Calorimeters and Calorimetry

Calorimeters and Calorimetry Calorimetry is the science associated with determining the changes in energy of a system by measuring the heat exchanged with the surroundings. Now that sounds very textbooky; but in this last part of Lesson 2, we are going to try to make some meaning of this definition of calorimetry. In physics class (and for some, in chemistry class), calorimetry labs are frequently performed in order to determine the heat of reaction or the heat of fusion or the heat of dissolution or even the specific heat capacity of a metal. These types of labs are rather popular because the equipment is relatively inexpensive and the measurements are usually straightforward. In such labs, a calorimeter is used. A calorimeter is a device used to measure the quantity of heat transferred to or from an object. Most students likely do not remember using such a fancy piece of equipment known as a calorimeter. Fear not; the reason for the lack of memory is not a sign of early Alzheimers. Rather, it is because the ca lorimeter used in high school science labs is more commonly referred to as a Styrofoam cup. It is a coffee cup calorimeter usually filled with water. The more sophisticated cases include a lid on the cup with an inserted thermometer and maybe even a stirrer. Coffee Cup Calorimetry So how can such simple equipment be used to measure the quantity of heat gained or lost by a system? We have learned on the previous page, that water will change its temperature when it gains or loses energy. And in fact, the quantity of energy gained or lost is given by the equation Q = mwater†¢Cwater†¢ÃŽâ€Twater where Cwater is 4.18 J/g/ °C. So if the mass of water and the temperature change of the water in the coffee cup calorimeter can be measured, the quantity of energy gained or lost by the water can be calculated. The assumption behind the science of calorimetry is that the energy gained or lost by the water is equal to the energy lost or gained by the object under study. So if an attempt is being made to determine the specific heat of fusion of ice using a coffee cup calorimeter, then the assumption is that the energy gained by the ice when melting is equal to the energy lost by the surrounding water. It is assumed that there is a heat exchange between the iceand the water in the cup and that no other objects are involved in the heat exchanged. This statement could be placed in equation form as Qice = Qsurroundings = -Qcalorimeter The role of the Styrofoam in a coffee cup calorimeter is that it reduces the amount of heat exchange between the water in the coffee cup and the surrounding air. The value of a lid on the coffee cup is that it also reduces the amount of heat exchange between the water and the surrounding air. The more that these other heat exchanges are reduced, the more true that the above mathematical equation will be. Any error analysis of a calorimetry experiment must take into consideration the flow of heat from system to calorimeter to other parts of the surroundings. And any design of a calorimeter experiment must give attention to reducing the exchanges of heat between the calorimeter contents and the surroundings. Bomb Calorimetry The coffee cup calorimeters used in high school science labs provides students with a worthwhile exercise in calorimetry. But at the professional level, a cheap Styrofoam cup and a thermometer isnt going to assist a commercial food manufacturer in determining the Calorie content of their products. For situations in which exactness and accuracy is at stake, a more expensive calorimeter is needed. Chemists often use a device known as a bomb calorimeter to measure the heat exchanges associated with chemical reactions, especially combustion reactions. Having little to nothing to do with bombs of the military variety, a bomb calorimeter includes a reaction chamber where the reaction (usually a combustion reaction) takes place. The reaction chamber is a strong vessel that can withstand the intense pressure of