Modeling the registration efficiency of thermal neutrons by gadolinium foils

In the paper we present the results of mathematical modeling of the registration efficiency of thermal neutrons for the converters made of natural Gd and its 157 isotope plane-parallel foils. In the performed calculations four fixed energies of neutrons with the corresponding wavelengths of 1, 1.8, 3 and 4 $A^0$ are taken into account. We calculate the efficiencies of the converter for electron escapes to frontward and backward hemispheres and their sum, depending on thickness of converting foils. Results of comparison of our calculations with the experimental data are presented.Comment: 19 pages, 8 figure

Characterization of Fabric-to-Fabric Friction: Application to Medical Compression Bandages

Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics

Engineering access to higher education through higher education fairs

Text from van Zanten A., Legavre A. “Engineering access to higher education through higher education fairs”, in Goastellec G., Picard F. (ed.) The Roles of Higher Education and Research in the Fabric of Societies, Leuven, Sense Publishers, 2014 (in press). Transition to higher education is a major social process. This transition has been mostly studied by French sociologists of education and higher education from perspectives focusing predominantly on the role of the socio-economic status, academic profiles and different tracks followed by secondary school students (Merle 1996, Duru-Bellat and Kieffer 2008, Convert 2010), and, to a lesser extent, on the types of secondary schools attended (Duru-Bellat and Mingat 1998, Nakhili 2005) and the local higher education provision (Berthet et al. 2010, Orange 2013). Although these structural determinants play a major role in explaining significant regularities, they provide more powerful explanations for individuals representing the extremes of the different variables considered, leaving room for the influence of other major factors for those students in intermediate situations. In addition, even in the case of students occupying extreme positions, structural perspectives better explain the distribution of students between different higher education tracks than they do between institutions and disciplines. In this chapter, we adopt a perspective that we see as complementary to and interacting with the perspective centred on structural determinants by focusing on the role of the devices that mediate the exchanges between students and higher education institutions, and more specifically on one device: higher education fairs. Our purpose in doing so is not only to document how these various devices frame, in ways that remain largely unexplored by researchers, exchanges between providers and consumers of higher education but also to point out – and further explore in future publications – how these devices, and the specific features of fairs, contribute to the reproduction and transformation of educational inequalities in access to higher education (Benninghoff et al. 2012)

Interaction of substance P with phospholipid bilayers: A neutron diffraction study

AbstractNeutron diffraction has been used to study the membrane-bound structure of substance P (SP), a member of the tachykinin family of neuropeptides. The depth of penetration of its C-terminus in zwitterionic and anionic phospholipid bilayers was probed by specific deuteration of leucine 10, the penultimate amino acid residue. The results show that the interaction of SP with bilayers, composed of either dioleoylphosphatidylcholine (DOPC), or a 50:50 mixture of DOPC and the anionic phospholipid dioleoylphosphatidylglycerol (DOPG), takes place at two locations. One requires insertion of the peptide into the hydrophobic region of the bilayer, the other is much more peripheral. The penetration of the peptide into the hydrophobic region of the bilayer is reflected in a marked difference in the water distribution profiles. SP is seen to insert into DOPC bilayers, but a larger proportion of the peptide is found at the surface when compared to the anionic bilayers. The positions of the two label populations show only minor differences between the two types of bilayer

Pt-Sn/C as a possible methanol-tolerant cathode catalyst for DMFC

An effective method was developed for preparing highly dispersed nano-sized Pt–Sn/C electrocatalyst synthesised by a modified polyol reduction method. From XRD patterns, the Pt–Sn/C peaks shifted slightly to lower 2θ angles when compared with commercial Pt/C catalyst, suggesting that Sn formed alloy with Pt. Based on HR-TEM images, the Pt–Sn/C nanoparticles showed small particle sizes and well dispersed onto the carbon support with a narrow particle distribution. The methanol oxidation reaction on the as-prepared Pt–Sn/C catalyst appeared at lower currents (+7.08 mA at +480 mV vs. Ag/AgCl) compared to the commercial Pt/C (+8.25 mA at +480 mV vs. Ag/AgCl) suggesting that the Pt–Sn/C catalyst has ‘methanol tolerance capabilities’. Pt–Sn/C HA Slurry pH3 catalysts showed better activity towards the oxygen-reduction reaction (ORR) than commercial Pt/C which could be attributed to smaller particle sizes. In our study, the Pt–Sn/C catalyst appears to be a promising methanol-tolerant catalyst with activity towards the ORR in the DMFC.Web of Scienc

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C