Spectrophotovoltaic orbital power generation

A subscale model of a photovoltaic power system employing spectral splitting and 1000:1 concentration was fabricated and tested. The 10-in. aperture model demonstrated 15.5% efficiency with 86% of the energy produced by a GaAs solar cell and 14% of the energy produced by an Si cell. The calculated efficiency of the system using the same solar cells, but having perfect optics, would be approximately 20%. The model design, component measurements, test results, and mathematical model are presented

Incorporation of cytochrome oxidase into cardiolipin bilayers and induction of nonlamellar phases.

Cytochrome oxidase from beef heart has been lipid-substituted with beef heart cardiolipin. The lipid phase behavior and protein aggregation state of the reconstituted complexes have been studied with 31P NMR, freeze-fracture electron microscopy, and saturation-transfer ESR of the spin-labeled protein. In the absence of salt, the lipid has a lamellar arrangement, and the protein is integrated and uniformly distributed in the membrane vesicles and undergoes rapid rotational diffusion. The presence of the protein stabilizes the cardiolipin lamellar phase against salt-induced transitions to the inverted hexagonal phase. The threshold salt concentration becomes higher and the extent of conversion becomes lower with decreasing lipid:protein ratio. In high salt, lamellar-phase lipid with integrated protein coexists with hexagonal-phase lipid free of protein, and the rotational diffusion of the protein is drastically reduced as a result of the high packing density

Learning from the experts: exploring playground experience and activities using a write and draw technique.

BACKGROUND: Qualitative research into the effect of school recess on children's physical activity is currently limited. This study used a write and draw technique to explore children's perceptions of physical activity opportunities during recess. METHODS: 299 children age 7-11 years from 3 primary schools were enlisted. Children were grouped into Years 3 & 4 and Years 5 & 6 and completed a write and draw task focusing on likes and dislikes. Pen profiles were used to analyze the data. RESULTS: Results indicated 'likes' focused on play, positive social interaction, and games across both age groups but showed an increasing dominance of games with an appreciation for being outdoors with age. 'Dislikes' focused on dysfunctional interactions linked with bullying, membership, equipment, and conflict for playground space. Football was a dominant feature across both age groups and 'likes/dislikes' that caused conflict and dominated the physically active games undertaken. CONCLUSION: Recess was important for the development of conflict management and social skills and contributed to physical activity engagement. The findings contradict suggestions that time spent in recess should be reduced because of behavioral issues

The η6\eta_6 at LEP and TRISTAN

The $\eta_6$ is a ``heavy axion'' remnant of dynamical electroweak symmetry breaking by a color sextet quark condensate. Electroweak scale color instanton interactions allow it to be both very massive and yet be responsible for Strong CP conservation in the color triplet quark sector. It may have been seen at LEP via its two-photon decay mode and at TRISTAN via its hadronic decay modes.Comment: 11 pages, ANL-HEP-PR-93-4/BROWN-HET-87

A sound card based multi-channel frequency measurement system

For physical processes which express themselves as a frequency, for example magnetic field measurements using optically-pumped alkali-vapor magnetometers, the precise extraction of the frequency from the noisy signal is a classical problem. We describe herein a frequency measurement system based on an inexpensive commercially available computer sound card coupled with a software single-tone estimator which reaches Cram\'er--Rao limited performance, a feature which commercial frequency counters often lack. Characterization of the system and examples of its successful application to magnetometry are presented.Comment: 4 pages, 3 figures, 1 tabl

Mountain Plover Population Trends in 3 Montana Areas

Permanent point count transects were established in 1992 in central, northeastern and southwestern Montana to monitor mountain plover population trends in these areas.   At the time, these were considered to be Montana’s 2nd, 3rd and 4th largest mountain plover populations.  During the 23 year period from 1992 to 2014, these transects were surveyed during 10 different years with the last counts for the Central and Northeastern Montana Study Areas occurring in 2014, and the last count for the Southwestern Montana Study area occurring in 2004.  The count of adult mountain plovers in the Central Study Area declined from 103 adult birds in 1992 to 13 birds in 2014.  In the Northeastern Study Area, mountain plover started at 17 in 1992, peaked at 36 in 1996, dipped to 12 in 2004, and ended with a final count of 17 in 2014.   Mountain plover numbers in the Southwestern Study Area progressively declined from a high of 33 adult birds in 1992 to no birds found in the Study Area in 2004.  Cause of mountain plover decline in the Central Study Area was attributed to conversion of native grasslands to cultivated cropland and introduced grasses, a drastic decline in domestic sheep numbers, and an overall reduction in livestock grazing.  In the Southwestern study area, the collapse of the mountain plover population was attributed to a housing development, a log home factory, prairie dog poisoning, and the lack of livestock grazing.  The Northeastern Study Area was almost entirely public lands with relatively stable habitat conditions

