Benito Mussolini Essays - Politics, Political Philosophy

Benito Mussolini Essays - Politics, Political Philosophy Benito Mussolini Benito Mussolini In my perspective, my biography is based on one of the most interesting men of the 20th Century. My biography would not have been done without the knowledge of Edwin Hoyt. He was the author of the biography based on Benito Mussolini called Mussolinis Empire. This 298-page book describes Mussolinis rise and fall of the Fascist Empire. Benito Mussolini also known as il duce, was born in Predappio, Romagna on July 29, 1883. His father Alessandro was a blacksmith, and his mother Rosa was a Schoolteacher. Mussolini followed in his fathers footsteps and became a devoted socialist. In 1901 he qualified as an elementary schoolmaster. In 1902 he went to Switzerland to find a job. They arrested him and kicked him out of the country because he was vagabonding. They took him back to Italy where he joined a staff of a newspaper in the Austrian town of Trento in 1908. Mussolinis contributions to society werent really contributions; they were more like threats to society. One of the biggest threats that he introduced was in March 1919 when he founded the Fasci de Combattimento. This brought him up for elections in 1919, where he failed to enter the parliament. In 1921, Mussolini was introduced to the parliament as a right-wing member. Italy was growing in revolutionary confusion, and it was up for the liberal governments to prevent the spread of anarchy because Mussolini gave his approval in strikebreaking, so that meant that the Fascisti also known as armed squads would be stagnant and not try to prevent any revolutionary agitation. The liberal governments failed to stop the spread of anarchy. Due to their failure the king had no choice but to ask Mussolini to form his own government. In 1925-1926 he was able to assume dictatorial parties and dissolve all other political parties. Now you might ask yourself How is this a threat to society? Well, this was not only a threat to society but also a threat to his society. This man had power to control the whole country. He was able to choose and make any rules that he w anted. Now if you ask me, this man was incredible. Started out as an editor of a socialist newspaper and ended up as a dictator controlling Italy. This man controlled the armed Fascist militia, this power gave him the ability to declare war and use them in any way he wanted. Now that their was dictatorship there was no need for the parliamentary system, so it was practically abolished, law codes were rewritten, teachers in schools and universities had to swear an oath to defend the Fascist regime. Newspaper editors were chosen by Mussolini himself. If you didnt have a certificate approved by the Fascist party you could forget about having a journalism career. All industries went from public to private ownership. Everything was under governmental control. As you can see Italys society was hit hard. I mean their whole history was wiped out like it was never there, and all of a sudden Italy was introduced to a beginning of a new era. Dictatorship also affected society itself outside Italy. In Mussolinis footsteps followed Adolf Hitler dictator of Germany. Mussolini had an imperial dream, and Hitler had no dream he just wanted to wipe out Jews and take over as many lands as possible. Everything was going well for Mussolini until 1943 when the Italians got defeated by Anglo-Americans landing in Sicily. After this happened Mussolinis colleagues turned against him at a meeting of the Fascist Grand Council on July 25, 1943. This enabled the king to dismiss and arrest him. Hitler being the subordinate partner of Mussolini ordered his troops to rescue him. Mussolini infuriated that his Fascist leaders let him down, he got some to get executed including his son in law, Galeazzo Ciano. Another conflict that he was faced with was trying to make it to Switzerland without getting caught by any Italians. In April 1945 just before the allied armies reached Milan, Mussolini along with his mistress Clara Petacci, were caught by Italian partisans as he tried to take refuge in Switzerland. Unfortunately they were both executed by getting Shot. Even after Mussolini got shot he got beat up.

How to Extract Caffeine From Tea

How to Extract Caffeine From Tea Plants and other natural materials are sources of many chemicals. Sometimes you want to isolate a single compound from the thousands that may be present. Here is an example of how to use solvent extraction to isolate and purify caffeine from tea. The same principle may be used to extract other chemicals from natural sources. Caffeine From Tea: Materials List 2 tea bagsDichloromethane0.2 M NaOH (sodium hydroxide)Celite (diatomaceous earth - silicon dioxide)HexaneDiethyl ether2-propanol (isopropyl alcohol) Procedure Extraction of Caffeine: Open the tea bags and weigh the contents. This will help you determine how well your procedure worked.Place the tea leaves in a 125-ml Erlenmeyer flask.Add 20 ml dichloromethane and 10 ml 0.2 M NaOH.Extraction: Seal the flask and gently swirl it for 5-10 minutes to allow the solvent mixture to penetrate the leaves. Caffeine dissolves in the solvent, while most of the other compounds in the leaves do not. Also, caffeine is more soluble in dichloromethane than it is in water.Filtration: Use a Buchner funnel, filter paper, and Celite to use vacuum filtration to separate the tea leaves from the solution. To do this, dampen the filter paper with dichloromethane, add a Celite pad (about 3 grams Celite). Turn on the vacuum and slowly pour the solution over the Celite. Rinse the Celite with 15 ml dichloromethane. At this point, you may discard the tea leaves. Retain the liquid you have collected it contains the caffeine.In a fume hood, gently heat a 100-ml beaker containing the washings to evaporate the solvent. Purification of Caffeine: The solid that remains after the solvent has evaporated contains caffeine and several other compounds. You need to separate the caffeine from these compounds. One method is to use the different solubility of caffeine versus other compounds to purify it. Allow the beaker to cool. Wash the crude caffeine with 1 ml portions of a 1:1 mixture of hexane and diethyl ether.Carefully use a pipette to remove the liquid. Retain the solid caffeine.Dissolve the impure caffeine in 2 ml dichloromethane. Filter the liquid through a thin layer of cotton into a small test tube. Rinse the beaker twice with 0.5 ml portions of dichloromethane and filter the liquid through the cotton to minimize the loss of caffeine.in a fume hood, heat the test tube in a warm water bath (50-60 Â °C) to evaporate the solvent.Leave the test tube in the warm water bath. Add 2-propanol a drop at a time until the solid dissolves. Use the minimum amount required. This should be no more than 2 milliliters.Now you can remove the test tube from the water bath and allow it to cool to room temperature.Add 1 ml of hexane to the test tube. This will cause the caffeine to crystallize out of solution.Carefully remove the liquid using a pipette, leaving the purified caffeine.Wash the caffeine with 1 ml of a 1:1 mix of hexane and diethyl ether. Use a pipette to remove the liquid. Allow the solid to dry before weighing it to determine your yield. With any purification, its a good idea to check the melting point of the sample. This will give you an idea of how pure it is. The melting point of caffeine is 234 Â °C. Additional Methods Another way to extract caffeine from tea is to brew tea in hot water, allow it to cool to room temperature or below, and add dichloromethane to the tea. The caffeine preferentially dissolves in dichloromethane, so if you swirl the solution and allow the solvent layers to separate. you will get caffeine in the heavier dichloromethane layer. The top layer is decaffeinated tea. If you remove the dichloromethane layer and evaporate the solvent, you will get slightly impure greenish-yellow crystalline caffeine. Safety Information There are hazards associated with these and any chemicals used in a lab procedure. Be sure to read the MSDS for each chemical and wear safety goggles, a lab coat, gloves, and other appropriate lab attire. In general, be aware the solvents are flammable and should be kept away from open flames. A fume hood is used because the chemicals may be irritating or toxic. Avoid contact with sodium hydroxide solution, as it is caustic and can cause a chemical burn on contact. Although you encounter caffeine in coffee, tea, and other foods, it is toxic in relatively low doses. Dont taste your product!

Managing change at Bingham Business College Essay

Managing change at Bingham Business College - Essay Example The paper tells that in recent years, organizations have experienced increased need for change in order to remain relevant and be successful. The inevitability of change in organizations has been brought about by several factors key among them; competition, technological advancements, new innovations, and increased customers and public expectations. As a result, managers have been forced to initiate and implement change in the organizations to meet the new organizational challenges that are emerging. Forest argues that in as a much as managers understand the importance of introducing and implementing change, they are often unsuccessful in managing change. Most change processes do not achieve their intended purpose; sometimes change has more adverse effects to the company. Managing change in organizations often present managers with challenges that if not well addressed may lead to unintended consequences of change. Learning Organization framework is a critical tool that can be used t o identify and analyze problems and challenges that managers face in while implementing change within the organization, both in the short and long term. According to Senge, learning organization is defined as the organization where individuals continually expand and enhance their capacity in order to create their desired results, where expansive and new thinking patterns are nurtured, where aspirations are set free collectively, and where individuals are learning continually to see the whole together. Learning organizations are characterized by full involvement of employee in a collectively conducted process, and collectively accountable change that is directed towards shared principles or values (Smith and Tosey, 1999, p. 73). It is important to note that learning organization is ideal towards which organizations need to evolve so as to be in a suitable situation to respond to the various challenges and problems that the face at a given time (Finger and Brand, 1999, p. 136). Learni ng organization is a powerful tool for transforming employees and places where they work. It creates room where people can learn from experience, even though it does not usually do so when individuals are learning on behalf of the system (Ellinger, Yang, and Ellinger, 2000, p. 106). Senge (2006, p. 13) explains that Learning Organization framework is made up five major disciplines namely systems thinking, mental models, team learning, shared vision, and personal mastery. These disciplines provide framework in which change management problems can be identified and analysed. Senge (2006, p. 40) identifies systems thinking as one of the concept that underpins Learning Organization. According to him, systems thinking aim at bringing about change and promoting interdependency within the organization in order to achieve organizational goals. Under this concept, the focus is mostly on the whole rather than individual parts. Also, systems thinking concept evaluates the long- term goals vers us short- term benefits. It is based on the belief that better appreciation of systems will lead to more appropriate action (Smith and Tosey, 1999, p. 70). The second concept that underpins Leadership Organization is mental modes that entail generalizations and assumptions deeply ingrained within an organization. Senge (2006, p. 46) argues that there should be

