Movement in an Idealized Dam-break Configuration

Movement in an Idealized Dam-break Configuration For doing the research of the fluid dynamics with the open channel flow, to derive and understanding different waves equations in partial differential approximation with conservation form such as the explicit centered convection approximation and the explicit upwind convection approximation in different condition. Trying to substitutive the values into the equations to derive the appropriate method base on the finite- volume method in the fluid dynamics and using the software to calculate the flux and the stability which will depend on the direction of the wave and must be under the distance travel must not exceed the step way condition. The aim is staring to go through the details of the equations, get the brand new Flux functions which called lax Wendorff burgers equation scheme and Dam break scheme, based on those approximation to estimate the wave direction, wave speed, height, density and momentum in the certain and instant time for the water wave and at different conditions property and combinations. Putting the values to get the approximate results with those two methods and compare with each other. Plot the appropriate graphs. Abstract The purpose of this study is to model the flow movement in an idealized dam-break configuration. One-dimensional motion of a shallow flow over a rigid inclined bed is considered. The resulting shallow water equations are solved by finite volumes using the Lax-Wendroff schemes. At first, the one-dimensional model is considered in the development process. With conservative finite volume method, splitting is applied to manage the combination of hyperbolic term and source term of the shallow water equation and then to promote 1D. The simulations are validated by the comparison with flume experiments. Unsteady dam-break flow movement is found to be reasonably well captured by the model. The proposed concept could be further developed to the numerical calculation of non-Newtonian fluid or multilayers fluid flow. All the calculations, data and graphs represent are all through MATLAB programming with an individual code and all the units and symbols were labeled in the code. A. Units and constant for the approximations Equations Theory Partial Differentials Partial differential equations are complicated method to solve as they contain more than one variable and instead are used to Describe problems involving the parameters in use which can be solved using the variation of schemes. They describe the certain rate of change of variables which are related to each other, in this project, the first convection are the wave equation in conservation form which are to approximate the velocity of the flow in different directions and the flux approximation with changing time. Two different methods are considered which are the explicit upwind convection approximation and explicit centered convection approximation respectively. When dt = 0 and dx = 0, Discretization Schemes Explicit centered convection approximation and explicit upwind convection approximation, these methods include finite volume method which approximating the variables around discrete nodes with dissected into too many small elements that are approximated. Finite-Difference Approximation Finite-difference approximations are one of the most derivative methods for solving differential equations. The system can approximate the solution with the necessary boundary and initial conditions imposed, providing an accurate solution for the previous unfathomable equation. They are of particular use in aerodynamics as their time and space dependent nature lends itself to computing shock wave propagation or other energy transfer flows. Their approach uses discretization to approximate the differential, by applying a finite grid, of points at which the variables are estimated, with the process continuing as the local points govern their approximation values from the neighboring nodes. Iterative approximation in this manner produces an obvious error, known as the discretization or truncation error, diverging from the true value. The key to the principle is, like anything, minimizing this error in the system. Monitoring this error then is something of paramount importance and through the implementation of the Taylor Series. In addition, there are three critical properties that any approximation of a partial differential should maintain, which are consistency, stability and convergence. Forward-Time, Backward-Space Scheme The form of approximation method is a backward, explicit, hyperbolic system which means that at the next set of results are only calculated from the nodes immediately behind them geometrically, in relation to their pervious counterparts, for examples, When dt = 0 and dx = 0, This also gives the system an inherent advantage as this encourages convergence, through the fact that the approximation method has a domain of dependence which are include the initial data, shared by the partial differential at t = 0, only apply on the first set of data. Also, further