322 research outputs found
SRG110 Stirling Generator Dynamic Simulator Vibration Test Results and Analysis Correlation
The U.S. Department of Energy (DOE), Lockheed Martin (LM), and NASA Glenn Research Center (GRC) have been developing the Stirling Radioisotope Generator (SRG110) for use as a power system for space science missions. The launch environment enveloping potential missions results in a random input spectrum that is significantly higher than historical radioisotope power system (RPS) launch levels and is a challenge for designers. Analysis presented in prior work predicted that tailoring the compliance at the generator-spacecraft interface reduced the dynamic response of the system thereby allowing higher launch load input levels and expanding the range of potential generator missions. To confirm analytical predictions, a dynamic simulator representing the generator structure, Stirling convertors and heat sources were designed and built for testing with and without a compliant interface. Finite element analysis was performed to guide the generator simulator and compliant interface design so that test modes and frequencies were representative of the SRG110 generator. This paper presents the dynamic simulator design, the test setup and methodology, test article modes and frequencies and dynamic responses, and post-test analysis results. With the compliant interface, component responses to an input environment exceeding the SRG110 qualification level spectrum were all within design allowables. Post-test analysis included finite element model tuning to match test frequencies and random response analysis using the test input spectrum. Analytical results were in good overall agreement with the test results and confirmed previous predictions that the SRG110 power system may be considered for a broad range of potential missions, including those with demanding launch environments
Legal Institutions for the Allocation of Water and Their Impact on Coal Conversion Operations in Kentucky
The conversion of coal into other types of fuel through gasification and liquefaction has been proposed as a means of coping with America\u27s increasing energy needs. Coal conversion plants require large quantities of water for cooling purposes and for use as a raw material.
There are three types of water allocation presently used in the United States, riparianism, prior appropriation, and administrative permit systems. The common law riparian system is undesirable because under it water rights are insecure and subject to locational use restrictions. Prior appropriation is better, but the permanent water right created under this system results in excessive rigidity. A system of administrative regulation by means of a consumptive use permit system offers the best allocation framework for both coal conversion facilities and other water users as well.
Kentucky presently has such a system of administrative allocation. However, this legislation could be improved by (1) clarifying the planning functions of the Department for Natural Resources and Environmental Protection and the Water Resources Authority; (2) expanding the scope of the consumptive use permit system by removing most of the exempted use categories; (3) adopting beneficial use as the basis upon which consumptive use permits will be granted; (4) imposing a durational limit on water use permits and delineating renewal procedures; (5) adopting a scheme for both voluntary and involuntary transfers of water rights; and (6) specifying more explicit provision for dealing with temporary water shortages.
Finally, it should be noted that the federal government has an important role with respect to navigation, water resources development, and water pollution control. Federal powers in these areas may impose some constraints on state allocation policies, although major conflicts can be avoided if proper coordination among state and federal officials is maintained
RegenBase: a knowledge base of spinal cord injury biology for translational research.
Spinal cord injury (SCI) research is a data-rich field that aims to identify the biological mechanisms resulting in loss of function and mobility after SCI, as well as develop therapies that promote recovery after injury. SCI experimental methods, data and domain knowledge are locked in the largely unstructured text of scientific publications, making large scale integration with existing bioinformatics resources and subsequent analysis infeasible. The lack of standard reporting for experiment variables and results also makes experiment replicability a significant challenge. To address these challenges, we have developed RegenBase, a knowledge base of SCI biology. RegenBase integrates curated literature-sourced facts and experimental details, raw assay data profiling the effect of compounds on enzyme activity and cell growth, and structured SCI domain knowledge in the form of the first ontology for SCI, using Semantic Web representation languages and frameworks. RegenBase uses consistent identifier schemes and data representations that enable automated linking among RegenBase statements and also to other biological databases and electronic resources. By querying RegenBase, we have identified novel biological hypotheses linking the effects of perturbagens to observed behavioral outcomes after SCI. RegenBase is publicly available for browsing, querying and download.Database URL:http://regenbase.org
The Size and Culturability of Patient-Generated SARS-CoV-2 Aerosol
BACKGROUND: Aerosol transmission of COVID-19 is the subject of ongoing policy debate. Characterizing aerosol produced by people with COVID-19 is critical to understanding the role of aerosols in transmission.
OBJECTIVE: We investigated the presence of virus in size-fractioned aerosols from six COVID-19 patients admitted into mixed acuity wards in April of 2020.
METHODS: Size-fractionated aerosol samples and aerosol size distributions were collected from COVID-19 positive patients. Aerosol samples were analyzed for viral RNA, positive samples were cultured in Vero E6 cells. Serial RT-PCR of cells indicated samples where viral replication was likely occurring. Viral presence was also investigated by western blot and transmission electron microscopy (TEM).
RESULTS: SARS-CoV-2 RNA was detected by rRT-PCR in all samples. Three samples confidently indicated the presence of viral replication, all of which were from collected sub-micron aerosol. Western blot indicated the presence of viral proteins in all but one of these samples, and intact virions were observed by TEM in one sample.
SIGNIFICANCE: Observations of viral replication in the culture of submicron aerosol samples provides additional evidence that airborne transmission of COVID-19 is possible. These results support the use of efficient respiratory protection in both healthcare and by the public to limit transmission
Lifespan extension and the doctrine of double effect
Recent developments in biogerontology—the study of the biology of ageing—suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan—a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the ‘double effect argument’, has gone unnoticed. This article exposes and critically evaluates this ‘double effect argument’. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the ‘double effect argument’ is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning
Client and therapist views of contextual factors related to termination from psychotherapy: A comparison between unilateral and mutual terminators
Contextual variables potentially influencing premature termination were examined. Clients (n = 83) and therapists (n = 35) provided parallel data on early working alliance, psychotherapy termination decision (unilateral vs. mutual), clients’ reasons for termination, and barriers to treatment participation. When clients unilaterally ended therapy, therapists were only partially aware of either the extent of clients’ perceived improvements or their dissatisfaction. When termination was mutually determined, there were no differences between client and therapist ratings of termination reasons. Although working alliance and barriers to treatment participation were rated as lower in the context of unilateral termination by clients and therapists, all clients rated the early alliance and barriers to treatment more highly than did therapists. Results have implications for understanding premature termination and suggest future research examining the utility of therapist feedback regarding contextual variables in terms of retaining clients in therapy
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