Climate Change and the Experience of Poverty Essay

Climate Change and the Experience of Poverty - Essay Example Mitigation encompasses reducing the impact that one has on the environment through reduction of one’s carbon footprint among other activities. Conversely, adaptation involves dealing with consequences of climate change by say, establishing methods of coping with regular floods. A gap exists in current literature on the relationship between climate change and poverty. Several analysts tend to focus on mitigation at the community level. Institutions have been formed to minimise energy use through transport. Others have addressed housing and urban development (Berrang-Ford et. al., 2011). While these efforts may contribute to long term solutions for the country in general, they do not address the direct challenges that disadvantaged community members face when dealing with extreme weather events. ... It is imperative for stakeholders at the national, corporate and local levels to target this group when creating interventions. Extreme weather events (Such as floods, storms, and cyclones) are a manifestation of climate change and have adverse effects on disadvantaged communities. Poor people live in less-robust settlements that often leave them defenceless against these situations. Furthermore, they lack information of how to protect themselves during such events. Demetriades and Esplen (2008) note that actions are necessary in order to strengthen the resilience of the vulnerable during extreme weather events. Stakeholders may empower the disadvantaged through information dissemination, infrastructural preparedness, housing tenure agreements, among others (McCright, 2010. One of the ways in which these changes are manifested is through community projects. Nongovernmental organizations and special interest groups may carry out community projects to build resilience among disadvantag ed communities. It is imperative to understand why such groups are performing this role, and whether their activities arose from gaps in policy interventions from the national and local governments. Community projects are insufficient as a coping strategy for disadvantaged communities (Zsamboky et. al., 2011). However, they represent an attempt by non-state actors to participate in an issue of grave national consequences. Their presence in deprived areas indicates that policy-makers may not be doing enough to prepare these communities for extreme weather conditions. Runhaar et. al. (2012) carried out a study in the Netherlands to assess the stimuli and barriers to climate change adaptations in urban areas. They found that a gap

An Analysis of the Plot of True Grit Essay Example | Topics and Well Written Essays - 750 words

An Analysis of the Plot of True Grit - Essay Example III. Maddie begins for her search for Chaney A. Marshall Cogburn tries to discourage her from joining the quest but she refuses to be dissuaded from doing so. B. Marshall Cogburn and Maddie begin looking for clues to Chaney’s wherea\bouts 1. They discover that Chaney used one of Frank’s gold pieces in the Indian territory. 2. They meet Quincey and Moon and encounter the Pepper Gang. IV. Maddie comes face to face with Chaney who tries to kill her. A. Chaney gets killed B. Maddie gets bitten by a snake but Cogburn saves him The movie â€Å"True Grit† is the story of a young girl’s determination to seek justice for the death of her father. The viewer learns this immediately from the girl named Maddie Ross who explains at the beginning of the film how her father was killed by a man named Tom Chaney. The succeeding segment of the film show the steps taken by Maddie as she goes on a quest to find her father’s killer. One of the important things that she d oes is find a person like Marshall Cogburn to help her in bringing Tom Chaney to justice. At the onset, it appears that it is only Maddie who is on a quest to seek her father’s killer. The viewer discovers however that a Texas Ranger named Le Bouef is also looking for Tom Chaney who murdered a senator in Texas. ... One of the important elements of the film that was significant was the characters themselves. The quest for Tom Chaney brought out the best in Maddie, Marshall Cogburn, and the Texas Ranger LeBouef. Maddie was able to demonstrate that in spite of her age, she acted with great courage and wisdom. She knew where she was going and what she had to do. It is for this reason that Cogburn, who thought of her as a child acting on impulse, could not easily get rid of her. One must remember that the reason why she bought a horse and went along on the quest was to make sure that she’s going to get her money’s worth. Marshall Cogburn who was portrayed as a drunk showed that he has some decency left in him when he decided to forget all about the reward money and honor the deal he and Maddie made. He also showed his displeasure for cruelty when he stopped LeBouef from spanking Maddie and when he knocked off two Indian boys who were hurting a mule. Above all, he showed true grit when he carried the wounded Maddie for several miles to get her to a doctor. LeBouef also lived up to his being a Texas Ranger when he came back for Maddie who almost got killed by Tom Chaney. The pattern followed by the film involves an incident that takes place and forces the leading character to go on a quest. Knowing that the quest is difficult, the leading character recruits others to help him or her succeed in achieving his or her goal. In the case of Maddie, she gets help from Cogburn and LeBouef. The characters encounter several challenges that tend to derail them from achieving their goal but they are able to overcome these obstacles. Maddie for instance failed to be dissuaded by Cogburn and LeBouef,