information gathered from the equation itself shows is a first order method and most suitable to simple differential approximations. Lax Scheme This kind of approximations are most likely the previous is explicit hyperbolic in nature, however, it is a scheme which to demonstrated that all the velocity of the water flow terms are either side of and is first order accurate for u, and also approximate the accuracy for x. When dt = 0 and dx = 0, Moreover, the stability of the method has to be considered as the Courant-Friedrichs-Lewy (CFL) condition is a necessary condition for convergence while solving certain partial differential equations usually hyperbolic numerically by the method of finite differences. It arises in the numerical analysis of explicit time integration schemes, when these are used for the numerical solution. As a consequence, the time step must be less than a certain time in many explicit time-marching computer simulations, otherwise the simulation will produce incorrect results. Lax-Wendroff Scheme This scheme is a common numerical method for the solution of hyperbolic partial differential equations like the previous schemes which are based on the finite differences to accurate for both space and time apparently. There are two different cases are going to consider and approximate which are the 1st for the linear case, while , where a is a constant which to define the direction of the flow and u is the wave speed, when, the flow is to the right, and to the left when a is negative. As two different approximations have considered, for the centered method For the upwind method Or Or And for the Lax-Wendroff in first-order Predictor, Corrector, For the 2nd case, Centered method For the upwind method Or Or And for the Lax-Wendroff in first-order Predictor, Corrector, Calculate for the half grid points and time steps approximation as different predictors first and then recalculate the scheme by the value of half grid points and time steps into same Corrector which putting a two steps approximation rather than a single step to make it more accurate. This is a feature unique for the Lax-Wendroff method. Also, the stability of CFL condition is the same as the previous scheme. Taylor Series The Taylor series is a form of evaluating and representing partial differentials, as an infinite sum of its terms at a single point, in form of series expansion. The use of the series has many applications in engineering, with its main being the approximation of functions through the expansion to the necessary number of terms. Through collating the appropriate number of terms and then truncating the series a valid approximation of the function can be made. The act of truncating the series generates an error, although as the expansion continues the effect of each term dwindles, a characteristic that allows the truncation after a certain term number. The truncation error can also be computed and gives an indication as to the validity and performance of the initial approximation made using the series expansion. B. Dam break schme The simplest situations will first be considered, of mass, momentum and energy conservation laws in primitive form, so stripped of all energy-diffusing terms, such as bed slope , resistance, change of section. Governing Equations The mass entering t element in time dt is While the amount leaving is For the mass For the momentum For the simplest case, X1 Figures and Tables Figure 1 Figure 1 shows the relationship of the velocity against the postion of the flow in linear first-order which (f = a*u) , where a is 1, Lax-Wendroff is used for approximation, and it shows a steady flow with a certain time and positions with the input data, there are 50 nodes in total and the grid spacing are 400 as the detla time was 0.0015s, so the grid spacing should have to take a really large value to maintain the CFL. Figure 2 Figure 2 shows the relationship of the velocity against the postion of the flow in non-linear first-order which (f = u2/2), Lax-Wendroff is used for approximation, and it shows a steady flow with a certain time and positions with the input data, there are 50 nodes in total and the grid spacing are 30 as the detla time was 0.0015s, the grid spacing take a really smaller value to maintain the CFL. Figure 3 Figure 4 Figure 3 Figure 4 shows the relationship between the height against the spacing and the momentum against the spacing respectively, dam break scheme is used with base on a Lax-Wendroff approximation and for Figure 3, the running time is 10 seconds which is shorter then Figure 4 and the depth of the dam wall sets as 0.2m and break at 30m while Figure 4 sets as 0.5m depth and break at 50m. As the results show, the longer running time it takes, the stability and convergence of the approximation comes out. Also, both of the results withdraw the boundary which take an error while plot graph. So, a function for boundary condition has to be considered as well. References Guymon, Gary L. A Finite Element Solution Of The One-Dimensional Diffusion-Convection Equation. Water Resources Research 6.1 (1970): 204-210. Web.

