272 research outputs found
Small Capacity Low Cost (NiH2) Design Concept for Commercial, Military and Higher-Volume Aerospace Applications
Nickel-Hydrogen (Ni-H2) batteries have become the technology of choice for both commercial and defense-related satellites in geosynchronous orbits. Their use for low-earth-orbit (LEO) applications is not as advanced, but seems just as inevitable because of their inherent advantages over nickel-cadmium batteries. These include superior energy density, longer cycle life, and better tolerance to over-charge and reversal. Ni-H2 cells have the added advantage in both construction and operation of not presenting the environmental possibility of cadmium pollution. Unfortunately, but necessarily, the design of these cells has been driven to high cost by the sophistication of the satellites and their uses. Now, using most of the same concepts but less costly materials and techniques, a low-cost, small cell design has been developed. Combined with the concept of the common pressure vessel, this new design promises to be ideal for the small-sat and commercial markets which, increasingly, are calling for large numbers of less-expensive satellites
Experimental Design and Laboratory Characterization of a Medium- and High-Efficiency Rooftop Unit for use in Building Energy Simulations
Commercial rooftop units (RTUs) that incorporate variable-speed components are quickly entering the marketplace; however, the design and modeling tools that calculate the energy benefits of these units cannot properly estimate performance. This is because 1) there are insufficient measured performance data of real systems that can be input into these simulations, and 2) building energy simulators are unable to properly interpret performance data. Therefore, publicly available data sets designed to encompass the entire performance map coupled with control sequence information are needed as inputs for these modeling programs to accurately estimate energy savings and promote the benefits of variable-speed RTUs. As part of the Validation and Uncertainty Characterization for Energy Simulation project funded by the U.S. Department of Energy, the National Renewable Energy Laboratory recorded and published data across the entire performance range for two commercially available RTUs: one with a two-stage compressor and variable-speed supply fan and another with a fully variable-speed compressor, supply fan, and condenser fan. This paper details 1) how the design of experiments was created and 2) the operational limitations of the two units that complicate the measurement and interpretation of the performance maps. This paper also discusses methods for improving energy simulation programs to properly interpret these data sets and integrate them into building energy simulation models
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A Framework for Testing Regulatory Authority
In this article, we consider whether certain provisions of the Regulatory Package (including regulations proposed and issued under Section 385, Section 956, Section 7701(l) and Section 7874) are outside the scope of the IRS’s authority. We approach these questions first by formulating our own set of “underlying principles” that we believe are necessary guideposts to any question of regulatory authority. We believe using our own “underlying principles” as the lens through which to focus the question allows us to develop tax-specific examples to illustrate the limits of regulatory authority rather than rely on the facts of non-tax cases in which similar questions of regulatory authority were considered. Not surprisingly, the principles we outline below are echoed in the case law involving questions of statutory interpretation and the Administrative Procedure Act (the “APA”).
Even with the changes to the Regulatory Package, as well as potential tax reform which may further limit the impact of any Section 385 regulations,[11] attempting to define the limits of regulatory authority is as important a task as ever. The expansion of executive power, the seeming impossibility of bipartisan legislation, and the potential of radical tax reform which would involve, inevitably, Congress charging the Treasury Department and the IRS to fill in statutory gaps mean the limits of administrative authority will continue to be tested in the near future
Dietary Patterns and Alcohol Consumption During Pregnancy: Secondary Analysis of Avon Longitudinal Study of Parents and Children
Background: Large general population surveys show that heavy regular and episodic alcohol consumption are associated with lower intakes of fruits and vegetables, and higher intakes of processed and fried meat. This is of particular concern regarding pregnant women, as both alcohol intake and inadequate maternal nutrition are independently associated with adverse fetal outcomes. The current study aimed to determine associations between maternal dietary patterns and alcohol consumption during pregnancy. Methods: Women were participating in the Avon Longitudinal Study of Parents and Children, and provided details of alcohol consumption at 18weeks’ gestation and diet at 32weeks’ gestation (n=9,839). Dietary patterns were derived from the food frequency questionnaire data using principal components analysis. Associations between alcohol consumption and dietary patterns were determined using multiple linear regression, adjusted for various sociodemographic and lifestyle factors. Results: After adjustment, drinking ≥1 unit/d during the first trimester (β=0.23 [95% CI: 0.08, 0.38]; p=0.002) and binge drinking (≥4 units in 1day) during the first half of pregnancy (β=0.14 [95% CI: 0.07, 0.21];
