Electron Emission Cross Sections from a Polycrystalline Gold Surface

The angle dependence of emitted electron spectra from a polycrystalline Au surface has been measured at several incident electron beam energies. The range of incident energies (~ 1 00 e V to 2500 e V) extends from below the first crossover energy, through Emax. to above the second crossover energy. The traditional distinction between secondary electrons «50 eV) and backscattered electrons (\u3e50 eV) is found to be inconsistent with our energy- and angle-resolved measurements. We suggest a more natural delineation occurs at the local minima of the emission spectra; this feature is studied as a function of incident energy and emission angle. This work is also supported by the NASA Space Environments and Effects Program

LabView Interface for School-Network DAQ Card

A low-cost DAQ card has been developed for school-network cosmic ray detector projects, providing digitized data from photomultiplier tubes via a standard serial interface. To facilitate analysis of these data and to provide students with a starting point for custom readout systems, a model interface has been developed using the National Instruments LabVIEW(R) system. This user-friendly interface allows one to initialize the trigger coincidence conditions for data-taking runs and to monitor incoming or pre-recorded data sets with updating singles- and coincidence-rate plots and other user-selectable histograms.Comment: 4 pages, 6 figures. Presented as Paper NS26-119 at IEEE-NSS 2003, Portland, OR, by R. J. Wilke

Extended BEG Model of Monhalogenated Methanes Physisorbed on Ionic Crystals

The 2D dielectric phases and phase transitions of adsorbed dipolar molecules are modeled using a dilute spin-one Ising model. This model is studied in the Blume–Emery–Griffiths formalism, using a mean-field approximation, where the interaction parameters are uniquely determined from the system interaction energies using an averaging procedure. The model is applied to four monhalogenated methane species physisorbed on MgO(1 0 0) and NaCl(1 0 0) surfaces using previous experimental and theoretical studies to estimate the interaction energy parameters. We find that temperature- and coverage-dependent antiferroelectric to ferroelectric, coverage-dependent ferroelectric up to ferroelectric down, reentrant ferroelectric to ferrielectric, and order-disorder dipole phase transitions can occur. Phase diagrams based on this model are presented

High-velocity power training has similar effects to traditional resistance training for functional performance in older adults: a systematic review

What is the effect of high-velocity power training (HVPT) compared with traditional resistance training (TRT) on functional performance in older adults? What is the quality of intervention reporting for the relevant literature? Systematic review and meta-analysis of randomised controlled trials. Older adults (aged > 60 years), regardless of health status, baseline functional capacity or residential status. High-velocity power training with the intent to perform the concentric phase as quickly as possible compared with traditional moderate-velocity resistance training performed with a concentric phase of ≥ 2 seconds. Short Physical Performance Battery (SPPB), Timed Up and Go test (TUG), five times sit-to-stand test (5-STS), 30-second sit-to-stand test (30-STS), gait speed tests, static or dynamic balance tests, stair climb tests and walking tests for distance. The quality of intervention reporting was assessed with the Consensus on Exercise Reporting Template (CERT) score. Nineteen trials with 1,055 participants were included in the meta-analysis. Compared with TRT, HVPT had a weak-to-moderate effect on change from baseline scores for the SPPB (SMD 0.27, 95% CI 0.02 to 0.53; low-quality evidence) and TUG (SMD 0.35, 95% CI 0.06 to 0.63; low-quality evidence). The effect of HVPT relative to TRT for other outcomes remained very uncertain. The average CERT score across all trials was 53%, with two trials rated high quality and four rated moderate quality. HVPT had similar effects to TRT for functional performance in older adults, but there is considerable uncertainty in most estimates. HVPT had better effects on the SPPB and TUG, but it is unclear whether the benefit is large enough to be clinically worthwhile. [Abstract copyright: Copyright © 2023 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

State Evaluation of Foreign Sales Efforts.