heated gases with exploding. The chamber is typically filled with mostly oxygen gas and the fuel. An electrical circuit is wired into the chamber in order to electrically ignite the c ontents in order to perform a study of the heat released upon combustion. The reaction chamber is surrounded by a jacket of water with a thermometer inserted. The heat released from the chamber warms the water-filled jacket, allowing a scientist to determine the quantity of energy released by the reaction. Source: Wikimedia Commons; thanks to Lisdavid89. Solving Calorimetry Problems Now lets look at a few examples of how a coffee cup calorimeter can be used as a tool to answer some typical lab questions. The next three examples are all based on laboratory experiments involving calorimetry. Example Problem 1:A physics class has been assigned the task of determining an experimental value for the heat of fusion of ice. Anna Litical and Noah Formula dry and mass out 25.8-gram of ice and place it into a coffee cup with 100.0 g of water at 35.4 °C. They place a lid on the coffee cup and insert a thermometer. After several minutes, the ice has completely melted and the water temperature has lowered to 18.1 °C. What is their experimental value for the specific heat of fusion of ice? The basis for the solution to this problem is the recognition that the quantity of energy lost by the water when cooling is equal to the quantity of energy required to melt the ice. In equation form, this could be stated as Qice = -Qcalorimeter (The negative sign indicates that the ice is gaining energy and the water in the calorimeter is losing energy.) Here the calorimeter (as in the Qcalorimeterterm) is considered to be the water in the coffee cup. Since the mass of this water and its temperature change are known, the value of Qcalorimeter can be determined. Qcalorimeter = m†¢C†¢ÃŽâ€TQcalorimeter = (100.0 g)†¢(4.18 J/g/ °C)†¢(18.1 °C 35.4 °C)Qcalorimeter = -7231.4 J The negative sign indicates that the water lost energy. The assumption is that this energy lost by the water is equal to the quantity of energy gained by the ice. So Qice = +7231.4 J. (The positive sign indicates an energy gain.) This value can be used with the equation from the previous page to determine the heat of fusion of the ice. Qice = mice†¢ÃŽâ€Hfusion-ice+7231.4 J = (25.8 g)†¢ÃŽâ€Hfusion-iceΔHfusion-ice = (+7231.4 J)/(25.8 g)ΔHfusion-ice = 280.28 J/gΔHfusion-ice = 2.80102 J/g (rounded to two significant figures) Example Problem 2:A chemistry student dissolves 4.51 grams of sodium hydroxide in 100.0 mL of water at 19.5 °C (in a calorimeter cup). As the sodium hydroxide dissolves, the temperature of the surrounding water increases to 31.7 °C. Determine the heat of solution of the sodium hydroxide in J/g. Once more, the solution to this problem is based on the recognition that the quantity of energy released when sodium hydroxide dissolves is equal to the quantity of energy absorbed by the water in the calorimeter. In equation form, this could be stated as QNaOH dissolving = -Qcalorimeter (The negative sign indicates that the NaOH is losing energy and the water in the calorimeter is gaining energy.) Since the mass and temperature change of the water have been measured, the energy gained by the water (calorimeter) can be determined. Qcalorimeter = m†¢C†¢ÃŽâ€TQcalorimeter = (100.0 g)†¢(4.18 J/g/ °C)†¢(31.7 °C 19.5 °C)Qcalorimeter = 5099.6 J The assumption is that this energy gained by the water is equal to the quantity of energy released by the sodium hydroxide when dissolving. So QNaOH-dissolving = -5099.6 J. (The negative sign indicates an energy lost.) This quantity is the amount of heat released when dissolving 4.51 grams of the sodium hydroxide. When the heat of solution is determined on a per gram basis, this 5099.6 J of energy must be divided by the mass of sodium hydroxide that is being dissolved. ΔHsolution = QNaOH-dissolving / mNaOHΔHsolution = (-5099.6 J) / (4.51 g)ΔHsolution = -1130.7 J/gΔHsolution = -1.13103 J/g (rounded to three significant