Tuesday, October 29, 2019

Edit Essay Example | Topics and Well Written Essays - 250 words - 6

Edit - Essay Example The main challenge of managing more flourishing and a stable economy in Qatar is that most of the citizens living in this region are foreigners who usually come because of employment related businesses. It is important to note that Qatar has an overall population of about 1.8 million people, whereby 1.5 million of them are expatriates (QFINANCE, 2013). Therefore, the government has been forced to rely mainly on oil and gas in meeting its budget needs. In order for the Qatar government to maintain a healthy and a stable economy in the future, it ought to expand revenue sources, utilize its assets to hedge against instability and create a legacy for the future in by measures mentioned below. Firstly, the government needs to apply a tax on water and electricity as part of expanding its revenue sources. In this case all the households should pay a given fraction of tax to the state so that it can continue sustaining provision of the water and electricity to the people of Qatar. The revenue raised from the water and electricity will be useful in maintaining and expanding the country’s national power grid in the future to cater for the growing demand for electricity from investors in the recent years (QFINANCE, 2013). Additionally, given Qatar is a desert country the taxes on water will be critical in digging more boreholes. This idea will in turn improve the national water supply with an end goal of handling the increasing demand for water used for domestic and commercial purposes. Secondly, the government needs to lease its land for 99 years whereby those who rent the land will be expected to pay a certain percentage of annual rates to the government. It is important to note that the government will be leasing land to expatriates who plans to use the land for various economic activities. Given that currently most of the land in Qatar is not leased to any expatriate, renting the

