Long-Time Evolution of Gas-Free Disc Galaxies in Binary Systems

We present the results of several detailed numerical N-body simulations of the dynamical interactions of two equal mass disc galaxies. Both galaxies are embedded in spherical halos of dark matter and contain central bulges. Our analysis of the dynamical evolution of the binary system focuses on the morphological evolution of the stellar distribution of the discs. The satellite galaxy has coplanar or polar disc orientation in relation to the disc of the primary galaxy and their initial orbits are prograde eccentric ($e=0.1$, $e=0.4$ or $e=0.7$). Both galaxies have mass and size comparable to the Milky Way. We show that the merger of the two disc galaxies, depending on the relative orientation of the discs, can yield either a disc or lenticular remnant, instead of an elliptical one. These are the first simulations in the literature to show the formation of S0-like galaxies from protracted binary galaxy interactions. Additionally, we demonstrate that the time to merger increases linearly with the initial apocentric distance between the galaxies, and decreases with the initial orbital eccentricity. We also show that the tidal forces of the discs excite transient $m=1$ and $m=2$ wave modes, i.e., lopsidedness, spiral arms, and bars. However, after the merging of the discs, such instabilities fade completely, and the remnant is thicker and bigger than the original discs. The maximum relative amplitude of these waves is at most about 15 times greater compared to the control case. of these two wave modes. Finally, the disc settles down quickly, after the merger, in less than one outer disc rotation period.Comment: 23 pages, 3 tables and 16 figures. Accepted for publication in A&

Physics of heat pipe rewetting

Although several studies have been made to determine the rewetting characteristics of liquid films on heated rods, tubes, and flat plates, no solutions are yet available to describe the rewetting process of a hot plate subjected to a uniform heating. A model is presented to analyze the rewetting process of such plates with and without grooves. Approximate analytical solutions are presented for the prediction of the rewetting velocity and the transient temperature profiles of the plates. It is shown that the present rewetting velocity solution reduces correctly to the existing solution for the rewetting of an initially hot isothermal plate without heating from beneath the plate. Numerical solutions have also been obtained to validate the analytical solutions

Characterization of the potential yield of clone IRCA230

The experiment on Yield Potential Comparison on S/2 d3 and S/2d4 Tapping Systems of Clones IRCA230 were practiced on farm research at Chup Rubber Research Station of Cambodian Rubber Research Institute (CRRI). The experimental design was the RCBD with 8 treatments and 4 replications with a total number 400 trees per replication. They were opened at the standard girth of 50 cm measured at 1m high. All the trees were opened at 1.3 m from the ground. The tapping systems were S/2 d3 7d/7 and S/2 d4 7d/7. This clonal typology is based on measurements issued from the latex diagnosis. The objective of the experiment was to investigate the yield potential comparison of the tapping system S/2 d3 7d/7 and S/2 d4 7d/7 based on frequency of ethephon stimulation. Stimulation was related to the sucrose and inorganic phosphorus contents of the latex cells. Clone IRCA 230, with higher sugar content, with high ethephon stimulations per year obtained the highest yield. The cumulative yield in gram per tree over 8 years of tapping showed frequency d3 higher yield than frequency d4. The yield of tapping frequency with stimulation 1.5% 7/y control was higher than them. (Résumé d'auteur

Identity, environment and mental wellbeing in the veterinary profession

Mental health and career dissatisfaction are of increasing concern to the veterinary profession. The influence of identity on the psychological wellbeing of veterinarians has not been widely explored. Twelve recent veterinary graduates were enrolled in a private social media discussion group, and their identities investigated through narrative inquiry: a methodology which enables identity priorities to be extrapolated from stories of experience. Two distinct variants of the veterinary identity were identified: an academic, ‘diagnosis-focused’ identity, which prioritised definitive diagnosis and best-evidence treatment; and a broader ‘challenge-focused’ identity, where priorities additionally included engaging with the client, challenging environment or veterinary business. Contextual challenges (such as a client with limited finances or difficult interpersonal interactions) were seen as a source of frustration for those with a diagnosis-focused identity, as they obstructed the realisation of identity goals. Overcoming these challenges provided satisfaction to those with a challenge-focused identity. The employment environment of the graduates (general veterinary practice) provided more opportunities for those with a challenge-focused identity to realise identity goals, and more markers of emotional wellbeing were apparent in their stories. Markers of poor emotional health were evident in the stories of those with a diagnosis-focused identity

