Going home Essay Example for Free

Going home Essay This is a first person narration of a soldier in Iraq who had been victim to an evening ambush by offensive troops. The narration begins with the soldier already in the infirmary, months after the ambush incident, nursing a fractured right foot. At about this time, word also came out that President Bush was going to withdraw five thousand plus men from Iraq so that they could be home for the holidays. The soldier hopes that he is part of the list of men who would be recalled. In the meantime, the soldier recounts the events that led to his current situation. The soldier reveals that many had died in the ambush and he was merely one of those who survived. The ambush took place while they were on their way to the North US Detachment. While recounting the story of how he had become a wounded US soldier, the narrator also offers insights into how war can be patriotic and how it can change the course of events for the world at large. The soldier also mentions in his reminiscing that they were not the true heroes of war, rather the true heroes were the families they left back home. The narrator dwells on this topic and comprehensively explains how the families back home should be the real heroes in a war and not the soldiers who are actually in the war. The soldier also offers insights into how gruesome a war can be and how wasteful it is when it comes to lives wasted; but despite his views on the war, the soldier remains steadfast in his beliefs and holds on to the thought of his family waiting back home. The narration ends with the soldier being called to the mess hall along with many others for the announcement of the list of recalled soldiers. Find out if he is one of those who will return home. (YOUR FULL NAME) (PROFESSOR’S NAME) (COURSE AND SUBJECT) (DATE OF SUBMISSION) GOING HOME – A SOLDIER’S STORY Christmas is fast approaching and I am hoping to have an early Christmas gift as President Bust announced last September that about 5,000 plus of us would be home for the Christmas holidays. This was part of the limited troop reduction that was to be implemented on US troops before the military surge in March next year. We are still waiting for the final list of soldiers who would be sent home and I am hoping that I would be in the list. I am useless here in the field anyway. I have been in the infirmary tent for the past three months because my right foot suffered segmented fractures after an ambush attack on our team while we were driving to the North detachment. We were fifteen in the truck. I was one of the lucky seven who came out of the attack alive. I was in the back of the truck and as usual, I felt like I had to watch my own back as well as I was watching the backs of the other soldiers who were with me in the truck. It was about eleven in the evening. We all had to travel in the cover of darkness to avoid being detected by hostile troops. From a distance, the sound of mortar seemed as natural as the crack of thunder on a balmy evening. A false, red sunrise could be seen from the horizon as flames from explosives incessantly lighted up the horizon. It was cold – in the desert, the temperatures are extreme. Daytime is extremely hot and the evening can be as cold as it is hot during the day. We were all in our camouflage uniforms, but these were only flimsy fabric – weak protection from possible bullets coming our way or even stray shrapnel from distant explosions. I feared for my life but also thought of the country, and the world, and what it would be like if the US did not launch an offensive against hostile troops here in Iraq. In my heart I could not understand why I had to go through such horror and put my life on the line for such a cause; but when I think of my young wife waiting for me back home, and my three month old daughter, I understand why I have to be here. The weapons of mass destruction that Iraq may be hiding from the world may be cause for the destruction not only of the US but also of the world as we know it and this alone told me that my being here was worth everything I had; but then again, I can never deny the fact that there could have been better days. About an hour into the trip, the truck grinded to a halt; a co-soldier who was seated beside the driver saw something through his night vision binoculars. A group of armed men were stationed about half a mile away and it seemed that they did not notice our approach because they were huddled together in a close circle seemingly having a drink. We did not find this cause for alarm because sporadically, throughout the road, were friendly troops from the other side who were securing travel routes for civilians. However, since we could not identify them from a distance, there was no choice but to be on guard and move forward until we were close enough to identify them. The driver had turned off the headlights and slowed down to a crawl to prepare for our approach. When we were just a few meters away, I heard one of the men stationed at the road cry out a piercing yell that to me sounded like a death sentence. At that very moment a volley of gunfire punctuated the distant explosions and we all lay flat on the floor of the truck. In what seemed like forever, the truck turned around and sped towards the other direction back to the camp. The gunfire continued and it was at this moment that I felt warm liquid seeping into the fabric of my uniform from the back. I turned around to see one of my co-soldiers slumped on my back with blood streaming from his neck. I quickly stood to check on the other men with me in the back of the truck. Four of them had been badly hit, two were unharmed, and seven of us suffered minor injuries. Mine was a gunshot wound that pierced my right ankle. Later, it