231 research outputs found
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Seismic, high wind, tornado, and probabilistic risk assessments of the High Flux Isotope Reactor
Natural phenomena analyses were performed on the High Flux Isotope Reactor (HFIR) Deterministic and probabilistic evaluations were made to determine the risks resulting from earthquakes, high winds, and tornadoes. Analytic methods in conjunction with field evaluations and an earthquake experience data base evaluation methods were used to provide more realistic results in a shorter amount of time. Plant modifications completed in preparation for HFIR restart and potential future enhancements are discussed. 5 figs
Violent video games and morality: a meta-ethical approach
This paper considers what it is about violent video games that leads one reasonably minded person to declare "That is immoral" while another denies it. Three interpretations of video game content a re discussed: reductionist, narrow, and broad. It is argued that a broad interpretation is required for a moral objection to be justified. It is further argued that understanding the meaning of moral utterances – like "x is immoral" – is important to an understanding of why there is a lack of moral consensus when it comes to the content of violent video games. Constructive ecumenical expressivism is presented as a means of explaining what it is that we are doing when we make moral pronouncements and why, when it comes to video game content, differing moral attitudes abound. Constructive ecumenical expressivism is also presented as a means of illuminating what would be required for moral consensus to be achieved
Exploring the lived experience of Long Covid in black and minority ethnic groups in the UK: Protocol for qualitative interviews and art-based methods.
Some people experience prolonged symptoms following an acute COVID-19 infection including fatigue, chest pain and breathlessness, headache and cognitive impairment. When symptoms persist for over 12 weeks following the initial infection, and are not explained by an alternative diagnosis, the term post-COVID-19 syndrome is used, or the patient-defined term of Long Covid. Understanding the lived experiences of Long Covid is crucial to supporting its management. However, research on patient experiences of Long Covid is currently not ethnically diverse enough. The study aim is to explore the lived experience of Long Covid, using qualitative interviews and art-based methods, among people from ethnically diverse backgrounds (in the UK), to better understand wider systems of support and healthcare support needs. Co-created artwork will be used to build on the interview findings. A purposive sampling strategy will be used to gain diverse experiences of Long Covid, sampling by demographics, geographic locations and experiences of Long Covid. Individuals (aged >18 years) from Black and ethnic minority backgrounds, who self-report Long Covid symptoms, will be invited to take part in a semi-structured interview. Interviews will be analysed thematically. A sub-sample of participants will be invited to co-create visual artwork to further explore shared narratives of Long Covid, enhance storytelling and increase understanding about the condition. A patient advisory group, representing diversity in ethnicity and experiences of Long Covid, will inform all research stages. Stakeholder workshops with healthcare professionals and persons, systems or networks important to people's management of Long Covid, will advise on the integration of findings to inform management of Long Covid. The study will use patient narratives from people from diverse ethnic backgrounds, to raise awareness of Long Covid and help inform management of Long Covid and how wider social systems and networks may inform better healthcare service access and experiences
Persistent isolated impairment of gas transfer following COVID-19 pneumonitis relates to perfusion defects on dual-energy computed tomography
Breathlessness is common in patients after COVID-19 [1]. Patients may have an isolated impairment of gas transfer (diffusion of the lung for carbon monoxide, DLCO) at lung function testing, often without obvious interstitial lung disease or classical pulmonary emboli (PE) on imaging. Iodine maps from post-COVID patients undergoing dual energy computed tomography (DECT) demonstrate hypoenhancement in areas of normal lung parenchyma [2] (figure 1). We hypothesized that in breathless patients recovering from COVID-19, low DLCO would correlate with a CT marker of lung perfusion, measured using DECT-derived iodine enhancement, including in patients where parenchymal disease was absent. As an even more specific indicator for the pulmonary vascular compartment, we hypothesized that KCO (DLCO corrected for alveolar volume) would even better correlate with DECT perfusion, and more so than forced vital capacity (FVC) and CT measures of interstitial lung involvement
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Results of analyses of fur samples from the San Joaquin Kit Fox and associated soil and water samples from the Naval Petroleum Reserve No. 1, Tupman, California
The purpose of this study was to determine whether analysis of the elemental content of fur from San Joaquin kit foxes (Vulpes macrotis mutica) and of water and soil from kit fox habitats could be used to make inferences concerning the cause of an observed decline in the kit fox population on Naval Petroleum Reserve No. 1 (NPR-1). Fur samples that had been collected previously from NPR-1, another oil field (NPR-2), and two sites with no oil development were subjected to neutron activation analysis. In addition, soil samples were collected from the home ranges of individual foxes from undisturbed portions of major soil types on NPR-1 and from wastewater samples were collected from tanks and sumps and subjected to neutron activation analysis. Most elemental concentrations in fur were highest at Camp Roberts and lowest on the undeveloped portions of NPR-I. Fur concentrations were intermediate on the developed oil fields but were correlated with percent disturbance and with number of wells on NPR-1 and NPR-2. The fact that most elements covaried across the range of sites suggests that some pervasive source such as soil was responsible. However, fur concentrations were not correlated with soft concentrations. The kit foxes on the developed portion of NPR-1 did not have concentrations of elements in fur relative to other sites that would account for the population decline in the early 1980s. The oil-related elements As, Ba, and V were elevated in fox fur from oil fields, but only As was sufficiently elevated to suggest a risk of toxicity in individual foxes. However, arsenic concentrations suggestive of sublethal toxicity were found in only 0.56% of foxes from developed oil fields, too few to account for a population decline