Literature Survey on Hydrogen Separation Technique

Literature Survey on Hydrogen Separation Technique Literature review has been performed in order to identify recent publications on hydrogen separation methods, hydrogen solubility, materials and concepts in research institutes and laboratories. The aim of the performed literature survey was to monitor recent worldwide literature and find out whether some of the developed and reported solutions might possibly help to improve existing hydrogen separation concept in PDh system, enabling efficient complete separation of hydrogen from all unwanted hydrocarbons. Literature survey on hydrogen separation technique Basically there are four important methods applied to the separation of gases in the industry: absorption, adsorption, cryogenic and membranes. Pressure swing adsorption (PSA) is a gas purification process consisting of the removal of impurities on adsorbent beds. The usual adsorbents and gases adsorbed are molecular sieves for carbon monoxide, activated carbon for CO2, activated alumina or silica gel. Industrial PSA plants consist of up to 12 adsorbers and along with the number of valves required this makes the system rather complicated and complex. The PSA process is usually a repeating sequence of the following steps: adsorption at feed pressure, co-current depressurisation to intermediate pressure, counter-current depressurisation to atmospheric pressure usually starting at 10 % to 70 % of the feed pressure, counter-current purge with hydrogen enriched or product gas at ambient pressure, co-current pressure equalisation and finally, co-current pressurisation with feed or secondary process gas[1]. For hydrogen purification by PSA hydrogen purity is high but the amount of rejected hydrogen is also relatively high (10 †“ 35 %). It seems also that cryogenic technology might not be applicable for PDh process gas separation. Cooling down the mixture will finally end in a solid jet fuel and a gas phase. Handling the solid is more difficult when compared with liquid. During the survey it became evident that membrane technology is the most popular, used and still investigating for the improvement process for hydrogen separation therefore the focus of the study is mainly on this technique. The membrane separation process involves several elementary steps, which include the solution of hydrogen and its diffusion as atomic hydrogen through the membrane bulk material. Nowadays, membrane technologies are becoming more frequently used for separation of wide varying mixtures in the petrochemical related industries. According to Sutherland[2] it is estimated that bulk chemicals and petrochemicals applications represented about 40% of the membrane market in the whole chemicals industry or about $ 1.5 billions, growing over 5 % per year. Membrane gas separation is attractive because of its simplicity and low energy cost. The advantages of using membrane gas separation technologies could be summarized as following: Continuous and clean process, membranes do not require regeneration, unlike the adsorption or the absorption processes, which require regeneration step leading to the use of two solid beds or a solvent regeneration unit. Required filtration system is simple and inexpensive. Compared with conventional techniques, membranes can offer a simple, easy-to-operate, low-maintenance process. Membrane process is simple, generally carried out at atmospheric conditions which, besides being energy efficient, can be important for sensitive applications in pharmaceutical and food industry. The recovery of components from a main stream using membranes can be done without substantial additional energy costs. Membrane is defined essentially as a barrier, which separates two phases and restricts transport of various chemicals in a selective manner. A membrane can be homogenous or heterogeneous, symmetric or asymmetric in structure, solid or liquid; can carry a positive or negative charge or be neutral or bipolar. Transport through a membrane can be affected by convection or by diffusion of individual molecules, induced by an electric field or concentration, pressure or temperature gradient. It takes place when a driving force is applied to the components in the feed. In most of the membrane processes, the driving force is a pressure difference or a concentration (or activity) difference across the membrane. Another driving force in membrane separations is the electrical potential difference. This driving force only influences the transport of charged particles or molecules. The hydrogen separation factor is sometimes used to specify membrane quality. It is defined as following: where ni stands for moles of species i transferred through the membrane and ?pi stands for the partial pressure difference of species i through the membrane. The membrane thickness may vary from as small as 10 microns to few hundred micrometers. Basic types of membranes are presented in Figure 4. Membranes in petrochemical industry are mainly used for concentration, purification and fractionation however they may be coupled to a chemical reaction to shift the chemical equilibrium in a combination defined as a membrane reactor. Using a membrane is adding costs to any process, therefore in order to overcome the cost issue another advantages must overcome the added expenses like material with a very good separation factor, high flux, high quality membrane materials (stable during many months of operation). In a membrane separation reactor both organic and inorganic membranes can be used. Many industrial catalytic processes involve the combination of high temperature and chemically harsh environments favouring therefore inorganic membranes due to their thermal stability, resistance to organic solvents, chlorine and other chemicals. Some promising applications using inorganic membranes include certain dehydrogenation, hydrogenation and oxidation reactions like formation of butane from dehydrogenation of ethyl benzene, styrene production from dehydrogenation of ethyl benzene, dehydrogenation of ethane to ethane, oxidative coupling of methane etc. In membrane reactor two basic concepts can be distinguished as can be seen in Figure 5. reaction and separation combined in one reactor (catalytic membrane reactor) reaction and separation are not combined and the reactants are recycled along a membrane system (membrane recycle reactor) Catalytic membrane reactor concept is used especially with inorganic membranes (ceramics, metals) and polymeric membranes where the catalyst is coupled to the membrane. Membrane recycle reactor can be applied with any membrane process and type of membranes. Most of the chemical reactions need catalyst to enhance the reaction kinetics. The catalyst must be combined with the membrane system and various arrangements are possible, as can be seen in Figure 6. The advantage of the catalyst located inside the bore of the tube is simplicity in preparation and operation. When needed the catalyst could be easily replaced. In case of top layer filled with catalyst and membrane wall, the catalyst is immobilized onto the membrane. Palladium has been known to be a highly hydrogen permeable and selective material since the 19th century. The existing Pd-based membranes can be mainly classified into two types according to the structure of the membrane as (i) self-supporting Pd-based membranes and (ii) composite structures composed of thin Pd-based layers on porous materials. Most self-supporting Pd-based membranes are commercially available in the forms that are easily integrated into a separation setup. However these membranes are relatively thick (50 mm or more) and therefore the hydrogen flux through them is limited. Thick palladium membranes are expensive and rather suitable for use in large scale chemical production. For practical use it is necessary to develop separation units with reduced thickness of the layer. An additional problem is that in order to have adequate mechanical strength, relatively thick porous supports have to be used. In the last decade a significant research has been carried out to achie ve higher fluxes by depositing thin layers of Pd or Pd alloys on porous supports like ceramics or stainless steel. A submicron thick and defect-free palladium-silver (Pd-Ag) alloy membrane was fabricated on a supportive microsieve by using microfabrication technique and tested by Tong et al[4]. The technique also allowed production of a robust wafer-scale membrane module which could be easily inserted into a membrane holder to have gas-tight connections to outside. Fabricated membrane had a great potential for hydrogen purification and in application like dehydrogenation industry. One membrane module was investigated for a period of ca. 1000 hours during which the membrane experienced a change in gas type and its concentration as well as temperature cycling between 20 – 450  °C. The measured results showed no significant reduction in flux or selectivity, suggesting thus very good membrane stability. The authors carried out experiments with varying hydrogen concentration in the feed from 18 to 83 kPa at 450  °C to determine the steps limiting H2 transport rate. It is assumed that the fabricated membrane may be used as a membrane reactor for dehydrogenation reactions to synthesize high value products although its use may be limited due to high pressures of tens of bars. Schematic drawing of the hydrogen separation setup is presented in Figure 7. The membrane module was placed in a stainless steel holder installed in a temperature controlled oven to ensure isothermal operation. The H2/He feed (from 300 to 100 ml/mol) was preheated in spirals placed in the same oven. The setup was running automatically for 24 h/day and could handle 100 recipes without user intervention. Tucho et al.[5] performed microstructural studies of self-supported Pd / 23 wt. % Ag hydrogen separation membranes subjected to different heat treatments (300/400/450  °C for 4 days) and then tested for hydrogen permeation. It was noted that changes in permeability were dependent on the treatment atmosphere and temperature as well as membrane thickness. At higher temperatures significant grain growth was observed and stress relaxation occurred. Nam et al.[6] were able to fabricate a highly stable palladium alloy composite membrane for hydrogen separation on a porous stainless steel support by the vacuum electrodeposition and laminating procedure. The membrane was manufactured without microstructural change therefore it was possible to obtain both high performance (above 3 months of operation) and physical and morphological stability of the membrane. It was observed that the composite membrane had a capability to separate hydrogen from gas mixture with complete hydrogen selectivity and could be used to produce ultra-pure hydrogen for applications in membrane reactor. Tanaka et al.[7] aimed at the improved thermal stability of mesoporous Pd-YSZ-g-Al2O3 composite membrane. The improved thermal stability allowed operation at elevated temperature (> 500  °C for 200 hours). This was probably the result of improved fracture toughness of YSZ-g-Al2O3 layer and matching thermal expansion coefficient between palladium and YSZ. Kuraoka, Zhao and Yazawa[8] demonstrated that pore-filled palladium glass composite membranes for hydrogen separation prepared by electroless plating technique have both higher hydrogen permeance, and better mechanical properties than unsupported Pd films. The same technique was applied by Paglieri et al.[9] for plating a layer of Pd and then copper onto porous ?-substrate. Zahedi et al.[10] developed a thin palladium membrane by depositing Pd onto a tungsten oxide WO3 modified porous stainless steel disc and reported that permeability measureme nts at 723, 773 and 823 K showed high permeability and selectivity for hydrogen. The membrane was stable with regards to hydrogen for about 25 days. Certain effort has been performed for improving hydrothermal stability and application to hydrogen separation membranes at high temperatures. Igi et al.[11] prepared a hydrogen separation microporous membranes with enhanced hydrothermal stability at 500  °C under a steam pressure of 300 kPa. Co-doped silica sol solutions with varying Co composition (Co / (Si + Co) from 10 to 50 mol. %) were prepared and used for manufacturing the membranes. The membranes showed increased hydrothermal stability and high selectivity and permeability towards hydrogen when compared with pure silica membranes. The Co-doped silica membranes with a Co composition of 33 mol. % showed the highest selectivity for hydrogen, with a H2 permeance of 4.00 x 10-6 (m3 (STP) Ãâ€" (m Ãâ€" s Ãâ€" kPa)-1) and a H2/N2 permeance ratio of 730. It was observed that as the Co composition increased as high as 33 %, the activation energy of hydrogen permeation decreased and the H2 permeance increased. Additional increase in Co concentration resulted in increased H2 activation energy and decreased H2 permeance. Due to high permselectivity of Pd membranes, high purity of hydrogen can be obtained directly from hydrogen containing mixture at high temperatures without further purification providing if sufficient pressure gradient is applied. Therefore it is possible to integrate the reforming reaction and the separation step in a single unit. A membrane reformer system is simpler, more compact and more efficient than the conventional PSA system (Pressure Swing Adsorption) because stem reforming reaction of hydrocarbon fuels and hydrogen separation process take place in a single reactor simultaneously and without a separate shift converter and a purification system. Gepert et al.[12] have aimed at development of heat-integrated compact membrane reformer for d ecentralized hydrogen production and worked on composite ceramic capillaries (made of ?-Al2O3) coated with thin palladium membranes for production of CO-free hydrogen for PEM fuel cells by alcohol reforming. The membranes were tested for pure hydrogen and N2 as well as for synthetic reformate gas. The process steps comprised the evaporation and overheating of the water/alcohol feed, water gas shift combined with highly selective hydrogen separation. The authors have focused on the step concerned with the membrane separation of hydrogen from the reforming mixture and on the challenges and requirements of that process. The challenges encountered with the development of capillary Pd membranes were as following: long term temperature and pressure cycling stability in a reformate gas atmosphere, the ability to withstand frequent heating up and cooling down to room temperature, avoidance of the formation of pin-holes during operation and the integration of the membranes into reactor housi ng. It was observed that palladium membranes should not be operated at temperatures below 300  °C and pressures lower than 20 bar, while the upper operating range is between 500 and 900  °C. Alloying the membrane with copper and silver extend their operating temperature down to a room temperature. The introduction of silver into palladium membrane increases the lifetime, but also the costs when compared with copper. Detailed procedure of membrane manufacturing, integration into reformer unit and testing is described by the authors. Schematic of the concept of the integrated reformer is shown in Figure 8. The membrane was integrated in a metal tube embedded in electrically heated copper plates. Before entering the test tube, the gases were preheated to avoid local cooling of the membrane. Single gas measurements with pure N2 and H2 allowed the testing of the general performance of the membrane and the permselectivity for the respective gases to be reached. Synthetic reformate gas consisting of 75 % H2, 23.5 % CO2 and 1.5 % CO was used to get information about the performance. The membranes were tested between 370 – 450  °C and pressures up to 8 bar. The authors concluded that in general the membranes have shown good performance in terms of permeance and permselectivity including operation under reformate gas conditions. However, several problems were indicated concerning long-term stability under real reforming conditions, mainly related to structural nature (combination of different materials: ceramic, glaze, palladium resulted on incoherent potential for causing membrane failure). At operation times up to four weeks the continuous Pd layer remained essentially free from defects and pinholes. Han et al.