2,846 research outputs found
Entropy for Colored Quark States at Finite Temperature
The quantum entropy at finite temperatures is analyzed by using models for
colored quarks making up the physical states of the hadrons. We explicitly work
out some special models for the structure of the states of SU(2) and SU(3)
relating to the effects of the temperature on the quantum entropy. We show that
the entropy of the singlet states monotonically decreases meaning that the
mixing of these states continually diminishes with the temperature. It has been
found that the structure of the octet states is more complex so that it can be
best characterized by two parts. One part is very similar to that of the
singlet states. The other one reflects the existence of strong correlations
between two of the three color states. Furthermore, we work out the entropy for
the {\it classical} Ising and the {\it quantum} XY spin chains. In Ising model
the quantum (ground state) entropy does not directly enter into the canonical
partition function. It also does not depend on the number of spatial
dimensions, but only on the number of quantum states making up the ground
state. Whereas, the XY spin chain has a finite entropy at vanishing
temperature. The results from the spin models qualitatively analogous to our
models for the states of SU(2) and SU(3).Comment: 19 pages, 4 eps figure
The effects of colored quark entropy on the bag pressure
We study the effects of the ground state entropy of colored quarks upon the
bag pressure at low temperatures. The vacuum expectation values of the quark
and gluon fields are used to express the interactions in QCD ground state in
the limit of low temperatures and chemical potentials. Apparently, the
inclusion of this entropy in the equation of state provides the hadron
constituents with an additional heat which causes a decrease in the effective
latent heat inside the hadronic bag and consequently decreases the
non-perturbative bag pressure. We have considered two types of baryonic bags,
and . In both cases we have found that the bag pressure
decreases with the temperature. On the other hand, when the colored quark
ground state entropy is not considered, the bag pressure as conventionally
believed remains constant for finite temperature.Comment: 13 pages, 2 eps-figures (2 parts each
Stratigraphic Sequence and Basin development of the Mishrif Formation in Selected Oil fields in the Mesopotamian Zone, Southeastern Iraq
The Mishrif Formation represents an important succession in the southern Iraq and has extensive distribution in the Middle East. The present study is focused upon the stratigraphic sequence and basin development of Mishrif Formation in three important oil fields in the Mesopotamian Zone of Iraq are:- Halfaya oil field (Hf-1, Hf-272, Hf-316), Noor oil field (No-1) and Buzurgan oil field (Bu-2, Bu-3, Bu-4).There are several types of microfacies were recognized in the succession of the Mishrif Formation. Their characteristic grain types and depositional texture enabled the recognition of six facies associations (depositional environments) were distinguished in this Formation, they are: Basinal, Slope, Shoal, Biostorm, Back Shoal (restricted) and Lagoon associations facies.The microfacies analysis and reconstructed the paleoenvironments of the Cenomanian-Early Turonian basin in the studied area; there are three stages of the deposition: -First stage:- during this stage the basin of Rumaila Formation was continued to deposition the lower part of Mishrif within the basinal environment. The end of this basin (Rumaila basin) marked by appeared the open marine associated facies to the northwest basin which represent the mfs surface. The Highstand system distinguished by sequential the open sea facies to the shoal facies and biostorm. The first stage was finished by widespread of shoal facies in all studied area to marked a sequence boundary type II (prograde stage A).Second stage:- is represented by the developed the basin from the shoal to biostorm dominated facies with slow sea level rise. The presence of the open marine associated facies within the biostorm-shoal sequence marked the mfs surface. The final step of this stage was shown the shallowing up-ward by appeared the lagoon/restricted association facies overlying the biostorm. At the end of this period, the lagoon/restricted facies were spread in the studied area to mark the prograde stage B as sequence boundary type II.Third stage:- the sea level was raised from the northwest direction as open sea association facies, while to the southeast the biostorme and shoal facies was dominated. The first appeared for the shoal facies upon the open sea facies marked the mfs surface to start the final highstand deposition within the restricted and biostorm/shoal facies. This stage is represent the prograde stage C for the Mishrif Formation, where the deposition has ended to mark the unconformable surface (SBI) with Khasib Formation
Seroprevalence of cytomegalovirus and rubella among pregnant women in western Sudan
