International management Essay Example | Topics and Well Written Essays - 3000 words - 2

International management - Essay Example The organizations worldwide face a number of challenges when they decide to go global. This is a common problem that they face since they do not have any prior knowledge or understanding of the new territory that they will do their business from. However, what best they can do is to find out and research the strengths and weaknesses of this area and hence upon getting the much-needed knowledge, base their theories and strategies in a much more effective and efficient manner. This will help one and all to better understand what the new territory, region or country offers the business and the people associated with it. The best thing is that the benefits and disadvantages are determined even before the organization goes the global way and thus it saves itself from embarrassment which it might face without having the proper knowledge and adequate research within it. The ways and means that are usually taken care of whilst managing a business are aplenty and it is only up to the top mana gement within a company that the same can be handled in several different methods. They are the ones to decide as to what is the real manner in which the firm’s operations would be handled as well as who will head the respective departments, lead the business strategic units and act as legal and media representatives of the said business.

Sunlight on the Grass Essay Example for Free

Sunlight on the Grass Essay For the purpose of this assignment I will analyse two stories. Firstly I will examine the â€Å"Compass and Torch† by Elizabeth Baines and will demonstrate how the objects in the title relate to the characters of the story and represent key themes. I will then discuss â€Å"Something Old, Something New† by Leila Aboulela and highlight the ways in which the title relates to the story. Firstly the â€Å"Compass and Torch† is a story about a young boy setting out on a camping trip with his estranged father. The compass and torch are used symbolically throughout the narrative to reflect the boy’s feelings and relationship to his family. I feel that the compass symbolises a lack of direction or the absence of a relationship between father and son. This can be demonstrated when they are about to leave the car for their journey together at the bottom of the hill. â€Å"The man looks up – for the first time – at the path they will take, which runs from the gate to the brow of the hill. Then he groans: I didn’t bring a compass†. The lack of compass showing with nothing to guide them the chance for them to get closer in their relationship is doomed. However, the narrative continues to suggest that the compass is not required, that with love and hope in their hearts, father and son will always be bonded. â€Å"Compasses are things boys and dads tend to have, but which, when they are alert and strong at heart, they can leave behind.† The compass can also be seen as a metaphor for the pull of the boy between his divorced parents. This idea is shown when the boy had gone upstairs looking for his torch and overhears his Mother and her boyfriend Jim talking in the kitchen. â€Å"The boy might have remembered it, the compass, as they were leaving. But he couldn’t wait to get going, for it all to be over †¦Ã¢â‚¬ ¦ And the way his mother said hardly anything, and made her face blank whenever Dad spoke to her or looked her way†. This text demonstrates that mother and father remain hostile following their divorce and reflects the boy’s awareness of this and feelings of being in the middle of it all. The story demonstrates how the camping trip is an opportunity to strengthen the father son relationship, with the torch signifying the path of reconciliation, used as a tool to light the way to a new future. This is highlighted when, as the boy is sitting in his father’s car, he shows him he has brought his torch, representing the boys longing to bond with his dad.â€Å" as the man drops into the driving seat something in the boy’s chest gives a little hop of joy and he cries excitedly, ’oh I brought my torch!’†. This idea is further reinforced in the narrative when we discover both father and son have torches, â€Å"Two torches are for lighting a bigger space in the wilderness, for lighting it together. Two torches are for father and son to back each other up.† Furthermore, the colour of the torches seems to hold some significance. It is shown that the boy has a red torch whilst the father has a green one. I feel this is deliberate and hold connotations similar to a traffic light system where the red torch symbolises the lack of relationship with this father, with no way of moving forward whilst the fathers green torch reflects the idea of rebuilding the relationship, with the possibility of new horizons. Although not in the title of the story the horse is also symbolic of the boy’s mother and highlights further how Baines uses symbolism to represent characters throughout the narrative. For example whilst on his journey with his father a horse appears. â€Å"The horse comes up to the car. She nudges up, puts her nose over the edge of the door. The man bats her away† I feel this represents the mothers need to protect her son and the struggle the boy feels between his parents. The quote above illustrates the father not wanting the mother to be involved, to take a step back. Similarly â€Å"the horse nuzzles the rucksack top and the man pushes her away†. In Something Old, Something New, Leila Aboulela writes about a wedding due to take place between a Scottish man and his Sudanese bride. The title is therefore appropriate to the story as the popular wedding phrase something old, something new, something borrowed, and something blue. However, the title goes deeper than that and relates to the story in many more ways representing a number of key themes. The groom is depicted as a man desperate to find himself. He has dropped out of medical school and is unsure on which direction his life should take. He converts from Catholicism to Islam and his new spiritual world seems to have saved him. Indeed, the narrative demonstrates how his view of Islam is different to his brides. â€Å"She associated Islam with her dark skin, her African blood, her own weakness. She couldn’t really understand why anyone like him would want to join the wretched of the world. But he spoke with warmth†. Religion for her seems a flaw, but for him represents a new beginning in life. This theme of conflicting ideas of old and new is also depicted when he arrives in Egypt to meet his bride and her brother. Back in Scotland, her ethnic difference seemed exotic, exciting but once in her home country he realises its nothing new any more â€Å"He became aware that everyone looked like her, shared her colour, the women were dressed like her†. The author also utilises the Nile as a metaphor for the proposed marriage. The Nile is one of Egypt’s most anticipated sights, but on closer inspection the groom finds it is not as he expected â€Å"yes it’s beautiful he replied. But as he spoke he noticed that the rivers flow was forceful, not innocent, not playful. Crocodiles no doubt lurked beneath the surface.† I feel this represents the marriage that his idealised view of his wedding and his bride suddenly turning fearful, with the lurking crocodiles a metaphor perhaps for her overbearing brother. With this fear in place, the groom begins to yearn for the comforts of home and staying at the Hilton hotel represents to some degree the characters longing for home comforts. The Hilton used as sign of the Western world in contrast to the barren landscape of Egypt. †The hotel lobby was impressive, the cool tingling blast of the air-conditioner, music playing, an expanse of marble. He felt soothed somehow, more in control†. Another example of this is when the character struggles to follow the strict Islamic custom of mourning following the girls Uncle’s death. â€Å"He shrugged, he did not want to talk about it, was numbed by what had happened, dulled by the separation from her that the mourning customs seemed to impose.† Furthermore the anxiety he feels about this new culture is noted again â€Å"He had thought, from the books he’d read and the particular British Islam he had been exposed to, that in a Muslim country he would find elegance and reason. Instead he found melancholy, a sensuous place, stripped to the bare bones†. The idea of a new life and a new culture suddenly turning sour in his mind is reinforced with the theft of his British passport contributing to a feeling of a loss of identity. To conclude I feel I have demonstrated how the stories titles relate to the overall meaning of the story and how symbolism is used to portray characters and to enhance the mood and tone of the narrative. Where possible I have provided key examples to support my ideas and to illustrate my understanding of the texts.

