Megawatt solar power systems for lunar surface operations

The work presented here shows that a solar power system can provide power on the order of one megawatt to a lunar base with a fairly high specific power. The main drawback to using solar power is still the high mass, and therefore, cost of supplying energy storage through the solar night. The use of cryogenic reactant storage in a fuel cell system, however, greatly reduces the total system mass over conventional energy storage schemes

Characterization of an hrp-aox-polyaniline-graphite composite biosensor

Nowadays there is an increasing demand to develop new and robust biosensors in order to detect low concentrations of different chemicals, in practical and small devices, giving fast and confident responses. The electrode material was a polyaniline-graphite-epoxy composite (PANI/GEC). Alcohol oxidase (AOX) and horseradish peroxidase (HRP) enzymes were immobilized and the responses were tested by cyclic voltammetry. The conductivities for the composites of graphite/polyaniline were determined. The cyclic voltammograms allowed detecting ethanol in pure diluted samples in a range from 0.036 to 2.62 M. Differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA) were used to verify the thermal characteristics of the composites (0, 10, 20, 30 and 100 % of graphite). The Imax value was determined for the dual enzyme biosensor (0.0724 mA), and the Kapp m as 1.41 M (with R2 =0.9912)

Identifying environmental safety and health requirements for the Fernald Environmental Restoration Management Corporation

This presentation will describe the Fernald Environmental Restoration Management Corporation`s (FERMCO) Standards/Requirements Identification Documents (S/RlDs) Program, the unique process used to implement it, and the status of the program. We will also discuss the lessons learned as the program was implemented. The Department of Energy (DOE) established the Fernald site to produce uranium metals for the nation`s defense programs in 1953. In 1989, DOE suspended production and, in 1991, the mission of the site was formally changed to one of environmental cleanup and restoration. The site was renamed the Fernald Environmental Management Project (FEMP). FERMCO`s mission is to provide safe, early, and least-cost final clean-up of the site in compliance with all regulations and commitments. DOE has managed nuclear facilities primarily through its oversight of Management and Operating contractors. Comprehensive nuclear industry standards were absent when most DOE sites were first established, Management and Operating contractors had to apply existing non-nuclear industry standards and, in many cases, formulate new technical standards. Because it was satisfied with the operation of its facilities, DOE did not incorporate modern practices and standards as they became available. In March 1990, the Defense Nuclear Facilities Safety Board issued Recommendation 90-2, which called for DOE to identify relevant standards and requirements, conduct adequacy assessments of requirements in protecting environmental, public, and worker health and safety, and determine the extent to which the requirements are being implemented. The Environmental Restoration and Waste Management Office of DOE embraced the recommendation for facilities under its control. Strict accountability requirements made it essential that FERMCO and DOE clearly identify applicable requirements necessary, determine the requirements` adequacy, and assess FERMCO`s level of compliance

How PETE comes to matter in the performance of social justice education

Background: For over four decades there have been calls for physical education (PE) and physical education teacher education (PETE) to address social inequality and foster social justice. Yet, as numerous studies demonstrate, attempts to educate for social justice in PETE are infrequent and rarely comprehensive. This raises the question why it appears to be possible in some situations but not others, and for some students and not others.    Purpose: The purpose of this paper is to examine the multiple socio-political networks or assemblages in which PETE is embedded and explore how these shape the possibilities for students to engage with the concept of social justice and sociocultural issues when learning to teach PE. Two research questions guided this study: How does an orientation for social justice education within education policy affect the standards for enacting PETE programs? How is social justice education encouraged within PETE programs? Methodology: Methodology: Drawing from a broader study of over 70 key personnel in more than 40 PETE programs, we examined how faculty in PETE understand their professional world, identify their subjective meanings of their experiences, and address sociocultural issues (SCI) and social justice education (SJE) within PETE. Data sources included an initial survey, a semi-structured interview, and program artifacts. We analyze the ways that SJE/SCI was represented in three national settings (England, the United States, and New Zealand) and identified common themes. Results:  Examination of each national setting reveals ways that SJE and SCI were enabled and constrained across the national, programmatic, and individual level in each of the countries. The coherence of explicit National policy and curricula, PETE program philosophies, and the presence of multiple individual interests in social justice served to reify a sociocultural agenda. Conversely possibilities were nullified by narrow or general National Standards, programs that failed to acknowledge sociocultural interests, and the absence of a critical mass of actors with a socio-critical orientation. These differences in assemblage culminated in variations in curriculum time that served to restrict or enable the breadth, frequency, and consistency of the messages surrounding SCI in PETE Conclusion: These findings highlight the importance of acknowledging socio-political networks where PETE operates. The agency of PETEs to enact pedagogies that foreground sociocultural interests is contingent on congruity of the networks. The authors caution that although the ‘perfect storm’ of conditions have a profound influence of the possibility of transformational learning of SCI in PETE, this arrangement is always temporary, fluid, and subject to changes in any of the three network levels. Additionally, the success of PETE in enabling graduating PE teachers to recognize the inequities that may be reinforced through the ‘hidden curriculum’ and to problematize the subject area is contingent on the expectations of the schools in which they teach.   

