Potential structural material problems in a hydrogen energy system

Potential structural material problems that may be encountered in the three components of a hydrogen energy system - production, transmission/storage, and utilization - were identified. Hydrogen embrittlement, corrosion, oxidation, and erosion may occur during the production of hydrogen. Hydrogen embrittlement is of major concern during both transmission and utilization of hydrogen. Specific materials research and development programs necessary to support a hydrogen energy system are described

A KINEMATIC FOCUS ON THE RELATIONSHIP BETWEEN THE MAIN PHASES OF SKI JUMPING AND PERFORMANCE AT THE INNSBRUCK 1995 EVENT

Ski jumping is a unique sport discipline with a wide range of movements consisting of several follow-up phases. There is a selection of studies which have described each of the separate phases of the ski jump performance. However, the interaction between the movements of each of the main ski jump phases and their influence on the final performance have not been explored. The purpose of this project was to carry out a kinematic analysis of the entire ski jump performance and to determine the interrelationships between the various phases of the ski jump and between the final performance. The research was complete during the K120 world cup event Intersporttournee at Innsbruck on January 4th, 1995. The Innsbruck jumping hill provided an ideal environment for the location of each of the required cameras. In addition, the competition attracts a great a great number of top world athletes. The h t(n =50) and final (n=30) jump rounds were taped using seven cameras. Seven researchers from the three research groups who participated in this project (Czech Republic, Canada, and Slovenia) each operated a camera in order to record each of the five main phases: in-run, take-off, transition, flight 1 and flight 2. The kinematic data for each of the different phases were elaborated by using the 2D System of hematic Analysis of Ski-jumping (In-run, take-o& transition), the 3D Consport Motion Analysis System (transition), and the 2D Peak Performance System (flight 1, flight 2). The analysis also included measures of body dimensions (height, weight, and other anthropometric parameters), the length of jump, and the official in-run velocity. Analysis of variance, correlation, regression and factor analyses were used to statistically examine the data. The results of this research have added a new dimension to our understanding of the world's best ski jumpeis performances and the interrelationships between the movements in each of the critical phases

1004-59 Vascular Acoustic Emissions During Angioplasty: Potential Role in Identification of Induced Dissection

A fundamental mechanism of balloon angioplasty (BA) is plaque rupture. Rupture leading to dissection, however, has been implicated as an underlyIng factor responsible for both acute and chronic adverse outcomes. Acoustic emissions (AE) — transient sound waves generated by microstructural alterations of a material subjected to mechanical stress — may provide a novel means of characterizing BA-induced tissue trauma. Using a novel acoustic sensor system, we examined the relationship between cumulative AE energy released by human arterial tissue during BA and the observed pathologic injury. Post-mortem human arterial specimens (19) were subjected to identical SA with simultaneous monitoring of intraluminal pressure and AE. Sound energy was integrated throughout the pressurization period to obtain an estimate of the cumulative AE energy released during dilatation. Postangioplasty inspection revealed a marked difference in AE energy released by specimens that experienced traumatic dissection vs. non-dissection dilatation:Sound energy released by vascular tissue undergoing balloon angioplasty discriminates dissection from non-dissection tissue trauma. Given the deleterious role that dissection can play in SA, this novel system may provide a means of improving procedural outcome

Effectiveness of a simple lymphoedema treatment regimen in podoconiosis management in southern Ethiopia: one year follow-up

Background: Podoconiosis is a non-filarial elephantiasis caused by long-term barefoot exposure to volcanic soils in endemic areas. Irritant silicate particles penetrate the skin, causing a progressive, debilitating lymphoedema of the lower leg, often starting in the second decade of life. A simple patient-led treatment approach appropriate for resource poor settings has been developed, comprising (1) education on aetiology and prevention of podoconiosis, (2) foot hygiene (daily washing with soap, water and an antiseptic), (3) the regular use of emollient, (4) elevation of the limb at night, and (5) emphasis on the consistent use of shoes and socks. Methodology/Principal Findings: We did a 12-month, non-comparative, longitudinal evaluation of 33 patients newly presenting to one clinic site of a non-government organization (the Mossy Foot Treatment & Prevention Association, MFTPA) in southern Ethiopia. Outcome measures used for the monitoring of disease progress were (1) the clinical staging system for podoconiosis, and (2) the Amharic Dermatology Life Quality Index (DLQI), both of which have been recently validated for use in this setting. Digital photographs were also taken at each visit. Twenty-seven patients completed follow up. Characteristics of patients completing follow-up were not significantly different to those not. Mean clinical stage and lower leg circumference decreased significantly (mean difference -0.67 (95% CI -0.38 to -0.96) and -2.00 (95% CI -1.26 to -2.74), respectively, p<0.001 for both changes). Mean DLQI diminished from 21 (out of a maximum of 30) to 6 (p<0.001). There was a non-significant change in proportion of patients with mossy lesions (p = 0.375). Conclusions/Significance: This simple, resource-appropriate regimen has a considerable impact both on clinical progression and self-reported quality of life of affected individuals. The regimen appears ideal for scaling up to other endemic regions in Ethiopia and internationally. We recommend that further research in the area include analysis of cost-effectiveness of the regimen