Children With Sickle Cell Disease Health And Social Care Essay

Transcranial Doppler scanning ( TCD ) is a critical technique which can place kids with reaping hook cell disease at high hazard for shot ( Deane et al. , 2007 ) .This non-invasive imagination technique uses an ultrasound investigation, that produces high frequence sound waves to mensurate intellectual blood flow. In this survey, cubic decimeter will be looking at the undermentioned everyday hematologic and biochemical research lab trials, hemoglobin, reticulocytes, white count, lactate dehydrogenase, aspartate aminotransferase and creatinine in 250 reaping hook cell disease ( SCD ) affected kids with in the age group of 3-16years who attend the Brent Sickle and Thalassaemia Clinic at Central Middlesex Hospital in May 2010 to May 2011. My purpose is to utilize the above listed research lab trials to place all kids who are at hazard of enduring from the complications of SCD like vaso-occlusive hurting crisis, acute chest syndrome, infections, stroke to multi organ failure. TCD is perf ormed one time a twelvemonth at one-year reappraisal assignments on all kids with reaping hook cell disease to find if they are at hazard of developing any SCD complications. During this survey any kid identified to hold unnatural hematologic and biochemical research lab trials listed supra will hold a TCD regardless of whenever it was done. If the TCD identifies that any kid with those unnatural hematologic and biochemical parametric quantities is at a high hazard of developing complications of SCD particularly stroke, so the current National Health Service ( NHS ) intervention program for kids with SCD must be changed to supply an even more robust intervention plan.The significance of this survey hence is to better hereafter pattern and attention for kids with SCD. This will intend that any SCD affected kid with those unnatural hematologic and biochemical parametric quantities will be referred for TCD regardless of whether they have had their annual scan in a pursuit to better the ir wellness and wellness attention direction. Prevention is better than remedy.2. IntroductionHemoglobinopathies are a broad group of diseases impacting the production and or the maps of hemoglobin. ( Kirkham F.J, 2007 ) . They are one of the most common familial upsets worldwide and can be really terrible, if non fatal. They are classed into two groups: Haemoglobin discrepancies which arise from an change in the hematohiston concatenation, for illustration, Sickle hemoglobin ( Hb S ) Thalassaemias which arise from reduced production of the normal hematohiston concatenation. ( Kirkham F.J, 2007 ) SCD is one of the most common familial upsets impacting the hemoglobin molecule of ruddy blood cells ( Kirkham F.J, 2007 ) . SCD is an autosomal recessionary disease, intending a individual needs two faulty cistrons to hold the disease ( Kirkham F.J, 2007 ) . There are several reaping hooks cell diseases: homozygous reaping hook cell anemia or disease ( HbSS ) and heterozygote conditions including Hb SC and Hb S? thalassemia ( Kirkham F.J, 2007 ) . HbSS is responsible for the most terrible complications seen in reaping hook cell disease ( Kirkham F.J, 2007 ) . The prevalence of SCD is highest among people of African, Afro-Caribbean, Arab and Mediterranean lineage ( Kirkham F.J, 2007 ) It is widespread in the United States, impacting over 70,000 Afro- Americans and impacting about 12,500 people in the UK ( Howard et Al ; Kirkham et al. , 2007 ) . Sickle cell is progressively going common in the UK as a effect of migration ( Howard et al.,2007 ) . The life anticipation in SCD is between 42 and 53 old ages for work forces and 48 and 58 old ages for adult females. This low life anticipation is likely to increase as the wellness service have put in topographic point national showing programmes, instruction for parents and wellness professionals and better directions attention. Complications SCD is a multi-organ upset with a assortment of complications. The most common complications include, vaso-occlusive hurting crisis, acute chest syndrome, infections, shot, priapism, leg ulcers, cholecystitis, acute splenic or hepatic segregation to multi organ failure. ( Gladwin et al, 2008 ) . Vaso-occlusine hurting crises is due to sickle cells blockading vass in the microcirculation taking to ischemic harm in the castanetss, the lung, the kidneys and in the tegument ( leg ulcers ) , ( Gladwin et al, 2008 ) . Stroke is