Carbon Mesoporous Material Hybrid Catalyst

Carbon Mesoporous Material Hybrid Catalyst Facile and clean transformation for synthesizing secondary arylamines through one-pot reductive amination of aniline, using aldehyde catalyzed by the supported nickel and poly(vinyl sulfonic acid) on mesoporous carbon CMK-3 (Ni/PVSA/CMK-3) as a novel acid-metal bi-functional heterogeneous catalyst. Sodium borohydride was used as the source of hydrogen for the reduction of imine. The reaction was performed at room temperature, in a short reaction time, without any by-products. Various characterization techniques including FT-IR, XRD, TG, BET, SEM, TEM, DRS-UV and AAS were employed to reveal the relationship between catalyst nature and catalytic performance. Reaction results demonstrate that the optimized Ni/PVSA/CMK-3 catalyst shows comparable catalytic performance thanks to the nickel metals and the acidic nature of polymer in mesopore channels of CMK-3. This method has several advantages such as, eco-friendly (used water as solvent), moderate to high yields, simple work-up procedure and catalyst filtered easily and reused without obvious loss of activity. 1. Introduction Nowadays, amines are privileged in industry that have found prevalent applications as intermediates for pharmaceuticals, biologically active compounds, rubber, solvents, fine chemicals, dyes, herbicides, and in the manufacture of detergents and plastics. Reductive amination demonstrate one of the most versatile and convenient methods of amine synthesis. This reaction has two steps including formation of an imine during reaction between primary amine and a carbonyl substrate, and reduction of the imine with adequate hydride source. There are two detached approaches for the reductive amination: the direct approach, which uses the in situ-generated imine, and the indirect approach, which uses the prior isolated imine. The former approach has several advantages such as one-pot procedure, increasing yields, having simple setup, easily separated from the product, being stable and compatible reagents, and the mild reaction conditions. To this end, over the past decades, researchers have been reported several studies on reductive amination reaction with several different catalysts, which among them, heterogeneous catalysis are prominent than homogenous catalysis owing to separate and recover capabilities. Moreover, it has been proven that accomplish this reaction needs two character including metallic and acidic; consequently, bi-functional heterogeneous catalysts are useful in this reaction. Recently, several metal nanoparticles acted as a hydride transfer such as Pt, Ni, Cu, and Pd. Despite of the fact that an effective control of particle size and a uniform distribution of nanoparticles in catalytic applications are generally predicted, nanoparticles typically accumulate together in bulk-like materials that hardly reduce selectivity and the activity of catalysts. To overcome with this problem, mesoporous silica, zeolites, polymers or macromolecular organic ligands have been used in order to immobilize metal nanoparticles in their pores. Mesoporous silica materials and zeolites have excellent order and surface area than other materials like polymer and etc.; subsequently, they are sufficient for catalysis approaches. Lately, mesoporous silica used for producing mesoporous carbon (CMK-n) as hard template. These materials contain several benefits compared to mesoporous silica and zeolites for instance, high mechanical stability, high thermal stability in nitrogen atmosphere, superb stability in strong acids and bases, and other engrossing properties such as narrow pore size distributions, high surface areas, and ordered frameworks. In addition, mesoporous carbon materials have hydrophobic nature on their surfaces and it helps to embed nanopolymers in their pores. In our previous studies, it asserts that when polymer embedded into mesoporous materials, they have perfect function. Owing to the fact that they have small particles and subsequently having high surface areas. Moreover, polymer nanoparticles fix in porous and they could not leach from their supporters. Accordingly, in this work, we will introduce a novel heterogeneous organic hybrid catalyst based on a carbon mesoporous material. In this circumstance, mesoporous carbon CMK-3 replicating from mesoporous silica SBA-15 was prepared and used as suitable support for Nickel nanoparticle/poly vinyl sulfonic acid/CMK-3 (Ni/PVSA/CMK-3). Furthermore, the catalyst was used effectively for the one-pot reductive amination of amine compounds using aldehyde in the presence of a small amount of NaBH4 as a mild reducing agent and two sort of solvent containing water and acetonitrile at room temperature without any by-products. 