figures) Example Problem 3:A large paraffin candle has a mass of 96.83 gram. A metal cup with 100.0 mL of water at 16.2 °C absorbs the heat from the burning candle and increases its temperature to 35.7 °C. Once the burning is ceased, the temperature of the water was 35.7 °C and the paraffin had a mass of 96.14 gram. Determine the heat of combustion of paraffin in kJ/gram. GIVEN: density of water = 1.0 g/mL. As is always the case, calorimetry is based on the assumption that all the heat lost by the system is gained by the surroundings. It is assumed that the surroundings is the water that undergoes the temperature change. In equation form, it could be stated that

Department of Electrical and Computer Engineering: Final Examination

University of Waterloo Department of Electrical & Computer Engineering E&CE 231 Final Examination – Spring 2000 Aids: Formula Sheets (attached), Scientific Calculator Time Allowed: 3 hours Exam Type: Closed Book Instructor: C. R. Selvakumar Date: August 10, 2000 Max Marks: 100 Instructions: Answer all questions in PART-A and any two questions in full from PART-B. State your assumptions clearly. Be concise, precise and clear in your answers General assumptions to be made when not specified in a question: (a) Assume that the semiconductor is Silicon. (b) Assume that the temperature T = 300K c) Use the data given in the formula sheets where needed. (d) Use the following expressions for the Effective Density of States in the Conduction Band (NC) and in the Valence Band (NV) respectively: 3 2 3 3 3 ? m ? ? T ? 2 ? 3 N C = 2. 5 ? 1019 ? ? cm ? m 0 ? ? 300 ? * n ? m* ? 2 ? T ? 2 p ?3 19 N V = 2. 5 ? 10 ? ? m ? ? 300? cm ? ? 0? PART -A 1a) Consider a Silicon p+-n diode with the foll owing doping densities: NA = 1019 cm-3 and ND is 1016 cm-3. The diode has an area of 100  µm by 20  µm. (i) Without doing any calculations, sketch the capacitance versus reverse voltage (VR) starting from VR = 0. (4 marks) (ii)Calculate the voltage at which you will obtain the minimum capacitance and also determine (calculate) the minimum capacitance at that voltage. (10 marks) (iii) Derive the mathematical relations you use in calculating the quantities in (ii) above. (16 marks) 1b) Assuming that the p+ region and the n-region of the diode described in 1a) above are ‘long’ compared to the minority carrier diffusion lengths in those regions, show how you would obtain the complete Current-Voltage (I-V) Characteristic of the diode. You can assume that there is no recombination in the space-charge layer and you need not solve the continuity equation.Sketch the electron and hole current distributions in the entire device. (10 marks) Page 1 PART B 2a) Draw a clearly labe lled band diagram of an n-p-n transistor under thermal equilibrium and superimpose on it a band diagram of the same transistor when it is under normal forward active mode of operations. (8 marks) 2b) Derive an expression for the common emitter current gain $ ($ = IC/IB), in terms of the doping densities in the different regions, thickness and carrier diffusivities and diffusion lengths. Assume that there is no recombination in the neutral base or in the space-charge layers.Also, assume that the conventional reverse saturation current of the reverse-biased diode, IC0, is negligible. Assume that short-region approximation is valid in the base and that the bandgap narrowing in the emitter is important. No need to solve continuity equations and you can assume the expected carrier distributions. (12 marks) 2c) Obtain the modified Ebers-Moll (EM) equations from the original EM equations given in the formula sheet. Sketch Common-Base output characteristics based on the modified EM equation s and show the Forward Active Region of operation, Saturation Region and Cut-off Region. 10 marks) 3a) A silicon n-p-n transistor has an emitter doping NDE = 1020 cm-3 and a base doping NAB = 1016 cm-3. The emitter is 1  µm thick and assume that the hole diffusion length in the emitter is 0. 1 :m. The base is 0. 