turned out that the driver had been badly hit as well, so it was the other army officer with him in the front seat who was already driving the truck. We made camp about three hours after the incident. We had already been halfway through the six hour trip that was supposed to take us to the North detachment. We were all brought to the infirmary and the dead immediately interred into shiny black body bags that reflected the red glare that rose up from the distant horizon. The camp chaplain said a prayer over the dead and another officer bend down to take out their dog tags, they name patches, and some of their personal effects. I imagined how difficult this was for the officer. I imagined how it would have been had I been one of them. The following day two or three officers from the US Military back home would be at the porch of our house delivering the sad news to my wife and my daughter. I imagined how they would feel, and how much they would hate the state for sending me to war; but I was lucky to be alive, or not. Now, I had to deal with the gruesome images that I had witnessed. I had to spend my life thinking of what is and what could have been. I would probably be found gazing into the blackness for many solitary hours trying to find a decent and even logical reason for this manslaughter – but I was determined to go home in one piece, if not for my wife and daughter, at least for a country and a world that was waiting for a glimmer of hope that could come out of this bloodshed. Logically, bloodshed is bloodshed and nothing good could come out of war. It was always like choosing between two evils – the lives of hundreds of men and women in exchange for the peaceful future of my country and the world. The choice was always easy and I found it an honor to be fighting for this cause, albeit momentary periods of questioning and reasoning and questioning again. I felt that I was not a hero here; the real heroes are the families we have left behind; mothers, fathers, wives, husbands, daughters, and sons. They are the real heroes for having to deal with our absence and having to live their lives every day with the knowledge that we may not even return alive. They are the real heroes for having to lie to the innocent ones about fathers and mothers who were out there fighting for the country because this was the only way to ensure the future – of course, there are other ways, but when some other ways seem bleak and unfeasible, war is often the method of choice. These people are the real heroes not because they sacrificed anything but because they refuse to just fade into the sunset and let go of the prospects of peace and unity for the whole world. They are there back home not for any reason, but for a reason that all of us in this world would one day recall and be grateful about. We, in the field, we are here because of them and their unfailing belief and hope in our cause; we are here because of their love and the fact that before we sleep at night our minds swim in oceans of faces – the faces of our real heroes. The bugle had been sounded. Our superior had called us all to the mess hall to announce who would be going home for Christmas and who wouldn’t. With my crutch in tow and a foot heavy with plaster dragging behind, I go to the mess hall. The superior went through the list. The lights have been turned out after the list was read. I was walking back to the infirmary. I was going home.

Chapter Study Questions 1 & 2 Essay Example for Free

Chapter Study Questions 1 2 Essay 1.What percentage of Texans live in urban areas (cities suburbs)?   90% of the population now lives in crowed cities and suburbs. 2.Name the three cities in Texas that are three of the largest in US?   Houston, San Antonio and Dallas 3.What are the three diverse economic businesses in Texas? 4 Oil and gas producer now work alongside high-tech companies, telecommunications giants, and other important business sectors. 4.In what areas does Texas consistently rank at the bottom in state spending compared to other states? 4 Texas consistently ranks near the bottom of the states in spending on education, welfare, and healthcare for poor. 5.Is Texas a high-tax, high-business regulatory state or is it low-tax, low-regulatory?   Texas is low-tax and low-regulatory climate. 6.Are Texas well informed about government and elected officials? Do they trust government? 4 Texans are woefully ignorant of their state and local government and the public officials who make important decisions affecting their daily lives. 7.Does Texas have a regressive or progressive tax system and what do these mean?   Texas has a regressive tax system, which means a tax that imposes a disproportionately heavier burden on low-income people than on the more affluent. 8.What is meant by economic diversification and has Texas done this? 6 Economic diversification is the development of new and varied business activities. New business were encouraged to relocated to or expand in Texas after the oil and gas industry, which had been the base of the state’s economy, suffered a major recession in the 1980’s. 9.What is meant by ‘cowboy rugged individualism’ and how has this impacted Texans’ views of government as a solution to problems?   The cowboy rugged individualism, with strong connotations of self-help and independence, symbolizes a political culture in Texas that does not like to look to government as a solution to many of its problems. It is the kind of individualism that continues to be exploited by political candidates in campaign ads. 10. What impact did having a frontier have on Texans? On might argue that the â€Å"wide-open spaces† of the frontier shaped Texan’s  view of their autonomy, independence, and vulnerability. It has clearly shaped attitudes toward land and the legal right to use land as one sees fit. 11. What three combined groups now make up the majority of Texans and how does their historical experiences differ from that of Anglos? What celebration are part of their political culture?   