2. Experimental method 2.1. Catalyst characterization The samples have been analyzed by FT-IR spectroscopy (using a PerkinElmer 65 in KBr matrix in the range of 4000-400 cm-1). The thermal gravimetric analysis (TGA) data were obtained by a Setaram Labsys TG (STA) in a temperature range of 30-650 -C and heating rate 10 -C min-1 in nitrogen atmosphere. The X-ray powder diffraction (XRD) of the catalyst was carried out on a Bruker D8Advance X-ray diffractometer using nickel filtered Cu KÃŽ ± radiation at 40 kV and 20 mA. The BET specific surface areas and BJH pore size distribution of the samples were determined by adsorption-desorption of nitrogen at liquid nitrogen temperature, using a Series BEL SORP 18. For the measurement of nickel, a Perkin Elmer AAnalyst 300 atomic absorption spectrophotometer was used. The slit width, linear range and wave length for Ni were 0.2 nm, 2 and ppm232 nm, respectively. Scanning electron microscope (SEM) studies were performed on Philips, XL30, SE detector. Transmission electron microscope (TEM) observati ons were performed on a JEOL JEM.2011 electron microscope at an accelerating voltage of 200.00 kV using EX24093JGT detector in order to obtain information on the size of nickel nanoparticles and the DRS UV-vis spectra were recorded with JASCO spectrometer, V-670 from 190 to 2700 nm. Moreover, X-ray photoelectron spectra (XPS) was recorded on ESCA SSX-100 (Shimadzu) using a non-monochromatized Mg KÃŽ ± X-ray as the excitation source. The products were characterized by 1H NMR and 13C NMR spectra (Bruker DRX-500 Avance spectrometer at 500.13 and 125.47 MHz, respectively). Melting points were measured on an Electrothermal 9100 apparatus and they were uncorrected. All the products were known compounds and they were characterized by FT-IR, 1H NMR and 13C NMR. All melting points are compared satisfactorily with those reported in the literature. 2.2. Catalyst preparation The employed mesoporous carbon (CMK-3) was synthesized following the method reported by Ryoo using SBA-15 as template. 2.2.1. Preparation of SBA-15 Mesoporous silica SBA-15 was prepared using block copolymer Pluronic P123 (EO20PO70EO20) template as a structure directing agent and tetraethylorthosilicate (TEOS) as the silica precursor through the addition of H3PO4 by novel method as described in the literature. In a general synthesis, Pluronic P123 (2 g) was dissolved at room temperature in deionized water (75.4 mL) and H3PO4 (4.2 mL, 85%), after that TEOS (4.6 mL) was added to the solution and synthesis was fulfilled by stirring at 35 -C for 24 h in sealed Teflon breakers, and it was consequently placed at 100 -C for 24 h. Afterwards, the solution was filtered, washed with deionized water, and lastly dried at 95 -C for 12 h in air. Template removal was accomplished by calcination in air using two successive steps; first heating at 250 -C for 3 h and then at 550 -C for 4 h. 2.2.2. Preparation of CMK-3 Mesoporous carbon CMK-3 was prepared using mesoporous silica SBA-15 as template and sucrose as the carbon precursor. 1.0 g SBA-15 was added to 5 mL aqueous solution containing 1.25 g (3.65 mmol) sucrose and 0.14 g (1.42 mmol) of H2SO4 (98%). The resulting mixture was heated in an oven at 100 -C for 6 h and next 160 -C for another 6 h. In order to obtain entirely polymerized sucrose inside the pores of the SBA-15 template, 5 mL aqueous solution containing 0.8 g (2.33 mmol) sucrose and 0.09 g (0.917 mmol) of H2SO4 were added again, and the mixture was subjected to the thermal treatment described above one more time. Then, it was carbonized under nitrogen gas flow at 900 -C for 6 h with a heating rate of 5 -C min-1. Finally, the resulting solid was washed with 1 M NaOH solution (50 vol. % ethanol-50 vol. % H2O) twice to remove the silica template, filtered, washed with ethanol until pH = 7, and dried at 100 -C for 4 h. 2.2.3. Preparation of Poly(vinyl sulfonic acid)/CMK-3 2.2.4. Preparation of Ni nanoparticle-poly(vinyl sulfonic acid)/CMK-3 At first, Vinylsulfonic acid sodium was converted into its acidic form using the ion exchange resin (Amberjet 1200 H, 2 equiv. L-1, Aldrich). Ni/PVSA/CMK-3 was synthesized as follows: in the first place, 1 mL aqueous solution of NiCl2.6H2O (0.5 M) was added to the obtained PVSA/CMK-3 (0.1 g) together with 3 mL of H2O. The mixture was heated for 5 h at 353 K. Next, the solution of NaBH4 [0.057 g (1.5 mmol)] dissolved in 5 mL methanol was added to the mixture drop by drop in 20-30 min. Then, the solution was stirred for 3 h. After that, adding the same amount of NaBH4 was repeated and again the mixture was stirred for 3 h. Consequently, the solution was filtered and washed sequentially with deionized water and methanol to remove excess NaBH4 and NiCl2, and was dried in room temperature to yield Ni/PVSA/CMK-3. The Ni content of the catalyst was estimated by decomposing. Known amount of the catalyst by perchloric acid, nitric acid, fluoric acid, hydrochloric acid, and the Ni content was estimated by atomic absorption spectrometer. The Ni content of Ni/PVSA/CMK-3 estimated by atomic absorption spectrometer was 2.1 mmol g−1. 2.3. General procedure for one-pot reductive amination of aldehydes. A mixture of Aniline (2 mmol) and benzaldehyde (2 mmol) in water or acetonitrile (3 mL) was placed in a round bottom flask and stirred for 1 min at room temperature. Afterward, to the resulting mixture, Ni/PVSA/CMK-3 (0.04 g) and NaBH4 (6 mmol) were added and the mixture was stirred at room temperature until TLC showed the complete disappearance of the benzaldehyde. Then, the reaction mixture was quenched with water (10 mL) and the product was extracted with diethylether (2 10 mL). After they finished, the organic phase was dried over anhydrous Na2SO4, filtered and concentrated. In the end, the products were obtained very pure just by extract with diethylether in the majority of the reactions. The product was identified with a melting point, FT-IR spectroscopy techniques, 1HNMR and 13CNMR. 3. Results and discussion 3.1. Catalyst characterization Figure 1 shows the FTIR spectra of CMK-3 (a), PVSA/CMK-3 (b) and Ni/PVSA/CMK-3 (c). A broad band at around 3380-3470 cm−1 was observed in all samples. The O-H stretching vibration of the adsorbed water molecules mainly caused it. Moreover, in the CMK-3 spectrum, there are not any signals belong to organic bonds, resulting from the