35 :m thick and you can use the values of mobilities and lifetimes given in the tables in the formula sheet to determine the electron diffusion length in the base. Verify that the short-region approximation is applicable to the base. Assume that the carrier recombinations in the neutral base an in the emitter-base depletion layer are zero. When this transistor is operating in the normal forward active mode with 0. volts forward bias across the emitter-base junction and a 2 volt reverse bias across the collector-base junction, what is the collector current density (JC) and the base current density (JB) ? You can assume that the depletion layer thicknesses are negligible at both junctions. Assume that bandgap narrowing for the emitter doping is 100 meV and the room temperature is 300K. (15 marks) 3b) What is the emitter efficiency of the transistor in 3a)? (5 marks) 3c) What do you understand by diffusion capacitance of a diode? Show (derive) that the diffusion capacitance of a p+ – n diode is approximately given by C Diffusion ?Qp Vt where Qp is the total injected minority hole charge on the n-side quasi-neutral=region and Vt is the thermal voltage (kT/q). Prove that the quantity Q p ? qAL p pn 0 e V Vt (10 marks) Page 2 4a) Consider an n-channel MOSFET and explain how the MOSFET operates using key band diagrams (along source, channel and drain and vertically along the metal gate, oxide and the channel region) and cross-sectional diagrams. State clearly wherefrom the channel electrons come and explain how this is controlled by the gate voltage. (10 marks) 4b) With reference to an n-p-n transistor, explain what is Early Effect and how it arises. Using an approximate sketch show the Early Voltage. Clearly illustrate your answer with the aid of carrier profiles and common-emitter output characteristics. (10 marks) 4c) Contrast the Temperature-dependence of Avalanche Breakdown Mechanism and Zener breakdown Mechanism. Illustrate your answer with sketches of Reverse bias I-V characteristics giving physical reasons. (10 marks) Page 3 E&CE 231 1/4 Formula Sheet C. R. Selvakumar E&CE 231 Formula Sheet 3 1 4? *2 g c (E) = 3 (2m n ) ( E ? E C )) 2 ; (E ? E c ) h 3 1 4? *2 2 g V (E) = 3 2m p ( E V ? E)) ; (E ? E V ) h 1 f FD (E) = (E-E F )/kT 1+ e p 0 = N V e (E V ? E F )/kT = n i e (Ei ?E F )/kT () n 0 p0 = n 2 i 3/2 ? 2? m* kT ? p N V = 2? ? 2 ? ? ?h ?  µn = q? c,n m* n and  µ p = q? c,p m* p ? max = ? qN A x p0 ? 0? r qN + x n0 D = ?0? r 1/2 x n0 ? 2? r ? 0 V0 ? NA =? ? q N D (N A + N D ) ? ? ? 2? r ? 0 V0 ? ND =? ? q N A (N A + N D ) ? ? 1/2 3/2 ? p 0 + N + = n0 + N A D + ? ?2 ? N D ? NA N + ? NA ? D ? + n2 ? + n0 = i 2 2 ? ? ? ? + ? N D x n0 = N A x p0 x p0 n 0 = N C e (E F ? EC )/ kT = n i e (E F ? E i )/kT ? 2? m* kT ? n N C = 2? ? 2 ?h ? ? kT ? n no p po ? kT ? N + N A ? D V0 = ln? ?= ln? ? q ? n2 ? q ? n2 ? i i p( x n0 ) = pn e qV / kT and ? pn = pn ( e qV / kT ? 1) 1/2 for n ? type , where ? c,n and ? ,p are mean time between collisions ? = qmn n + qm p p and r = 1/s dn ? dp ? ? ? J n = q? n µn ? + Dn ? ; J p = q ? p µ p ? ? D p ? ? ? dx ? dx ? D p Dn kT = = = 0. 0259 V at 300K  µ p  µn q n( ? x p0 ) = n p e qV / kT and ? n p = n p (e qV / kT ? 1) ? p( x n ) = ? pn e or ? p( x n ) = ? pn ( 0) e ? x p / Ln or ? n( x p ) = ? n p ( 0) e ?n( x p ) = ? n p e ? xn / L p ? x p / Ln ? Dn ? Dp ? I = qA? n p0 + p n0 ? (e qV/ kT ? 1) ? Lp ? Ln ? ? ? qN ? C j = A? Si d ? ? 2(V0 ? V ) ? 1/ 2 for p + ? n diffusion capacitance: C s = q 2 AL p kT p n0 e qV/kT for p + ? n n ? type regions of width, W: long base diode approx: I p = qAD p ? pn ( 0 )Lp short base diode approx: I p = qAD p ?p 1 dJ p ?n 1 dJ n =? + G ? Rp; = ? + G ? Rn ?t q dx ?t q dx Wm = L p = D p ? p and Ln = Dn ? n VT = d 2V d? ? ? 2= = where ? = q ( p ? n + N d ? N a ) dx ? 0 ? r dx dV 1 dE c 1 dE v 1 dE t ?= ? = = = dx q dx q dx q dx ? xn / L p 2? Si ( 2? F ) qN a for VG > Vth ? pn ( 0 ) W ? Si = ? 0 ? r ? Qd Qi + 2? F + ? ms ? , Ci Ci Q d = Q B = ? qN a x dm ,x dm = Wm ? Ci = Cox = 0 ox = i t ox d 1 2? ? Z? ? I D =  µ n Ci ? ? ? (VG ? VT )V D ? VD ? ? L? ? 