Spectrophotovoltaic orbital power generation

A system with 1000 : 1 concentration ratio is defined, using a cassegrain telescope as the first stage concentration (270 x) and compound parabolic concentrators (CPC) for the second stage concentration of 4.7 x for each spectral band. Using reported state of the art (S.O.A.) solar cells device parameters and considering structural losses due to optics and beamsplitters, the efficiencies of one to four cell systems were calculated with efficiencies varying from approximately 22% to 30%. Taking into account cost of the optics, beamsplitter, radiator, and the cost of developing new cells the most cost effective system is the GaAs/Si system

Particle Flow Calorimetry at the ILC

One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the goal of 0.3/sqrt(E[GeV]). This paper describes the current performance of the PandoraPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, the ILC jet energy resolution goal is reached. At higher energies the jet energy resolution becomes worse and can be described by the empirical expression: sigma_E/E ~ 0.265/sqrt(E[GeV]) + 1.2x10^{-4}E[GeV].Comment: 5 pages, 2 .eps figures, to appear in Proc. LCWS06, Bangalore, March 200

The epidemiology of Mycobacterium bovis in wild deer and feral pigs and their roles in the establishment and spread of bovine tuberculosis in New Zealand wildlife

In New Zealand, wild deer and feral pigs are assumed to be spillover hosts for Mycobacterium bovis, and so are not targeted in efforts aimed at locally eradicating bovine tuberculosis (TB) from possums (Trichosurus vulpecula), the main wildlife host. Here we review the epidemiology of TB in deer and pigs, and assess whether New Zealand's TB management programme could be undermined if these species sometimes achieve maintenance host status. In New Zealand, TB prevalences of up to 47% have been recorded in wild deer sympatric with tuberculous possums. Patterns of lesion distribution, age-specific prevalences and behavioural observations suggest that deer become infected mainly through exposure to dead or moribund possums. TB can progress rapidly in some deer (<10%), but generalised disease is uncommon in wild deer; conversely some infected animals can survive for many years. Deer-to-deer transmission of M. bovis is rare, but transmission from tuberculous deer carcasses to scavengers, including possums, is likely. That creates a small spillback risk that could persist for a decade after transmission of new infection to wild deer has been halted. Tuberculosis prevalence in New Zealand feral pigs can reach 100%. Infections in lymph nodes of the head and alimentary tract predominate, indicating that TB is mostly acquired through scavenging tuberculous carrion, particularly possums. Infection is usually well contained, and transmission between pigs is rare. Large reductions in local possum density result in gradual declines (over 10 years) in TB prevalence among sympatric wild deer, and faster declines in feral pigs. Elimination of TB from possums (and livestock) therefore results in eventual disappearance of TB from feral pigs and wild deer. However, the risk of spillback infection from deer to possums substantially extends the time needed to locally eradicate TB from all wildlife (compared to that which would be required to eradicate disease from possums alone), while dispersal or translocation of pigs (e.g. by hunters) creates a risk of long-distance spread of disease. The high rate at which pigs acquire M. bovis infection from dead possums makes them useful as sentinels for detecting TB in wildlife. It is unlikely that wild deer and feral pigs act as maintenance hosts anywhere in New Zealand, because unrestricted year-round hunting keeps densities low, with far less aggregation than on New Zealand farms. We conclude that active management of wild deer or feral pigs is not required for local TB eradication in New Zealand.Funding to support the drafting of this review was provided by TBfree New Zealand (Project R10735-01), with co-funding from the Ministry of Business, Innovation and Employment (Contact C09X0803); Christian Gortazar additionally acknowledges support from Plan Nacional I+D+i AGL2011-30041 (MINECO, Spain) for his contribution to this review.Peer Reviewe