African American, Hispanic, and Asian Americans. The white population have limited relevance to the relevance to the cultural and historical experiences of many African American and Hispanic Texans. For African American is Martin Luther King Jr’s birthday as state holiday in 1991. And for Hispanics is the Cinco de Mayo. 12.Just what does political culture mean and describe the individualistic subculture in terms of government size, assistance, politics, and primary goals? 9 Political culture a widely shared set of views, attitudes, beliefs and customs of a people as to how their government should be organized and run. Individualistic subculture holds that politics and government function as a marketplace. Government does not have to be concerned with creating a good or moral society but exists for strictly. Government should be limited, and its intervention in the private activities of its citizens should be kept to a minimum. The Government primary function is to ensure the stability of a society so that individuals can pursue their own interests. 13. Describe the moralistic subculture in terms of government size, assistance, politics, and primary goals? 9-10 Moralistic subculture is a view that government’s primary reasonability is to promote the public welfare and should actively use its authority and power to improve the social and economic well-being of its citizens. The Moralistic subculture regards politics as one of the great activities of a man in his search for the good society. 14.Describe the traditionalistic subculture in terms of government size, assistance, politics, and primary goals? 10 a view that political power should e concentrated in the hands of a few elite citizens who belong to established families or influential social groups. Public policy basically serves the interests of this small group. The traditionalistic subculture  holds the view that there is a hierarchical arrangement to the political order. This hierarchy serves to limit the power and influence of general public, while allocating authority to few individuals who comprise self-perpetuating elites. 15. In what states or colonies did you originally find these three subcultures and what two best describe Texas? 16. How big is the Native American population in Texas and of the three remaining groups, do they have the right to have casinos? 11 Alabama-Coushatta, Tigua and Kickappo are the three small Native American groups that live on reservations in Texas. And the Native American population is less than one-half of 1 percent of the States total population. They have been denied the right to run casinos on their reservation. Even thought, their leader consider casinos a major potential source of revenue, jobs and economic development for their people, but recent efforts to change state law have been unsuccessful. 17. Were there ever a great many Hispanics in Texas prior to 1830 and what was it down to by 1887? How much had this increased by 1930, 1990, and 2012? 12 Prior 1830 the Hispanic population were a small minority of the population. By 1887 the Hispanic population had declined to approximately 4 percent of state’s population. In 1930 it was 12 percent and was concentrated in the border counties from Brownsville to el Paso. By 1990s, it had reached 25 percent, spurred by immigration from Mexico and other Latin American countries. By 2012 the Hispanics comprised 37.6 percent of the state’s population. 18.What two ethnic or racial groups are growing the fastest in Texas and by 2030-what group will be the largest? How have Hispanics done in terms of elected officials compared to other states?12 The two ethnic will be Asian and Hispanics. However the Hispanics are likely to exceed 50 percent of the state’s total. 19. Compare the %s of Anglos, African Americans, Hispanics, and Asians found in Texas in 1860 and those found in 2010? Chart 13 In 1860 it was a percent of 63.2% of Anglo. The 30.3 % are African American and 6.5% were Hispanic. However in 2010, 45.3% were Anglo, 11.5% were African American, 37.6% were Hispanic and 5.6% were other. 20.Where do African Americans tend to live in Texas?   African American settled in large numbers in the urban areas of Dallas, Fort Worth, Houston and Austin. 21. In 2010, how many Texans were there and what was the growth rate of the state compared to the national growth rate and where did people move from and to in the US? 16 According to the 2010 census, the state’s population was 25,145,561, an increase of approximately 4.3 million people in ten years. This growth rate of 20.6 percent was significantly higher than the national growth rate of growth rate of 9.7 percent.

Chemistry of All-carbon Materials: Structure and Properties