Comparison of the transcriptomes of American chestnut (Castanea dentata) and Chinese chestnut (Castanea mollissima) in response to the chestnut blight infection
<p>Abstract</p> <p>Background1471-2229-9-51</p> <p>American chestnut (<it>Castanea dentata</it>) was devastated by an exotic pathogen in the beginning of the twentieth century. This chestnut blight is caused by <it>Cryphonectria parasitica</it>, a fungus that infects stem tissues and kills the trees by girdling them. Because of the great economic and ecological value of this species, significant efforts have been made over the century to combat this disease, but it wasn't until recently that a focused genomics approach was initiated. Prior to the Genomic Tool Development for the Fagaceae project, genomic resources available in public databases for this species were limited to a few hundred ESTs. To identify genes involved in resistance to <it>C. parasitica</it>, we have sequenced the transcriptome from fungal infected and healthy stem tissues collected from blight-sensitive American chestnut and blight-resistant Chinese chestnut (<it>Castanea mollissima</it>) trees using ultra high throughput pyrosequencing.</p> <p>Results</p> <p>We produced over a million 454 reads, totaling over 250 million bp, from which we generated 40,039 and 28,890 unigenes in total from <it>C. mollissima </it>and <it>C. dentata </it>respectively.</p> <p>The functions of the unigenes, from GO annotation, cover a diverse set of molecular functions and biological processes, among which we identified a large number of genes associated with resistance to stresses and response to biotic stimuli. <it>In silico </it>expression analyses showed that many of the stress response unigenes were expressed more in canker tissues versus healthy stem tissues in both American and Chinese chestnut. Comparative analysis also identified genes belonging to different pathways of plant defense against biotic stresses that are differentially expressed in either American or Chinese chestnut canker tissues.</p> <p>Conclusion</p> <p>Our study resulted in the identification of a large set of cDNA unigenes from American chestnut and Chinese chestnut. The ESTs and unigenes from this study constitute an important resource to the scientific community interested in the discovery of genes involved in various biological processes in Chestnut and other species. The identification of many defense-related genes differentially expressed in canker vs. healthy stem in chestnuts provides many new candidate genes for developing resistance to the chestnut blight and for studying pathways involved in responses of trees to necrotrophic pathogens. We also identified several candidate genes that may underline the difference in resistance to <it>Cryphonectria parasitica </it>between American chestnut and Chinese chestnut.</p
Herbicide Evaluation in Arkansas Rice, 1998
Weed control is economically important for production of rice, a major crop in Arkansas. These findings summarize efforts of the team of Arkansas scientists working on weed control strategies for rice during 1998. Various technologies were evaluated in field studies involving the major weed problems and rice production systems used in the state. Results from these studies will add to the arsenal of weed control options for producers. The preliminary results reported here generally warrant further testing for more advanced findings and for the labeling of new technologies and, finally, are the basis for updating safe, effective, and economical recommendations to Arkansas rice producers
DIR-visible grey matter lesions and atrophy in multiple sclerosis: partners in crime?
The extent and clinical relevance of grey matter (GM) pathology in multiple sclerosis (MS) are increasingly recognised. GM pathology may present as focal lesions, which can be visualised using double inversion recovery (DIR) MRI, or as diffuse pathology, which can manifest as atrophy. It is, however, unclear whether the diffuse atrophy centres on focal lesions. This study aimed to determine if GM lesions and GM atrophy colocalise, and to assess their independent relationship with motor and cognitive deficits in MS
MS Cortical Lesions on DIR: Not Quite What They Seem?
Accurate identification and localization of cortical gray matter (CGM) lesions in MS is important when determining their clinical relevance. Double inversion recovery (DIR) scans have been widely used to detect MS CGM lesions. Phase sensitive inversion recovery (PSIR) scans have a higher signal to noise, and can therefore be obtained at a higher resolution within clinically acceptable times. This enables detection of more CGM lesions depicting a clearer cortical and juxtacortical anatomy. In this study, we systematically investigated if the use of high resolution PSIR scans changes the classification of CGM lesions, when compared with standard resolution DIR scans
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