On the Maxwellian distribution, symmetric form, and entropy conservation for the Euler equations

The Euler equations of gas dynamics have some very interesting properties in that the flux vector is a homogeneous function of the unknowns and the equations can be cast in symmetric hyperbolic form and satisfy the entropy conservation. The Euler equations are the moments of the Boltzmann equation of the kinetic theory of gases when the velocity distribution function is a Maxwellian. The present paper shows the relationship between the symmetrizability and the Maxwellian velocity distribution. The entropy conservation is in terms of the H-function, which is a slight modification of the H-function first introduced by Boltzmann in his famous H-theorem. In view of the H-theorem, it is suggested that the development of total H-diminishing (THD) numerical methods may be more profitable than the usual total variation diminishing (TVD) methods for obtaining wiggle-free solutions

Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays

We study effects of new physics beyond the Standard Model on SU(3) symmetry in charmless hadronic two body B decays. It is found that several equalities for some of the decay amplitudes, such as $A(B_d (B_u) \to \pi^+\pi^-,\pi^+ K^- (\pi^- \bar K^0)) =A(B_s \to K^+ \pi^-, K^- K^+ (K^0 \bar K^0))$, $A(B_d \to \pi^+\rho^-, \pi^- \rho^+, K^-\rho^+, \pi^+ K^{*-}) = A(B_s \to K^+ \rho^-, \pi^- K^{*+}, K^- K^{*+}, K^+ K^{*-})$, $A(B_d (B_u) \to \rho^+\rho^-, \rho^+ K^{*-}(\rho^- \bar K^{*0})) =A(B_s \to K^{*+} \rho^-, K^{*-} K^{*+} (K^{*0} \bar K^{*0}))$, predicted by SU(3) symmetry in the SM are not affected by new physics. These relations provide important electroweak model independent tests for SU(3) symmetry in B decays.Comment: 4 pages, revte

Least squares kinetic upwind method on moving grids for unsteady Euler computations

The present paper describes the extension of least squares kinetic upwind method for moving grids (LSKUM-MG). LSKUM is a kinetic theory based upwind Euler solver. LSKUM is a node based solver and can operate on any type of mesh or even on an arbitrary distribution of points. LSKUM-MG also has the capability to work on arbitrary meshes with arbitrary grid velocities. Results are presented for a moving piston problem and flow past an airfoil oscillating in pitch

Hybrid vehicle assessment. Phase 1: Petroleum savings analysis

The results of a comprehensive analysis of near term electric hybrid vehicles are presented, with emphasis on their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles are first modeled. The projected U.S. fleet composition is estimated, and conceptual hybrid vehicle designs are conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates are then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of sevral conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle mission battery combination. Conclusions and recommendations are presented, and development recommendations are identified

Constraints on the phase γ\gamma and new physics from B→KπB\to K\pi Decays

Recent results from CLEO on $B\to K\pi$ indicate that the phase $\gamma$ may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that $\gamma$ extracted using $B\to K\pi, \pi\pi$ is sensitive to new physics occurring at loop level. It provides a powerful method to probe new physics in electroweak penguin interactions. Using effects due to anomalous gauge couplings as an example, we show that within the allowed ranges for these couplings information about $\gamma$ obtained from $B\to K \pi, \pi\pi$ can be very different from the Standard Model prediction.Comment: Revised version with analysis done using new data from CLEO. RevTex, 11 Pages with two figure

The CP violating phase γ\gamma from global fit of rare charmless hadronic B decays

We study constraints on the CP violating phase $\gamma$ in the Kobayashi-Maskawa model using available experimental data. We first follow the conventional method to up date the constraint on $\gamma$ by performing a $\chi^2$ analysis using data from $|\epsilon_K|$, $\Delta m_{B_{d,s}}$ and $|V_{ub}/V_{cb}|$. We also include the recent information on $\sin2\beta$ in the analysis. We obtain the best fit for $\gamma$ to be $66^\circ$ and the 95% C.L. allowed range to be $42^\circ \sim 87^\circ$. We then develop a method to carry out a $\chi^2$ analysis based on SU(3) symmetry using data from $B\to \pi \pi$ and $B\to K \pi$. We also discuss SU(3) breaking effects from model estimate. We find that present data on $B\to \pi\pi, K \pi$ can also give some constraint on $\gamma$ although weaker than the earlier method limited by the present experimental errors. Future improved data will provide more stringent constraint. Finally we perform a combined fit using data from $|\epsilon_K|$, $\Delta m_{B_{d,s}}$, $|V_{ub}/V_{cb}|$, $\sin2\beta$ and rare charmless hadronic B decays. The combined analysis gives $\gamma=67^\circ$ for the best fit value and $43^\circ \sim 87^\circ$ as the 95% C.L. allowed range. Several comments on other methods to determine $\gamma$ based on SU(3) symmetry are also provided.Comment: Revised verion with the new experimental data from Belle and Babar included in the analysis to obtain the global fit for the CP violating phase gamma. RevTex, 32 pages and 8 figure