Chemistry of All-carbon Materials: Structure and Properties All-carbon materials have received lots of attention in the past. Carbyne, a new allotrope of carbon, is still in controversy towards its synthesis and property. Combining with the Goroff group’s research, this project is to prepare the polymer PIDA (polydiiododiacetylene) as a polyrotaxane complex, encapsulated in a column of macrocyclic hosts. The polyrotaxane structure will prevent aggregation of the PIDA strands, allowing for the complete dehalogenation of the polymer to make carbyne. The proposed route is shown in Scheme 1.1. PIDA, a precursor of carbyne, can be made from diiodobutadiyne and macrocyclic hosts via topochemical polymerization and host-guest strategy, in which macrocyclic host will self-assemble into column structure and diiodobutadiyne will form halogen bonds with host. All-carbon materials have been widely investigated because of their potential properties, such as electrical conductivity, thermal conductivity and hardness. They exist in different morphologies with various properties, such as diamond, graphite, carbon nanotube, graphere, fullerene and carbyne . Diamond, consisting of all sp3 hybridized carbons, has many unusual properties, such as extreme hardness, high optical transmittance and wide band gap and so on.1 Because of these potential properties, the synthesis of diamond is of great interest. It can be synthesized through chemical vapor deposition, including hot filament chemical vapor deposition (HFCVD); high frequency plasma-assisted chemical vapor deposition (PACVD); and DC plasma discharge.1b Graphite is made of sp2 hybridized carbon. It has a layered honeycomb structure and behaves as a good conductor.2 Fullerenes exist in different sizes, such as C60, C70 and C82. The C60 fullerene was first reported by Kroto and coworkers.3 It is an all-carbon polyhedral cage molecule with each atom sp2 hybridized and directly bonded to three neighbors. All valences of carbon atom in the molecule are satisfied by two single bonds and one double bond. Graphene is single atom thick layer of graphite, which can be used in composite material , electric battery and hydrogen storage.4 Carbon nanotubes usually have cylindrical nanostructure and made of different length-to-diameter ratio. Because of its special electrical, electrochemical and optical properties, carbon nanotubes were widely investigated in electronics, biological and energy application.5 Carbyne, having all-sp-hybridized carbon, is highly reactive. Carbyne, an sp hybridized all-carbon chain, is a new allotrope of carbon and has potential special properties as all carbon material, which has attracted considerable interest since discovery back in 1960. Because of its instability, it is less well known than the other carbon allotropes. The investigation of carbyne or carbyne-like structures is still underway while the results are often unclear. Researchers have tried to synthesize carbyne or carbyne-like materials in several ways, such as chemical dehydrohalogenation and electrochemical synthesis. Evsyukov et al.6 studied dehydrohalogenation of poly (ethylene-alt-chlorotrifluoroethylene)(PE-a-CTFE)to make carbyne. PE-a-CTFE was treated with potassium tert-butoxide in tetrahydrofuran to form a halogen-substituted polyenyne structure with randomly distributed isolated triple bonds. Theoretically, the synthesis was showed below. Elimination of hydrogen halides was incomplete, which could result from the insufficient strength of the base, sterical hindrances caused by its bulkiness and alternation defects in the original copolymer. Wang and coworkers7 claimed to form carbyne-like material via electrochemical method. 1, 1, 2-trichloroethylene was dehydrochlorinated with t-buthanolate, which was formed from t-butylalcohol on a Ni cathode in dimethylsulfoxide electrolyte solution under anaerobic conditions. However, this method was not effective because of reactive carbon, oxidation with O2 and cross-linking of polyyne-like chains. In above reports, no evidence of formation of carbyne is observed and the properties of carbyne remain unrealized. Recently, polyynes, analogues of carbyne, have been widely investigated to predict the properties of carbyne. Polyynes are one-dimensional chains with alternating single and triple bonds. The synthesis of long polyynes chains was first reported by Walton and coworkers.8 They used Cu-catalyzed oxidative Hay coupling techniques to synthesize triethylsilyl-capped polyynes. Tykwinski and coworkers also synthesized several polyynes with a variety of end groups, in which bulky end groups would increase the stability and solubility of polyynes. In 2010, Tykwinski reported the synthesis of polyynes with as manys as 44 sp-carbons.9 They used bulky tris(3,5-di-t-butylphenyl)methyl (Tr) as end groups and stabilize the chain. The synthesis method is shown in Scheme 1.4. When the polyynes become larger and larger, the effect on stability of end groups becomes insufficient. In order to overcome this issue, some researchers encapsulated polyynes into macrocycles to form rotaxanes or polyrotaxanes. Sugiyama and coworkers10 prepared pseudo-rotaxanes and rotaxanes with cyclodextrin simultaneously to stabilize and to solubilize the carbyne chains. Tykwinski and coworkers11 synthesized polyyne rotaxanes with 4, 6 and 10 triple bonds in length through active copper-templated coupling. Inspired by these cases, I am trying to design a polyrotaxane, allowing for complete dehalogenation of PIDA to make carbyne. Polydiacetylenes (PDAs), conjugated polymers with alternating double and triple bonds in the backbone, are prepared via topochemical polymerization of aligned diynes. Generally, topochemical polymerizations occur in a condensed phase, in which the monomers are preorganized and the final structures of the product are determined by the preorganization. In 1969, the synthesis of PDA was first described by Wegner,12 introducing the 1, 4-polymization of monomers. In addition, Baughman demonstrated how 1, 4-polymerization of diynes works and reported necessary parameters for the 1, 4-polymerization.13 The monomers are held in alignment. The distance between adjacent monomers is near 5 Ã…. The intermolecular distance of reacting carbons (C4 and C1’) is close to 3.5 Ã…, which is close to the van der Waals radius of carbon. The tilt angle between monomer diyne and the vertical translation axis should be 45 °. Ideal 1, 4-polymerization of diynes is showed below. Host-guest strategy is used to describe how monomers are aligned for polymerization. Different molecules or