an of import complication as it is a major cause of mortality and morbidity in SCD kids. ( NHS Standard and Guidance, March 2009 ) . It has been reported as a taking cause of decease in both kids and grownups. Infarctive shot is seen chiefly in kids whereas hemorrhagic shot is normally seen in the 20-29 age groups, ( Ohene-frempong et Al, 1998 ) . The grounds for this age division are non good understood. ( Kirkham F.J, 2007 ) . By the age of 10, about 6 % of SCD kids are affected by ischemic shot ( .Kirkham F.J, 2007 ) . It is caused by the progressive narrowing of the center, distal and anterior carotid arterias providing blood to the encephalon consequences in shot ( Deane et al, 2007 ) . However, grounds for this progressive narrowing are yet to be established ( Deane et al, 2007 ) , but recent surveies suggest an association between high degrees of plasma free hemoglobin ( PTH ) from hemolysis, quickly devouring azotic oxide ( NO ) , which may ensue in events suppressing blood flow. ( Nelson et al, 2006 ) . Even though it is a really serious complication in SCD kids, it can be preventable. ( Quinn et al 2004 ) , if these kids are identified. Transcranial Doppler scanning ( TCD ) has been shown to place patients at high hazard of shot ( Deane et al, 2007 ) . TCD is an ultrasound that measures blood flow speed in the intracerebral vass. ( Bulas et al, 2000 ) . It is non invasive, reasonably expensive and a painless process that is good tolerated in kids. ( Bulas et al, 2000 ) . This high hazard of shot brought approximately by The Stroke Prevention Trial in Sickle Cell Anaemia ( STOP ) survey. This survey was perfomed by a group of scientist in 1996. It showed that high blood speeds as measured by TCD in the in-between intellectual arteria ( MCA ) , the distal internal arteria ( dICA ) and the bifurcation were associated with an increased hazard of shot. . ( Bulas et al, 2000 ) . These kids with high blood flow speeds were so on a regular basis transfused to cut down the hazard of shot [ new ref Adams RJ. , 1998 ] . The STOP survey has has proven important consequences on TCD as an valuable wellness technique in forestalling shot hazard in kids. ( Adams RJ. , 1998 ) given Furthermore, an experimental survey by Fullerton et Al, 2004 on SCD kids in California showed that there was a diminution in shot after the debut of TCD with contraceptive transfusion preventative steps were taken. . ( Rees et al, 2008 ) . Many surveies have shown the benefits of mensurating high blood speeds on TCD and subsequent transfusion to cut down hemoglobin S can cut down the hazard of shot. ( ) . Based on these surveies, National counsel from the NHS Sickle and Thalassaemia testing programmes recommended the usage of TCD scans all over the state. The guidelines proposed that by 2010, 99 % of reaping hook cell Centres in England should offer one-year TCD scans to kids with SCD from age 2 to 16 old ages. The scan consequences are classed into classs depending on the clip averaged maximum average speed ( TAMMV ) of the in-between intellectual arteria or the intracranial internal carotid arterias or the bifurcation of the two arterias, ( Standard and Guidance, March 2008 ) . TAMMV values & A ; lt ; 170 cm/s are normal, 170-199cm/s are conditional and & A ; gt ; 200cm/s are important forecasters of shot. ( Standard and Guidance, March 2008 ) . However, studies in the UK have shown that many kids do non hold entree to TCD scans ( Rees et al 2008 ) . Therefore it is imperative to place kids at high hazard for shot so that effectual preventative steps are taken. In this survey, based on cardinal hematologic and biochemical modus operandi trials we aim to happen research lab parametric quantities which can be used as showing tools for shot and be used in placing those kids most likely to hold an unnatural TCD scan. If these labaoratory paramaters can place SCD kids at increased hazard for shot it may take to recommendations for future pattern to include precedence for TCD scans to be given to these kids.TreatmentIn the UK, the National Health Service ( NHS ) has developed local guidelines for the intervention and direction of SCD, including: a combination of antibiotics, hurting slayers, fluids and ruddy cell transfusion when required. ( Kirkham F.J, 2007 ) . Hydroxyurea, an unwritten anticancer drug is besides used in some SC D patients to forestall painful crises ( Frenette et al, 2007 ) . Hydroxyurea works by increasing fetal hemoglobin F ( Hb