Resonant Spin-Flavor Conversion of Supernova Neutrinos: Dependence on Electron Mole Fraction

Detailed dependence of resonant spin-flavor (RSF) conversion of supernova neutrinos on electron mole fraction Ye is investigated. Supernova explosion forms a hot-bubble and neutrino-driven wind region of which electron mole fraction exceeds 0.5 in several seconds after the core collapse. When a higher resonance of the RSF conversion is located in the innermost region, flavor change of the neutrinos strongly depends on the sign of 1-2Ye. At an adiabatic high RSF resonance the flavor conversion of bar{nu}_e -> nu_{mu,tau} occurs in Ye 0.5 and inverted mass hierarchy. In other cases of Ye values and mass hierarchies, the conversion of nu_e -> bar{nu}_{mu,tau} occurs. The final bar{nu}_e spectrum is evaluated in the cases of Ye 0.5 taking account of the RSF conversion. Based on the obtained result, time variation of the event number ratios of low bar{nu}_e energy to high bar{nu}_e energy is discussed. In normal mass hierarchy, an enhancement of the event ratio should be seen in the period when the electron fraction in the innermost region exceeds 0.5. In inverted mass hierarchy, on the other hand, a dip of the event ratio should be observed. Therefore, the time variation of the event number ratio is useful to investigate the effect of the RSF conversion.Comment: 16 pages, 33 figures, accepted for publication in Physical Review

Optimal Transmission Scheduling for a Hybrid of Full- and Half-Duplex Relaying

Full-duplex relaying (FDR), i.e., simultaneous transmission and reception using the same frequency channel at a radio relay, can be used to achieve a spectral efficiency higher than that in the case of half-duplex relaying (HDR) if loop-back interference is well-managed. To achieve spectral efficiency that is higher than that achieved when using FDR and HDR separately, an optimal transmission-scheduling scheme for an FDR-HDR hybrid is proposed. The scheme is formulated as an optimization problem. The conditions required to achieve the maximum spectral efficiency are determined analytically. Numerical results confirm that the proposed scheme is superior to FDR and HDR

Long-term stability of flow-path structure in crystalline rocks distributed in an orogenic belt, Japan

Abstract Most evaluations of the contaminant retardation processes likely to be important in geological disposal (e.g. for high level radioactive waste (HLW)) consider only the present characteristics of fractures and associated mineral infills. Relatively little attention has been given to possible long-term changes in these features, and their influence on groundwater flow. The work reported here seeks to provide analogous evidence that such changes are not likely to be important and hence to improve confidence in the presently adopted evaluation methodology and its long-term applicability. In the orogenic belt that is formed by the Japanese islands, there are wide areas of crystalline rock. The rocks in each area have a distinctive age sequence which is partly reflected in the characteristics of the fracture systems and associated mineral fillings that occur. These characteristics generally imply that groundwater and solutes can be conducted through fracture networks, except in the cases of fault zones or crushed zones. The structural and mineralogical features of these networks readily illustrate how certain contaminants might react and be retarded by the fracture fillings and open pore geometry, due to chemical sorption and/or physical retardation. Here, we describe the fracture systems developed in crystalline rocks with different ages that are intruded into the Japanese orogenic belt. The aim is to build a model for the long-term fracturing process and hence to evaluate fracture dstabilityT. In particular, the comparisons are made between the fracture geometries and the frequencies observed in the 1.9-0.8 Ma Takidani Granodiorite (the youngest exposed pluton in the world), the ca. 67 Ma Toki Granite and the ca. 117 Ma Kurihashi Granodiorite located in central to northwest Japan. The observations show that all these crystalline rocks have similar fracture frequencies, with 1 to 2 fractures per meter in the massive part of rock bodies. Mineralogical studies and dating analyses of fracture fillings also suggest that fractures are relatively physically stable. Major new fractures tend not to be created in the massive part of rock bodies even when a pluton has been subjected to the regional stresses of plate movements with a duration of about 100 Ma. The results show the unique characteristics of the fracture forming process and the relatively stable geometries of fracture network systems in crystalline rocks distributed within the orogenic belt. This analogue also enables us to provide a model to build confidence in a technical approach applicable for modeling of hydrogeology and geology over long time scales under th

Confectionery intake and serum phosphorus

Hyperphosphatemia is associated with an increased risk of developing cardiovascular disease. Recently, it has been shown that high serum phosphorus levels are associated with increased cardiovascular events in healthy subjects, but the dietary factors determining serum phosphorus level have not been fully investigated. The study investigated the influence of habitual dietary factors on serum phosphorus levels in healthy young participants. This cross-sectional study conducted fasting blood sampling in 109 healthy young people and used a brief-type self-administered diet history questionnaire to evaluate the subject's habitual meals. Since the bioavailability of dietary phosphorus depends on the food sources, habitual phosphorus intakes from different food groups and intake frequency (times/month) of processed foods were calculated. The mean serum phosphorus level was 3.9±0.5 mg/dl ; 10.1% of the subjects had serum phosphorus levels that exceeded the reference levels of ≤4.5 mg/dl. Total phosphorus intake and phosphorus intake from animal-based food did not differ between serum phosphorus quartiles. Higher intake of confectionery was associated with increased serum phosphorus levels. This study showed that frequent consumption of confectionery was associated with elevated serum phosphorus levels. Additional studies are needed to determine whether this is a causal relationship

Large-scale stem cell production system by newly designed bioreactor

Large scale cell production system is required in drug discovery and cell based therapy. However there are technically challenges in maintaining high quality and low cost for practical biomanufacturing industry. 3D suspension culture is one of attractive process, especially static culture is ultimate free from shear force. Utilizing static 3D suspension culture, automated closed system is newly designed and demonstrated expansion culture over several subcultures. Cell growth curves of this system and conventional manual method have good accordance. The system is also compatible with good scalability for scale up and scale out use. Please click Additional Files below to see the full abstract

Supernova Neutrino Nucleosynthesis of Light Elements with Neutrino Oscillations

Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the ν-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current ν-process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a non-adiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations of the 7Li/11B ratio in stars showing signs of supernova enrichment could thus provide a unique test of neutrino oscillations and constrain their parameters and the mass hierarchy

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Supernova Neutrino Nucleosynthesis of Light Elements with Neutrino Oscillations

Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the nu-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current nu-process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a non-adiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations of the 7Li/11B ratio in stars showing signs of supernova enrichment could thus provide a unique test of neutrino oscillations and constrain their parameters and the mass hierarchy.Comment: 5 pages, 3 figures, accepted for publication in Physical Review Letter