ions are held together by some forces to form complexes. In order for topochemical polymerization, monomers should be aligned to meet the geometric requirements. However, some monomers cannot form the right geometry required to polymerize. Host-guest strategy is applied to adjust the monomers to meet the requirements reported by Baughman. Here, hydrogen bonding and halogen bonding work in 1, 4-polymerization through host-guest strategy. Recently, Fowler and Lauher developed different kinds of diyne monomers to undergo 1, 4-polymerization using the host-guest strategy. In this way, the diyne monomers played the role of guests, which then formed hydrogen bonds with host molecules. The host molecules possessing oxalamides and ureas self-assembled into a structure via hydrogen bonding. Because of hydrogen bonding interactions, the diyne monomers were aligned in proper geometry for 1, 4-polymerization. The following is an example of host-gust strategy for one diyne.14 In the cocrystals, the oxalamide host molecule was organized through hydrogen bond with a repeat distance of 4.97 Ã…. The nicotinyl ester groups of the diyne guest monomers form strong pyridine-carboxylic acid hydrogen bonds to the host molecules. In addition to Fowler and Lauher’ work, the Goroff group also showed halogen bonding interaction could be applied for 1, 4-polymerization with the host-guest strategy. sp2 and sp hybridized carbon is more electronegative than iodine. Iodoalkynes behaves as Lewis acids and form halogen bonds with Lewis bases, such as pyridine and nitriles. The following is an example of host-gust strategy for diiodobutadiyne (figure 1.3).15 In this case, diiodobutadiyne played the role of guest. The hosts with oxalamide group were also organized through hydrogen bonds and designed to align diiodobutadiyne in the right geometry for 1, 4-topochemcal polymerization. The repeat distance of diyne monomers was 5.11 Ã…. The tilt angle was 51 °. Halogen bonds (XBs) is a non-covalent interaction which consists of halogen atom and other neutral atom or anions. The general structure of halogen bonds is showed in Figure 1.4.16 In this structure, X is halogen atom, which accepts electron density. It can be Lewis acid and halogen bond donor. D is the one donate electron density, which behaves as Lewis base and halogen bond acceptor. Y is a carbon, nitrogen, or halogen atom. The investigation of XB has been continuing for near 200 years. In 1863, the first report on the ability of halogen atoms to form well-defined adducts with electron donor species was described by Frederick Guthrie.17 In his experiment, I2 was added to saturated ammonium salt (nitrate or carbonate) and a diiodine/ ammonia system NH3†¢I2 formed. After exposed to air, it decomposes spontaneously into ammonia and iodine, without permanent gas being evolved. After that, halogen bonds became widely investigated. H. A. Benesi and J. H. Hildebrand identified the iodine-benzene complexe through UV-vis spectra in 1948.18 In 1954, Hassel’s group used X-ray to show the structure of bromine 1, 4-dioxanate.19 The experiment showed there was a short intermolecular interaction between the oxygen atoms of dioxane and bromine atoms. The interaction was halogen bond. The distance of O−Br bond was just 2.71 Ã…, which indicated a strong interaction between the bromine and oxygen atom s. Pierangleo Metrangolo and Guiseppe Resnati, whose research focused on halogen bonds, summarized the characteristic of halogen bonds and their interaction.16, 20 Polarizability increases when you move down the periodic table from fluorine atom to the iodine atom. This makes Cl, Br and I have the positive potential charge, which is showed in Figure 1.5. When the halogen atom is attached to an electron-withdrawing group, the positively polarized area will increase. On the one hand, the halogen atom can be the acceptor of electron density. On the other hand, the positive charge locates at sphere’s end, which is surrounded by electron neutral ring and negative charge belt. Because of the special location of positive charge, the angle of covalent bond and noncovalent bond around halogen atom in D†¢Ã¢â‚¬ ¢Ã¢â‚¬ ¢Ã¢â‚¬ ¢X—Y is near 180 °. This is consistent with research results. Hongjian Jin et al.21 used diiodobutadiyne and bis(pyridyl)oxalamides to make cocrystal, whi ch was based on halogen bonds between pyridine group’s nitrogen and iodine. Polymerization of cocrystal was induced under 3.5 GPa pressure. Although the N†¢Ã¢â‚¬ ¢Ã¢â‚¬ ¢Ã¢â‚¬ ¢I—C angle changed after polymerization, both angles were still near 180 °. They were 169.7 ° and 161.4 °. Investigation of halogen bonds examples in the Cambridge Structure Database is also shown. Metrangolo and Resnati16, 20 showed that halogen bond was relative stronger than hydrogen bond. However, a halogen is larger and more polarizable than hydrogen and halogen bonds are more sensitive to steric hindrance than hydrogen bonds. Halogen atom, electron acceptor in XBs, has some general characteristics. Among the four halogen atoms, the order for forming strong halogen bonding is I >Br > Cl >F. The more electron withdrawing atom is, the stronger is the halogen bonds. As to halocarbons, the strength order for halogen bonding is C-X (sp)>C-X (sp2)> C-X (sp3). If the halocarbons are unfunctionalized monohaloalkanes, no halogen bonds are observed. Diiodobutadiyne, in which the C is sp hybridized, is a good Lewis acid.22 The Goroff group used diiodobutadiyne as a guest to make poly (diiododiacetylene) (PIDA) with several hosts. Self-assembly of macrocycles Supramolecular chemistry is a rapidly growing field, emphasizing on assembly of discrete molecules. Traditional chemistry deals with covalent interaction while supramolecular chemistry focuses more on noncovalent