A Ulysses Detection of Secondary Helium Neutrals

The Interstellar Boundary EXplorer (IBEX) mission has recently studied the flow of interstellar neutral He atoms through the solar system, and discovered the existence of a secondary He flow likely originating in the outer heliosheath. We find evidence for this secondary component in Ulysses data. By coadding hundreds of Ulysses He beam maps together to maximize signal-to-noise, we identify a weak signal that is credibly associated with the secondary component. Assuming a laminar flow from infinity, we infer the following He flow parameters: V=12.8+/-1.9 km/s, lambda=74.4+/-1.8 deg, beta=-10.5+/-4.1 deg, and T=3000+/-1100 K; where lambda and beta are the ecliptic longitude and latitude direction in J2000 coordinates. The secondary component has a density that is 4.9+/-0.9% that of the primary component. These measurements are reasonably consistent with measurements from IBEX, with the exception of temperature, where our temperature is much lower than IBEX's T=9500 K. Even the higher IBEX temperature is suspiciously low compared to expectactions for the outer heliosheath source region. The implausibly low temperatures are due to the incorrect assumption of a laminar flow instead of a diverging one, given that the flow in the outer heliosheath source region will be deflecting around the heliopause. As for why the IBEX and Ulysses T values are different, difficulties with background subtraction in the Ulysses data are a potential source of concern, but the discrepancy may also be another effect of the improper laminar flow assumption, which could affect the IBEX and Ulysses analyses differently.Comment: 9 pages, 4 figures, to appear in The Astrophysical Journa

Revisiting Ulysses Observations of Interstellar Helium

We report the results of a comprehensive reanalysis of Ulysses observations of interstellar He atoms flowing through the solar system, the goal being to reassess the interstellar He flow vector and to search for evidence of variability in this vector. We find no evidence that the He beam seen by Ulysses changes at all from 1994-2007. The direction of flow changes by no more than ~0.3 deg and the speed by no more than ~0.3 km/s. A global fit to all acceptable He beam maps from 1994-2007 yields the following He flow parameters: V_ISM=26.08+/-0.21 km/s, lambda=75.54+/-0.19 deg, beta=-5.44+/-0.24 deg, and T=7260+/-270 K; where lambda and beta are the ecliptic longitude and latitude direction in J2000 coordinates. The flow vector is consistent with the original analysis of the Ulysses team, but our temperature is significantly higher. The higher temperature somewhat mitigates a discrepancy that exists in the He flow parameters measured by Ulysses and the Interstellar Boundary Explorer, but does not resolve it entirely. Using a novel technique to infer photoionization loss rates directly from Ulysses data, we estimate a density of n_He=0.0196+/-0.0033 cm^-3 in the interstellar medium.Comment: to appear in The Astrophysical Journa

The MX beamlines BL14.1-3 at BESSY II

The Macromolecular Crystallography (MX) group at the Helmholtz-Zentrum Berlin (HZB) is operating three state-of-the-art synchrotron beamlines for MX at BESSY II in Berlin (Heinemann et al., 2003; Mueller et al., 2012, 2015). The radiation source for all three beamlines BL14.1-3 is a superconducting 7T-wavelength shifter. Currently, the three beam lines are the most productive stations for MX in Germany, with about 250 PDB depositions per year and over 1500 PDB depositions in total (Status 10/2015). BL14.1 and BL14.2 are energy tuneable in the range 5.5-15.5 keV, while beam line BL14.3 is a fixed-energy side station operated at 13.8 keV. The HZB-MX beamlines are in regular user operation providing close to 200 beam days per year and about 600 user shifts to approximately 100 research groups across Europe. Additional user facilities include office space adjacent to the beam lines, a sample preparation laboratory, a biology laboratory (safety level 1) and high-end computing resources

Закономерности формирования структуры и фазового состава поверхностного слоя силумина, подвергнутого электронно-пучковой обработке

It has been shown that electron beam treatment of silumin is accompanied by the formation of multilayer submicro-and nanocrystalline structure and result in increasing the microhardness of the surface layer (towards the core) is ~ 1.5 times up to 2 GPa

Experimental Evidence for Non-Thermal Contributions to Plasmon-Enhanced Electrochemical Oxidation Reactions

Photocatalysis based on plasmonic nanoparticles has emerged as a promising approach to facilitate light-driven reactions under far milder conditions than thermal catalysis. Several effects, such as strong local electromagnetic fields, increased electron and lattice temperatures, or the transfer of non-thermal charge carriers could contribute to the reaction rate enhancement. In order to understand plasmon-enhanced catalysis and to enable plasmonic platforms, a distinction between the different underlying effects is required. We investigate the electrochemical model reactions oxidative hydroxide adsorption and glucose oxidation and deconvolve the enhancement processes via their dependence on excitation wavelength. We observe that non-thermal effects contribute significantly to the plasmonic enhancement

Osteoporosis case finding in the general practice: phalangeal radiographic absorptiometry with and without risk factors for osteoporosis to select postmenopausal women eligible for lumbar spine and hip densitometry

Mass screening for osteoporosis using DXA measurements at the spine and hip is presently not recommended by health authorities. Instead, risk factor questionnaires and peripheral bone measurements may facilitate the selection of women eligible for axial bone densitometry. The aim of this study was to validate a case finding strategy for postmenopausal women who would benefit most from subsequent DXA measurement by using phalangeal radiographic absorptiometry (RA) alone or in combination with risk factors in a general practice setting. The sensitivity and specificity of this strategy in detecting osteoporosis (T-score ≤2.5SD at the spine and/or the hip) were compared with those of the current reimbursement criteria for DXA measurements in Switzerland. Four hundred and twenty-three postmenopausal women with one or more risk factors for osteoporosis were recruited by 90 primary care physicians who also performed the phalangeal RA measurements. All women underwent subsequent DXA measurement of the spine and the hip at the Osteoporosis Policlinic of the University Hospital of Berne. They were allocated to one of two groups depending on whether they matched with the Swiss reimbursement conditions for DXA measurement or not. Logistic regression models were used to predict the likelihood of osteoporosis versus "no osteoporosis” and to derive ROC curves for the various strategies. Differences in the areas under the ROC curves (AUC) were tested for significance. In women lacking reimbursement criteria, RA achieved a significantly larger AUC (0.81; 95% CI 0.72-0.89) than the risk factors associated with patients' age, height and weight (0.71; 95% C.I. 0.62-0.80). Furthermore, in this study, RA provided a better sensitivity and specificity in identifying women with underlying osteoporosis than the currently accepted criteria for reimbursement of DXA measurement. In the Swiss environment, RA is a valid case finding tool for patients with risk factors for osteoporosis, especially for those who do not qualify for DXA reimbursemen