Megawatt solar power systems for lunar surface operations

Lunar surface operations require habitation, transportation, life support, scientific, and manufacturing systems, all of which require some form of power. As an alternative to nuclear power, the development of a modular one megawatt solar power system is studied, examining both photovoltaic and dynamic cycle conversion methods, along with energy storage, heat rejection, and power backup subsystems. For photovoltaic power conversion, two systems are examined. First, a substantial increase in photovoltaic conversion efficiency is realized with the use of new GaAs/GaSb tandem photovoltaic cells, offering an impressive overall array efficiency of 23.5 percent. Since these new cells are still in the experimental phase of development, a currently available GaAs cell providing 18 percent efficiency is examined as an alternate to the experimental cells. Both Brayton and Stirling cycles, powered by linear parabolic solar concentrators, are examined for dynamic cycle power conversion. The Brayton cycle is studied in depth since it is already well developed and can provide high power levels fairly efficiently in a compact, low mass system. The dynamic conversion system requires large scale waste heat rejection capability. To provide this heat rejection, a comparison is made between a heat pipe/radiative fin system using advanced composites, and a potentially less massive liquid droplet radiator system. To supply power through the lunar night, both a low temperature alkaline fuel cell system and an experimental high temperature monolithic solid-oxide fuel cell system are considered. The reactants for the fuel cells are stored cryogenically in order to avoid the high tankage mass required by conventional gaseous storage. In addition, it is proposed that the propellant tanks from a spent, prototype lunar excursion vehicle be used for this purpose, therefore resulting in a significant overall reduction in effective storage system mass

Survey of parasitoids and hyperparasitoids (Hymenoptera) of the green peach aphid, Myzus persicae and the foxglove aphid, Aulacorthum solani (Hemiptera: Aphididae) in British Columbia

We surveyed the parasitoids and hyperparasitoids of the green peach aphid, Myzus persicae, and the foxglove aphid, Aulacorthum solani in the lower Fraser Valley of British Columbia, Canada. Field surveys were conducted using isolated pepper plants, with aphids, as trap plants. Primary parasitoids recorded from field surveys were Aphidius ervi, A. matricariae, Praon gallicum, P. unicum, P. humulaphidis, Ephedrus californicus, Diaeretiella rapae, Monoctonus paulensis, Aphelinus abdominalis and A. asychis. Diaretiella rapae only emerged from green peach aphids, and Ephedrus californicus only emerged from foxglove aphids. Aphidius matricariae was the most abundant primary parasitoid species reared from both aphid species. Hyperparasitoid species collected belonged to the genera Dendrocerus, Asaphes, Alloxysta, Pachyneuron and Syrphophagous. In greenhouses, Dendrocerus carpenteri was the dominant hyperparasitoid species. Aphidius and Aphelinus spp. were attacked by hyperparasitoids at similar rates. In the field, Aphidius spp. were attacked by five species of hyperparasitoid, and Aphelinus spp. were attacked by one, Alloxysta ramulifera. In general, the rate of attack by hyperparasitoids was much lower in field surveys than in our collections from greenhouses

BASIS WEIGHT UNIFORMITY OF LIGHTLY NEEDLED HYDROENTANGLED COTTON AND COTTON BLEND WEBS

New nonwoven products containing cotton and Lyocell (Trademarked name Tencel), low temperature thermal-bondable bicomponent olefin/polyester, or comber noils were developed using needlepunching and spunlacing (hydroentanglement). Webs containing five different blends were prepared by either light needlepunching, or light needlepunching followed by hydroentangling. We acquired detailed basis weight uniformity measurements to learn about processing and the influence of fiber blend composition on web uniformity. Basis weight uniformity was evaluated without regard to web direction ("Total" uniformity), along the machine direction (MD uniformity) and across the cross direction (CD uniformity) at numerous size resolutions. We observed that blending manufactured fibers (either Tencel or olefin/polyester) with bleached cotton and comber noils substantially improved basis weight uniformity of both types of nonwovens. We also observed that subjecting needled webs to hydroentangling significantly improved Total and MD uniformities

Pennsylvania Folklife Vol. 20, No. 3

• Gardens and Gardening Among the Pennsylvania Germans • Historical Sources For American Traditional Cookery: Examples from the Pennsylvania German Culture • The Use of Amulets Among Greek-Philadelphians • Work and the Farmer: The Almanac as Cultural Index, 1858-1898 • Pennsylvania German and High German: Folk-Cultural Questionnaire No. 19 • Engravings of Western Pennsylvania Sceneshttps://digitalcommons.ursinus.edu/pafolklifemag/1043/thumbnail.jp

Assistance to Oil and Gas State Agencies and Industry through Continuation of Environmental and Production Data Management and a Water Regulatory Initiative

This grant project was a major step toward completion of the Risk Based Data Management System (RBDMS) project. Additionally the project addresses the needs identified during the projects initial phases. By implementing this project, the following outcomes were sought: (1) State regulatory agencies implemented more formalized environmental risk management practices as they pertain to the production of oil and gas, and injection via Class II wells. (2) Enhancement of oil and gas production by implementing a management system supporting the saving of abandoned or idle wells located in areas with a relatively low environmental risk of endangering underground sources of drinking water (USDWs) in a particular state. (3) Verification that protection of USDWs is adequate and additional restrictions of requirements are not necessary in areas with a relatively low environmental risk. (4) Standardization of data and information maintained by state regulatory agencies and decrease the regulatory cost burden on producers operating in multiple states, and (5) Development of a system for electronic data transfer among operators and state regulatory agencies and reduction of overall operator reporting burdens