interactions, such as hydrogen bonding23, van der Waals forces24 and Ï€-Ï€ interactions25. Self-assembly, a main process involved in supramolecular chemistry, will take advantage of these noncovalent interactions to organize discrete molecules into high order structures. Macrocycles, which have cyclic structures with other functional groups, can be self-assembled in a specific manner to form high order structures. Here I will introduce the self-assembly of macrocycles through hydrogen bonding and Ï€-Ï€ interactions. Ï€-Ï€ interactions, well known noncovalent intermolecular interactions, play important roles in self-assembly of macrocycles. The arrangement of aromatic rings has following geometries, such as face-to-face, edge-to-face and slipped stack. Hill and coworkers26 synthesized amphiphilic hexa-peri-hexabenzocoronene, self-assembling via Ï€-Ï€ stacking to form a discrete nanotubular object. The object has a uniform and 14-nanometer-wide hollow space. Lauher and coworkers27 also took advantage of Ï€-Ï€ stacking to design a tubular macrocyclic polymer. The monomer structure and route to a tubular polymer are shown in Figure 1.7. The diacetylene-based macrocycles self-assembled into polymerizable slipped Ï€-Ï€ stack and polymerized via slow annealing. The macrocycle had two different crystalline forms, which were monoclinic and triclinic form, respectively. After slow annealing at 40 à ¢Ã¢â‚¬Å¾Ã†â€™, the triclinic forms appeared to undergo crystal-to-crystal polymeriz ation. Hydrogen bond is an attraction force involves a hydrogen and strong electronegative atom, such as oxygen, nitrogen and fluorine. The electronegative atoms behave as hydrogen bond acceptor and hydrogen is hydrogen bond donor.28 Macrocyclic peptides and ureas can form high order tubular structures via hydrogen bonds. Ghadiri and coworkers29 used cyclo[-(L-Gln-D-Ala-L-Glu-D-Ala)2-] to self-assemble into hollow tubes via amide hydrogen bonds. Shimizu and coworkers30 also took advantage of amide hydrogen bond to organize diacetylene macrocycles for topochemical polymerization. In addition, Shimizu and coworkers used macrocyclic bis-ureas to self-assemble into columnar structures through urea hydrogen bonds. In the structure of macrocyclic bis-ureas, two hydrogen atoms in NH group are hydrogen bond donors and the carbonyl groups are hydrogen bond acceptors. The structures of the macrocyclic ureas are shown in figure 1.8. In 2001, they used bis-urea macrocycles with m-xylene to form the sel f-assembly tubular structures.31 The m-xylene kept the macrocycles rigid. However, this macrocycle formed intramolecular hydrogen bonds. Another bis-urea macrocycle with m-phenylether avoided forming intramolecular hydrogen bonds and organized into tubular structures with ordered acetic acid dimer filling inside as guest. The columns were stabilized by hydrogen bonding as well as Ï€-Ï€ staking interactions of phenylether. Except ureas, oxalamides are also used to form hydrogen bonding networks (figure 1.8). The repeat distances are 4.6 Ã… and 5.0 Ã…, respectively.33 Inspired by above work, we plan to design a macrocycle with pyridine, alkyne and oxalamide segments. Pyridine and alkyne segments provide beneficial rigidity, helping the macrocycles cocrystalize with diiodobutadiyne through halogen bonds. oxalamide segments are used for forming hydrogen bonding networks.

Free College Essays - Mr. Shimerda in My Antonia :: My Antonia Essays

Mr. Shimerda of My Antonia Most people find it very hard to pull up roots in their native land and move to a strange country. Throughout history, countless millions of people have done so. People forsake their homeland and move to another country for various reasons. Some people emigrate to avoid starvation. Some seek adventure. Others wish to escape unbearable family situations. Still others desire to be reunited with loved ones. However, the main reason for immigration has long been economic opportunity--the lure of better land or a better job. Yet, some people can't conform to the American way of life. Like replanting a flower's roots, completely moving a person so attached to their homeland and customs, can prove to be fatal. In the book, "My Ántonia," the Shimerdas seemed to be very religious. For example, on Christmas evening, "When the candle ends sent up their conical yellow flames, all the colored figures from Austria stood out clear and full of meaning against the green boughs. Mr. Shimerda rose, crossed himself, and quietly knelt down before the tree†¦Ã¢â‚¬ ¦" History shows that the Bohemian people were constantly revolting for their freedom. This was probably one of the reasons for the religious Shimerdas move to America, to get away from those many "hard times." "All the time she say: 'America big country; much money, much land for my boys, much husband for my girls†¦my mama, she want Ambrosch for be rich, with many cattle." This must have been the main factor for the move from their "kawn-tree." Unfortunately, not all the Shimerdas were excited by the move. "My papa sad for the old country. He not look good. He never make music anymore†¦He don't like this kawn-tree†¦M y papa, he cry for leave his old friends what make music with him." These quotations were the warning signs of what happened next. "Why, mam, it was simple enough; he pulled the trigger with his big toe. He layed over on his side and put the end of the barrel in his mouth, then he drew up one foot and felt for the trigger. He found it all right!" Mr. Shimerda was so depressed about losing everything and anything that was familiar to him that he felt there was no use in living. Jim thought, "I knew it was homesickness that had killed Mr. Shimerda, and I wondered whether his released spirit would not eventually find its way back to his own country.