Distinct fos-expressing neuronal ensembles in the ventromedial prefrontal cortex mediate food reward and extinction memories

In operant learning, initial reward-associated memories are thought to be distinct from subsequent extinction-associated memories. Memories formed during operant learning are thought to be stored in “neuronal ensembles.” Thus, we hypothesize that different neuronal ensembles encode reward- and extinction-associated memories. Here, we examined prefrontal cortex neuronal ensembles involved in the recall of reward and extinction memories of food self-administration.Wefirst trained rats to lever press for palatable food pellets for 7 d (1 h/d) and then exposed them to 0, 2, or 7 daily extinction sessions in which lever presses were not reinforced. Twenty-four hours after the last training or extinction session, we exposed the rats to either a short 15 min extinction test session or left them in their homecage (a control condition). We found maximal Fos (a neuronal activity marker) immunoreactivity in the ventral medial prefrontal cortex of rats that previously received 2 extinction sessions, suggesting that neuronal ensembles in this area encode extinction memories. We then used the Daun02 inactivation procedure to selectively disrupt ventral medial prefrontal cortex neuronal ensembles that were activated during the 15 min extinction session following 0 (no extinction) or 2 prior extinction sessions to determine the effects of inactivating the putative food reward and extinction ensembles, respectively, on subsequent nonreinforced food seeking 2 d later. Inactivation of the food reward ensembles decreased food seeking, whereas inactivation of the extinction ensembles increased food seeking. Our results indicate that distinct neuronal ensembles encoding operant reward and extinction memories intermingle within the same cortical area

Octupole strength in the neutron-rich calcium isotopes

Low-lying excited states of the neutron-rich calcium isotopes $^{48-52}$Ca have been studied via $\gamma$-ray spectroscopy following inverse-kinematics proton scattering on a liquid hydrogen target using the GRETINA $\gamma$-ray tracking array. The energies and strengths of the octupole states in these isotopes are remarkably constant, indicating that these states are dominated by proton excitations.Comment: 15 pages, 3 figure

Spectroscopy of 54^{54}Ti and the systematic behavior of low energy octupole states in Ca and Ti isotopes

Excited states of the $N=32$ nucleus $^{54}$Ti have been studied, via both inverse-kinematics proton scattering and one-neutron knockout from $^{55}$Ti by a liquid hydrogen target, using the GRETINA $\gamma$-ray tracking array. Inelastic proton-scattering cross sections and deformation lengths have been determined. A low-lying octupole state has been tentatively identified in $^{54}$Ti for the first time. A comparison of $(p,p')$ results on low-energy octupole states in the neutron-rich Ca and Ti isotopes with the results of Random Phase Approximation calculations demonstrates that the observed systematic behavior of these states is unexpected.Comment: 7 pages, 8 figure

Spectroscopy of 54^{54}Ti and the systematic behavior of low energy octupole states in Ca and Ti isotopes

Excited states of the $N=32$ nucleus $^{54}$Ti have been studied, via both inverse-kinematics proton scattering and one-neutron knockout from $^{55}$Ti by a liquid hydrogen target, using the GRETINA $\gamma$-ray tracking array. Inelastic proton-scattering cross sections and deformation lengths have been determined. A low-lying octupole state has been tentatively identified in $^{54}$Ti for the first time. A comparison of $(p,p')$ results on low-energy octupole states in the neutron-rich Ca and Ti isotopes with the results of Random Phase Approximation calculations demonstrates that the observed systematic behavior of these states is unexpected.Comment: 7 pages, 8 figure

Two-Fermion Production in Electron-Positron Collisions

This report summarizes the results of the two-fermion working group of the LEP2-MC workshop, held at CERN from 1999 to 2000. Recent developments in the theoretical calculations of the two fermion production process in the electron-positron collision at LEP2 center of the mass energies are reported. The Bhabha process and the production of muon, tau, neutrino and quark pairs is covered. On the basis of comparison of various calculations, theoretical uncertainties are estimated and compared with those needed for the final LEP2 data analysis. The subjects for the further studies are identified.Comment: 2-fermion working group report of the LEP2 Monte Carlo Workshop 1999/2000, 113 pages, 24 figures, 35 table