An analysis of the quality of experimental design and reliability of results in tribology research

In recent years several high profile projects have questioned the repeatability and validity of scientific research in the fields of psychology and medicine. In general, these studies have shown or estimated that less than 50% of published research findings are true or replicable even when no breaches of ethics are made. This high percentage stems from widespread poor study design; either through the use of underpowered studies or designs that allow the introduction of bias into the results. In this work, we have aimed to assess, for the first time, the prevalence of good study design in the field of tribology. A set of simple criteria for factors such as randomisation, blinding, use of control and repeated tests has been made. These criteria have been used in a mass review of the output of five highly regarded tribology journals for the year 2017. In total 379 papers were reviewed by 26 reviewers, 28% of the total output of the journals selected for 2017. Our results show that the prevalence of these simple aspects of study design is poor. Out of 290 experimental studies, 2.2% used any form of blinding, 3.2% used randomisation of either the tests or the test samples, while none randomised both. 30% repeated experiments 3 or more times and 86% of those who repeated tests used single batches of test materials. 4.4% completed statistical tests on their data. Due to the low prevalence of repeated tests and statistical analysis it is impossible to give a realistic indication of the percentage of the published works that are likely to be false positives, however these results compare poorly to other more well studied fields. Finally, recommendations for improved study design for researchers and group design for research group leaders are given

Promiscuous Binding in a Selective Protein: The Bacterial Na+/H+ Antiporter

The ability to discriminate between highly similar substrates is one of the remarkable properties of enzymes. For example, transporters and channels that selectively distinguish between various solutes enable living organisms to maintain and control their internal environment in the face of a constantly changing surrounding. Herein, we examine in detail the selectivity properties of one of the most important salt transporters: the bacterial Na/H antiporter. Selectivity can be achieved at either the substrate binding step or in subsequent antiporting. Surprisingly, using both computational and experimental analyses synergistically, we show that binding per se is not a sufficient determinant of selectively. All alkali ions from Li to Cs were able to competitively bind the antiporter's binding site, whether the protein was capable of pumping them or not. Hence, we propose that NhaA's binding site is relatively promiscuous and that the selectivity is determined at a later stage of the transport cycle

Role of Appetite-Regulating Peptides in the Pathophysiology of Addiction: Implications for Pharmacotherapy

Food intake and appetite are regulated by various circulating hormones including ghrelin and glucagon-like-peptide 1 (GLP-1). Ghrelin, mainly released from the stomach, increases food intake, induces appetite, enhances adiposity as well as releases growth hormone. Hypothalamic “ghrelin receptors” (GHS-R1A) have a critical role in food intake regulation, but GHS-R1A are also expressed in reward related areas. GLP-1 is produced in the intestinal mucosa as well as in the hindbrain in response to nutrient ingestion. This gut-brain hormone reduces food intake as well as regulates glucose homeostasis, foremost via GLP-1 receptors in hypothalamus and brain stem. However, GLP-1 receptors are expressed in areas intimately associated with reward regulation. Given that regulation of food and drug intake share common neurobiological substrates, the possibility that ghrelin and GLP-1 play an important role in reward regulation should be considered. Indeed, this leading article describes that the orexigenic peptide ghrelin activates the cholinergic–dopaminergic reward link, an important part of the reward systems in the brain associated with reinforcement and thereby increases the incentive salience for motivated behaviors via this system. We also review the role of ghrelin signaling for reward induced by alcohol and addictive drugs from a preclinical, clinical and human genetic perspective. In addition, the recent findings showing that GLP-1 controls reward induced by alcohol, amphetamine, cocaine and nicotine in rodents are overviewed herein. Finally, the role of several other appetite regulatory hormones for reward and addiction is briefly discussed. Collectively, these data suggest that ghrelin and GLP-1 receptors may be novel targets for development of pharmacological treatments of alcohol and drug dependence

Rearrangements and deletions of immunoglobulin heavy chain genes in the double-producing B cell lymphoma I.29

The B cell lymphoma I.29 consists of a mixture of cells expressing membrane-bound immunoglobulin M (IgM) (lambda) and IgA (lambda) of identical idiotypes. Whereas most of the cells express either IgM or IgA alone, 1 to 5% of the cells in this tumor express IgM and IgA simultaneously within the cytoplasm and on the cell membrane (R. Sitia et al., J. Immunol. 127:1388-1394, 1981; R. Sitia, unpublished data). When IgM+ cells are purified from the lymphoma and passaged in mice or cultured, a portion of the cells convert to IgA+. These properties suggest that some cells of the I.29 lymphoma may undergo immunoglobulin heavy chain switching, although it is also possible that the mixed population was derived by a prior switching event in a clone of cells. We performed Southern blotting experiments on genomic DNAs isolated from populations of I.29 cells containing variable proportions of IgM+ and IgA+ cells and on a number of cell lines derived from the lymphoma. The results were consistent with the deletion model for heavy chain switching, as the IgM+ cells contained rearranged mu genes and alpha genes in the germ line configuration on both the expressed and nonexpressed heavy chain chromosomes, whereas the IgA+ cells had deleted both mu genes and contained one rearranged and one germ line alpha gene. In addition, segments of DNA located within the intervening sequence 5' to the mu gene, near the site of switch recombination, were deleted from both the expressed and the nonexpressed chromosomes. Although mu genes were deleted from both chromosomes in the IgA+ cells, the sites of DNA recombination differed on the two chromosomes. On the expressed chromosome, Smu sequences were recombined with S alpha sequences, whereas on the nonexpressed chromosome, Smu sequences were recombined with S gamma 3 sequences