[13] have developed a membrane separation module for a power equivalent of 10 kWel. A palladium membrane containing 40 wt. % copper and of 25 mm thickness was bonded into a metal frame. The separation module for a capacity of 10 Nm3 h-1 of hydrogen had a diameter of 10.8 cm and a length of 56 cm. Reformate fed to the modules contained 65 vol. % of hydrogen and the hydrogen recovery through the membrane was in the range of 75 %. Stable operation of the membrane separation was achieved for 750 pressure swing tests at 350  °C. The membrane separation device was integrated into a methanol fuel processor. Pientka et al.[14] have utilized a closed-cell polystyrene foam (Ursa XPS NIII, porosity 97 %) as a membrane buffer for separation of (bio)hydrogen. In the foam the cell walls formed a structured complex of membranes. The cells served as pressure containers of separated gases. The foam membrane was able to buffer the difference between the feed injection rate and the rate of consumption of the product. Using the difference in time-lags of different gases in polymeric foam, efficient gas separation was achieved during transient state and high purity hydrogen was obtained. Argonne National Laboratory (ANL) is involved in developing dense hydrogen-permeable membranes for separating hydrogen from mixed gases, particularly product streams during coal gasification and/or methane reforming. Novel cermet (ceramic-metal composite) membranes have been developed. Hydrogen separation with these membranes is non-galvanic (does not use electrodes or external power supply to drive the separation and hydrogen selectivity is nearly 100 % because the membrane contain no interconnected porosity). The membrane development at ANL initially concentrated on a mixed proton/electron conductor based on BaCe0.8Y0.2O3-d (BCY), but it turned to be insufficient to allow high non-galvanic hydrogen flux. To increase the electronic conductivity and thereby to increase the hydrogen flux the development focused on various cermet membranes with 40-50 vol. % of metal or alloy dispersed in the ceramic matrix. Balachandran et al.[15],[16] described the development performed at ANL. The powder mixture for fabricating cermet membranes was prepared by mechanical mixing Pd (50 vol. %) with YSZ, after that the powder mixture was pressed into discs. Polished cermet membranes were affixed to one end of alumina tube using a gold casket for a seal (as can be seen in Figure 9). In order to measure the hydrogen permeation rate, the alumina tube was inserted into a furnace with a sealed membrane and the associated gas flow tubes. Hydrogen permeation rate for Pd/YSZ membranes has been measured as a function of temperature (500-900  °C), partial pressure of hydrogen in the feed stream (0.04-1.0 atm.) and membrane thickness ( » 22-210 mm) as well as versus time during exposure to feed gases containing H2, CO, CO2, CH4 and H2S. The highest hydrogen flux was  » 20.0 cm3 (STP)/min cm2 for  » 22- mm thick membrane at 900  °C using 100 % hydrogen as the feed gas. These results suggested that membranes with thickness In the last decade Matrimid 5218 (Polyimide of 3,3,4,4-benzophenone tetracarboxylic dianhydride and diamino-phenylindane) has attracted a lot of attention as a material for gas separation membranes due to the combination of relatively high gas permeability coefficients and separation factors combined with excellent mechanical properties, solubility in non-hazard organic solvents and commercial availability. Shishatskiy et al.[18] have developed asymmetric flat sheet membranes for hydrogen separation from its mixtures with other gases. The composition and conditions of membrane preparation were optimized for pilot scale membrane production. The resulting membrane had a high hydrogen flux (1 m3 (STP)/m2h*bar) and selectivity of H2/CH4 at least 100, close to the selectivity of Matrimid 5218, material used for asymmetric structure formation. The hydrogen flux through the membranes increased with the decrease of polymer concentration and increase of non-solvent concentration. In addition, the influence of N2 blowing over the membrane surface (0, 2, 3, 4 Nm3 h-1 flow rate) was studied and it was proved that the selectivity of the membrane decreased with increase of the gas flow. The SEM image of the membrane supported by Matrimid 5218 is shown in Figure 10. The stability against hydrocarbons was tested by immersion of the membrane into the mixture of n-pentane/n-hexane/toluene in 1:1:1 ratio. Stability tests showed that the developed membrane was stable against mixtures of liquid hydrocarbons and could withstand continuous heating up to 200  °C for 24 and 120 hours and did not lose gas separation properties after exposure to a mixture of liquid hydrocarbons. The polyester non-woven fabric used as a support for the asymmetric membrane gave to the membrane excellent mechanical properties and allowed to use the membrane in gas separation modules. Interesting report on development of compact hydrogen separation module called MOC (Membrane On Catalyst) with structured Ni-based catalyst for use in the membrane reactor was presented by Kurokawa et al[19]. In the MOC concept a porous support itself had a function of reforming catalyst in addition to the role of membrane support. The integrated structure of support and catalyst made the membrane reformer more compact because the separate catalysts placed around the membrane modules in the conventional membrane reformers could be eliminated. In that idea first a porous catalytic structure 8YSZ (mixture of NiO and 8 mol. % Y2O3-ZrO2 at the weight ratio 60:40) was prepared as the support structure of the hydrogen membrane. The mixture was pressed into a tube closed at one end and sintered then in air. Slurry of 8YSZ was coated on the external surface of the porous support and heat-treated for alloying. Obtained module of size 10 mm outside and 8 mm inside diameter, 100 ~ 300 mm length and the membrane thickness was 7 ~ 20 mm were heated in flowing hydrogen at 600  °C for 3 hours to reduce NiO in the support structure into Ni before use (the porosity of the support after reduction was 43 %). A stainless steel cap and pipe were bonded to the module to introduce H2 into the inside of the tubular module. Figure 11 presents the conceptual structure design of the MOC module as compared with the structure of the conventional membrane reformer. The sample module in the reaction chamber was placed in the furnace and heated at 600  °C, pre-heated hydrogen (or humidified methane) was supplied inside MOC at the pressure of 0.1 MPa and the permeated hydrogen was collected from the outside chamber around the module at ambient pressure. The 100 ~ 300 mm long modules with 10 mm membrane showed hydrogen flux of 30 cm3 per minute per cm2 which was two times higher than the permeability of the conventional modules with palladium based alloy films. Membrane On Catalyst modules have a great potential to be applied to membrane reformer systems. In this concept a porous support itself has a function of reforming catalyst in addition to the role of membrane support. It seems that Membrane On Catalyst modules have a great potential to be applied to membrane reformer systems. Amorphous alloy membranes composed primarily of Ni and early transition metals (ETM) are an inexpensive alternative to Pd-based alloy membranes, and these materials are therefore of particular interest for the large-scale production of hydrogen from carbon-based fuels. Catalytic membrane reactors can produce hydrogen directly from coal-derived synthesis gas at 400 °C, by combining a commercial water-gas shift (WGS) catalyst with a hydrogen-selective membrane. Three main classes of membrane are capable of operating at the high temperatures demanded by existing WGS catalysts: ceramic membranes producing pure hydrogen via ion-transfer mechanism at  ³ 600  °C, alloy membranes which produce pure hydrogen via a solution-diffusion mechanism between 300 – 500  °C and microporous membranes, typically silica or carbon, whose purity depends on the pore size of the membrane and which operate over a wide temperature range dependent on the membrane material. In order to explore the suitability of Ni-based amorphous alloys for this application, the thermal stability and hydrogen permeation characteristics of Ni-ETM amorphous alloy membranes has been examined by Dolan et al[20]. Fundamental limitation of these materials is that hydrogen permeability is inversely proportional to the thermal stability of the alloy. Alloy design is therefore a compromise between hydrogen production rate and durability. Amorphous Ni60Nb(40-x)Zr(x) membranes have been tested at 400 °C in pure hydrogen, and in simulated coal-derived gas streams with high steam, CO and CO2 levels, without severe degradation or corrosion-induced failure. The authors have concluded that Ni-Nb-Zr amorphous alloys are therefore prospective materials for use in a catalytic membrane reactor for coal-derived syngas. Much attention has been given to inorganic materials such as zeolite, silica, zirconia and titania for development of gas- and liquid- separation membranes because they can be utilized under har sh conditions where organic polymer membranes cannot be applied. Silica membranes have been studied extensively for the preparation of various kinds of separation membranes: hydrogen, CO2 and C3 isomers. Kanezeashi[21] have proposed silica networks using an organo-inorganic hybrid alkoxide structure containing the organic groups between two silicon atoms, such as bis(triethoxysilyl)ethane (BTESE) for development of highly permeable hydrogen separation membranes with hydrothermal stability. The concept for improvement of hydrogen permeability of silica membrane was to design a loose-organic-inorganic hybrid silica network using mentioned BTESE (to shift the silica networks to a larger pore size for an increase in H2 permeability). A hybrid silica layer was prepared by coating a silica-zirconia intermediate layer with a BTESE polymer sol followed by drying and calcination at 300 °C in nitrogen. A thin, continuous separation layer of hybrid silica for selective H2 permeation was observed on top of the SiO2-ZrO2 intermediate layer as presented in Figure 12. Hybrid silica membranes showed a very high H2 permeance, ~ 1 order of magnitude higher (~ 10-5 mol m-2 s-1 Pa-1) than previously r eported silica membranes using TEOS (Tetraethoxysilane). The hydrothermal stability of the hybrid silica membranes due to the presence of Si-C-C-Si bonds in the silica networks was also confirmed. Nitodas et al.[22] for the development of composite silica membranes have used the method of chemical vapour deposition (CVD) in the counter current configuration from TEOS and ozone mixtures. The experiments were conducted in a horizontal hot-wall CVD quartz reactor (Figure 13) under controlled temperature conditions (523 – 543 K) and at various reaction times (0 -15 hours) and differential pressures across the substrate sides using two types of substrates: a porous Vycor tube and alumina (g-Al2O3) nanofiltration (NF) tube. The permeance of hydrogen and other gases (He, N2, Ar, CO2) were measured in a home-made apparatus (able to operate under high vacuum conditions 10-3 Torr, feed pressure up to 70 bar) and the separation capability of the composite membranes was determined by calculating the selectivity of hydrogen over He, N2, Ar, CO2. The in-situ monitoring of gas permeance during the CVD development of nanoporous membranes created a tool to detect pore size alterations i n the micro to nanometer scale of thickness. The highest permeance values in both modified and unmodified membranes are observed for H2 and the lowest for CO2. This indicated that the developed membranes were ideal candidates for H2/CO2 separations, like for example in reforming units of natural gas and biogas (H2/CO2/CO/CH4). Moon et al.[23] have studied the separation characteristics and dynamics of hydrogen mixture produced from natural gas reformer on tubular type methyltriethoxysilane (MTES) silica / ?-alumina composite membranes. The permeation and separation of CO pure gas, H2/CO (50/50 vol. %) binary mixture and H2/CH4/CO/CO2 (69/3/2/26 vol. %) quaternary mixture was investigated. The authors developed a membrane process suitable for separating H2 from CO and other reformate gases (CO2 or CH4) that showed a molecular sieving effect. Since the permeance of pure CO on the MTES membrane was very low (CO  » 4.79 – 6.46 x 10-11 mol m-2 s-1 Pa-1), comparatively high hydrogen selectivity could be obtained from the H2/CO mixture (separation factor: 93 – 110). This meant that CO (which shall be eliminated before entering fuel cell) can be separated from hydrogen mixtures using MTES membranes. The permeance of the hydrogen quaternary mixture on MTES membrane was 2.07 – 3.37 x 10-9 mol m-2 s-1 Pa-1 and the separation factor of H2 / (CO + CH4 + CO2) was 2.61 – 10.33 at 323 – 473 K (Figure 14). The permeation and selectivity of hydrogen were increased with temperature because of activation of H2 molecules and unfavourable conditions for CO2 adsorption. Compared to other impurities, CO was most successfully removed from the H2 mixture. The MTES membranes showed great potential for hydrogen separation from reforming gas with high selectivity and high permeance and therefore they have good potential for fuel cell systems and for use in hydrogen stations. According to the authors, the silica membranes are expected to be used for separating hydrogen in reforming environment at high temperatures. Silica membranes prepared by the CVD or sol-gel methods on mesoporous support are effective for selective hydrogen permeation, however it is known that hydrogen-selective silica materials are not thermally stable at high temperatures. Most researchers reported a loss of permeability of silica membranes even 50 % or greater in the first 12 hours on exposure to moisture at high temperature. Much effort has been spent on the improvement of the stability of silica membranes. Gu et al.