such that the analog meter is not able to detect the changes. The use of an analog meter also depends on how the person judges the values of the readings when the needle is in between the markings on the meter. This might result in random errors. A digital conductivity meter or data logger should be used to minimise the random errors that might be introduced if an analog meter is used. A digital conductivity meter or data logger would be more able to reflect the small changes in conductivity of the solution, giving us readings that are more accurate and more precise. 10. The temperature of the sodium chloride solution in the diffusion cell and the water in the vessel is assumed to be the same and constant throughout the experiment. However, this may not be true due to the fact that the experimental setup is exposed to the surroundings, thus it is very difficult to ensure constant temperature within the system, unlike the case of a water bath. Temperature, however, does affect the diffusion coefficient. Conduct the experiment in an enclosed environment to minimise contact with the surroundings. Measure the temperature of the water and sodium chloride solution constantly to ensure constant and identical temperature throughout the experiment. Discussions Solute-Solvent interaction (hydration) In the experiment, the species that are diffusing are not just pure sodium and chloride ions. In fact, sodium chloride and water interact to give a new species which is the actual species diffusing in the solvent. The effect of hydration can be studied by using the following flux equation: (10) j1 = D0 (1 + ) c1 (11) j1 = (1 + ) c1 where D0 is the new diffusion coefficient, ÃŽÂ ¼ is the solvent viscosity, R0 is the solute radius, and Ɔ1 is the activity coefficient. Equation (10) and (11) can be affected by hydration in two ways. These two factors are the hydrated species radius R0, and the concentration dependence of diffusion. From equation (11), the solute radius R0 is that of the hydrated species. This can be related to the true solute radius R0 by the following equation: à Ã¢â€š ¬ R03 = à Ã¢â€š ¬ (R0)3 + n() (12) Where VH2O is the molar volume of water and n is the hydration number. The third column of Table 3 shows the values obtained from equation (12). If we were to take the values of Na+ (0.5) and Cl- (-0.7) and compute the average radius R0, the radius obtained will be a smaller value as compared to the case when no hydration is considered. Therefore, we will obtain a larger D0 if we substitute a smaller R0 into equation (11). This explains why we get a larger D0 from experimental results as compared to literature values. Convection In our experiment, the sodium chloride solution has a molarity of 2M, which is a concentrated solution. Such concentrated solution may cause convection in our experiment, thus affecting the rate of diffusion. Total mass transported = Mass transported by diffusion + Mass transported by convection (13) The total mass flux n1, (mass transported per unit area per unit time): n1 = j1a + c1va where j1a is the diffusion flux and c1va represents the convection. From equation (7): (7) D = If we add in the convection term, it becomes (7.1) D = + (convection) From equation (7.1), we can see that the presence of convection in the experiment will mean a bigger value for diffusion coefficient since the total mass transported is now dependent not solely on diffusion only. Convection does play a part in the transporting of mass. In order to examine whether the effect of convection is significant in our experiment, we can carry the experiment with sodium chloride solution at lower concentrations. The diffusion coefficient obtained will then be compared against literature values. If the degree of difference between experimental results and literature values is similar to that of using 2M sodium chloride solution, then we can say that the effect of convection is negligible in our experiment, and vice versa. Temperature dependence of diffusion coefficient In our experiment, the temperature of the water in the vessel and the sodium chloride solution is assumed to be the same and constant throughout the experiment. The dependence of diffusion coefficient on temperature in liquids can be determined using the Stokes- Einstein equation: (14) where T1 and T2 denote temperature 1 and 2 respectively D is the diffusion coefficient is the dynamic viscosity of the solvent From the equation, we can see that temperature does affect the diffusivity of the sodium chloride ions. In order to ensure that this problem does not affect our experiment, we should continuously measure the temperature of the water in the vessel and the sodium chloride solution to ensure identical and constant temperature throughout the experiment. Conclusions The aim of the experiment was to determine the diffusion coefficient of 2M Sodium Chloride solution in de-ionised water. The purpose of the experiment is achieved through the use of diffusion cell and the conductivity meter to study the change in