Condensation of MgS in outflows from carbon stars

The basic mechanism responsible for the widespread condensation of MgS in the outflows from carbon rich stars on the tip of the AGB is discussed with the aim of developing a condensation model that can be applied in model calculations of dust formation in stellar winds. The different possibilities how MgS may be formed in the chemical environment of outflows from carbon stars are explored by some thermochemical calculations and by a detailed analysis of the growth kinetics of grains in stellar winds. The optical properties of core-mantle grains with a MgS mantle are calculated to demonstrate that such grains reproduce the structure of the observed 30 $\mu$m feature. These considerations are complemented by model calculations of circumstellar dust shells around carbon stars. It is argued that MgS is formed via precipitation on silicon carbide grains. This formation mechanism explains some of the basic observed features of MgS condensation in dust shells around carbon stars. A weak secondary peak at about 33 ... 36 $\mu$m is shown to exist in certain cases if MgS forms a coating on SiC.Comment: 9 pages, 7 figure

MGS accelerometer data analysis with the LMD GCM

Mars Global Surveyor aerobreaking phases, required to achieve its mapping orbit, have yielded vertical profiles of thermospheric densities, scale heights and temperatures covering a broad range of local times, seasons and spatial coordinates [Keating et al. 1998, 2001]. Phase I covered local times from 11 to 16 h (assuming 24 "martian hours” per martian day or sols), with a latitude coverage of approximately 40deg to 60deg N. Seasons observed during this phase were centered around winter solstice and altitudes of periapsis range from 115 to 135 km. The altitudes for Phase II were lower, with a minimum around 100 km and a maximum around 120. Martian spring was the season covered during this phase and the local time was between 15 and 16 h. The latitude covered by Phase II, however, was more extense than that seen during Phase I, with a coverage from 60deg N to basically the South Pole

Keterampilan Manajerial Kepala Sekolah

The general purpose of this study was to determine the skills of junior High School number 7 Lubuklinggau. While the specific purpose of this research are: (1) to describe the conceptual skills of Principal. (2) to describe human relations skills of Principal. (3) to describe the technical skills of Principal. This research used descriptive qualitative method is based on the formulation of research that requires researchers to explore in order to understand and explain the problems examined through an intensive relationship with the source data. In General researcherscan deduce that the Principal of the junior high school number 7 Lubuklinggau.Keywod: managerial skills, principa

Strategi Pemasaran Jasa Pendidikan (Analisis Pengembangan Madrasah)

The existence of Islamic School in the context of national education had not shown to the quality expected in every province there were Islamic schools (State) were built and managed specifically to be a superior Islamic schools. But other Islamic schools that were not built and managed specifically still cannot compete optimally. A form of competition was the quality, integrity, credibility and accountability in the eyes of the community and parents. Islamic schools were still viewed as "an alternative educational institution" which prepared their vacant locals for students who failed to compete at another schools. In connection with it (in order to improve the competitiveness of Islamic schools) might be tried to use marketing models of the industry by market logic approach

Current-voltage relation for superconducting d-wave junctions

We calculate the current-voltage (I-V) relation for planar superconducting d-wave junctions for both arbitrary transmission of the junction and arbitrary orientation of the d-wave superconductors. The midgap states (MGS) present at interfaces/surfaces of a d-wave superconductor influence the I-V relation. In some arrangements we find considerable negative differential conductance and lower threshold voltage for non-zero current due to resonant conduction through MGS.Comment: 4 pages, 2 figure

HP-multigrid as smoother algorithm for higher order discontinuous Galerkin discretizations of advection dominated flows. Part II. Optimization of the Runge-Kutta smoother

Using a detailed multilevel analysis of the complete hp-Multigrid as Smoother algorithm accurate predictions are obtained of the spectral radius and operator norms of the multigrid error transformation operator. This multilevel analysis is used to optimize the coefficients in the semi-implicit Runge-Kutta smoother, such that the spectral radius of the multigrid error transformation operator is minimal under properly chosen constraints. The Runge-Kutta coefficients for a wide range of cell Reynolds numbers and a detailed analysis of the performance of the hp-MGS algorithm are presented. In addition, the computational complexity of the hp-MGS algorithm is investigated. The hp-MGS algorithm is tested on a fourth order accurate space-time discontinuous Galerkin finite element discretization of the advection-diffusion equation for a number of model problems, which include thin boundary layers and highly stretched meshes, and a non-constant advection velocity. For all test cases excellent multigrid convergence is obtained

Three Moving Groups Detected in the LAMOST DR1 Archive

We analyze the kinematics of thick disk and halo stars observed by the Large sky Area Multi-Object Fiber Spectroscopic Telescope. We have constructed a sample of 7,993 F, G and K nearby main-sequence stars (\textit{d} $<$ 2 kpc) with estimates of position (x, y, z) and space velocity ($U$, $V$, $W$) based on color and proper motion from the SDSS DR9 catalog. Three `phase-space overdensities' are identified in [\textit{V}, $\sqrt{U^{2}+2V^{2}}$] with significance levels of $\sigma$ $>$ 3. %[L$_{Z}$, eccentricity], [L$_{Z}$, L$_{\bot}$], and [V$_{az}$, V$_{\triangle}E$]. Two of them (Hyades-Pleiades stream, Arcturus-AF06 stream) have been identified previously. We also find evidence for a new stream (centered at \textit{V} $\sim$ -180 km s$^{-1}$) in the halo. The formation mechanisms of these three streams are analyzed. Our results support the hypothesis the Arcturus-AF06 stream and the new stream originated from the debris of a disrupted satellite, while Hyades-Pleiades stream has a dynamical origin.Comment: 7 pages, 5 figure

Defining Petrophysical Units of the Palmer Deep Sites from Leg 178

Palmer Deep, on the inner continental shelf southwest of Anvers Island off the Antarctic Peninsula, is a glacially overdeepened basin consisting of three subbasins. Two sites, 1098 and 1099, were drilled in the Palmer Deep area. A high-resolution porosity curve has been calculated from density data and subsequently plotted against the shipboard lithologic logs. These new data correspond accurately to the lithologic logs, magnetic susceptibility, and gamma ray attenuation (GRA) density data and offer information on the heterogeneity of the sediments. Petrophysical groups have been generated to investigate interrelationships between different physical attributes. To develop these petrophysical groups, crossplots of the available physical properties data were performed. The results for the GRA density and magnetic susceptibility crossplots demonstrate distinct clusters. Plotting the magnetic susceptibility and GRA density data logs (divided into these new petrophysical groups) against lithology provided information to subdivide the lithologic unit(s) into a series of petrophysical units