F ) degrees which prevents the polymerization of the deoxygenated HbS in ruddy cells, therefore diminishing the frequence of painful crises ( Hoffbrand et al, 2001 ) . Reports from Howard et al 2007 and Frenate et Al 2007 besides explain that Hydroxyurea improves ruddy cell hydration, diminishing the adhesion of reaping hook cells to the endothelium and act as a azotic oxide giver, doing this drug rather good to utilize. A multi-centre survey of hydroyurea ( MSH ) in 299 grownups with SCD showed important benefits of utilizing this drug as patients had less one-year painful crises ( Charache et al.,1995 ) . A follow-up survey nine old ages on showed that these patients had a better quality of life ( Steinberg et al. , 2003 ) . Despite its clinical benefits, many patients are disbelieving about it being a chemotherapeutic drug and are hence disquieted about the lo ng term side effects ( Frennete et al. , 2007 ) . Bone marrow organ transplant can bring around SCD. About 175 HLA matched sibling grafts have been reported with greater than 80 % disease free patients holding a quality life ( Howard et al. , 2007 ) , nevertheless, troubles lie in happening a blood-donor lucifer and there is a hazard of decease associated with this procedure due to high doses of chemotherapy and radiation ( Frenette et al, 2007 ) . A possible remedy for SCD is cistron therapy, where infixing a normal cistron will convey about production a normal hemoglobin or shift of the faulty cistron. This is presently being investigated in research surveies as there are frights over the safety of genomic interpolation ( Sadelain et al, 2006 ) . Present surveies have shown that prenatal and neonatal showing for hemoglobinopathies in England has led to early sensing of affected kids, therefore, cut downing the post-natal and childhood morbidity and mortality ( Old J M 2007 ) .3. HistoryHaemoglobin ( Hb ) is an Fe incorporating protein, which carries O from the lungs to the organic structure ‘s cells and tissues ( Hoffbrand et al, 2001 ) . After 3-6months of age Hb A is the dominant hemoglobin, with little measures of hemoglobins F and A2 ( Hofbrand et el, 2001 ) . Normal hemoglobins in grownup human blood are as follows: HbA: ?2 I?2 ( 96-98 % ) HbF: ?2?2 ( 0.5-0.8 % ) Hb A2: ?2?2 ( 1.5-3.2 % ) Sickle cell disease is caused by a permutation at place 6 of a individual amino acid in the DNA sequence of the ? hematohiston concatenation ( fig. 1 ) . The minor alteration of glutamic acid for valine, as illustrated in figure 1, consequences in an altered hemoglobin discrepancy known as the Sickle Hb ( Hb S ) ( Hoffbrand et al, 2001 ) , which reduces the endurance of ruddy cells and causes irreversible sickling of ruddy cells at low O conditions ( Hoffbrand et al, 2001 ) . Consequently SCD patients endure a assortment of symptoms runing from anemia, terrible bone hurting ( referred to as sickle crisis ) , stroke, acute thorax hurting, to multi organ harm ( Gladwin et al, 2008 ) .Amino acidproglugluNormal ?- concatenationBase composing CCT Joke Joke Base composing CCT GTG JokeSickle concatenationprovalgluFig 1. Showing a individual base alteration in the he DNA sequence, where A ( A ) is replaced by T ( T ) . This permutation consequences in an amino acid alteration from glutamic acid to valine in the 6th place. ( Adapted from Hoffbrand et Al, 2001 ) . Normal ruddy blood cells are flexible and round in form. Their flexibleness and form allows them to go freely through little blood vass, known as capillaries ( Hoffbrand et al, 2001 ) . ) . Hb S is indissoluble when exposed to low O environments and may organize polymers which may change the ruddy cell membrane from a biconcave form to a sickle form. In oxygenated environments, sickled molded cells can alter back to the biconcave form ; nevertheless frequent form alterations may do lasting harm doing some cells to stay sickled. ( Hoffbrand et al, 2001 ) . Furthermore, these sickled cells circulate at a slower rate compared to normal ruddy cells and tend to go stuck, therefore barricading vass in the microcirculation and doing infarcts of assorted variety meats ( Hoffbrand et al, 2001 ) .DiscussionSurveies in the last two decennaries were more focused on direction of the return of cerebrovascular diseases ( CVA ) . Recently the focal point is now on forestalling the happening of a fir st CVA ( Ohene-frempong et Al, 1998 ) . Hemolytic anemia is associated to many complications of SCD ( Lezcano et al, 2006 ) . Assorted