[24] have investigated a hydrothermally stable and hydrogen-selective membrane composed of silica and alumina prepared on a macroporous alumina support by CVD in an inert atmosphere at high temperature. Before the deposition of the silica-alumina composite multiple graded layers of alumina were coated on the alumina support with three sols of decreasing particle sizes. The resulting supported composite silica-alumina membrane had high permeability for hydrogen (in the order of 10-7 mol m-2 s-1 Pa-1) at 873 K . Significantly the composite membrane exhibited much higher stability to water vapour at the high temperature of 873 K in comparison to pure silica membranes. The introduction of alumina into silica made the silica structure more stable and slowed down the silica disintegration process. As mentioned, silica membranes produced by sol-gel technique or by CVD applied for gas separation, especially for H2 production are quite stable in dry gases and exhibit high separation ratio, but lose the permeability when used in the steamed gases because of sintering or tightening. Thi Literature Survey on Hydrogen Separation Technique Literature Survey on Hydrogen Separation Technique Literature review has been performed in order to identify recent publications on hydrogen separation methods, hydrogen solubility, materials and concepts in research institutes and laboratories. The aim of the performed literature survey was to monitor recent worldwide literature and find out whether some of the developed and reported solutions might possibly help to improve existing hydrogen separation concept in PDh system, enabling efficient complete separation of hydrogen from all unwanted hydrocarbons. Literature survey on hydrogen separation technique Basically there are four important methods applied to the separation of gases in the industry: absorption, adsorption, cryogenic and membranes. Pressure swing adsorption (PSA) is a gas purification process consisting of the removal of impurities on adsorbent beds. The usual adsorbents and gases adsorbed are molecular sieves for carbon monoxide, activated carbon for CO2, activated alumina or silica gel. Industrial PSA plants consist of up to 12 adsorbers and along with the number of valves required this makes the system rather complicated and complex. The PSA process is usually a repeating sequence of the following steps: adsorption at feed pressure, co-current depressurisation to intermediate pressure, counter-current depressurisation to atmospheric pressure usually starting at 10 % to 70 % of the feed pressure, counter-current purge with hydrogen enriched or product gas at ambient pressure, co-current pressure equalisation and finally, co-current pressurisation with feed or secondary process gas[1]. For hydrogen purification by PSA hydrogen purity is high but the amount of rejected hydrogen is also relatively high (10 †“ 35 %). It seems also that cryogenic technology might not be applicable for PDh process gas separation. Cooling down the mixture will finally end in a solid jet fuel and a gas phase. Handling the solid is more difficult when compared with liquid. During the survey it became evident that membrane technology is the most popular, used and still investigating for the improvement process for hydrogen separation therefore the focus of the study is mainly on this technique. The membrane separation process involves several elementary steps, which include the solution of hydrogen and its diffusion as atomic hydrogen through the membrane bulk material. Nowadays, membrane technologies are becoming more frequently used for separation of wide varying mixtures in the petrochemical related industries. According to Sutherland[2] it is estimated that bulk chemicals and petrochemicals applications represented about 40% of the membrane market in the whole chemicals industry or about $ 1.5 billions, growing over 5 % per year. Membrane gas separation is attractive because of its simplicity and low energy cost. The advantages of using membrane gas separation technologies could be summarized as following: Continuous and clean process, membranes do not require regeneration, unlike the adsorption or the absorption processes, which require regeneration step leading to the use of two solid beds or a solvent regeneration unit. Required filtration system is simple and inexpensive. Compared with conventional techniques, membranes can offer a simple, easy-to-operate, low-maintenance process. Membrane process is simple, generally carried out at atmospheric conditions which, besides being energy efficient, can be important for sensitive applications in pharmaceutical and food industry. The recovery of components from a main stream using membranes can be done without substantial additional energy costs. Membrane is defined essentially as a barrier, which separates two phases and restricts transport of various chemicals in a selective manner. A membrane can be homogenous or heterogeneous, symmetric or asymmetric in structure, solid or liquid; can carry a positive or negative charge or be neutral or bipolar. Transport through a membrane can be affected by convection or by diffusion of individual molecules, induced by an electric field or concentration, pressure or temperature gradient. It takes place when a driving force is applied to the components in the feed. In most of the membrane processes, the driving force is a pressure difference or a concentration (or activity) difference across the membrane. Another driving force in membrane separations is the electrical potential difference. This driving force only influences the transport of charged particles or molecules. The hydrogen separation factor is sometimes used to specify membrane quality. It is defined as following: where ni stands for moles of species i transferred through the membrane and ?pi stands for the partial pressure difference of species i through the membrane. The membrane thickness may vary from as small as 10 microns to few hundred micrometers. Basic types of membranes are presented in Figure 4. Membranes in petrochemical industry are mainly used for concentration, purification and fractionation however they may be coupled to a chemical reaction to shift the chemical equilibrium in a combination defined as a membrane reactor. Using a membrane is adding costs to any process, therefore in order to overcome the cost issue another advantages must overcome the added expenses like material with a very good separation factor, high flux, high quality membrane materials (stable during many months of operation). In a membrane separation reactor both organic and inorganic membranes can be used. Many industrial catalytic processes involve the combination of high temperature and chemically harsh environments favouring therefore inorganic membranes due to their thermal stability, resistance to organic solvents, chlorine and other chemicals. Some promising applications using inorganic membranes include certain dehydrogenation, hydrogenation and oxidation reactions like formation of butane from dehydrogenation of ethyl benzene, styrene production from dehydrogenation of ethyl benzene, dehydrogenation of ethane to ethane, oxidative coupling of methane etc. In membrane reactor two basic concepts can be distinguished as can be seen in Figure 5. reaction and separation combined in one reactor (catalytic membrane reactor) reaction and separation are not combined and the reactants are recycled along a membrane system (membrane recycle reactor) Catalytic membrane reactor concept is used especially with inorganic membranes (ceramics, metals) and polymeric membranes where the catalyst is coupled to the membrane. Membrane recycle reactor can be applied with any membrane process and type of membranes. Most of the chemical reactions need catalyst to enhance the reaction kinetics. The catalyst must be combined with the membrane system and various arrangements are possible, as can be seen in Figure 6. The advantage of the catalyst located inside the bore of the tube is simplicity in preparation and operation. When needed the catalyst could be easily replaced. In case of top layer filled with catalyst and membrane wall, the catalyst is immobilized onto the membrane. Palladium has been known to be a highly hydrogen permeable and selective material since the 19th century. The existing Pd-based membranes can be mainly classified into two types according to the structure of the membrane as (i) self-supporting Pd-based membranes and (ii) composite structures composed of thin Pd-based layers on porous materials. Most self-supporting Pd-based membranes are commercially available in the forms that are easily integrated into a separation setup. However these membranes are relatively thick (50 mm or more) and therefore the hydrogen flux through them is limited. Thick palladium membranes are expensive and rather suitable for use in large scale chemical production. For practical use it is necessary to develop separation units with reduced thickness of the layer. An additional problem is that in order to have adequate mechanical strength, relatively thick porous supports have to be used. In the last decade a significant research has been carried out to achie ve higher fluxes by depositing thin layers of Pd or Pd alloys on porous supports like ceramics or stainless steel. A submicron thick and defect-free palladium-silver (Pd-Ag) alloy membrane was fabricated on a supportive microsieve by using microfabrication technique and tested by Tong et al[4]. The technique also allowed production of a robust wafer-scale membrane module which could be easily inserted into a membrane holder to have gas-tight connections to outside. Fabricated membrane had a great potential for hydrogen purification and in application like dehydrogenation industry. One membrane module was investigated for a period of ca. 1000 hours during which the membrane experienced a change in gas type and its concentration as well as temperature cycling between 20 – 450  °C. The measured results showed no significant reduction in flux or selectivity, suggesting thus very good membrane stability. The authors carried out experiments with varying hydrogen concentration in the feed from 18 to 83 kPa at 450  °C to determine the steps limiting H2 transport rate. It is assumed that the fabricated membrane may be used as a membrane reactor for dehydrogenation reactions to synthesize high value products although its use may be limited due to high pressures of tens of bars. Schematic drawing of the hydrogen separation setup is presented in Figure 7. The membrane module was placed in a stainless steel holder installed in a temperature controlled oven to ensure isothermal operation. The H2/He feed (from 300 to 100 ml/mol) was preheated in spirals placed in the same oven. The setup was running automatically for 24 h/day and could handle 100 recipes without user intervention. Tucho et al.[5] performed microstructural studies of self-supported Pd / 23 wt. % Ag hydrogen separation membranes subjected to different heat treatments (300/400/450  °C for 4 days) and then tested for hydrogen permeation. It was noted that changes in permeability were dependent on the treatment atmosphere and temperature as well as membrane thickness. At higher temperatures significant grain growth was observed and stress relaxation occurred. Nam et al.[6] were able to fabricate a highly stable palladium alloy composite membrane for hydrogen separation on a porous stainless steel support by the vacuum electrodeposition and laminating procedure. The membrane was manufactured without microstructural change therefore it was possible to obtain both high performance (above 3 months of operation) and physical and morphological stability of the membrane. It was observed that the composite membrane had a capability to separate hydrogen from gas mixture with complete hydrogen selectivity and could be used to produce ultra-pure hydrogen for applications in membrane reactor. Tanaka et al.[7] aimed at the improved thermal stability of mesoporous Pd-YSZ-g-Al2O3 composite membrane. The improved thermal stability allowed operation at elevated temperature (> 500  °C for 200 hours). This was probably the result of improved fracture toughness of YSZ-g-Al2O3 layer and matching thermal expansion coefficient between palladium and YSZ. Kuraoka, Zhao and Yazawa[8] demonstrated that pore-filled palladium glass composite membranes for hydrogen separation prepared by electroless plating technique have both higher hydrogen permeance, and better mechanical properties than unsupported Pd films. The same technique was applied by Paglieri et al.[9] for plating a layer of Pd and then copper onto porous ?-substrate. Zahedi et al.[10] developed a thin palladium membrane by depositing Pd onto a tungsten oxide WO3 modified porous stainless steel disc and reported that permeability measureme nts at 723, 773 and 823 K showed high permeability and selectivity for hydrogen. The membrane was stable with regards to hydrogen for about 25 days. Certain effort has been performed for improving hydrothermal stability and application to hydrogen separation membranes at high temperatures. Igi et al.[11] prepared a hydrogen separation microporous membranes with enhanced hydrothermal stability at 500  °C under a steam pressure of 300 kPa. Co-doped silica sol solutions with varying Co composition (Co / (Si + Co) from 10 to 50 mol. %) were prepared and used for manufacturing the membranes. The membranes showed increased hydrothermal stability and high selectivity and permeability towards hydrogen when compared with pure silica membranes. The Co-doped silica membranes with a Co composition of 33 mol. % showed the highest selectivity for hydrogen, with a H2 permeance of 4.00 x 10-6 (m3 (STP) Ãâ€" (m Ãâ€" s Ãâ€" kPa)-1) and a H2/N2 permeance ratio of 730. It was observed that as the Co composition increased as high as 33 %, the activation energy of hydrogen permeation decreased and the H2 permeance increased. Additional increase in Co concentration resulted in increased H2 activation energy and decreased H2 permeance. Due to high permselectivity of Pd membranes, high purity of hydrogen can be obtained directly from hydrogen containing mixture at high temperatures without further purification providing if sufficient pressure gradient is applied. Therefore it is possible to integrate the reforming reaction and the separation step in a single unit. A membrane reformer system is simpler, more compact and more efficient than the conventional PSA system (Pressure Swing Adsorption) because stem reforming reaction of hydrocarbon fuels and hydrogen separation process take place in a single reactor simultaneously and without a separate shift converter and a purification system. Gepert et al.[12] have aimed at development of heat-integrated compact membrane reformer for d ecentralized hydrogen production and worked on composite ceramic capillaries (made of ?-Al2O3) coated with thin palladium membranes for production of CO-free hydrogen for PEM fuel cells by alcohol reforming. The membranes were tested for pure hydrogen and N2 as well as for synthetic reformate gas. The process steps comprised the evaporation and overheating of the water/alcohol feed, water gas shift combined with highly selective hydrogen separation. The authors have focused on the step concerned with the membrane separation of hydrogen from the reforming mixture and on the challenges and requirements of that process. The challenges encountered with the development of capillary Pd membranes were as following: long term temperature and pressure cycling stability in a reformate gas atmosphere, the ability to withstand frequent heating up and cooling down to room temperature, avoidance of the formation of pin-holes during operation and the integration of the membranes into reactor housi ng. It was observed that palladium membranes should not be operated at temperatures below 300  °C and pressures lower than 20 bar, while the upper operating range is between 500 and 900  °C. Alloying the membrane with copper and silver extend their operating temperature down to a room temperature. The introduction of silver into palladium membrane increases the lifetime, but also the costs when compared with copper. Detailed procedure of membrane manufacturing, integration into reformer unit and testing is described by the authors. Schematic of the concept of the integrated reformer is shown in Figure 8. The membrane was integrated in a metal tube embedded in electrically heated copper plates. Before entering the test tube, the gases were preheated to avoid local cooling of the membrane. Single gas measurements with pure N2 and H2 allowed the testing of the general performance of the membrane and the permselectivity for the respective gases to be reached. Synthetic reformate gas consisting of 75 % H2, 23.5 % CO2 and 1.5 % CO was used to get information about the performance. The membranes were tested between 370 – 450  °C and pressures up to 8 bar. The authors concluded that in general the membranes have shown good performance in terms of permeance and permselectivity including operation under reformate gas conditions. However, several problems were indicated concerning long-term stability under real reforming conditions, mainly related to structural nature (combination of different materials: ceramic, glaze, palladium resulted on incoherent potential for causing membrane failure). At operation times up to four weeks the continuous Pd layer remained essentially free from defects and pinholes. Han et al.