concentration along the vessel at regular intervals. The value of our experimental result is of the order of 10-9 m2/s, which is common for liquid mixtures. This implies that the method of using honeycomb diffusion cell and measuring the change in conductivity to calculate the accumulation of the sodium chloride in the de-ionized water is appropriate for the determination of diffusion in a liquid mixture in this experiment. However, one should be aware that the conductivity method is only applicable for solute which fully dissociates in water. Solutes which do not dissociate in water will not give any changes in conductivity of the de-ionized water. It was found that the diffusion coefficient determined in the experiment is 39.8% larger than the literature values. This is most likely due to the fact that the literature values did not consider the effect of hydration on the sodium and chloride ions. The effect of hydration tends to increase the rate of diffusion, and this was the case for sodium chloride solution. Therefore, if we were to take into consideration the effect of hydration on the ions in our calculation of the literature values, the diffusion coefficient calculated will be close to our experimental value. We have discussed that convection is an important factor that might affect the reliability and accuracy of the experimental results. Due to the limitations of the experiment procedure, we were unable to determine the extent in which convection affects the experiment. Dyes could have been used to detect the presence of any significant convection currents due to the rotation of the magnetic stirrer. This experiment has showed that it is very difficult to calculate the actual diffusion coefficient very accurately using mathematical models and scientific concepts that we currently have. Due to the fact that the values of diffusion coefficients for liquid mixtures are very small, of the order of 10-9 m2/s, any slight error during the experiment will result in a big difference from the actual value. This difference might be small in magnitude, but the application of this value may have large implications in actual situations, such as in chemical plants. Therefore, much effort should be utilised for future research works to accurately determine the actual diffusion coefficients under different situations and conditions.

The Ivory Coast Overview and Media Analysis Essay -- essays research p

Part 1: Country Background The Rà ©publique de Cà ´te d'Ivoire, also known as the Ivory Coast, is a country in West Africa bordering Liberia and Guinea to the west, Mali and Burkina Faso to the north, Ghana to the east, and the Gulf of Guinea to the south. The location now known as the Ivory Coast was made a protectorate of France during the era of imperialism by a treaty in the 1840's, and became a French colony in 1893. The country gained its independence in 1960, at which point it was led by Fà ©lix Houphouà «t-Boigny until 1993. During these years, the country was closely tied with its' West African neighbors economically and politically, but also maintained trade with the Western world, furthering the nations economic development. However, since the end of Houphouà «t-Boigny?s rule the countries stability has been in serious decline, brought on by a number of coups vying for power. Following the takeover by two militia groups in 1999 and 2001 that served to replace the preexisting political pow ers, the country has been subject to a civil war since 2002. Today, the government is identified as a republic with strong executive power embodied by the president, President Gbagbo. The nation?s current state of unrest has greatly hampered its economic development and social and political stability, and the violent state of the country poses a serious threat for those wishing to do business with the Ivory Coast. Part 2: Country Profile ? Population: According to UN census data in 2005, Cà ´te d'Ivoire has a population of 17.1 million individuals. According to data in 2003, 43.6% of the population is female. The largest city in the country is Abidjan, which is the center for most of the countries economic activity and host t... ...urces receive pressure from parties in power to present a specific point of view. Additionally, I believe that the widespread poverty throughout the country further inhibits the local freedom of press. My findings of limited internet access and low literacy rates suggest a lack of social mobility that may correlate with people?s inability to demand truth from local media forces. It is clear that the powers in charge have not accepted the responsibility to place value on a high standard of media, and therefore it is the role of the citizens to pursue such freedoms. Because local citizens have not been able to express these wishes, perhaps it is at this point that Western influences must intervene. Although Western influence has been hampered in the Ivory Coast by civil war, our global awareness of the situation in the country provides grounds for intervention.