2 ?  µ n Ci ? Z ? 2 I DSat = ? ? (V ? VT ) V Dsat = VG ? VT 2 ? L? G E&CE 231 2/4 Formula Sheet C. R. Selvakumar Eber-Moll Model (n-p-n transistor)I EBO (e VBE / Vt ? 1) â€Å"RIC I CBO (e VBC /Vt ? 1) â€Å"FIE ? VBE ? ? VBC ? I E = ? I ES ? e Vt ? 1? + ? R I CS ? e Vt ? 1? ? ? ? ? ? ? ? ? ? VBE ? ? VBC ? Vt ?e ? + I CS ? e Vt ? 1? I C = ? R I ES ? ? 1? ? ? ? ? ? ? E&CE 231 3/4 Formula Sheet C. R. Selvakumar Mobilities in Silicon N = doping density (cm ? 3 )  µ (N) =  µ min + Carrier type  µ0 N 1+ N ref :min :0 cm2 / (v. s) Nref cm-3 electron 88 1 251. 8 1. 26 x 1017 hole 54. 3 406. 97 2. 35 x 1017 Doping density Mobilities Lifetimes (J) as function of doping density N :n :p 1 1 = + cA N2 ? ? SRH 1015 1016 1017 1018 1019 1020 1322. 3 1218. 2 777. 3 262. 1 114. 1 91. 5 457. 96 437. 87 330. 87 43. 23 68. 77 56. 28 cm 2 v. sec cm 2 v. sec cm ? 3 Doping density N cm-3 Lifetime J sec For both electrons and holes 1015 1016 1017 1018 1019 1020 9. 8 x 10-6 8. 3 x 10-6 3. 3 x 10-6 4. 5 x 10-7 3. 3 x 10-8 8. 3 x 10-10 Obtained using the above formula for lifetime using: JSRH = 10-5/(1 + 5 x 1016/N) and CA = 10-31 cm6s-1 E&CE 231 4/4 Formula Sheet C. R. Selvakumar Properties of Silicon and Gallium Arsenide PROPERTY Si GaAs atoms or molecules/ cm3 5. 0 x 1022 4. 42 x 1022 atomic or molecular weight 28. 08 144. 63 density g/cm3 2. 33 5. 32 breakdown field V/cm 3 x 105 4 x 105 dielectric constant, gr 11. 8 13. 1 effective density of tates: Nc cm-3 Nv cm-3 Physical Constants ?1. 38Ãâ€"10 ? 23 J / K ? k ? ?8. 62Ãâ€"10 ? 5 eV / K ? ? 31 m0 9. 11Ãâ€"10 kg ?0 8. 85Ãâ€"10 ? 14 ? r (Si) 2. 8 x 1019 1. 04 x 1019 4. 7 x 1017 7. 0 x 1018 11. 8 ? r (SiO 2 ) 3. 9 h electron affinity, eV 4. 05 6. 62Ãâ€"10 c 3Ãâ€"10 q 1. 6Ãâ€"10 4. 07 energy gap, eV 1. 12 1. 43 intrinsic carrier conc. , ni cm-3 at T = 300K 1. 5 x 1010 1. 8 x 106 effective mass electrons holes m*n = 1. 1 m0 m*p = 0. 56 m0 m*n = 0. 067 m0 m*p = 0. 48 m0 intrinsic mobility @ 300K electrons cm2/Vs holes cm2/Vs 1350 480 8500 400 diffusivity @300K: electrons cm2/s holes cm2/s 35 12. 5 220 10 F / cm 10 ? 34 J ? s cm / s ? 19 C

My (Not So Unique) Holiday Family Traditions Essay

When our Sociology class was assigned to write about family traditions, I instantly became nervous because I couldn’t think of one tradition off the top of my head that was special and unique to my family. I sat there and wondered, should I tell the truth and reveal the fact that my family doesn’t have any traditions? Should I make one up and fake my way through the entire thing just to get a good grade? Should I take someone else’s family tradition and call it my own? As you can probably tell, I was completely stuck. I feel as though my family traditions are ones that are shared with other families around the world. The typical family traditions that I’m referring to are about are during the Thanksgiving and Christmas holidays. During Thanksgiving, we always have our annual family dinner down at my grandmother’s house. All the women of the family cook different dishes such as turkey, stuffing, mashed potatoes, green beans, etc. The women usually si t around the dinner table while the men of the family assemble in the living room and watch TV, typically football. The children of the family usually sit at a separate table and after they are done, they usually go outside to play. Christmas traditions and the traditions of Thanksgiving are much in the same. Occasionally after everyone gets their stomachs full, we usually play a game called â€Å"catch phrase.† There is never a dull moment when we play this game. It is similar to charades in which you hold a device that shows you a word that you must describe to your teammates without saying the word directly. When I was assigned this essay, I went to my mother, hoping that we had a tradition that I just overlooked. Needless to say, I was back at square one, she couldn’t think of any that were unique! I began to look to my peers for help, which resulted in the usual, â€Å"Just say something obvious, like, ‘On the twenty-fifth day of December, my family opens presents that are left underneath an artificial tree by an obese man who has some strange obsession with red clothes and non-existent animals who can fly’!