<p>Abstract</p> <p>Background</p> <p>Maternal cytomegalovirus (CMV) and rubella infections have adverse neonatal outcomes. Basic epidemiological data concerning CMV and rubella is necessary for health planners and care providers.</p> <p>Methods</p> <p>A cross sectional study was conducted at El-Rahad hospital, Sudan to investigate seroprevalence of CMV and rubella infections and associated possible risk factors among pregnant women. Structured questionnaires were used to gather socio-demographic data and ELISA was used to detect CMV and rubella infections using IgG and IgM.</p> <p>Results</p> <p>Out of 231 pregnant women, 167 (72.2%) and 151 (65.3%) were CMV-IgG and rubella-IgG positive, respectively. Only 6 (2.5%) and 8 women (3.4%) were CMV-IgM and rubella-IgM positive, respectively. While, high parity (OR = 14.7, 95%CI = 1.7 - 123.6; <it>P </it>= 0.01] and illiteracy (OR = 3.0, CI = 1.4 - 6.5; <it>P </it>= 0.004) were significantly associated with seropostive CMV-IgG in multivariate analysis, none of the other obstetrical and medical characteristics were significantly associated with CMV or rubella infections.</p> <p>Conclusion</p> <p>CMV prevalence was 72.2% and rubella susceptibility among pregnant women was 34.6%. Rubella vaccine and routine screening for rubella and CMV should be introduced for pregnant women in this setting. Further research is needed.</p
Entropija stanja obojenih kvarkova na konaÄnoj temperaturi
The quantum entropy at finite temperatures is analyzed by using models for colored quarks making up the physical states of the hadrons. We explicitly work out some special models for the structure of the states of SU(2)c and SU(3)c related to the effects of temperature on the quantum entropy. We show that the entropy of the singlet states monotonically changes with the temperature. However, the structure of the octet states has a greater complexity which can be best characterized by two types, one of which is similar to that of the singlet states, while the other one reflects the existence of strong correlations between only two of the color states. For the sake of comparison, we work out the entropy for the classical Ising and the quantum XY spin chains. In the Ising model, the quantum entropy in the ground state does not directly enter into the partition function. It also does not depend on the number of spatial dimensions, but only on the number of quantum states making up the ground state. But the XY spin chain has a finite entropy at vanishing temperature. With the inclusion of the ground state, the results from the spin models are qualitatively similar to our models for the states of SU(2)c and SU(3)c.Analiziramo kvantnu entropiju na konaÄnim temperaturama prouÄavajuÄi modele obojenih kvarkova koji grade fiziÄka stanja hadrona. Podrobno razlaĆŸemo posebne modele za strukturu stanja SU(2)c i SU(3)c koji tumaÄe uÄinke temperature na kvantnu entropiju. Pokazujemo da se entropija singletnih stanja monotono mijenja s temperaturom. MeÄutim, struktura tripletnih stanja znatno je zamrĆĄenija, ĆĄto se najbolje moĆŸe prikazati dvama opisima, jednom koji je sliÄan opisu singletnih stanja, i drugom koji odraĆŸava pojavu snaĆŸnih korelacija samo meÄu dvama stanjima boje. Radi usporedbe, raÄunamo entropiju za klasiÄni Isingov model i kvantnih XY spinskih lanaca. U Isingovom modelu, kvantna entropija osnovnog stanja ne ulazi izravno u particijsku funkciju. Ona takoÄer ne ovisi o broju prostornim dimenzija, veÄ samo o broju kvantnih stanja koja tvore osnovno stanje. Ali XY spinski lanac zadrĆŸava konaÄnu entropiju ako temperatura iĆĄÄezava. Ako se ukljuÄi osnovno stanje, ishodi spinskih modela sliÄni su naĆĄim modelima za SU(2)c i SU(3)c
Operating Cash Flow, Earning Response Coefficient, and Fixed Asset Revaluation: Study on Manufacturing Company
The purpose of this study to determine the effect of operating cash flow to the abnormal return and the effect of operating cash flow to the abnormal return of companies that conduct the revaluation is higher than that of non revaluation which adopted SFAS No. 16 (2012). The analysis used in this study are multiple regression, for the period 2012-2015. The results showed that operating cash flow has no effect on non-sampled companies revaluation, while the sample of firms that perform revaluation proves that operating cash flow has a positive and significant impact on the abnormal return. Moreover, the effect of revaluation policy can strengthen the influence between operating cash flow to the firm abnormal return than non revaluation.DOI: 10.15408/etk.v16i1.482
To Insure Prejudice: Racial Disparities in Taxicab Tipping Essay
It has become increasingly common to test whether sellers in retail markets discriminate against buyers. But this Essay is one of the first efforts to test the other side of the market. It examines whether retail consumers discriminate against sellers on the basis of the sellers\u27 race. Even though Gary Becker long ago understood that consumers\u27 taste[] for discrimination could cause sellers to discriminate against other customersâfor example, leading restaurant owners to maintain racially segregated lunch countersâalmost no one has tested whether consumers\u27 taste for discrimination might be directed at a seller\u27s race itself (or the race of a seller\u27s employees).
This failure to test is unjustified. Tests of consumer-side race discrimination are just as feasible as seller-side testing. Consumer price discrimination might be observed in car and house negotiations and auction markets (including online markets such as eBay). Of course, the ability of consumers to discriminate in terms of pricing is often severely constrained. Outside of auction and negotiated-pricing regimes, consumers are generally presented with a fixed price
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