HIV infection and sexual risk behaviour among youth who have experienced orphanhood: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Previous research has suggested that orphaned children and adolescents might have elevated risk for HIV infection. We examined the state of evidence regarding the association between orphan status and HIV risk in studies of youth aged 24 years and younger.</p> <p>Methods</p> <p>Using systematic review methodology, we identified 10 studies reporting data from 12 countries comparing orphaned and non-orphaned youth on HIV-related risk indicators, including HIV serostatus, other sexually transmitted infections, pregnancy and sexual behaviours. We meta-analyzed data from six studies reporting prevalence data on the association between orphan status and HIV serostatus, and we qualitatively summarized data from all studies on behavioural risk factors for HIV among orphaned youth.</p> <p>Results</p> <p>Meta-analysis of HIV testing data from 19,140 participants indicated significantly greater HIV seroprevalence among orphaned (10.8%) compared with non-orphaned youth (5.9%) (odds ratio = 1.97; 95% confidence interval = 1.41-2.75). Trends across studies showed evidence for greater sexual risk behaviour in orphaned youth.</p> <p>Conclusions</p> <p>Studies on HIV risk in orphaned populations, which mostly include samples from sub-Saharan Africa, show nearly two-fold greater odds of HIV infection among orphaned youth and higher levels of sexual risk behaviour than among their non-orphaned peers. Interventions to reduce risk for HIV transmission in orphaned youth are needed to address the sequelae of parental illness and death that might contribute to sexual risk and HIV infection.</p

The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs

We describe the design and performance of the near-infrared (1.51--1.70 micron), fiber-fed, multi-object (300 fibers), high resolution (R = lambda/delta lambda ~ 22,500) spectrograph built for the Apache Point Observatory Galactic Evolution Experiment (APOGEE). APOGEE is a survey of ~ 10^5 red giant stars that systematically sampled all Milky Way populations (bulge, disk, and halo) to study the Galaxy's chemical and kinematical history. It was part of the Sloan Digital Sky Survey III (SDSS-III) from 2011 -- 2014 using the 2.5 m Sloan Foundation Telescope at Apache Point Observatory, New Mexico. The APOGEE-2 survey is now using the spectrograph as part of SDSS-IV, as well as a second spectrograph, a close copy of the first, operating at the 2.5 m du Pont Telescope at Las Campanas Observatory in Chile. Although several fiber-fed, multi-object, high resolution spectrographs have been built for visual wavelength spectroscopy, the APOGEE spectrograph is one of the first such instruments built for observations in the near-infrared. The instrument's successful development was enabled by several key innovations, including a "gang connector" to allow simultaneous connections of 300 fibers; hermetically sealed feedthroughs to allow fibers to pass through the cryostat wall continuously; the first cryogenically deployed mosaic volume phase holographic grating; and a large refractive camera that includes mono-crystalline silicon and fused silica elements with diameters as large as ~ 400 mm. This paper contains a comprehensive description of all aspects of the instrument including the fiber system, optics and opto-mechanics, detector arrays, mechanics and cryogenics, instrument control, calibration system, optical performance and stability, lessons learned, and design changes for the second instrument.Comment: 81 pages, 67 figures, PASP, accepte

Cosmological parameters from SDSS and WMAP

We measure cosmological parameters using the three-dimensional power spectrum P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in combination with WMAP and other data. Our results are consistent with a ``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt, tensor modes or massive neutrinos. Adding SDSS information more than halves the WMAP-only error bars on some parameters, tightening 1 sigma constraints on the Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state. Our results are in substantial agreement with the joint analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive consistency check with independent redshift survey data and analysis techniques. In this paper, we place particular emphasis on clarifying the physical origin of the constraints, i.e., what we do and do not know when using different data sets and prior assumptions. For instance, dropping the assumption that space is perfectly flat, the WMAP-only constraint on the measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running tilt, neutrino mass and equation of state in the list of free parameters, many constraints are still quite weak, but future cosmological measurements from SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt figures available at http://www.hep.upenn.edu/~max/sdsspars.htm

Unitary Ca2+ current through recombinant type 3 InsP3 receptor channels under physiological ionic conditions

The ubiquitous inositol 1,4,5-trisphosphate (InsP3) receptor (InsP3R) channel, localized primarily in the endoplasmic reticulum (ER) membrane, releases Ca2+ into the cytoplasm upon binding InsP3, generating and modulating intracellular Ca2+ signals that regulate numerous physiological processes. Together with the number of channels activated and the open probability of the active channels, the size of the unitary Ca2+ current (iCa) passing through an open InsP3R channel determines the amount of Ca2+ released from the ER store, and thus the amplitude and the spatial and temporal nature of Ca2+ signals generated in response to extracellular stimuli. Despite its significance, iCa for InsP3R channels in physiological ionic conditions has not been directly measured. Here, we report the first measurement of iCa through an InsP3R channel in its native membrane environment under physiological ionic conditions. Nuclear patch clamp electrophysiology with rapid perfusion solution exchanges was used to study the conductance properties of recombinant homotetrameric rat type 3 InsP3R channels. Within physiological ranges of free Ca2+ concentrations in the ER lumen ([Ca2+]ER), free cytoplasmic [Ca2+] ([Ca2+]i), and symmetric free [Mg2+] ([Mg2+]f), the iCa–[Ca2+]ER relation was linear, with no detectable dependence on [Mg2+]f. iCa was 0.15 ± 0.01 pA for a filled ER store with 500 µM [Ca2+]ER. The iCa–[Ca2+]ER relation suggests that Ca2+ released by an InsP3R channel raises [Ca2+]i near the open channel to ∼13–70 µM, depending on [Ca2+]ER. These measurements have implications for the activities of nearby InsP3-liganded InsP3R channels, and they confirm that Ca2+ released by an open InsP3R channel is sufficient to activate neighboring channels at appropriate distances away, promoting Ca2+-induced Ca2+ release