Ramsey vs. Fletcher :: essays research papers

As a student at Southern Methodist University, I have acquired knowledge from requisite classes to not only better myself, but also for the betterment of my community. I feel, as apart of the human race, that we should continue to strive for an enhanced community by gaining information from other humans. However, in order for this greater sense of community to occur, we must realize there are morals to withstand. Socrates posed the question â€Å"have we learned how to teach virtue?† I believe that it is a work in progress. Although, ethics did not have a primary role in society until the mid twentieth century, I feel that we are making progress leaps and bounds to achieve this goal in a short amount of time. After reading ethicists Paul Ramsey and Joseph Fletcher’s words many questions were raised that would seem to have contradicting answers. Therefore, other ethicists and students are obligated to lean toward one side or the other.   Ã‚  Ã‚  Ã‚  Ã‚  In Paul Ramsey’s preface to The Patient as Person, we get a clear depiction of where he stands on ethics today. Ramsey says that it is important to keep the covenant between man and man and man and God. The covenant between man and man is that men need to have a kind of faithfulness to each other that is righteous (Pg. 53). For example, when you visit the doctor you, as a patient, have an obligation to trust the doctor. The doctor has an advantage because he/she has been educated in the field of medicine. . You have faith that the doctor will do what is right for the enhancement of your health. Sometimes doctors abuse that aspect of their profession and use it to better science. James P. Scanlan uses the argument of finding the valuable truth and scientific knowledge which is morally impossible to obtain (Pg. 55). Ramsey responds by saying, â€Å"These are salutary warnings precisely because by them we are driven to make the most searching inquiry concerning more basic ethical principles governing medical practice.† While becoming a doctor, one may feel as if they must constantly better the field of health using science. â€Å"Doctors†, Ramsey says, â€Å"Need to become moral philosophers† (Pg.55). If the doctors do not think morally, then medical ethics will slowly become scoured till there is nothing left. Granted, there are doctors and medical students who have looked at this situation from a moral perspective, but I believe, as does Ramsey, that doctors will get caught up in the â€Å"omnivorous appetite of scientific research. Ramsey vs. Fletcher :: essays research papers As a student at Southern Methodist University, I have acquired knowledge from requisite classes to not only better myself, but also for the betterment of my community. I feel, as apart of the human race, that we should continue to strive for an enhanced community by gaining information from other humans. However, in order for this greater sense of community to occur, we must realize there are morals to withstand. Socrates posed the question â€Å"have we learned how to teach virtue?† I believe that it is a work in progress. Although, ethics did not have a primary role in society until the mid twentieth century, I feel that we are making progress leaps and bounds to achieve this goal in a short amount of time. After reading ethicists Paul Ramsey and Joseph Fletcher’s words many questions were raised that would seem to have contradicting answers. Therefore, other ethicists and students are obligated to lean toward one side or the other.   Ã‚  Ã‚  Ã‚  Ã‚  In Paul Ramsey’s preface to The Patient as Person, we get a clear depiction of where he stands on ethics today. Ramsey says that it is important to keep the covenant between man and man and man and God. The covenant between man and man is that men need to have a kind of faithfulness to each other that is righteous (Pg. 53). For example, when you visit the doctor you, as a patient, have an obligation to trust the doctor. The doctor has an advantage because he/she has been educated in the field of medicine. . You have faith that the doctor will do what is right for the enhancement of your health. Sometimes doctors abuse that aspect of their profession and use it to better science. James P. Scanlan uses the argument of finding the valuable truth and scientific knowledge which is morally impossible to obtain (Pg. 55). Ramsey responds by saying, â€Å"These are salutary warnings precisely because by them we are driven to make the most searching inquiry concerning more basic ethical principles governing medical practice.† While becoming a doctor, one may feel as if they must constantly better the field of health using science. â€Å"Doctors†, Ramsey says, â€Å"Need to become moral philosophers† (Pg.55). If the doctors do not think morally, then medical ethics will slowly become scoured till there is nothing left. Granted, there are doctors and medical students who have looked at this situation from a moral perspective, but I believe, as does Ramsey, that doctors will get caught up in the â€Å"omnivorous appetite of scientific research.