The efficiency of residential mortgage guarantee insurance markets

Mortgage Guarantee Insurance (MGI) provides protection to lenders against default by borrowers who have less than 20 percent equity interest in the mortgaged property. The existence of this form of insurance helps to stimulate home ownership by allowing consumers with less than twenty percent down payment access to credit markets. Initially an invention of lenders, MGI became dominated by government agencies after the Great Depression but recently private insurers have increased their market share to more than 75 percent. The domination of the industry by the private sector appears not to affirm competition, however. Despite varying loss ratios across states, MGI premiums appear to remain relatively uniform, suggesting price inflexibility. This paper uses cross-sectional data on loss ratio, mortgage delinquency rates, and housing prices to test empirically the level of competition in the MGI industry. The paper finds that the level of competition in the industry is not sufficient to drive the premiums to the competitive (efficient) level. The implication is that national cross subsidies occur where high risk insureds are subsidized by low risk insureds.Mortgages

Comparative studies on yield potential of some hevea clones in Cambodia

Cambodian Rubber Research Institute is carrying out researches on tapping systems to assess the influence of intensity of stimulation on yield at a given tapping frequency 1/2S d/3 7d/7. The objectives of these trials are to determine the yield potential of each clone at various intensity of hormonal stimulation. Five clones have been studied since March 2005. These clones are IRCA111, PB330, GT1, IRCA230 and AF261. Each trial consists of Fisher block design with 3 replications and four treatments per replication. Two protocols of stimulation were set up for different clones. The preliminary results show that the highest yields for the clone IRCA111 and PB330 are obtained with ET 1.5% Pa 1(1) 5/y (75 mg) and ET 2.5% Pa 1(1) 2/y (50 mg), respectively. Interestingly, the clones GT1 and IRCA230 give significant high yield at the most intensive treatments, ET 2.5% Pa 1(1) 6/y (150 mg). However, the clone AF261 does not response to more intensive stimulation system than ET 1.5% Pa 1(1) 5/y as the same yields are obtained at different intensities of stimulation. The clone GT1 gives the highest yield at increased stimulation intensity compared with other clones. (Texte intégral

Anomalous Josephson current through a ferromagnetic trilayer junction

We studied the anomalous Josephson current appearing at zero phase difference in junctions coupled with a ferromagnetic trilayer which has noncoplanar magnetizations. A $\pi/2$ junction with an equilibrium phase difference $\pi/2$ is obtained under suitable conditions. The equilibrium phase difference and the amplitude of the supercurrent are all tunable by the structure parameters. In addition to calculating the anomalous current using the Bogoliubov-de Gennes equation, we also developed a clear physical picture explaining the anomalous Josephson effect in the structure. We show that the triplet proximity correlation and the phase shift in the anomalous current-phase relation all stem from the spin precession in the first and third ferromagnet layers.Comment: 7 pages, 8 figures, accepted to PR

Discussion of "Feature Matching in Time Series Modeling" by Y. Xia and H. Tong

Discussion of "Feature Matching in Time Series Modeling" by Y. Xia and H. Tong [arXiv:1104.3073]Comment: Published in at http://dx.doi.org/10.1214/11-STS345B the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Duality Cascade and Oblique Phases in Non-Commutative Open String Theory

We investigate the complete phase diagram of the decoupled world-sheet theory of (P,Q) strings. These theories include 1+1 dimensional super Yang-Mills theory and non-commutative open string theory. We find that the system exhibits a rich fractal phase structure, including a cascade of alternating supergravity, gauge theory, and matrix string theory phases. The cascade proceeds via a series of SL(2,Z) S-duality transformations, and depends sensitively on P and Q. In particular, we find that the system may undergo multiple Hagedorn-type transitions as the temperature is varied.Comment: 21 pages, 4 figures, references adde