[13] have developed a membrane separation module for a power equivalent of 10 kWel. A palladium membrane containing 40 wt. % copper and of 25 mm thickness was bonded into a metal frame. The separation module for a capacity of 10 Nm3 h-1 of hydrogen had a diameter of 10.8 cm and a length of 56 cm. Reformate fed to the modules contained 65 vol. % of hydrogen and the hydrogen recovery through the membrane was in the range of 75 %. Stable operation of the membrane separation was achieved for 750 pressure swing tests at 350  °C. The membrane separation device was integrated into a methanol fuel processor. Pientka et al.[14] have utilized a closed-cell polystyrene foam (Ursa XPS NIII, porosity 97 %) as a membrane buffer for separation of (bio)hydrogen. In the foam the cell walls formed a structured complex of membranes. The cells served as pressure containers of separated gases. The foam membrane was able to buffer the difference between the feed injection rate and the rate of consumption of the product. Using the difference in time-lags of different gases in polymeric foam, efficient gas separation was achieved during transient state and high purity hydrogen was obtained. Argonne National Laboratory (ANL) is involved in developing dense hydrogen-permeable membranes for separating hydrogen from mixed gases, particularly product streams during coal gasification and/or methane reforming. Novel cermet (ceramic-metal composite) membranes have been developed. Hydrogen separation with these membranes is non-galvanic (does not use electrodes or external power supply to drive the separation and hydrogen selectivity is nearly 100 % because the membrane contain no interconnected porosity). The membrane development at ANL initially concentrated on a mixed proton/electron conductor based on BaCe0.8Y0.2O3-d (BCY), but it turned to be insufficient to allow high non-galvanic hydrogen flux. To increase the electronic conductivity and thereby to increase the hydrogen flux the development focused on various cermet membranes with 40-50 vol. % of metal or alloy dispersed in the ceramic matrix. Balachandran et al.[15],[16] described the development performed at ANL. The powder mixture for fabricating cermet membranes was prepared by mechanical mixing Pd (50 vol. %) with YSZ, after that the powder mixture was pressed into discs. Polished cermet membranes were affixed to one end of alumina tube using a gold casket for a seal (as can be seen in Figure 9). In order to measure the hydrogen permeation rate, the alumina tube was inserted into a furnace with a sealed membrane and the associated gas flow tubes. Hydrogen permeation rate for Pd/YSZ membranes has been measured as a function of temperature (500-900  °C), partial pressure of hydrogen in the feed stream (0.04-1.0 atm.) and membrane thickness ( » 22-210 mm) as well as versus time during exposure to feed gases containing H2, CO, CO2, CH4 and H2S. The highest hydrogen flux was  » 20.0 cm3 (STP)/min cm2 for  » 22- mm thick membrane at 900  °C using 100 % hydrogen as the feed gas. These results suggested that membranes with thickness In the last decade Matrimid 5218 (Polyimide of 3,3,4,4-benzophenone tetracarboxylic dianhydride and diamino-phenylindane) has attracted a lot of attention as a material for gas separation membranes due to the combination of relatively high gas permeability coefficients and separation factors combined with excellent mechanical properties, solubility in non-hazard organic solvents and commercial availability. Shishatskiy et al.[18] have developed asymmetric flat sheet membranes for hydrogen separation from its mixtures with other gases. The composition and conditions of membrane preparation were optimized for pilot scale membrane production. The resulting membrane had a high hydrogen flux (1 m3 (STP)/m2h*bar) and selectivity of H2/CH4 at least 100, close to the selectivity of Matrimid 5218, material used for asymmetric structure formation. The hydrogen flux through the membranes increased with the decrease of polymer concentration and increase of non-solvent concentration. In addition, the influence of N2 blowing over the membrane surface (0, 2, 3, 4 Nm3 h-1 flow rate) was studied and it was proved that the selectivity of the membrane decreased with increase of the gas flow. The SEM image of the membrane supported by Matrimid 5218 is shown in Figure 10. The stability against hydrocarbons was tested by immersion of the membrane into the mixture of n-pentane/n-hexane/toluene in 1:1:1 ratio. Stability tests showed that the developed membrane was stable against mixtures of liquid hydrocarbons and could withstand continuous heating up to 200  °C for 24 and 120 hours and did not lose gas separation properties after exposure to a mixture of liquid hydrocarbons. The polyester non-woven fabric used as a support for the asymmetric membrane gave to the membrane excellent mechanical properties and allowed to use the membrane in gas separation modules. Interesting report on development of compact hydrogen separation module called MOC (Membrane On Catalyst) with structured Ni-based catalyst for use in the membrane reactor was presented by Kurokawa et al[19]. In the MOC concept a porous support itself had a function of reforming catalyst in addition to the role of membrane support. The integrated structure of support and catalyst made the membrane reformer more compact because the separate catalysts placed around the membrane modules in the conventional membrane reformers could be eliminated. In that idea first a porous catalytic structure 8YSZ (mixture of NiO and 8 mol. % Y2O3-ZrO2 at the weight ratio 60:40) was prepared as the support structure of the hydrogen membrane. The mixture was pressed into a tube closed at one end and sintered then in air. Slurry of 8YSZ was coated on the external surface of the porous support and heat-treated for alloying. Obtained module of size 10 mm outside and 8 mm inside diameter, 100 ~ 300 mm length and the membrane thickness was 7 ~ 20 mm were heated in flowing hydrogen at 600  °C for 3 hours to reduce NiO in the support structure into Ni before use (the porosity of the support after reduction was 43 %). A stainless steel cap and pipe were bonded to the module to introduce H2 into the inside of the tubular module. Figure 11 presents the conceptual structure design of the MOC module as compared with the structure of the conventional membrane reformer. The sample module in the reaction chamber was placed in the furnace and heated at 600  °C, pre-heated hydrogen (or humidified methane) was supplied inside MOC at the pressure of 0.1 MPa and the permeated hydrogen was collected from the outside chamber around the module at ambient pressure. The 100 ~ 300 mm long modules with 10 mm membrane showed hydrogen flux of 30 cm3 per minute per cm2 which was two times higher than the permeability of the conventional modules with palladium based alloy films. Membrane On Catalyst modules have a great potential to be applied to membrane reformer systems. In this concept a porous support itself has a function of reforming catalyst in addition to the role of membrane support. It seems that Membrane On Catalyst modules have a great potential to be applied to membrane reformer systems. Amorphous alloy membranes composed primarily of Ni and early transition metals (ETM) are an inexpensive alternative to Pd-based alloy membranes, and these materials are therefore of particular interest for the large-scale production of hydrogen from carbon-based fuels. Catalytic membrane reactors can produce hydrogen directly from coal-derived synthesis gas at 400 °C, by combining a commercial water-gas shift (WGS) catalyst with a hydrogen-selective membrane. Three main classes of membrane are capable of operating at the high temperatures demanded by existing WGS catalysts: ceramic membranes producing pure hydrogen via ion-transfer mechanism at  ³ 600  °C, alloy membranes which produce pure hydrogen via a solution-diffusion mechanism between 300 – 500  °C and microporous membranes, typically silica or carbon, whose purity depends on the pore size of the membrane and which operate over a wide temperature range dependent on the membrane material. In order to explore the suitability of Ni-based amorphous alloys for this application, the thermal stability and hydrogen permeation characteristics of Ni-ETM amorphous alloy membranes has been examined by Dolan et al[20]. Fundamental limitation of these materials is that hydrogen permeability is inversely proportional to the thermal stability of the alloy. Alloy design is therefore a compromise between hydrogen production rate and durability. Amorphous Ni60Nb(40-x)Zr(x) membranes have been tested at 400 °C in pure hydrogen, and in simulated coal-derived gas streams with high steam, CO and CO2 levels, without severe degradation or corrosion-induced failure. The authors have concluded that Ni-Nb-Zr amorphous alloys are therefore prospective materials for use in a catalytic membrane reactor for coal-derived syngas. Much attention has been given to inorganic materials such as zeolite, silica, zirconia and titania for development of gas- and liquid- separation membranes because they can be utilized under har sh conditions where organic polymer membranes cannot be applied. Silica membranes have been studied extensively for the preparation of various kinds of separation membranes: hydrogen, CO2 and C3 isomers. Kanezeashi[21] have proposed silica networks using an organo-inorganic hybrid alkoxide structure containing the organic groups between two silicon atoms, such as bis(triethoxysilyl)ethane (BTESE) for development of highly permeable hydrogen separation membranes with hydrothermal stability. The concept for improvement of hydrogen permeability of silica membrane was to design a loose-organic-inorganic hybrid silica network using mentioned BTESE (to shift the silica networks to a larger pore size for an increase in H2 permeability). A hybrid silica layer was prepared by coating a silica-zirconia intermediate layer with a BTESE polymer sol followed by drying and calcination at 300 °C in nitrogen. A thin, continuous separation layer of hybrid silica for selective H2 permeation was observed on top of the SiO2-ZrO2 intermediate layer as presented in Figure 12. Hybrid silica membranes showed a very high H2 permeance, ~ 1 order of magnitude higher (~ 10-5 mol m-2 s-1 Pa-1) than previously r eported silica membranes using TEOS (Tetraethoxysilane). The hydrothermal stability of the hybrid silica membranes due to the presence of Si-C-C-Si bonds in the silica networks was also confirmed. Nitodas et al.[22] for the development of composite silica membranes have used the method of chemical vapour deposition (CVD) in the counter current configuration from TEOS and ozone mixtures. The experiments were conducted in a horizontal hot-wall CVD quartz reactor (Figure 13) under controlled temperature conditions (523 – 543 K) and at various reaction times (0 -15 hours) and differential pressures across the substrate sides using two types of substrates: a porous Vycor tube and alumina (g-Al2O3) nanofiltration (NF) tube. The permeance of hydrogen and other gases (He, N2, Ar, CO2) were measured in a home-made apparatus (able to operate under high vacuum conditions 10-3 Torr, feed pressure up to 70 bar) and the separation capability of the composite membranes was determined by calculating the selectivity of hydrogen over He, N2, Ar, CO2. The in-situ monitoring of gas permeance during the CVD development of nanoporous membranes created a tool to detect pore size alterations i n the micro to nanometer scale of thickness. The highest permeance values in both modified and unmodified membranes are observed for H2 and the lowest for CO2. This indicated that the developed membranes were ideal candidates for H2/CO2 separations, like for example in reforming units of natural gas and biogas (H2/CO2/CO/CH4). Moon et al.[23] have studied the separation characteristics and dynamics of hydrogen mixture produced from natural gas reformer on tubular type methyltriethoxysilane (MTES) silica / ?-alumina composite membranes. The permeation and separation of CO pure gas, H2/CO (50/50 vol. %) binary mixture and H2/CH4/CO/CO2 (69/3/2/26 vol. %) quaternary mixture was investigated. The authors developed a membrane process suitable for separating H2 from CO and other reformate gases (CO2 or CH4) that showed a molecular sieving effect. Since the permeance of pure CO on the MTES membrane was very low (CO  » 4.79 – 6.46 x 10-11 mol m-2 s-1 Pa-1), comparatively high hydrogen selectivity could be obtained from the H2/CO mixture (separation factor: 93 – 110). This meant that CO (which shall be eliminated before entering fuel cell) can be separated from hydrogen mixtures using MTES membranes. The permeance of the hydrogen quaternary mixture on MTES membrane was 2.07 – 3.37 x 10-9 mol m-2 s-1 Pa-1 and the separation factor of H2 / (CO + CH4 + CO2) was 2.61 – 10.33 at 323 – 473 K (Figure 14). The permeation and selectivity of hydrogen were increased with temperature because of activation of H2 molecules and unfavourable conditions for CO2 adsorption. Compared to other impurities, CO was most successfully removed from the H2 mixture. The MTES membranes showed great potential for hydrogen separation from reforming gas with high selectivity and high permeance and therefore they have good potential for fuel cell systems and for use in hydrogen stations. According to the authors, the silica membranes are expected to be used for separating hydrogen in reforming environment at high temperatures. Silica membranes prepared by the CVD or sol-gel methods on mesoporous support are effective for selective hydrogen permeation, however it is known that hydrogen-selective silica materials are not thermally stable at high temperatures. Most researchers reported a loss of permeability of silica membranes even 50 % or greater in the first 12 hours on exposure to moisture at high temperature. Much effort has been spent on the improvement of the stability of silica membranes. Gu et al.[24] have investigated a hydrothermally stable and hydrogen-selective membrane composed of silica and alumina prepared on a macroporous alumina support by CVD in an inert atmosphere at high temperature. Before the deposition of the silica-alumina composite multiple graded layers of alumina were coated on the alumina support with three sols of decreasing particle sizes. The resulting supported composite silica-alumina membrane had high permeability for hydrogen (in the order of 10-7 mol m-2 s-1 Pa-1) at 873 K . Significantly the composite membrane exhibited much higher stability to water vapour at the high temperature of 873 K in comparison to pure silica membranes. The introduction of alumina into silica made the silica structure more stable and slowed down the silica disintegration process. As mentioned, silica membranes produced by sol-gel technique or by CVD applied for gas separation, especially for H2 production are quite stable in dry gases and exhibit high separation ratio, but lose the permeability when used in the steamed gases because of sintering or tightening. Thi