complete carbonization of sucrose (Fig. 1a). The presence of a new absorption bands at 1041 and 1186 cm-1 attributed to the S=O group of PVS, affirming the existence of the grafted PVSA chains on the CMk-3. In addition, the band at about 1650 cm-1 is attributed to adsorbed water, which is similar to related reports[]. The presence of peaks at around 2940 cm−1 and 1450 cm−1 correspond to the aliphatic C-H stretching and bending in PVSA/CMK-3, respectively (Fig. 2b). The appearance of the above bands shows that PVSA has been attached into mesoporous of CMK-3 and the synthesis of PVSA/CMK-3 has been successful. The profiles of thermogravimetric analysis of PVSA/CMK-3 and Ni/PVSA/CMK-3 under nitrogen atmosphere are shown in Fig. 2. The degradation of Poly(vinyl-sulfonic acid) commences at 150C and this stage continues to a little less than 300C. The next stage involves only a little degradation and occurs over the temperature range of 300 to 500C. These evidence are shown Poly(vinyl-sulfonic acid) cannot tolerant the temperature due to polymers are not protect by any supporter. The TGA curves of PVSA/CMK-3 shows a small mass loss (around 5%, w/w) in the temperature range of 100-330 -C, which is apparently associated with degradation of SO2 and ethylene from PVSA (Fig. 2). At temperatures above 330 -C, PVSA shows one main stage of degradation. The mass loss for PVSA in the second step is equal to 11.5% (w/w) which correspond to the degradation of the methane. In light of the difference between the PVSA and PVSA/CMK-3 curves, it is clear that PVSA/CMK-3 has higher thermal stability and slower degradation rate than PVSAP. Hence, after hybridization, the thermal stability is enhanced significantly that is beneficial for the catalyst application. In addition, Ni/PVSA/CMK-3 shows two separate weight loss steps that are almost similar to the PVSA/CMK-3. The only difference is temperature between 330 and 445 C, which Ni/PVSA/CMK-3 shows slower degradation rate than PVSA/CMK-3 in these range. It asserts that the hybrid Ni/PVSA/CMK-3 had higher thermal stability than PVSA/CMK-3. It may be related to the presence of Nickel nanoparticles in the composite structure. Consequently, it is proper thermal stability is boosted after hybridization because of intense the catalyst application. Figure 1 shows the powder XRD patterns of SBA-15, CMK-3, PVSA/CMK-3 and Ni/PVSA/CMK-3. The low angle diffraction pattern of SBA-15 shows three reflections at 2à Ã‚ ´ values from 0.5 to 2 ° including one strong peak at (100) and two weak peaks at (110) and (200), which corresponds to the well-known ordered arrangement of SBA-15 in the space group p6mm of 2-D hexagonal symmetry. The silica SBA-15 used as template to synthesis CMK-3. As can be seen, the XRD pattern of CMK-3 show three diffraction peaks at 2à Ã‚ ´ = 1.04 °, 1.79 ° and 2.05 ° (Fig. 3b). It could be marked to (100), (110) and (200) diffractions of the 2D hexagonal space group p6mm, which is compatible with previous articles. After polymerization by poly (vinyl sulfonic acid), the X-ray diffraction of PVSA/CMK-3 shows the same pattern with CMK-3. This evidence indicates that the structure of the CMK-3 was retained after the polymerization (Fig. 3c). Albeit, the intensity of the characteristic reflection peaks of the PVSA/CMK-3 is found to be diminished (Fig. 1b). Composite contains less CMK-3 due to the dilution of the carbon material by PVSA; subsequently, this dilution can be responsible for a decrease in the peak intensity. By the way, the XRD patterns of CMK-3 and PVSA/CMK-3 are almost similar to SBA-15, which it shows CMK-3 is a accurate replica of the mesoporous silica SBA-15 and the polymerization process does not damage the structure of CMK-3. After immobilize nickel in the PVSA/CMK-3, Ni peak cannot be seen in XRD since the homogeneity of Ni particles in the Ni/PVSA/CMK-3, and it lonely shows an amorphous pattern at 2ÃŽ ¸ values of about 44ËÅ ¡ (Fig. 3, inside). In order to demonstrate the e xistence of Ni nanoparticles in the Ni/PVSA/CMK-3 catalyst was exposed to temperature (400ËÅ ¡C). Meanwhile, amorphous Ni changed to crystalline and appear a peak with low intensity at 2ÃŽ ¸ = 44.29ËÅ ¡, which can be attributed to the small size of nickel nanoparticles and the plane (111) of fcc nickel. Eventually, after immobilize the nickel nanoparticles on composite, structure has not changed and it is represented a successful synthesis of the catalyst. The specific surface area, pore volume and the pore size of the CMK-3, PVSA/CMK-3 and Ni/PVSA/CMK-3 samples are summarized in Table 1. All samples exhibit a type IV adsorption isotherm with an H1 hysteresis loop by capillary condensation at relative pressure around 0.3-0.7 (Fig. 4). It is clear in table 1 that the PVSA/CMK-3 and Ni/PVSA/CMK-3 exhibits a smaller specific surface area, and pore volume in comparison to those of pure CMK-3. Thanks to the successful incorporation of the poly(vinyl sulfonic acid) into the mesoporous carbon. As can be seen, pore diameter increases in the PVSA/CMK-3 and Ni/PVSA/CMK-3 in comparison to CMK-3. This evidence shows the incorporation and growth of hyperbranched polymers and consequently produces the pressure (physical pressure on the wall of the channels) inside the CMK-3 mesoporous. By adding Ni nanoparticles into the PVSA/CMK-3, the specific surface area and pore volume decrease, asserting that nickel nanoparticles are located inside the pores o f the CMK-3. In spite of the fact that there are significant decreases in the pore volume and surface area, the pores of Ni/PVSA/CMK-3 were not