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Multiple scattering theory for space filling potentials
Multiple scattering theory (MST) provides an efficient technique for solving the wave equation for the special case of muffin-tin potentials. Here MST is extended to treat space filling non-muffin tin potentials and its validity, accuracy and efficiency are tested by application of the two dimensional empty lattice test. For this test it is found that the traditional formulation of MST does not coverage as the number of partial waves is increased. A simple modification of MST, however, allows this problem to be solved exactly and efficiently. 15 refs., 3 tabs
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The design and fabrication of a toroidally continuous cryocondensation pump for the DIII-D Advanced Divertor
A cryocondensation pump will be installed in the baffle chamber of the DIII-D tokamak in the spring of 1992. The design is complete and fabrication of this pump is in progress. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long, in the lower outer corner of the vacuum vessel interior. It consists of a 1 m{sup 2} liquid helium cooled surface surrounded by a liquid nitrogen cooled shield to limit the heat load on the helium cooled surface. The stainless steel liquid nitrogen shell has a copper coating on it to enhance thermal conductivity, but the coating is broken to keep the toroidal electrical resistance high. The liquid nitrogen cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. The whole pump is supported off the water cooled vacuum vessel wall. Key design considerations were: how to accommodate the temperature differences between the various components, developing low heat leak paths for the various supports, and maintaining electrical insulation in a low pressure environment in the presence of induced voltage spikes. A single point ground for the system was used to limit disruption induced currents and the resulting electro-mechanical forces on the pump. A testing program was used to develop coating techniques to enhance heat transfer and emissivity of the various surfaces. Fabrication tests were done to determine the best method of attaching the liquid nitrogen flow tubes to their shield surfaces. A prototype sector of the pump was built to verify fabrication and assembly techniques
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A carbon-carbon composite materials development program for fusion energy applications
Carbon-carbon composites increasingly are being used for plasma-facing component (PFC) applications in magnetic-confinement plasma-fusion devices. They offer substantial advantages such as enhanced physical and mechanical properties and superior thermal shock resistance compared to the previously favored bulk graphite. Next-generation plasma-fusion reactors, such as the International Thermonuclear Experimental Reactor (ITER) and the Burning Plasma Experiment (BPX), will require advanced carbon-carbon composites possessing extremely high thermal conductivity to manage the anticipated extreme thermal heat loads. This report outlines a program that will facilitate the development of advanced carbon-carbon composites specifically tailored to meet the requirements of ITER and BPX. A strategy for developing the necessary associated design data base is described. Materials property needs, i.e., high thermal conductivity, radiation stability, tritium retention, etc., are assessed and prioritized through a systems analysis of the functional, operational, and component requirements for plasma-facing applications. The current Department of Energy (DOE) Office of Fusion Energy Program on carbon-carbon composites is summarized. Realistic property goals are set based upon our current understanding. The architectures of candidate PFC carbon-carbon composite materials are outlined, and architectural features considered desirable for maximum irradiation stability are described. The European and Japanese carbon-carbon composite development and irradiation programs are described. The Working Group conclusions and recommendations are listed. It is recommended that developmental carbon-carbon composite materials from the commercial sector be procured via request for proposal/request for quotation (RFP/RFQ) as soon as possible
Uncoordinated Transcription and Compromised Muscle Function in the Lmna-Null Mouse Model of Emery-Dreifuss Muscular Dystrophy
LMNA encodes both lamin A and C: major components of the nuclear lamina. Mutations in LMNA underlie a range of tissue-specific degenerative diseases, including those that affect skeletal muscle, such as autosomal-Emery-Dreifuss muscular dystrophy (A-EDMD) and limb girdle muscular dystrophy 1B. Here, we examine the morphology and transcriptional activity of myonuclei, the structure of the myotendinous junction and the muscle contraction dynamics in the lmna-null mouse model of A-EDMD. We found that there were fewer myonuclei in lmna-null mice, of which ∼50% had morphological abnormalities. Assaying transcriptional activity by examining acetylated histone H3 and PABPN1 levels indicated that there was a lack of coordinated transcription between myonuclei lacking lamin A/C. Myonuclei with abnormal morphology and transcriptional activity were distributed along the length of the myofibre, but accumulated at the myotendinous junction. Indeed, in addition to the presence of abnormal myonuclei, the structure of the myotendinous junction was perturbed, with disorganised sarcomeres and reduced interdigitation with the tendon, together with lipid and collagen deposition. Functionally, muscle contraction became severely affected within weeks of birth, with specific force generation dropping as low as ∼65% and ∼27% of control values in the extensor digitorum longus and soleus muscles respectively. These observations illustrate the importance of lamin A/C for correct myonuclear function, which likely acts synergistically with myotendinous junction disorganisation in the development of A-EDMD, and the consequential reduction in force generation and muscle wasting
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Neutron study of crystal-field transitions in ErPO[sub 4]
The crystal-field splitting of the Er[sup 3+] ground multiplet, [sup 4]I[sub 15/2], in ErPO[sub 4] is investigated by inelastic neutron scattering. Four excitations from the [Gamma][sub 7] ground state to the excited states and several transitions between the excited states have been identified. The observed transition energies and intensities are used to refine the parameters of the crystal-field potential. The calculated magnetic susceptibility, [chi](T), agrees well with experimental values from single-crystal measurements. A comparison of the neutron data with optical absorption and both nonresonance and resonance Raman scattering measurements has been made
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