Does watching too much television have an impact on behavior Essay

It is very evident that television plays a tremendous role in the society we live in. It can spark imagination, creativity, even take a person out of reality and put them into an imaginary world. Television keeps you informed with news and current events going on around the world, it can take you to unknown places that a person otherwise would never be able to visit, it provides access to the arts, even music and so much more. Although most people look at television as an entertaining and educational way to spend time, some people think there is too much violence in television and that is influencing young members of society into becoming aggressive in nature and learn tolerate violence. Can extensive watching of television cause a significant negative impact on the behavior of the youth today? TV can play a very important role in shaping a person attitude, and behavior but can all TV programs have a negative impact on behavior? Let’s take a look at some of the statistics of television for us to understand a little more about why TV is blamed for bad behavior in youth and adults. According to Nationmaster. com 98. 5 percent of homes in the United States have at least one TV with ninety percent having at least two televisions and eighty-seven percent of homes have at the least a DVD player or VCR. (Nationmaster) With so many homes having TV’s, television has become a debatable issue as many researchers and psychologist question the influence of programs on the attitudes and behavior of today’s youth. According to psychological researches done on youths, violence on television can have a negative impact on the youth. It is estimated that by the time a child starts high school that child will have viewed 8,000 to 10,000 acts of violence whether it be from watching cartoons or a drama crime show. (Villani) Children, who are allowed to view programs in which the violence is very realistic, are more likely to try to imitate what they see on the show. Children that already have emotional, behavioral or control problems may be even more heavily influenced than a child that does not have the emotional ties. Young children and young adults can even be affected by what they are watching even when they have a stable family atmosphere that shows no tendency towards violence. A Study done in October of 2007 showed that out of 3,205 children between the ages of eight and sixteen who watched more than two hours of television in a twenty-four hour period was associated with problems with aggressive behavior towards family and peers. â€Å"Most of the scientific evidence†¦ reveals a relationship between television and aggressive behavior. While few would say that there is absolute proof that watching television caused aggressive behavior, the overall cumulative weight of all the studies gives credence to the position that they are related. â€Å"Essentially, television violence is one of the things that may lead to aggressive, antisocial, or criminal behavior. † (Signorielli) Television is not the only factor in causing aggression among today’s youth, there are many factors. However, television is one of the greatest factors that can cause aggressive behavior in children. This is especially evident in the U. S.  Many criminals confess that their violent actions or attitudes were encouraged by TV. This is becoming a great problem of our society as the rate of criminal behavior is constantly growing. With so much crime being showed on television, it can negatively affect children’s attitude towards school, lifestyle, career, family, and even their future. Television programs should be monitored by parents and limited to the amount of time spent watching TV that does have crime related scenes. Parents should also explain to the child that the violence they see on television is not real and what the consequences would be if it were real.

System of Linear Equation

SYSTEM OF LINEAR EQUATIONS IN TWO VARIABLES Solve the following systems: 1. ? ? x ? y ? 8 ? x ? y ? 2 by graphing by substitution by elimination by Cramer’s rule 2. ? ?2 x ? 5 y ? 9 ? 0 ? x ? 3y ? 1 ? 0 by graphing by substitution by elimination by Cramer’s rule 3. ? ?4 x ? 5 y ? 7 ? 0 ? 2 x ? 3 y ? 11 ? 0 by graphing by substitution by elimination by Cramer’s rule CASE 1: intersecting lines independent & consistent m1? m2 CASE 2: parallel lines inconsistent m1 = m2 ; b1 ? b2 CASE 3: coinciding lines consistent & dependent m1 = m2 ; b1 = b2 Classify the following system, whether (a) intersecting, (b) parallel, or (c) coinciding lines 1. ? ? 3 x ? 4 y ? 1 ? 0 ? 3 x ? 4 y ? 2 ? 0 ? 3 x ? 4 y ? 1 ? 0 ? 6 x ? 8 y ? 2 ? 0 Solve the following systems in three variables: 1. ?3 x ? 4 y ? z ? 1 2. ? x ? y ? 2 ? ? x ? 4 y ? 3z ? 3 ? 3 x ? 2 y ? 2 z ? 0 ? ________ ? ? 3 y ? z ? 1 ? x ? 2 z ? 7 ? 2. ? ________ 3. ? ?2 x ? 5 y ? 1 ? 0 ? 5 ? x ? 2 y ? 2 ? 0 ? ?2 x ? ? 1 ? 4 x ? 2 y ? 3 ? x ? 2 y ? 1 ? 0 ? 2 x ? y ? 1 ________ 4. ? ________ 5. ? ________ ?1 ? x ? ? Solve ? ?1 ? ?x ? 2 ? 3 y 3 ? 2 y Problem solving Form a system of equations from the problems given below. A) (MIXTURE PROBLEM 1) How many pounds of a 35% salt solution and a 14% salt solution should be combined so that a 50 pounds of a 20% solution is obtained? B) (UNIFORM MOTION) Two motorists start at the same time from two places 128 km apart and drive toward each other. One drives 10kph than the other. If they met after 48 minutes (that is, 4/5 hr), find the average speed of each. C) A dietician is preparing a meal consisting of foods A, B, and C as shown in the table below. Fat Protein Carbohydrate If the meal must provide exactly 24 units of fat, 25 Food A 3 2 4 units of protein, and 21 units of carbohydrate, how Food B 2 3 1 many ounces of each food should be used? Food C 3 3 2