blocked by deposition of the hyperbranched homopolymer and nickel nanoparticles. Moreover, the BJH pore size distribution curves of the PVSA/CMK-3 and Ni/PVSA/CMK-3 are exhibited a narrow pore size distribution (Fig. 5). It clarifies that the homopolymer and nickel nanoparticles are satisfactory distributed on the channels of the Ni/PVSA/CMK-3. This result is agreement with TEM analysis and shows the effective role of the hyperbranched polymer to entrap and uniformly disperse nickel nanoparticles. , , Fig. 6 gave the scanning electron microscopy (SEM) photographs of CMK-3 and PVSA/CMK-3 and Ni/PVSA/CMK-3. All the SEM images are shown rod-like morphology, which is attributed to carbon mesoporous. Although, virtually no significant differences observe in surface morphology between CMK-3 and PVSA/CMK-3, it is obvious that after hybridization the surface of CMK-3 is become coarser; indicating the most of polymerization of PVSA occurred in the pores of CMK-3, which was also supported by the decrease in surface area and pore volume as shown in Table 1. In addition, by immobilizing Ni nanoparticles, several spherical beads are seen on the mesoporous carbon. However, most of them are incorporated inside the carbon mesoporous structure, which is not observable in the SEM images. It is necessary to mention that after loading nickel nanoparticles on the surface of CMK-3, the structure of the mesoporous carbon is remained. Moreover, XRD analysis and TEM images confirmed this claim. The PVSA/CMK-3 and Ni/PVSA/CMK-3 were inspected by means of TEM micrographs technique (Fig. 7). The ordered hexagonal p6mm mesostructure of PVSA/CMK-3 and Ni/PVSA/CMK- 3 can be seen, indicating after polymerization and incorporation of PVSA and Ni nanoparticles, the ordered structure of mesoporous carbon is retained. Additionally, the places with darker contrast could be assigned to the presence of Pd particles with different distribution (Fig. 7c-d). As can be seen, the small dark spots could be ascribed to nickel nanoparticles with ∠¼X nm average diameter, presumably located into the mesoporous channels. On the other hand, larger dark spots are shown in fig. 7 c-d, which are corresponded to Ni nanoparticles agglomerate on the external surface with average diameter of ∠¼5-10 nm. Fig. 8 shows the DRS-UV of PVSA/CMK-3 and Ni/PVSA/CMK-3. previous reports were proven that DRS-UV of the cationic nickel have only d-d transitions peaks including 3T1g(P)↠3A2g (F) (368 nm) and 3T1g (F)↠3A2g (F) (576 nm), which these two peak do not show in Ni/PVSA/CMK-3. Moreover, the DRS-UV of Ni/PVSA/CMK-3 shows feature bands around 205 nm and 330 nm, which are attributed to the presence of Ni nanoparticles in these samples. By comparing these data, it can be found that cationic nickels are converted to the nickel nanoparticles by reduction of NaBH4. 3.2. Catalytic activity Synthesized nanocomposite was characterized by different methods in the former section. This section is introduced the application of this bi-functional catalyst to the reductive amination reaction. During two decade, enormous investigation devoted to develop environmental friendly synthesis. Since, using water as a reaction medium in transition metal-catalyzed processes is one of the most essential goal of sustainable chemistry. Water is nontoxic solvent, readily available, an inexpensive, nontoxic solvent and non-inflammable. It provides privilege over organic solvents from an environmental and an economic aspect. Accordingly, the effect of several parameters on the one-pot tandem reductive amination of aldehydes with aniline over Ni/PVSA/CMK-3 as acid-metal bifunctional catalyst was perused in water at room temperature and the outcome are as follows: At the first monitoring of experiments, diverse amounts of NiCl2.6H2O were tested to identify the effect of nickel nanoparticles concentration on the reductive amination reaction. Hence, the amount of NiCl2.6H2O to prepare Ni/PVSA/CMK-3 was changed from 1 mmol/g to 15 mmol/g and then measured by the Atomic Absorption spectroscopy technique (AAS) which are shown in Table 2. It is clear that the activity of catalytic steadily improved by increasing NiCl2.6H2O form 1 mmol/g to 5 mmol/g. According to the catalytic reaction mechanism, nickel nanoparticle mediated electron transfer from BH4- ion to the imine intermediates (Scheme 1). Subsequently, the amounts of H- sites on the catalyst surface are grown by increasing nickel nanoparticles. Thus, larger amount of hydrides can be transferred to the imine groups through the catalyst. On the other hand, by further increasing the amount of NiCl2.6H2O (more than 5 mmol/g), the catalytic activity was diminished, which can be attributed to after a certain amount of nickel chloride increases, a larger amount of nanoparticles is loaded on the surface of the CMK-3 that may have caused the mesopore channels to narrow. In Fact, the nanoparticle size will increase by increasing the amount of NiCl2.6H2O. Therefore, in some places, the pore size will narrow and it is able to lessen the rate of reactants diffusion into the porous. In one word, lower performance of the catalyst produced with higher NiCl2.6H2O concentration will be anticipated. Despite of this fact, it does not mean the pores are throughout clogged. According to these results, the catalyst provided by 5 mmol/g NiCl2.6H2O presented the best catalytic activity. To identify the effect of NaBH4 amount (as a hydride donor) on the reductive amination the reaction was carried out using various amounts of NaBH4 in the presence of Ni/PVSA/CMK-3 as catalyst. As