† That wasn’t much help either. In comparison to the traditional Caucasian holiday traditions, I researched via internet on the African Am erican holiday traditions. A common statement that I found was that â€Å"Today’s Thanksgiving and Christmas dinners are just a taste of how African Americans used to eat.† Before you slice into that sweet potato pie, douse those greens in hot sauce or cut a corner of macaroni and cheese this holiday season, consider where those traditions came from. In the late 19th  century, geography factored in how people celebrated the yuletide season. During this time, African Americans lived mostly a rural existence, which translated into a farm-to-table lifestyle. I found a blog of two sisters discussing their African American culture during the holiday seasons. Sisters Norma Jean and Carole Darden discussed their history and recipes in recounting African-American life and culture. Their grandmother’s traditions were passed down to them in which they will pass them down to their children and so on. She lived on a dairy farm and wanted milk and cream in the family’s dishes. A favorite dish was painted Christmas cookies, made with rose water and orange-flower water. Norma will be preparing Thanksgiving dinner for her family in November. She’s been cooking since age 9. Her dinner table will have turkey with corn bread dressing on the side, many quarts of giblet gravy, whole cranberry sauce and mashed potatoes. But in h omage to her stepfather, she’ll make smoked oysters for an appetizer, corn and peas as a side dish as well as yams in a cast-iron pot, without marshmallows. Just as he taught her. We live in an age in which it is hard to spend time together as a family. Many families today wonder if having quality time together is a thing of the past. We are inordinately busy, for one thing, whether household bread-winners or college students. Also, the definition of family has changed. We are dealing with new definitions and characterizations of the idea of family. Some of us have traditional families. Some families have divorced, single, and/or remarried parents, creating a rather confusing family tree. Some people choose to live their lives alone, but may still be close enough to some friends to consider them family. Whatever the circumstances, many of us honestly don’t know how to celebrate together. We may even see the word â€Å"tradition† as something dulling and old, having no meaning for or application to us personally; something usually being forced upon us. It is up to us to create new family traditions. Celebrating is not hard. We all know about celebrating and have some ways of doing it. The only challenge is to find new ways. Why do we need to celebrate tradition? It gives us something to look forward to and makes a formal statement that there are some things in life to be grateful for. The notion of honoring tradition is unsettling for some people; let alone creating new ones. We seem to think that traditions must be heavy and complex ideas that had been around for hundreds of years and will be around  for a hundred more. In my opinion, this is not true. It need not be big or religious at all. I believe a tradition is something that you do once that feels good, so you do it again and again. Tradition is in all our lives in one way or another. Without participation in such activities there would be no family bond or pride. Being involved in these activities brings people closer and makes us understand who we are. Everything we do and every day of our lives we take part in a tradition in one form or another. After writing this paper, I realize that my family traditions may not be unique to others, but they are special to me and the members of my family and that is something that I will always cherish and hope to pass down to future generations.