Sunday, October 27, 2019

Analysis of S-d Exchange Interactions in Dilute Cu-mn Alloys

Analysis of S-d Exchange Interactions in Dilute Cu-mn Alloys Phenomenological analysis of the s-d exchange interactions in dilute Cu-Mn alloys at helium temperatures AL-Jalali, M. A. Abstract: The S-d exchange interactions in dilute Cu-Mn alloys was studied on concentration ( C ) varying between 10.5 and 2081.8 ppm of Mn in Cu within the ( 0.03K – 4.2K ) temperature range. Using electrical resistivity data on those alloys, the s-d exchange integral ( Jsd ), which is negative, has calculated to show a clear dependence on (Ln C). This dependence, confirming thus the dominance of Kondo effect below 1000 ppm impurity concentration, but above this concentration, we expected an interference between Kondo effect and spin glass regime, which mean that spin glass regime has to prevail more than Kondo effect. Keywords: s-d interaction; electrical resistivity; Jsd; Kondo effect; spin glass. PACS: 75: 50, 75:10, 75: 40, 75: 30. Introduction The main objective of this paper is to study the huge effects on the coupling between the dilute magnetic impurities (Mn), which gives rise to the formation of local magnetic moments, and the conduction electrons from the host noble metal (Cu). Electrical resistivity is a great source of information, especially to get the values of the s-d exchange integral Jsd . For a very dilute alloys (concentration below 100 ppm of Mn), the low-temperature resistivity is dominated by an anomalous Kondo scattering of the conduction electron spin at the local magnetic moments. A typical logarithmic divergence of the resistivity will begin above the Kondo’s temperature( TK ) until the minimum in the resistivity of Cu-Mn Kondo alloys, where higher temperatures is prevailed, and when the magnetic impurity concentration Increasing until ( 1 at. %), the interaction between the local magnetic moments and conduction electrons ,which is governed by the Ruderman-Kittel-Kasuya-Yosida (RKKY)[ 1,2,3] interaction will form a spin-glass phase [4]. The method, I have used, to calculate Jsd was the analysis of crude experimental data and by simi-emperical simple calculating, I found that the Jsd decreases logarithmically with concentration and gives a very important information about competition between Kondo effect and spin glass regime[5], which need a deeper study in the future. Theoretical background The introduction of few ppm of 3d or 4f magnetic impurity in a non-magnetic matrix leads to an s – d exchange interaction between the spins of the conduction electrons Se and the Localized magnetic moment Sd of the transition element, which can be described by a Hamiltonian: Where (Jsd) is the exchange coupling parameter, and is any ordinary scattering from the ion carrying the local moment. With a negative Jsd, the interaction leads to an increase of localized spin disorder resistivity with decreasing temperature. The competition between the spin disorder scattering and the phonon exhibits the minimum in the resistivity of this regime [6, 7, 8, 9]. Phenomenologically; the above competition is mainly manifested at low temperatures in the form: Where the spin scattering resistivity, and, ( EF =the Fermi energy),(Z=number of conduction electrons per atom). In this work, I endeavour to show the behaviour of Jsd in some Cu – Mn alloys, despite the fact that there is the bulk of information has been put forward on these alloys during and after the 1980s, the electrical resistivity one of many sources to provide a powerful means to trace the s – d exchange interaction dominating these alloys. Analysis of data Matula and others reported crude data [10, 11, 12] on electrical resistivity and methods of manufacturing of alloys, especially in respect of purity, constituting the major experimental background in this work. They come from direct measurements already carried on Cu – Mn alloys (and many others noble –transition metals alloys) with concentrations ranging from 10.5 ppm to 2081.3 ppm of Mn in Cu within the ( 0.03 – 4.2K ) range [ 11, 12,13 ]. Figure (1) scales versus Ln (T/c) give us by suit fitting an expression like a logarithm of power series solution: The first two terms (first- order approximation) show a bold line at figure (1), where pure magnetic resistivity could be defined from that lines as a function of ( LnT), and by using a fitting’s programming we can find from the ones of the bold lines a relation as following (figure(2)) :- This matches with Hamann’s expression [13, 14, 15, and 16]: Tk =Kondo temperature Figure (2) expresses exactly what a compatible between experimental relation (4) and theoretical Hamann’s expression (5) there are. Definitely, allowing the inclusion of potential scattering effect with single impurity kondo effect, and sharp determination of kondo temperature Tk = 36 mK. Calculated values of Jsd reveal a variation: (C is Mns concentration in ppm units), as it has shown in figure (3). Expression ( 6 ) was calculated according to a width of internal field distribution [ 12,16 ] at Tmax ( characterize the maximum value of the resistivity at figure(1): (7) Results and discussion As it is shown in figure ( 3 ), above 850 ppm, our calculation to Jsd leads, just as other works do [12,17 , 18 , 19, 20 ] to believe that magnetic transformation takes place from antiferromagnetic to ferromagnetic state and between 860 ppm and 2000 ppm may be a spin glass regime starts to prevail. When we come back to Kondo’s temperature at Hamann’s expression (5), it is most appropriately to denote that the Kondo’s temperature given as [21]: Where, initially, TF =8.12 104 k, and n (EF) =0.294 ev-1. It seems that Tk is not constant as we noted above, and is not consistent with [22], And has clear dependence on Jsd . Of course, we need more studying to pursue this point. Finally, as a [instead of] conclusion [put [(Result)], and from figure (3), we can classify a Kondo’s regime in respect of concentration as following: pure kondo regime vanishes at concentration 63 ppm of magnetic impurity (Mn) . Mixed regime ( kondo + SG ) from 63 ppm to 860 ppm. Ideal spin glass from 860 ppm to about 1%. Conclusion When we increase the concentration of magnetic impurity, The s-d exchange interactions will move to RKKY interactions, where Jsd will represent a phenomenological order parameter, which reflects a shift of interactions between conduction electrons and localized magnetic moments and discovers the new magnetic transformation from a regime to be other. 1

Friday, October 25, 2019

Gestational Diabetes Essay example -- Health, Diseases

Along with all the worries and complications a woman might face while pregnant, one of the more serious conditions is gestational diabetes. Gestational diabetes occurs in 4% of all pregnancies (Seibel, 2009). Many women are not informed about the disease, some may not know that they need to be tested, and others may have heard about it, but want more information on what may cause it and/or how to prevent and treat it. Either way this disease needs to be taken seriously by every pregnant woman or woman planning to get pregnant to protect not only herself but the unborn child. Gestational diabetes is a disorder characterized by impaired ability to metabolize carbohydrates, usually caused by a deficiency of insulin resistance, occurring in pregnancy (Seibel, 2009). After the baby is delivered the disorder disappears but in few cases it has returned as type 2 diabetes. There are many factors that increase the risk in women to acquire the disorder, being overweight prior to becoming pregnant, a family history of diabetes, having too much amniotic fluid, and having sugar in your urine are just some of them (Namak, 2010). During a normal pregnancy tissue resistance to insulin is present, and weight gain and presence of placental hormones can contribute to this insulin resistance ( Gutierrez, 2007). Pregnant women require two to three times more insulin than a woman who is not pregnant, and the insulin production and increased tissue resistance causes this glucose intolerance or increased blood sugar levels or gestational diabetes ( Gutierrez, 2007). â€Å"Almost all women have some type of impaired glucose in tolerance resulting from hormonal changes they go through during pregnancy. This means that their blood sugar levels may be higher... ...st twice the risk of developing diabetes compared to those who had breastfed (Doheny, 2010). Overall the study showed to be successful, but only for those women who breastfed all of their children for a month or longer. So with these studies it encourages women to take part in the well being of themselves and their unborn child by getting tested for gestational diabetes earlier than later. Gestational diabetes may only be a disease that last throughout a pregnancy, but it is very harmful to not only the mother but also can be for the unborn baby. It is important that gestational diabetes is widely known and understood because the earlier in the pregnancy the patient knows the better. Gestational diabetes can be extremely harmful so it is nothing to take lightly; patients have to know that they must follow the instructions given to prevent the disease to worsen.