Free Essays on Reconstruction Era 1865-1900

The Reconstruction Era was a very trying time for America. The country just ended the long deliberated, destructive civil war, leaving the south in utter ruins. The land that was previously used so prevalently with plantations was now almost unusable. Also the majority of the work force, namely the former slaves, no longer worked in such large numbers and for no pay. The Reconstruction Era was centered on rebuilding the south as well as finding a place for the newly freed slaves. There were countless ideas on how the country should treat the south but two main plans that went into play, Lincoln’s Plan and Johnson’s Plan. Lincoln’s Plan was started before the official end to the war. He first purposed the ten percent plan in which a full pardon would be given to any confederate soldier who would uphold the values of the constitution, and recognize any state where ten percent of the population vote to create a government which abolishes slavery. This plan did not go well with the radical republicans who wanted the south to pay for causing the north to go through complete hell. They also believed that if the south were treated to leniently they would just restore their previous power and cause more turmoil. Due to this belief congress tried to pass the Wade-Davis Bill, where fifty percent of voters had to take an "ironclad" oath that they had never voluntarily supported the Confederacy, Lincoln vetoed this bill. Lincoln started on his own plan but the states that went along were not accepted by congress and were not allowed to take a seat in the senate or the house. Before anything could get accomplished Lincoln was assassinated and Johnson became our new president. The next set of reconstruction plans put into action were instilled by the successor to Lincoln, Johnson. Johnson, largely because he was a southern senator and didn’t want the radical republicans to be negative toward him from the start, attacked the arist... Free Essays on Reconstruction Era 1865-1900 Free Essays on Reconstruction Era 1865-1900 The Reconstruction Era was a very trying time for America. The country just ended the long deliberated, destructive civil war, leaving the south in utter ruins. The land that was previously used so prevalently with plantations was now almost unusable. Also the majority of the work force, namely the former slaves, no longer worked in such large numbers and for no pay. The Reconstruction Era was centered on rebuilding the south as well as finding a place for the newly freed slaves. There were countless ideas on how the country should treat the south but two main plans that went into play, Lincoln’s Plan and Johnson’s Plan. Lincoln’s Plan was started before the official end to the war. He first purposed the ten percent plan in which a full pardon would be given to any confederate soldier who would uphold the values of the constitution, and recognize any state where ten percent of the population vote to create a government which abolishes slavery. This plan did not go well with the radical republicans who wanted the south to pay for causing the north to go through complete hell. They also believed that if the south were treated to leniently they would just restore their previous power and cause more turmoil. Due to this belief congress tried to pass the Wade-Davis Bill, where fifty percent of voters had to take an "ironclad" oath that they had never voluntarily supported the Confederacy, Lincoln vetoed this bill. Lincoln started on his own plan but the states that went along were not accepted by congress and were not allowed to take a seat in the senate or the house. Before anything could get accomplished Lincoln was assassinated and Johnson became our new president. The next set of reconstruction plans put into action were instilled by the successor to Lincoln, Johnson. Johnson, largely because he was a southern senator and didn’t want the radical republicans to be negative toward him from the start, attacked the arist...

5 Anthropology Essay Topics Interesting Topics to Write about Modern Humans

5 Anthropology Essay Topics Interesting Topics to Write about Modern Humans Neanderthals have always fascinated the imagination of anthropologists and people interested in the history of human race in general – after all, our ancient cousins are the closest thing to another sentient species we’ve managed to discover so far. The fact that there were two closely related yet distinctly different human subspecies on our planet breeds all kinds of questions. What were they like? What was their psychology? Did they have a language? Why did they go extinct? However, although it was a century and a half since the discovery of the Neanderthals, we know precious little about them. Here we have gathered some facts about Neanderthals that you may find interesting and useful for writing your own anthropology essay. Neanderthal Genes Live on in Modern Humans For a long while the general consensus was that anatomically modern humans and Neanderthals did not interbreed at all. However, a number of more recent researches suggest that this was not the case, and most modern non-Africans inherited about 1-3 percent of their genes from Neanderthals, with Asians showing a somewhat higher percentage than Europeans do. Geographically Neanderthals lived across Eurasia, which explains why people of African descent don’t show any traces of their genes. An intriguing fact is that there is little to no Neanderthal DNA on X chromosome, which suggests that biological compatibility between Neanderthals and our human ancestors was extremely weak, and the majority of male hybrids turned out to be sterile. As a result, most of Neanderthal genes were passed through females. Neanderthals Had Bigger Brains Than We Do Contrary to popular belief, cranial capacity of Neanderthals was considerably higher than that of modern humans: 1600 cm3 vs. 1400 cm3 on average. It stands to reason: Neanderthals lived in higher latitudes than anatomically modern humans originally did, and as a result were more massive in general and higher of stature, which usually leads to larger brain size. A question now arises: why did a biologically close species with larger brain capacity and, supposedly greater brain power, go extinct, while we go on? There is no clear-cut answer to this question, but some studies suggest that Neanderthals had to dedicate a much greater percentage of their brain power to controlling their bodies and their vision than we do. In other words, anatomically modern humans and Neanderthals evolved from a common ancestor but their brains evolved along two different trajectories. Neanderthals developed their somatic and visual regions (mostly dealing with body maintenance and visual perception) while AMHs mostly developed other parts of their brain. The most notable of these other parts is parietal lobe, responsible, among other things, for language processing – a crucial ability for long-term development. Neanderthals Most Likely Had a Language For quite some time the prevalent opinion was that Neanderthals were incapable of language and the array of sounds they could articulate was limited to a relatively poor set of guttural grunts. However, this theory became much less popular after the discovery of a Neanderthal hyoid bone in 1983. Hyoid bone is a small bone that connects the muscles of the larynx and the tongue, and more or less makes speech possible. It turned out that not only did Neanderthals have it, but it was also almost identical to the hyoid bone of modern human. In addition to that, recent studies of Neanderthal DNA shows that they possessed the same variant of FOXP2 gene, which is known to have been extremely important for the formation of language. Moreover, many artifacts left by Neanderthals show the degree of sophistication that would have made learning how to create and use them rather difficult without the assistance of some kind of language. It also pays to remember that they lived in extremely harsh conditions: Neanderthals inhabited colder regions of the planet in the times when climate was much colder than it is now in general, were surrounded by dangerous predators many times larger than themselves, and were capable of bringing down an occasional mammoth with nothing more than sharpened sticks and stones. All this requires a level of cooperation that is impossible without a language, although we are extremely unlikely to ever find out what it was like. Human and Neanderthal Genomes are almost 98.8% Similar Neanderthals and AMHs shared a common ancestor, so it is hardly surprising that they were rather similar genetically. However, this small difference was in a number of very important genes. The main difference lies in that Neanderthals lacked some genes connected with behaviors that are present in AMHs. And the reason why our ancestors were better at survival probably lies exactly there. Neanderthals made an emphasis on individual survival and initially their larger size and stronger muscles did the trick. However, they hardly developed socially, while AMHs traded larger size and better eyesight for improved cognitive power, which led to increased ability to work as a social entity and interact between each other. The fact that Neanderthal tools changed very little over the course of hundreds of thousands of years shows that they were resistant to change and innovation. Also, they were lactose-intolerant and lacked genes that in modern humans are associated with hyperactivity, aggression and syndromes like Autism. Neanderthals were not All That Different When all is said and done, Neanderthals, despite a number of notable differences, were still pretty similar to AMHs. There is evidence that they lived in complex social groups, made tools, were able to make fire, built shelters, wore jewelry, produced cave paintings, nursed their sick and wounded back to health, buried their dead, were capable of language and probably could appreciate music and singing. In their case the fact that a species that was isolated from Homo Sapiens for such a long time and developed by itself has so much in common with us socially is possibly even more mystifying than if they were absolutely different. Neanderthals went extinct about 30,000 years ago, and all that is left of them are a few bones and tools. Yet they are an important part of our history and heritage – and an extremely interesting and mysterious part at that. That’s why it’s a perfect pool of topics for your anthropology essay! References: 1. Schwartz JH, Tattersall I (1996) Toward distinguishing Homo neanderthalensis from Homo sapiens and vice versa. Anthropologie (Brno). 2. Tattersall I (1995) The Last Neanderthal. The Rise, Success and Mysterious Extinction of Our Closest Human Relatives. New York: Macmillan. 3. Schwartz JH, Tattersall I (1996) Significance of some previously unrecognized apomorphies in the nasal region of Homo neanderthalensis. Proc Natl Acad Sci USA. 4. Stringer CB, Hublin JJ, Vandermeersch B (1984) The origin of anatomically modern humans in western Europe. In Smith FH, Spencer F (eds): The Origins of Modem Humans: A World Survey of the Fossil Evidence. New York: Liss. 5. Coon CS (1962) The Origin of Races. New York: Knopf. 6. Krings M, Stone A, Schmitz RW, Krainitzki H, Stoneking M, Pabo S (1997) Neandertal DNA sequences and the origin of modern humans. 7. Tattersall I (1998) Neanderthal genes: What do they mean? Evol Anthropol.

International personality Assignment Example | Topics and Well Written Essays - 500 words

International personality - Assignment Example a lady, and the challenges she experienced as a young black girl in her upbringing have really contributed to the kind heart that Oprah Winfrey exhibits (Hanson, 2009). At her talk show, Oprah Winfrey addresses very many challenges, especially social, that affect either a huge population or a selected minority. The direct effects of the show on various people can be said to be overwhelming. This is because Oprah Winfrey is surrounded by a team of in-house experts, or guest experts, in various fields who normally provide their expert advice or understanding of the issues at hand. According to Garson (2011), as a successful entrepreneur, Oprah Winfrey has not left out the community that is needy. Her various acts of kindness has left no option but for her to be tagged as a philanthropist. She has been involved in several charity programs, as well as in the general commitment to raising the values of living for the less-fortunate in the community and the world over. Berkley and Economy (2008) say that her influence and success has impacted positively to the citizens all over the world thus making her one happy woman who is so much admired. While reading the articles about Oprah Winfrey, they really encourage someone and despite several cultural inclinations, it encourages someone and gives them hope .They show one that success is something that is brewed and it normally comes with several responsibilities. These responsibilities are normally a way that someone uses to bless the community around them. This human right is not limited to any extent, as long as the right does not infringe on the people’s rights. In any liberal country, the citizens of that nation practice freedom of speech in a manner that is indulgent. This means that they can talk about sensitive issues even the ones that touch directly on the government and even the powerful people. The freedom of speech in these liberal and democratic nations cannot pause as a security threat to the ones