Macbeth - Macbeth Character Study Essay example -- essays research pap

Thesis: Macbeth's changing character over the course of the play can be seen in his roles a general, husband and a king. I. General A. Early in the play he is brave 1. Captain reports 2. Duncan conversation B. Late in the play he is ineffective 1. Fearful 2. Cornered II. Husband A. Initially close to wife 1. Confides in her via letter 2. Has pet name B. Later becomes distant/cold 1. Tells doctor to cure Lady Macbeth 2. Feels resignation, not anguish at her death III. King A. At first is powerful 1. Malcolm and Donaldbain free Scotland 2. He succeeds in killing Banquo B. At end is powerless 1. Fleance escapes 2. Malcolm conquers Scotland The story of Macbeth is one of power at the expense of everything. The main character, Macbeth starts out greatly admired with strong character. As the play progresses, Macbeth's personality and actions become more deceitful leading to his destruction. Macbeth's changing character over the course of the play can be seen in his roles a general, husband and a king. First, Macbeth's changing character is evident in his role as a general. As the play begins, he is a brave general, well respected by his peers. The captain returning from battle reports of this saying, "But all's too weak; for brave Macbeth (he deserves that name)" (1.2. 17-18) Duncan later confers his title as king of Scotland, claiming, "No more that thane of Cawdor shall deceive our bosom interest. Go, pronounce his present death, and with his former title,... Macbeth - Macbeth Character Study Essay example -- essays research pap Thesis: Macbeth's changing character over the course of the play can be seen in his roles a general, husband and a king. I. General A. Early in the play he is brave 1. Captain reports 2. Duncan conversation B. Late in the play he is ineffective 1. Fearful 2. Cornered II. Husband A. Initially close to wife 1. Confides in her via letter 2. Has pet name B. Later becomes distant/cold 1. Tells doctor to cure Lady Macbeth 2. Feels resignation, not anguish at her death III. King A. At first is powerful 1. Malcolm and Donaldbain free Scotland 2. He succeeds in killing Banquo B. At end is powerless 1. Fleance escapes 2. Malcolm conquers Scotland The story of Macbeth is one of power at the expense of everything. The main character, Macbeth starts out greatly admired with strong character. As the play progresses, Macbeth's personality and actions become more deceitful leading to his destruction. Macbeth's changing character over the course of the play can be seen in his roles a general, husband and a king. First, Macbeth's changing character is evident in his role as a general. As the play begins, he is a brave general, well respected by his peers. The captain returning from battle reports of this saying, "But all's too weak; for brave Macbeth (he deserves that name)" (1.2. 17-18) Duncan later confers his title as king of Scotland, claiming, "No more that thane of Cawdor shall deceive our bosom interest. Go, pronounce his present death, and with his former title,...

The Beaux-Arts Style

The beaux-arts style of architecture dominate the architecture of public buildings from 1890 to 1920 because the style was first popularized during the well attended Columbian Exposition of 1893. This style was to be emulated by many entities far and wide. The term â€Å"Beaux Arts† refers to the com/music-appreciation-final/">American Renaissance period from about 1890 to 1920 and encompasses the French Renaissance, the Italian Renaissance, and the neoclassical Revivals.In addition, most of the leading American architects of that period had been academically trained many of whom had trained at Ecole des Beaux Arts in Paris.These facts, together with the fact that America was emerging as a dynamic industrially powerful nation and was becoming a world power at the same time, were proof that America had arrived. Added together, these facts pushed the citizens of the nation to desire architectural proofs of their aspirations and desire to prove to the word that America was a cult ural and political equal to any nation in the world. The Beaux-Arts style is extravagant reflecting the attitude and taste of the industrial barons of this pre-tax era. Their homes were flamboyant and theatrical reflecting a desire to flaunt their wealth.The Beaux-Arts style fits this desire precisely. These industrialists gave commissions to these architects to build their sumptuous residencies in fashionable neighborhoods and exclusive summer enclaves. These grand houses reflected the desire for â€Å"conspicuous consumption. † This spirit of grandeur prompted many cities to erect grand public buildings as well. Every city aspired to outdo its neighbor. The American dream was to emulate the lead of the industrialists and proclaim their wealth and solidity. Public libraries, train stations, town halls, courthouses, office buildings, even prisons manifested this grandeur.Because this style is classical in nature but grand in scale, the buildings are more extravagant. This sty le is theatrical. Elaborate moldings, pilasters, wreaths, garlands, festoons, dentils, cartouches and figure sculpture all are a part of this style. This proclaims to the world power and wealth. Exactly what the era was about. This reflected what the nation’s psyche was about during this period. Bold, new, powerful, and wealthy. This nation was finally a force to be reckoned with. No longer a colonial appendage, but a country equal to any and all.