shown in Table 3, the yield was increased by increasing the amount of NaBH4 (until 6 mmol). The excess values did not have any effect on the reaction. Therefore, 6 mmol NaBH4 was the best value to perform reductive amination reaction. The influence of the solvent on catalytic activity was investigated in the reductive amination reaction using Ni-PVSA/CMK-3 catalyst and NaBH4 as hydride donor, at room temperature. The results are gathered in Table 4. Four vital factor acts to fulfil reductive amination reaction including dielectric constant, dipole moment, solubility in NaBH4, hydrophobic effect, protic and aprotic solvent effect. The results revealed that the reaction time in ethanol solvent is slow due to NaBH4 hardly solving in ethanol and the reaction rate is tardy. In addition, the reaction rate in water solvent is slow because although dielectric constant and solubility of water in NaBH4 is high, carbon mesoporous CMK-3 have hydrophobic nature. It causes substances and catalyst cannot have perfect interaction together. The hydrophobic nature of acetonitrile and oxolane are higher than other solvent that presented above; thus, these two solvent have more similarity to hydrophobic nature of CMK-3. Moreover, dipole moment of acetonitrile is higher than other solvent. Thanks to this feature, the reaction rate increase. Whereas the methanol solvent has mediate circumstance of dielectric constant, solubility in NaBH4, and hydrophobic effect aspect, the reaction time diminish. It is noteworthy to mention that the combination of all these factors together cause this process. Regarding these situation, water and acetonitrile were finally selected as the solvent for the reaction because of their environmental friendly and highly efficient, respectively; and all other optimization and reaction separately accomplished by these two solvent. The effect of the amount of catalyst was defined for reductive amination reaction (Table 5). Due to the fact, the catalyst synthesized is worthy, it is decided that the amount of catalyst optimize by decreasing down to the 0.04 g, nevertheless the reaction time were increased. However, reducing the amount of catalysts until 0.02 g was not sufficient. Since, the quantity of 0.04 g for both solvent was found to be the best weight of catalyst. The reusability of the catalyst was studied by using Ni/PVSA/CMK-3 in water and acetonitrile solvent (Chart 1). After each cycle, the catalyst was filtered off, washed with water (10 mL) and ethanol (3 mL 5 mL). After that, catalyst dried at 60 ËÅ ¡C and reused in the reductive amination reaction with a fresh reaction substances. It might be noted that after each run, a slight amount of the catalysts were lost in the filtration process. Herein, to overcome this problem, after each experiment the amount of remaining catalyst was specified and the molar ratio of the reactants was adjusted according to the remaining amount of the catalyst. The catalyst was reused up to 5 times. The catalyst that react in acetonitrile solvent have serious loss activity. In further investigation, it recognized that the catalyst used in acetonitrile solvent was somewhat destroyed. It can be attributed to the interaction between acetonitrile as a solvent and PVSA/CMK-3 composite. In other cases, not o nly the reusability of the catalyst that performed in water was adequate, but also the catalyst exhibit high stability in this status. This result obtained by SEM and XRD characterization, which can be seen in Figure 9 and 10. As shown in SEM images of reused catalyst in water as reaction solvent is well retained, which is very essential for the catalyst applications. Similarly, the XRD pattern shows a diffraction peak at low angle (1.04 °). It display that the catalyst structure remain. Because of this fact that the reusability in the heterogeneous catalysts is fundamental, water in reductive amination reaction chosen as a compatible solvent. The catalytic activity of the Ni/PVSA/CMK-3 in the reductive amination was compared with CMK-3, PVSA/CMK-3, and without a catalyst. The results are available in Table 6. The consequences affirm the significance role of the acid-metal heterogeneous catalyst in sort of reaction. As shown, the reaction dose not fulfil up to 5% without catalyst. There is the important issue that NaBH4 function as a mild hydride donor agent, which is incapable reagent for reducing imine groups solely. In a similar manner, this result obtained by using CMK-3 due to the fact that mesoporous carbon CMK-3 does not have any active sites to carry out the reaction. By using the PVSA/CMK-3, with improve acidic feature of the mesoporous carbon the carbonyl group activated and thus the yield moderately increased to 40% and 35% in acetonitrile and water solvent, respectively. In addition, using Ni/PVSA/CMK-3, the reaction efficiency was increased to 97% in 35 and 63 min in acetonitrile and water solvent, respectivel y; Because of the role of nickel nanoparticles as species to transfer hydride ions from NaBH4 to imine groups. The interesting point in catalyst investigation is heterogeneous nature. In this regard, the catalyst was separated from the reaction mixture at approximately 50% conversion of the starting substances by filtration and then centrifugation. The reaction progress in the filtrate circumstance was monitored (data not shown). No further reductive amination reaction occurred even at addition times, representing that the nature of reaction process is heterogeneous and there is not any progress for the reaction in homogeneous phase.