surveies have linked low Hb, and hemolytic markers such as Retics, LDH, AST and creatinine to cerebrovascicar diseases such as shot. ( Kato et al, 2007 ) . Incidence of ischemic shot is higher in SCD kids impacting about 6 % by the age of 10years ( Howard et al, 2007, Deane et Al, 2008 ) . It is associated with an occlusive vasculopathy impacting the distal, proximal and anterior arterias ( Bulas et al, 2000 ) . The narrowing of these vass may develop over months to old ages before symptoms of a Stroke may happen ( Adams et al. , 1997 ; Bulas et Al, 2000 ) . Designation of hazard factors for shot is of import because it offers the possibilities of forestalling it. Clinical surveies have identified some research lab trials as hazard factors for shot. ( Kirkham et al, 2007 ) , but none has strong anticipation when compared to TCD ( Ohene-frempong et Al, 1998 ) . Surveies by Adams et al 1998 and Lezacano et Al 2006 have shown that the disposal of regular blood transfusion therapy in kids with unnatural TCD measurings reduces both plasma hemoglobin and serum LDH degrees. LDH has long been associated as a marker of intravascular hemolysis by Neely et Al, 1969. Surveies by Ballas et Al, 1991 and Kato et Al, 2006 found serum LDH the dominant biomarker in intravascular hemolysis and besides strong correlativities of LDH with hemolytic markers such as hemoglobin, retics and AST in grownups with SCD. A recent survey by O'driscoll and co-workers done at King ‘s College Hospital in London in 2007 reported that high serum LDH in kids with SCD correlatives to abnormal TCD measurings. This determination suggests that LDH can be a important biomarker or a hazard factor for shot in kids with SCD. They besides reported important correlativities between LDH, Hb, Retics and AST. Furthermore, Rees et Al in 2008 found important correlativities between unnatural TCD consequences and Hb, Retics, AST and age. These happening were used to develop an index which can be used to place kids with SCD probably to hold unnatural TCD values. The survey by O'driscoll and co-workers is the first survey which demonstrates that a high serum LDH degree in SCD kids has strong correlativities with unnatural TCD measurings. Therefore in this survey we aim to utilize LDH as one of the research lab parametric quantities and farther validate the survey at Kings in the patient population at CMH. Extra showing factors for shot are hence needed. With this attack in head, Hb F, Hb S and WBC will besides be analysed in this survey. The importance of WBC arise from observations that high leucocytes is associated to terrible complications of SCD and from findings by Platt et al.,1994 that leucocytosis is a hazard factor in clinically open shot and in acute thorax syndrome ( Ohene-frempong et Al, 1998 ; Mark et al. , 2008 ) . High WBC is reported to correlate significantly with shot ( Frenette et al, 2007 ) , therefore a good parametric quantity to mensurate in this survey. Hb F is said to cut down the hemolysis, thereby cut downing the hazard of shot in kids ( Kato et al, 2007 ) . The genotypes, HBSS and HBSC kids will be assessed to see which group is more at hazard for shot. The current theories of complications of SCD particularly with respects to cerebrovascular disease are largely focussed on hemolysis and the bioavailability of NO. ( Kato et al, 2007 ) . Chronic hemolysis leads to the release of plasma Hb which sucks up NO. NO is a vasodilative, hence less NO in the microcirculation upsets the balance between vasoconstriction and vasodilation which consequence in endothelial disfunction ( Kato et al, 2007 ) . More surveies in understanding hemolysis and the function played by NO will assist in understanding SCD complications and cut down its badness in the hereafter. ( Kato et al. , 2007 ) . Several surveies has suggested that, there is a nexus between shot and hemolysis and that shot is associated with low hemoglobin and compensatory reticulocytes. ( Kato et al.,2007 ) . With that attack, we aim to mensurate the undermentioned research lab parametric quantities: Hb, Retic, AST, Creatinine and LDH and correlate them to abnormal TCD measurings.Future PROSPECTSRecommendations for future pattern to include precedence for TCD scan given to kids who have been identified with these research lab parametric quantities so that primary stroke can be avoided and preventative steps such as, transfusion or exchange transfusion is given. This will so better their attention.

