Uncertainties in the nu p-process: supernova dynamics versus nuclear physics

We examine how the uncertainties involved in supernova dynamics as well as in nuclear data inputs affect the nup-process in the neutrino-driven winds. For the supernova dynamics, we find that the wind termination by the preceding dense ejecta shell, as well as the electron fraction (Y_{e, 3}; at 3 10^9 K) play a crucial role. A wind termination within the temperature range of (1.5-3) 10^9 K greatly enhances the efficiency of the nu p-process. This implies that the early wind phase, when the innermost layer of the preceding supernova ejecta is still 200-1000 km from the center, is most relevant to the nup-process. The outflows with Y_{e, 3} = 0.52-0.60 result in the production of the p-nuclei up to A=108 with interesting amounts. Furthermore, the p-nuclei up to A=152 can be produced if Y_{e, 3} = 0.65 is achieved. For the nuclear data inputs, we test the sensitivity to the rates relevant to the breakout from the pp-chain region (A < 12), to the (n, p) rates on heavy nuclei, and to the nuclear masses along the nup-process pathway. We find that a small variation of the rates of triple-alpha and of the (n, p) reaction on 56Ni leads to a substantial change in the p-nuclei production. We also find that 96Pd (N=50) on the nup-process path plays a role as a second seed nucleus for the production of heavier p-nuclei. The uncertainty in the nuclear mass of 82Zr can lead to a factor of two reduction in the abundance of the p-isotope 84Sr.Comment: 20 pages, 22 figures, accepted for publication in Ap

Enhancement Antimicrobial Activity of Hyphothiocyanite using Carrot Against Staphylococcus aureus and Escherichia coli

Hypothiocyanite has been known as antimicrobial agent that was generated from lactoperoxidase system (LPOS) but its antimicrobial activity was low against pathogenic bacteria in milk. This research has been done to enhance the antimicrobial activity of hypothiocyanite against pathogenic bacteria commonly found in milk: Staphylococcus aureus and Escherichia coli by addition of carrot extract. The result showed that carrot extract was able to enhance the antimicrobial activity of hypothiocyanite strongly against E. coli, however less enhancement has been found in the antibacterial activity of hypothiocyanite against S. aureus

Risk Factors for Nosocomial Infection in the Neonatal Intensive Care Unit by the Japanese Nosocomial Infection Surveillance (JANIS)

We evaluated the infection risks in the neonatal intensive care unit (NICU) using data of NICU infection surveillance data. The subjects were 871 NICU babies, consisting of 465 boys and 406 girls, who were cared for between June 2002 and January 2003 in 7 medical institutions that employed NICU infection surveillance. Infections were defined according to the National Nosocomial Infection Surveillance (NNIS) System. Of the 58 babies with nosocomial infections, 15 had methicillin-resistant Staphylococcus aureus (MRSA) infection. Multiple logistic regression analysis demonstrated that the odds ratio for nosocomial infections was significantly related to gender, birth weight and the insertion of a central venous catheter (CVC). When the birth weight group of more than 1, 500g was regarded as the reference, the odds ratio was 2.35 in the birth weight group of 1,000-1,499g and 8.82 in the birth weight group of less than 1,000g. The odds ratio of the CVC () for nosocomial infection was 2.27. However, other devices including artificial ventilation, umbilical artery catheter, umbilical venous catheter, and urinary catheter were not significant risk factors. The incidence of MRSA infection rapidly increased from 0.3% in the birth weight group of more than 1,500g to 2.1% in the birth weight group of 1,000-1,499g, and to 11.1% in the birth weight group of less than 1,000g. When the birth weight group of more than 1,500g was regarded as the reference, multiple logistic regression analysis demonstrated that the odds ratio was 7.25 in the birth weight group of 1,000-1,499g and 42.88 in the birth weight group of less than 1,000g. These odds ratios were significantly higher than that in the reference group. However, the application of devices did not cause any significant differences in the odds ratio for MRSA infection.</p

榛名山で古墳時代に起こった渋川噴火の理学的年代決定

Radiocarbon wiggle matching method was applied for precise dating of a tephra which was designated as one of the important key beds for archaeology. The FA tephra is a pyroclastic deposit from the Shibukawa eruption of Haruna Volcano during the Kofun period of Japan. The age of FA has been investigated using archaeological remains and also historical records of Japan and China. It has been estimated roughly as early 6th century. Three tumbled logs were found being buried in the tephra whose thickness was about 4 m. The logs were cut in many groups with five tree rings and every two groups were sampled for C measurement. As these trees were thought to have the same age from the occurrence,all data were used for wiggle matching analysis. The age of the outermost tree ring group is determined as AD 491-500(AD 497/＋3/－6)

Trojan Horse Method experiments with radioactive ion beams

The Trojan Horse Method (THM) is an indirect method that allows to get information about a two body reaction cross-section even at very low energy, avoiding the suppression effects due to the presence of the Coulomb barrier. The method requires a very accurate measurement of a three body reaction in order to reconstruct the whole kinematics and discriminate among different reaction mechanisms that can populate the same final state. These requirements hardly match with the typical low intensity and large divergence of radioactive ion beams (RIBs), and experimental improvements are mandatory for the applicability of the method. The first reaction induced by a radio activeion beam studied by applying the THM was the 18F(p,α)15O. Two experiments were performed in two different laboratories and using different experimental set-ups. The two experiments will be discussed and some results will be presented

measurement of the 30 s α system for type i x ray bursts

n/