Oedipus the King - The Character Transformations of Oedipus Essay

Oedipus the King - The Character Transformations of Oedipus Through the character of Oedipus, Sophocles shows the consequences of defying the divine order. Oedipus served Thebes as a great ruler, loved by his subjects; but, like most in the human race, he slipped through the cracks of perfection. Oedipus had many faults, but it was primarily the tragic flaw of hubris, arrogance from excessive pride, which doomed his existence, regardless of the character attributes that made him such a beloved king. He was doomed for downfall since his very beginning, because "to flee your fate is to rush to find it" (Oedipus Rex). Oedipus, throughout this work, seems more than a merely passive player lost in the hands of fate. He makes critical errors in judgment that set the events of the story into action. His pride and arrogance, blindness and ignorance, as well as foolishness and quick temper all play a part in the tragedy that befalls him. Oedipus's pride sets it all off; when a drunken man tells him that his father is not who he thinks, his pride is so wounded that he will not let the subject rest, eventually going to the oracle of Apollo at Delphi to find the truth. A less proud man may have not needed to visit the oracle, giving him no reason to leave Corinth in the first place (Segal, 121). It is impossible to speculate what may have happened to Oedipus had he stayed in Corinth, but it is the attempt to avoid his fate that dooms him not only to fulfill the prophesy, but to suffer yet greater consequences (Segal, 122). "I heard all that and ran. I abandoned Corinth, from that day on I gauged its landfall only by the stars, running, always running toward some place where I would never see the shame of ... ...rs were bold and daring, known for their intelligence and heroism. But they were also known for their arrogance and their "risk it all" attitudes. On one hand, they saw themselves as protectors of the city, while at the same time they were unable to defend themselves as individuals (Oedipus the King). Works Cited Bloom, Harold, ed. Sophocles. Philadelphia: Chelsea House Publishers, 2003. 54-57. Oedipus Rex. 25 February 2003. http://www.classicnote.com/ClassicNotes/Titles/oedipus/summ2.html. Oedipus the King. 26 February 2003. http://www.novelguide.com/oedipustheking/themeanalysis/html. Segal, Charles. Tragedy and Civilization: an interpretation of Sophocles. Norman: University of Oklahoma Press, c.1999. 121-122. Sophocles. Oedipus the King. Norton Anthology World Masterpieces. Ed. Sarah Lawall. New York: Norton, 1984. 599-639.

Group Project: Academic Insurance Model

Each group acts as an insurance company. You are required to offer an insurance policy to our entire current Health Economics class that insures against a student either getting a grade of ‘C' or lower (including ‘l' turning into ‘F) or withdrawing from the class towards the end of the semester. If either of those happen to a policy holder, you are required to pay that policy holder.You are NOT trying to make a profit, but what is important is that your group try its very best to avoid making a loss. Assume that there are no other costs associated with your business other than paying policy holders who make ‘C' or less or withdraw. Four different scenarios are offered below. Here's what you need to tell me for each (l would also like each group to orally present results to rest of class, don't need any more than 3 minutes): What is the premium that students will have to pay for the policy in this scenario?A brief Justification for the premium (a couple of sent ence is good enough. You can give me the math formula you used too – but don't JUST give me a math formula! ). A final couple of sentence (optional) if you believe that I have given you a situation where it is impossible to avoid making a loss, and why you think that. If you believe this, you may choose not to sell any policies under that scenario. In all cases, there are a total of 30 students who are your potential customers – I. E. Insurance policy buyers.Scenario l: You will be paying students who make ‘C' or less or withdraw the amount of $5000. I can give you this information – that when I teach the regular Master's level version of the class, approximately of all students make C or less, Incomplete that becomes F, or withdraw. Also, I will impose an individual mandate on the class, so that once you do offer the policy, every one of the 30 students will be required to buy this policy (but you only want to break even, no profits). What premium will yo u charge?Please note, in all scenarios you can only hare ONE premium to all customers, no variations allowed. Scenario II: All conditions in the above scenario hold (# of students, what you pay for C or less or withdraw, the individual mandate). However, one more thing is added. Students who get C or less or withdraw can then get tutoring to prepare them for retaking the class later. The tutoring costs $16 an hour, and the insurance policy now also has to pay 50% of each hour of tutoring (I. E. $8 per hour) up to a maximum of 40 hours. This is a new scheme, so I cannot tell you how many students have previously

Network Design The WritePass Journal

Network Design Introduction Network Design IntroductionTransport Layer SecurityHow it worksTLS Handshake ProtocolTLS Record ProtocolWhere TLS is usedHow Secure Is It?Secure ShellHow it worksBibliographyRelated Introduction I have been asked to research and compare two of the most widely used internet security protocols, Transport Layer Security (TLS) and Secure Shell (SSH). In this report I shall research both protocols and then compare the two listing similarities and differences in how they operate as security protocols. I shall examine the features of both giving advantages and disadvantages, examples will be given for both security protocols and any infrastructure needs. As per instruction I will be using varied sources for my research including books, magazines and the internet, as with any report I shall reference all of my sources of information. Transport Layer Security Today the need for network security is of uppermost importance. We would all like to think that data is transmitted securely, but what if it wasn’t. Credit card crime for example would be a lot easier if there was no network security. This is one of many reasons why we need network security, and to achieve this we need protocols to secure the end to end transmission of data. An earlier protocol that was widely used in the early 1990’s this was the Secure Socket Layer protocol (SSL). SSL was developed by Netscape but had some security flaws and used a weak algorithm and did not encrypt all of the information. Three versions of SSL where developed by Netscape and after the third the Internet Engineering Task Force (IETF) were called in to develop an Internet standard protocol. This protocol was called the Transport Layer Security (TLS) protocol.   