Thursday, October 24, 2019

Dark Child Essay

Ideology-Countries whose history is strongly marked by western European immigration or settlement, such as the Americans, and the Australians, and is not restricted to Western Europe (Wikidpedia. org). Many countries around the world have been influenced by the western ideology. Western Ideology includes components such as literary, education, political and philosophical views, and most of all, religion. In the autobiography, â€Å"The Dark Child†, Camara Laye, is a person who faces these types of challenges. He becomes stuck between his own traditional and the western ideologies. In the Dark Child, Camara Laye’s youth and development of his cultural and personal values as a young man is explained. He is part of the Malinke tribe in the village of Koroussa in Upper Guinea and is eldest out of many brothers and sisters. In the beginning, he learns about many of the traditions and customs his people. He is told about Totemism-the fact that everybody has a spiritual animal that is chosen by the person’s character. While learning about his people, he has attends a Koran school and then a French school in another part of town. Later in the book, he learns about Konden Diara- a ceremony that is a ritual used to conquer a boy’s fear before the initiation of circumcision. He undergoes the ritual and circumcision-represents a rite of passage –a boy is now a man. After graduating from his school, Laye leaves at 15 years of age to attend a technical college in Guinea’s capital city of Conakry. Like any mother, Laye’s warns him to â€Å"be careful with strangers† and sends him off on a train to live with his Uncles Sekou and Mamadou in Conakry where he comes across many cultural changes. In the school, in a new city for the first time in his experience, Laye encounters difficult language barriers and a hot, humid climate more taxing and oppressive than that in his Koroussa home. He also seeks changes during the day where people at their work are dressed in a Western style, but in boubou’s when they come home from work. Laye lives the life of a typical college school student, studying at the school’s campus and returning home to Koroussa during the holidays. When he returns, he sees the transformation within his family and friends. Later, he finishes his studies in Conakry and is offered a once in a lifetime opportunity to study in France. His mother greatly disapproves, but Laye and his father convinces his mother. At the end of the book, Laye leaves for France, and promises to himself that he will return to his people. As I was reading the book, it made realize the position of Africa and where it stood as a country. I felt distinctly as I was reading throughout the book, western values and traditions were overrunning the traditions of not only Africa but Laye’s life as well. Since the beginning of the book, he not an ordinary child in the village peoples eyes. He was one of the many who was sent out to attend school and be educated. His father knew what was to come of Africa, modernization. In my opinion, I think his father placed Laye in school for the purpose to contribute to his people, as oppose to being a goldsmith like himself. As he moved to Conakry, he moved in with his uncle Mamadou. His uncle lived in a European-style house. Was it unfamiliarity, or the humid heat of the town, or the fatigue of two days in the train that kept me from sleeping? Yet it was a very comfortable house: the room I slept in was large, and the bed soft, softer than any I had previously slept on† (147). Laye was astonished about his living headquarters. He was not used to this style and roominess. As I earlier stated, people in Conakry dressed differently during the day than at home. It took him a little while to get used to this as well. Later in the book, he woul d return home during the holidays. As he came back, he noticed that his mother had been plastered with white clay. â€Å"Originally it had been like the other huts, but gradually it began to acquire a European look† (169). His was trying to adapt to the style of the west through her son’s experience in Conakry. She was expressing not only her love for Laye, but also her feelings toward the western tradition. While he was in his village, one of his friends’ Chet was seriously ill. The medicine men gave him remedies and charms to help her but there was no significant change at all. Laye and his other friend knew that he had to see a white doctor at the hospital. Chet passed away after a week. Because of Laye’s education from the west, he knew that the medicine men were insufficient. From experiences and education of the west, he has become a man with wisdom of both cultures. â€Å"The Dark Child† is a wonderful journey through Camara Laye’s personal experiences. It shares many of his experiences and challenges through his life as a youth and young man. I really enjoyed the book and thought it was really educating.