The past fifteen years since 1972 have seen a dramatic increase in state attention to foreign countries as a source of economic stimulation. This study surveyed other states to see what Minnesota could learn from them. It features an analysis of evaluation methods used to assess foreign sales promotions and suggests ways that Minnesota can improve on these methods. Minnesota's activities and the Minnesota Trade Office are also reviewed.A project of the Interactive Research Grants Program, Center for Urban and Regional Affairs and the Office of the Vice President for Academic Affairs, University of Minnesota

DEVELOPING BETTER ECONOMIC INFORMATION ABOUT COASTAL RESOURCES AS A TOOL FOR INTEGRATED COASTAL MANAGEMENT

Measuring economic activity associated with the ocean through examination of the goods and services produced by specified industries and in coastal locations will provide answers to many of the most commonly asked questions about the ocean economy. But even this data will still be incomplete. Beyond are a variety of non-market values, which are needed to complete the picture. When someone goes to the beach in Florida or boats on Chesapeake Bay, there may be little that is directly purchased on that day. But the popularity of such activities is testament to their underlying value. Economists have developed a variety of techniques to measure such values, and a large number of studies have been done throughout the country using these techniques. The Project intends to compile the results of these studies into the ocean economy database to provide researchers with access to the information that has been generated. The resulting integrated, web-accessible database will provide as comprehensive a picture as possible of the economic values associated with the ocean. It will provide historical data, and because it is estimated as much as possible on a consistent basis, it can be used to compare these values across time and space. But there will still be important limitations. Requirements to maintain confidentiality of data will require that many smaller geographic areas cannot be described in the same level of detail as larger regions. The surveys of industries conducted by the Census Bureau that underlie the national data and which will be used to disaggregate to the industrial and geographic level will have sampling limitations that will require some indirect estimating techniques. The nonmarket values are estimated using complex techniques that can result in widely varying figures for the same resources

Materials Characterization at Utah State University: Facilities and Knowledgebase of Electronic Properties of Materials Applicable to Spacecraft Charging

In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function of incident energy, species and angle, plus investigations of ion-induced electron yields, photoelectron yields, sample charging and dielectric breakdown. Extensive surface science characterization capabilities are also available to fully characterize the samples in situ. Our measurements for a wide array of conducting and insulating spacecraft materials have been incorporated into the SEE Charge Collector Knowledgebase as a Database of Electronic Properties of Materials Applicable to Spacecraft Charging. This Database provides an extensive compilation of electronic properties, together with parameterization of these properties in a format that can be easily used with existing spacecraft charging engineering tools and with next generation plasma, charging, and radiation models. Tabulated properties in the Database include: electron-induced secondary electron yield, backscattered yield and emitted electron spectra; He, Ar and Xe ion-induced electron yields and emitted electron spectra; photoyield and solar emittance spectra; and materials characterization including reflectivity, dielectric constant, resistivity, arcing, optical microscopy images, scanning electron micrographs, scanning tunneling microscopy images, and Auger electron spectra. Further details of the instrumentation used for insulator measurements and representative measurements of insulating spacecraft materials are provided in other Spacecraft Charging Conference presentations. The NASA Space Environments and Effects Program, the Air Force Office of Scientific Research, the Boeing Corporation, NASA Graduate Research Fellowships, and the NASA Rocky Mountain Space Grant Consortium have provided support

Extended BEG model of halogenated methanes physisorbed on ionic crystals

The 2D dielectric phases and phase transitions of adsorbed dipolar molecules are modeled using a dilute spin-one Ising model. This model is studied in the Blume-Emery-Griffiths formalism, using a mean-field approximation, where the interaction parameters are related to system interaction energies using a unique averaging procedure. The model is applied to four halogenated methane species physisorbed on MgO(100) and NaCl(100) surfaces using previous experimental and theoretical studies to estimate the interaction energy parameters. We find that temperature- and coverage-dependent antiferroelectric to ferroelectric, coverage-dependant ferroelectric up to ferroelectric down, reentrant ferroelectric to ferroelectric, and order-disorder dipole phase transitions can occur. Phase diagrams based on this model are presented

Clarifying transfer function approximations for the large-scale gravitational wave background in ΛCDM

Theoretical Physic