The main goal was to supply a means to allow secure connections for networks including the internet.    How it works The Transport Layer Security protocol uses complex algorithms to encrypt information as it is sent over the network. The protocol comprises of two main layers the Transport Layer Security Record and the Handshake Protocol. TLS Handshake Protocol The TLS Handshake protocol is used to; in principle agree a secret between the two applications before any data is sent. This protocol works above the TLS Record protocol and sends the secrets in the order in which they have to be sent. The most important feature here is that no data is sent in securing connection, the first bit sent is a start bit to the whole process and only when secure connection achieved is data sent over the network. TLS Record Protocol The Transport Layer Security Record encrypts the data using cryptography and uses a unique key for connection which is received from the Handshake protocol. The TLS Record protocol may be used with or without encryption. The data which has been encrypted is then sent down to the Transmission Control (TCP) layer for transport. The record also adds a Message Authentication Code (MAC) to the outward data and confirms using the MAC. I have used the image below to show how this is achieved. Where TLS is used The Transport Layer Security protocol is normally used, above any of the Transport Layer protocols. So the TLS protocol operates at Open Systems Interconnection (OSI) level 4, where it joins itself to other transport layer protocols, for example Hypertext Protocol( HTTP) and File Transfer Protocol (FTP) although its main partner is Transmission Control Protocol( TCP). Main area of use would be the internet in applications that need end to end security. This data is usually carried by HTTP and with TLS becomes HTTPS. TLS is therefore used to secure connections with e-commerce sites. VoIP also uses TLS to secure its data transmissions.† TLS and SSL are most widely recognized as the protocols that provide secure HTTP (HTTPS) for Internet transactions between Web browsers and Web servers.† (Microsoft, 2011) The Transport Layer Security protocol is also used in setting up Virtual Private Networks (VPN), where end to end security is a must but again is used alongside other protocols. How Secure Is It? Secure Shell The Secure Shell (SSH) is used for safe remote access between clients through an untrusted network. SSH is widely used software in network security. The need for such protocols is paramount in today’s technology based world. In the modern office for example employees may wish to transfer files to their home computer for completion, this would be an unwise option if it wasn’t for security protocols. A man in the middle attack could take place by listening on the network for traffic and picking up all your company secrets or personal ones. How it works The Secure Shell develops a channel for executing a shell on a remote machine. The channel has encryption at both ends of the connection. The most important aspects of SSH is that it authenticates the connection and encrypts the data it also ensures that the data sent is the data received. Bibliography TLS protocol. (2011, 03 23). Retrieved March 23, 2011, from wikipedia: http://it.wikipedia.org/wiki/File:EAP-TLS_handshake.png Microsoft. (2011, March 23). What is TLS. Retrieved March 23, 2011, from Microsoft TechNet: http://technet.microsoft.com/en-us/library/cc784450%28WS.10%29.aspx

April fools day essays

April fools day essays Traditionally April fools day has been celebrated by millions through out the world as just a simple joke or a practical prank that have been practice by young and old alike, there is no age barrier. When questions are asked what is April fools day? Where did it come from, and how did you learn of it. Most people say their first experience was in grammar school most targeting groups between 1st grade and 2nd grade habitually practicing the bun but harmless jokes all the way through collage and continuing o to now end. The humorous fun is an excellent excuse to play it on people you may not like and b the same token you love just as well. Everyone and anyone can be a target for a April fools gag and not be held responsible for there own foolishness whether you are the foolee or the fooler. The history of April fools day or also know as All fools day had started in France around 1582 the result of a reformation of the calendar form the Julian calendar to the Gregorian calendar by pope Charles IX . Use of the Julian calendar dates back to the roman era and ruled by Julius Caesar and calendar inventor for which its was named after in 45b.c. The Julian Calendar composed of eleven months of 30 and or 31 days a 28 day in February (extended to 29 days every fourth year) was very precise and only errored 11 1/2 minutes per year. After centuries a small inaccuracy of the eleven and a half minutes per year ads up and by the sixteenth century the little but continuing minutes had put the Julian calendar behind the solar one 10 days. Under Cesars rule some one would have been thrown to the lions for such an inadequacy. An advancement of 10 days was no longer tolerant so pope Charles IX and new correction device to curb further error was Introduced, making century years of 1700 or 1800 wouldnt be counted as leap years unless they are divisible by 400. The new Gregorian calendar system is very precise and still used i...