The study of causes, mode of delivery in intrauterine fetal death and associated complications

Background: Intra uterine fetal death (IUFD) is defined as the baby born with no signs of life at or after 28 weeks of gestation. It is important to diagnose the cause in order to avoid further recurrence and to treat any maternal associated factors. The aim of the present study was to calculate incidence of IUFD in our hospital and know the causes, mode of delivery, associated complications. So we can take measures to prevent them in future.Methods: The retrospective study was conducted in the department of Obstetrics and Gynecology in Kanachur Medical College, Mangalore from January 2017 to January 2020. The women with confirmed diagnosis of IUFD on Ultrasound and beyond 28 weeks of gestation were included in the study.Results: In the study period, total 2026 patients delivered, of which 40 cases were IUFD, hence our incidence rate was 19.74 per 1000 population. 62.5% cases were multigravida. 15% had previous history of abortions while 5% previously had IUFD. In 37.5% cases, the cause was unknown, followed by 22.5% having pregnancy induced hypertension. Anemia contributed to 17.5% and placental causes in 12.5%. 10% of the women had PPH. One patient had sepsis, followed by acute renal failure and later died of multi organ failure.Conclusions: All the causes are not preventable, many of them can be identified early in pregnancy and thus IUFD can be prevented. All the high risk pregnancies should undergo antenatal fetal surveillance and should have frequent ante natal visits to reduce IUFD rates

The presence of ehealth support for childhood obesity guidance

A rising global obesity epidemic in children has implications for an increase in other chronic diseases and a negative social impact, which should not be ignored. A useful resource in this context could be eHealth due to its popularity amongst children. Additionally, telephone guidance is also considered a powerful health promotion tool. The aim of this study was to investigate the availability of mobile applications (apps), websites, helplines, and advice lines for child obesity guidance, in European countries. A survey was conducted in 28 European Member States and 2 European Economic Area countries, in 2017. Twenty-three responses were collected. Fourteen countries stated the presence of an obesity management website

Restricted Wiedemann-Franz law and vanishing thermoelectric power in one-dimensional conductors

In one-dimensional (1D) conductors with linear E-k dispersion (Dirac systems) intrabranch thermalization is favored by elastic electron-electron interaction in contrast to electron systems with a nonlinear (parabolic) dispersion. We show that under external electric fields or thermal gradients the carrier populations of different branches, treated as Fermi gases, have different temperatures as a consequence of self-consistent carrier-heat transport. Specifically, in the presence of elastic phonon scattering, the Wiedemann-Franz law is restricted to each branch with its specific temperature and is characterized by twice the Lorenz number. In addition thermoelectric power vanishes due to electron-hole symmetry, which is validated by experiment.Comment: 10 pages, 2 figure

Development of Tailorable Electrically Conductive Thermal Control Material Systems

The optical characteristics of surfaces on spacecraft are fundamental parameters in controlling its temperature. Passive thermal control coatings with designed solar absorptance and infrared emittance properties have been developed and have been in use for some time. In this total space environment, the coating must be stable and maintain its desired optical properties as well as mechanical properties for the course of the mission lifetime. The mission lifetimes are increasing and in our quest to save weight, newer substrates are being integrated which limit electrical grounding schemes. All of this has added to already existing concerns about spacecraft charging and related spacecraft failures or operational failures. The concern is even greater for thermal control surfaces that are very large. One way of alleviating such concerns is to design new thermal control material systems (TCMS) that can help to mitigate charging via providing charge leakage paths. The objective of this program was to develop two types of passive electrically conductive TCMS. The first was a highly absorbing/emitting black surface and the second was a low (alpha(sub s)/epsilon(sub N)) type white surface. The surface resistance goals for the black absorber was 10(exp 4) to 10(exp 9) Omega/square, and for the white surfaces it was 10(exp 6) to 10(exp 10) Omega/square. Several material system concepts were suggested and evaluated for space environment stability and electrical performance characterization. Our efforts in designing and evaluating these material systems have resulted in several developments. New concepts, pigments and binders have been developed to provide new engineering quality TCMS. Some of these have already found application on space hardware, some are waiting to be recognized by thermal designers, and some require further detailed studies to become state-of-the-art for future space hardware and space structures. Our studies on baseline state-of-the-art materials and conductive concepts have resulted in several important findings that are of interest to all thermal designers and systems integrators