R-process Nucleosynthesis from Three-Dimensional Magnetorotational Core-Collapse Supernovae

We investigate r-process nucleosynthesis in three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. The simulations include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission and absorption. We track the composition of the ejected material using the nuclear reaction network SkyNet. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae (CCSN) are important for their nucleosynthetic signature. We find that production of r-process material beyond the second peak is reduced by a factor of 100 when the magnetorotational jets produced by the rapidly rotating core undergo a kink instability. Our results indicate that 3D magnetorotationally powered CCSNe are a robust r-process source only if they are obtained by the collapse of cores with unrealistically large precollapse magnetic fields of order $10^{13}$G. Additionally, a comparison simulation that we restrict to axisymmetry, results in overly optimistic r-process production for lower magnetic field strengths.Comment: 10 pages, 9 figures, 2 tables. submitted to Ap

Dakwah Melalui Radio (Analisis Program Konsultasi Agama Islam Di Radio Mesra Fm)

For media information, radio playing a significant role in conveying the values of Islam which is very important in the formation of a true Muslim personalities in accordance with the demands of the Prophet Muhammad. The existence of an Islam-based radio is felt to be very important because Islam should be spread widely and truth telling is the responsibility of the Muslims as a whole. As word of Allah in Surah al-Imran: 104.`Dari permaslahan above authors take the title essay propaganda through radio (program analysis consultancy Islam in Mesra radio FM) as the research object because the writer wanted to know how the production process of consultation Islam, what enabling and inhibiting factors Islam consultation program and analyze descriptively Islam consultation program. This research is using the case study method with the aim to explain the phenomenon through data collection techniques. This type of research is descriptive qualitative approach and used the theory of critical theory and the theory of mechanics.Hasil penelitian yang didapat adalah program konsultasi agama Islam merupakan program mingguan yang mengudara mulai pukul 10.30-11.30 disetiap hari Jum\u27at. The program has a dialog format or interactive manner. Factors supporting the consultation program of Islam, namely: Supported by the government and people of the city of Pare Pare while the limiting factor is the lack of public interest in consulting the religion of Islam, the lack of infrastructure in implementing the program, bad weather at the time of the program which affects not maximal broadcasting. Islam consultation program is very useful for people, especially in the town of Pare Pare, for answering complaints or problems faced by the people in the religious practice of Islam

Millennial-scale climatic variability between 340000 and 270000 years ago in SW Europe : evidence from a NW Iberian margin pollen sequence

© 2009 The Authors. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Climate of the Past 5 (2009): 53-72, doi:10.5194/cp-5-53-2009We present a new high-resolution marine pollen record from NW Iberian margin sediments (core MD03-2697) covering the interval between 340 000 and 270 000 years ago, a time period centred on Marine Isotope Stage (MIS) 9 and characterized by particular baseline climate states. This study enables the documentation of vegetation changes in the north-western Iberian Peninsula and therefore the terrestrial climatic variability at orbital and in particular at millennial scales during MIS 9, directly on a marine stratigraphy. Suborbital vegetation changes in NW Iberia in response to cool/cold events are detected throughout the studied interval even during MIS 9e ice volume minimum. However, they appear more frequent and of higher amplitude during the 30 000 years following the MIS 9e interglacial period and during the MIS 9a-8 transition, which correspond to intervals of an intermediate to high ice volume and mainly periods of ice growth. Each suborbital cold event detected in NW Iberia has a counterpart in the Southern Iberian margin SST record. High to moderate amplitude cold episodes detected on land and in the ocean appear to be related to changes in deep water circulation and probably to iceberg discharges at least during MIS 9d, the mid-MIS 9c cold event and MIS 9b. This work provides therefore additional evidence of pervasive millennial-scale climatic variability in the North Atlantic borderlands throughout past climatic cycles of the Late Pleistocene, regardless of glacial state. However, ice volume might have an indirect influence on the amplitude of the millennial climatic changes in Southern Europe.This research was supported by IPEV (Institut Paul Emile Victor), PNEDC (Programme National d’Etude de la Dynamique du Climat), the Gary Comer Science and Education Foundation and the US National Science Foundation (OCE grants 8-4911100 and 8-256500)

Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal and cubic phases of methylammonium lead iodide

The hybrid halide perovskite CH3NH3PbI3 exhibits a complex structural behaviour, with successive transitions between orthorhombic, tetragonal and cubic polymorphs at ca. 165 K and 327 K. Herein we report first-principles lattice dynamics (phonon spectrum) for each phase of CH3NH3PbI3. The equilibrium structures compare well to solutions of temperature-dependent powder neutron diffraction. By following the normal modes we calculate infrared and Raman intensities of the vibrations, and compare them to the measurement of a single crystal where the Raman laser is controlled to avoid degradation of the sample. Despite a clear separation in energy between low frequency modes associated with the inorganic PbI3 network and high-frequency modes of the organic CH3NH3+ cation, significant coupling between them is found, which emphasises the interplay between molecular orientation and the corner-sharing octahedral networks in the structural transformations. Soft modes are found at the boundary of the Brillouin zone of the cubic phase, consistent with displacive instabilities and anharmonicity involving tilting of the PbI6 octahedra around room temperature.Comment: 9 pages, 4 figure

Prevalence of microalbuminuria in untreated Nigerian hypertensive patients

The burden of cardiovascular disease imposed by hypertension is a result of target organ damage. Microalbuminuria (MA) is the first clinical expression of nephropathy and has become acardiovascular and/or renal disease prognostic indicator for hypertensive subjects. Objectives: To establish the prevalence of MA among newly diagnosed hypertensive patients using thesimple spot urine Albumin-Creatinine Ratio (ACR). Method: : One hundred and eighty six newly diagnosed hypertensive patients were enrolled for assessment of MA using spot urine ACR. Those with overt proteinuria, diabetes mellitus, overt kidney disease and other potential causes of albuminuria were excluded. Spot urine was obtained for measurement of albuminand creatinine. Anthropometric variables were measured and body mass index calculated. All patients had echocardiographic assessment. Statistical analysis was performed using SPSS version 11.0 software. Multiple regression analysis was used in determining predictors of MA. A p-value of ≤ 0.05 was considered significant. Results: Results of 136 patients comprising of 66(48.53%) males and 70(51.47%) females was considered. The overall prevalence of microalbuminuria was 42.65%. Males had a prevalence of 51.52% compared to 34.27% for the females (p=0.29). Weight, BMI, LVM, LVMI, UAE, and ACR were significantly higher in patients with MA, whereas those without MA had a significantly higher urinary creatinine. Multiple regression analysis identified DBP, MAP, LVM and LVMI as significant predictors of increased urinary albumin excretion Microalbuminuria showed significant positive correlation with LVM and LVMI. Conclusion: The prevalence of microalbuminuria is high among untreated Nigerian hypertensive patients. The spot urine ACR provides a simple, accurate and cost effective way of identifying this high risk group of hypertensive patients, allowing for more aggressive treatment to reduce cardiovascular outcomes

Unscreened Coulomb repulsion in the one dimensional electron gas

A tight binding model of electrons interacting via bare Coulomb repulsion is numerically investigated by use of the Density Matrix Renormalization Group method which we prove applicable also to very long range potentials. From the analysis of the elementary excitations, of the spin and charge correlation functions and of the momentum distribution, a picture consistent with the formation of a one dimensional "Wigner crystal" emerges, in quantitative agreement with a previous bosonization study. At finite doping, Umklapp scattering is shown to be ineffective in the presence of long range forces.Comment: RevTex, 5 pages with 8 eps figures. To be published on Phys. Rev.

Insulator-Metal Transition in One Dimension Induced by Long-Range Electronic Interactions

The effects of a long range electronic potential on a one dimensional commensurate Charge Density Wave (CDW) state are investigated. Using numerical techniques it is shown that a transition to a metallic ground state is reached as the range of the electron-electron repulsion increases. In this metallic state, the optical conductivity exhibits a large Drude weight. Possible interpretations of our results are discussed.Comment: 5 pages, Revtex, minor misprints corrected and a reference to earlier work by V. Emery and C. Noguera adde