10 Actinium Facts

Actinium is a radioactive metal that is the first element of the actinide series. Its sometimes considered the third element in Row 7 (last row) of the periodic table or in Group 3 (IIIB), depending on which chemist you ask. Here are 10 interesting facts about actinium. 10 Actinium Facts Actinium has atomic number 89, meaning each atom of the element has 89 protons. Its element symbol is Ac. It is an actinide, which also makes it a member of the rare earth element group, which is itself a subset of the transition metals group.Actinium was discovered in 1899 by French chemist Andre Debierne, who suggested the name for the element. The name comes from the Greek word aktinos or aktis, meaning ray or beam. Debierne was a friend of Marie and Pierre Curie. Some sources suggest he worked with Marie Curie to discover actinium, using a pitchblende sample from which polonium and radium had already been extracted (discovered by the Curies).Actinium was independently discovered again in 1902 by German chemist Friedrich Giesel, who had not heard of Debiernes work. Giesel suggested the name emanium for the element, which comes from the word emanation, meaning to emit rays.All isotopes of actinium are radioactive. It was the first non-primordial radioactive element to be isolated, even though other radioactive elements had been identified. Radium, radon, and polonium were discovered before actinium but werent isolated until 1902.One of the more noteworthy actinium facts is that the element glows blue in the dark. The blue color comes from the ionization of gases in the air by radioactivity.Actinium is a silver-colored metal that has properties similar to those of lanthanum, the element located directly above it on the periodic table. The density of actinium is 10.07 grams per cubic centimeter. Its melting point is 1050.0Â °C and boiling point is 3200.0Â °C. Like other actinides, actinium readily tarnishes in the air (forming a white actinium oxide layer), is extremely dense, is highly electropositive, and likely forms numerous allotropes. The other actinides readily form compounds with nonmetals, although actinium compounds are not well-known.Although it is a rare natural element, actinium does occur in uranium ores, where it forms from the radioactive deca y of uranium and other radioisotopes, such as radium. Actinium is present at an abundance of 0.0005 parts per trillion by mass in the Earths crust. Its abundance in the solar system is negligible overall. There is about 0.15 mg of actinium per ton of pitchblende.Although it is found in ores, actinium is not commercially extracted from minerals. High-purity actinium may be made by bombarding radium with neutrons, causing the radium to decay in a predictable fashion into actinium. The primary use of the metal is for research purposes. It is valuable neutron source because of its high activity level. Ac-225 may be used for cancer treatment. Ac-227 may be used for thermoelectric generators, as for spacecraft.36 isotopes of actinium are known—all radioactive. Actinium-227 and actinium-228 are the two that occur naturally. The half-life of Ac-227 is 21.77 years, while the half-life of Ac-228 is 6.13 hours.One interesting factoid is that actinium is about 150 times more radioactive than radium!Actinium presents a health hazard. If ingested, it is deposited into the bones and the liver, where radioactive decay damages cells, potentially leading to bone cancer or other illnesses.

International Trade And Exchange Rates - 2916 Words

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The Forward Premium Puzzle Can Be Referred1494 Words   |  6 Pagespremium can be described as a situation where the future exchange or the spot future exchange trades at higher spot exchange rate compared to the domestic currency. Using descriptive measures, the forward premium can be measured as the difference between the forward rates. The prevailing spot rate and which also includes the domestic currency is expected to increase when the domestic interest rates (nominal) surpasses foreign interest rates (Lane, and Milesi†Ferretti, 2011). The premium puzzle canRead MoreEco372Internationa l Trade and Finance Speech903 Words   |  4 PagesInternational Trade and Finance Speech ECO/372 June 7, 2012 International trade and finance speech Hello ladies and gentlemen hope you day is going well so fair. 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How the level of wages, productivity and exchange rates affect the model of comparativeRead MoreWhat Happens When There Is a Surplus of Imports Brought Into the Us1065 Words   |  5 PagesInternational Trade and Finance Speech What happens when there is a surplus of imports into the U S: A surplus of imports is good for consumers but bad for local business. We have to produce and manufacture in order to export. As our export trade shrinks, so does our workforce and economy. The surplus of imported cars for 2012 has exceeded the exportation by $152 billion. Also the shelf life of cars is 1 year. Every year at the end of the cycle the existing models are sold off at huge discountsRead MoreEco/372 International Trade and Finance Speech Essay1268 Words   |  6 PagesInternational Trade and Finance Speech International Trade and Finance Speech Foreign exchange rates and International trade are important aspects of economics. The United States macroeconomy’s health is determined by these concepts and their factors. International Trade Exports and imports are what encompass international trade balance. When there are more exports over imports a trade surplus happens and when there are more imports over exports a trade deficit happens. A country will acquire