A People’s History of the United States essay

A People’s History of the United States essay A People’s History of the United States essay A People’s History of the United States essayFirst of all, I would like to state my viewpoint on what I have learnt about the discovery of America by Christopher Columbus. It has surely been a great discovery and a turning point in the history of the United States. I should admit that during the course I had learnt a number of things that I was not aware of before. The most impressive for me was to learn about the treatment of native population of America by the Spaniards. Howard Zinn stated that, â€Å"in the year 1495, they went on a great slave raid, rounded up fifteen hundred Arawak men, women, and children, put them in pens guarded by Spaniards and dogs, then picked the five hundred best specimens to load onto ships† (6). In fact, it was so frustrating to learn how evil and bloody the treatment of the native people of the New World by Spaniards was. I wonder if these were the first signs of slavery that would later become customary for the South of America. Was all this for the sake of gold, treasures and prosperity? It seems like it was indeed so. Zinn writes, â€Å"many slaves died in captivity† (6). I was really surprised to learn how great the number of the slaves who died for nothing was. So I think that although Spaniards wanted to bring Christian religion to the New World, they failed to follow the basic principles of the Bible.I was also so much surprised of what I learnt during this semester about slave marriages. I think not many people nowadays know â€Å"how high was the incidence of marriage among slave men and women, and how stable these marriages were† (Zinn 161). What I’ve learnt is that slave marriages were characterized with â€Å"unusual fidelity† (Zinn 161). Howard Zinn gave a great number of interesting and surprising examples of how married slave couples were devoted to each other and how they loved their children, so that even the separation from children could not destroy this affection. Mor eover, Zinn states that, â€Å"this family solidarity carried into the twentieth century† (162). All this is so unlike what we have today, as families being sacred social institutions more and more often lose their true meaning and value and we can see that more and more couples nowadays face conflicts and lack of loyalty or even get divorced.I have also learnt much about the social classes within the United States and it was new for me to learn that different classes have not only different educational opportunities, but also different attitudes to studying. In fact, it appears that children from low-income families tend to achieve more success in educational sphere than those coming from well-to-do families. Loewen states that â€Å"teachers are often surprised and even distressed when poor children excel† (198). Personally I think that in modern days more and more teachers stand for the equality of opportunities and quality of education disregarding the social class a child belongs to. Reading of Loewen’s study made me think that the poorer a child is the more he or she relies only on his or her own efforts in order to succeed in the future and that is why poor children try to achieve the best possible results in education so as to get a good job and become a more or less qualified worker.To conclude, all of the readings I studied during the semester were of much value to me. And although Loewen states that, â€Å"history is the only field in which the more courses [high school] students take, the stupider they become† (2), I consider that the history course I went through enriched my knowledge of history and other related issues with much valuable and simply interesting information.