Wednesday, October 23, 2019

Housing & Development Board Analysis Essay

This is the highest rate of increase this year compared to the 0. 1-per cent drop in the first quarter and the 0. 4-per cent increase in the second quarter. It was also higher than the flash estimate of 0. 5 per cent released earlier this month. Meanwhile, resale prices of Housing & Development Board (HDB) flats in Singapore hit a record high. HDB’s Resale Price Index (RPI) rose from 194 in the second quarter of this year to 197. 9 in the third quarter. This represents an increase of two per cent over the previous quarter, the same as that of the flash estimate released on October 1. – Evidence for an increase demand for resale flats  But with a bumper crop of 27,000 Build-to-Order flats being rolled out this year, analysts said the resale market may be showing signs of moderating. Growth for the first three-quarters of this year is 3. 9 per cent. This is lower than the annual RPI growth of 14. 1 per cent in 2010, and 10. 7 per cent last year. Donald Han, special advisor at HSR Property Consultants, said: â€Å"Buyers who are able to wait for the product to be completed in 24 to 36 months are getting better value proposition in terms of cheaper prices, and perhaps better amenities compared to one who’s buying a resale flat. The volume of resale transactions also fell for the first time in 12 months. Resale transactions also fell by about six per cent from 7,011 cases in second quarter to 6,560 cases in the third. – Number of buyers dropped The last fall in resale transactions was in the third quarter of last year when transactions fell from 6,581 in the second quarter, to 5,903 in the third. Analysts said that this might not be because buyers are staying away, but because there is a short supply of resale flats in the market. – Reason for the decrease in the demand (Isnt this is for supply? The number of sellers in market. ) They added that this has pushed the median cash-over-valuation (COV) up by S$4,000 to S$5,000 compared to the last quarter. According to real estate firm Propnex, COVs hovered between S$25,000 and $28,000 in the first two quarters, before rising to $30,000 in Q3. This means a 20 per cent increase quarter-on-quarter. Chris Koh, director of Chris International, said: â€Å"Regardless of whether there are BTO flats, if private property prices are too high, many are unable to afford private property. So they turn to a resale market to buy a flat instead. So you still see a strong demand from those not eligible to buy brand new flats, those who can’t afford private property and have to buy a resale flat. – Reason for the increase in the demand. (Price of related good) â€Å"There’s one more group, I call them the ‘downgraders’. They have cashed out their private property, that’s why they don’t mind paying a premium for some of these resale flats. † In the rental market, subletting transactions rose by about four per cent. The number of cases increased from 6,891 in the second quarter to 7,142 cases in the third quarter. The total number of HDB flats approved for subletting also rose to 42,920 units in the third quarter, compared to 41,814 units in the second. Mr Han said: â€Å"In the last five years, prices have not gone south. In fact, prices have grown by 92 to 93 per cent since five years ago†¦ So, a lot of the able sellers are keeping it for hopefully higher capital returns for the next 12 months. (supply) If you look into a rental proposition, HDB rental flats – if you look at average four-room or five-room, you’re looking at roughly about S$2,000 to S$2,500 per month. It provides a very good fertile ground support for tenants out in the market looking for cheap accommodation. â€Å"The yield coming from HDB apartments is fairly attractive as well, compared to other classes of residential property. We’re looking at yields of 4. 5 to five per cent, compared to private properties which would be about 2. 5 to about 3. 5 per cent. â€Å" Mr Koh added: â€Å"I’m not sure if there’s a co-relation, but I won’t deny that if prices of resale flats are too high, some would not be able to afford it. So the next best option will be to rent and wait for prices to come down. â€Å"- Reason for decrease in demand when price rise. (Taste and preference? ) The HDB said it introduced a new e-service on Monday to enable the public to search for the market rentals of entire HDB flats rented out by owners. It is hoped that this will allow better transparency in the subletting market, and help potential tenants and flat owners make informed decisions.