Food Inс. Essays

Food InÃ' . Essays Food InÃ' . Essay Food InÃ' . Essay Discussion Questions Watch the film and answer the following questions: 1. If animals should have certain rights, do you think those rights also apply to animals we raise for food, like chickens or pigs? Are there any rights that these farm animals should have? If so, what are they? One animal does not have greater importance over another, such as one human is not more life worthy than another. In this case to say certain animals should have rights whereas others should not is wrong. So yes a dog and a chicken should have rights and the same rights. The more difficult question is what exactly these rights should be. It is reasonable to try to prevent the most obvious cases of gratuitous suffering or torture of animals, but beyond that, non-human animals yes deserve to be given â€Å"rights†, but cannot simply be granted. The animals are treated like scum, kept in the dark with no concept of an outside world. Some rights they should be graced with are the right to the outdoors, and the right to roam. 2. How do you think farm animals should be treated? How do your ideas compare to what you saw in the film? It seems as if each industry in the film has the power to define cruelty. : This is as ridiculous as giving a burglar the power to determine their punishment. Why these industries are not charged with aggravated cruelty to animals is something I cannot understand. Is it not the same to kick a dog or kick a chicken with the same anger? 3. Richard Lobb of the National Chicken Council says in the film, â€Å"In a way, we’re not producing chickens, we’re producing food. † What does this statement mean? Do you agree or disagree with it? How might this perspective affect the way that chickens are raised? 4. Many of us were surprised to learn that corn is so prevalent in our foods. Why o you think we were so surprised? Of course people are surprised to find out corn is so prevalent because the problem is it’s not even just in foods! When there is some kind of soy or corn in batteries, diapers, Motrin, charcoal, etc. you know there is a big problem. 5. Do you think the government and food producers have kept it a secret? Why don’t more people know this fact? This unfortunately is not something you can blame on the food producers; it’s simply the consumers fault for not looking at the ingredients on a food label. I believe people do not know the facts due to ignorance and laziness. Bottom line is if people realize what is in their food they will have to make a change which is usually not cost effective and more time consuming which these days is very undesirable. 6. Food labels actually do list corn-based ingredients, but not always in a recognizable way. How do you feel about ingredients being included in your diet without your knowledge? If you have a question about something, isn’t it common knowledge to ask about it. Google these days tells you everything you want to know and more so people can easily read the ingredients and research a word unknown to them.

Argumentative essay Roman Fever By Edith Wharton

Moral Issues Related To Seven Deadly Sins - Essay Example The book is very comprehensive from the foreword to the content and yet, it appears that many people are still oblivious about these. Sin is elucidated in the forward and the sins to be tackled were likewise discussed beforehand. The stories and the beginning of the ideas behind seven deadly sins can be traced back to St. Gregory as well as his identification of the normal dangers of the soul while taking into consideration Mahatma Gandhi. It also examines the classifications and perils represented by the seven deadly sins one by one. The plot of Wharton’s short story can be compared to a house of cards. Each card has significant support to the entire structure that if one is taken out, it will lose its essence. The commencing scene where daughters, Barbara and Jenny, run off to meet young provokes Mrs. Slade’s memories of her as well as Mrs. Ansley’s romantic adventures in Rome, 25 years prior to the present scene. She tried to share how Ansley has changed physically. Her observation establishes the concealed rancor she feels towards her companion and predicts every so implicitly the incongruous ending. Edith Wharton defies the thought of knowledge as well as understanding, even a person’s private experiences. The employment of Jackie Royster’s scenic analysis to Wharton’s Roman fever represents the idea that any person just because of envy and competition never achieve an awareness of the reality of human life as well as existence. This can be seen in the story when â€Å"She wished that Jenny falls in love- with the wrong man, even; that she might have to be watched, outmaneuvered, rescued† (Wharton, p.50). This is already evidence of how evil can manipulate and poison one’s mind just because of envy.

Diversity Website Essay Example | Topics and Well Written Essays - 250 words

Diversity Website - Essay Example However, learning institutions no longer solely rely on the website for information on diversity owing to the online gush of diversity information on other diversity websites. The resources available at the website are fundamental for young persons to gain crucial knowledge about diversity and learnt to co-exist with one another. By linking diversity in education to general societal contexts, it helps individuals to develop deeper insight into the importance of diversity both in learning institutions and the society in general. Despite being an important agent for diversity, the website needs improvement. In as much as it provides crucial information about impacts of diversity in higher learning institutions, the website is more of unidirectional media. There is need to integrate an active interactive tab that allows users to post their views, comments and even post questions that they perceive to be most challenging and receive instant answers to the questions. Nonetheless, Diversityweb.org still provides substantial information about diversity in learning environments through its quarterly publication, Diversity & Democracy. The quarterly publication, available in the website provides critical information for higher education and also supports leaders in developing and implementing diversity initiatives aimed at preparing students to be socially accountable individuals of the