Theoretical aspects of quantum electrodynamics in a finite volume with periodic boundary conditions
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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
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Results for “aspect”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The structure of Synechococcus elongatus enolase reveals key aspects of phosphoenolpyruvate binding
A structure–function characterization of Synechococcus elongatus enolase ( Se EN) is presented, representing the first structural report on a cyanobacterial enolase. X-ray crystal structures of Se EN in its apoenzyme form and in complex with phosphoenolpyruvate are reported at 2.05 and 2.30 Å resolution, respectively. Se EN displays the typical fold of enolases, with a conformationally flexible loop that closes the active site upon substrate binding, assisted by two metal ions that stabilize the negatively charged groups. The enzyme exhibits a catalytic efficiency of 1.2 × 10 5 M −1 s −1 for the dehydration of 2-phospho-D-glycerate, which is comparable to the kinetic parameters of related enzymes. These results expand the understanding of the biophysical features of these enzymes, broadening the toolbox for metabolic engineering applications.
59 BASIC BIOLOGICAL SCIENCES↗
Characteristic Aspects of Additive Manufacturing Security From Security Awareness Perspectives
Additive manufacturing (AM) is expected to become an established manufacturing technology in the near future. The growing penetration of AM at manufacturers across the world and the dependence of this technology on computerization have already raised security concerns, some of which have been proven experimentally. In this paper, we analyze the AM Security from three awareness perspectives: exposure to an attack, evaluation of the system, and potential liability for a successful attack. For each of these perspectives, we first introduce the conceptual background and then provide the analysis of its applicability to AM, highlighting its distinctiveness from closely related subtractive manufacturing (SM). Our analysis shows that, while there is a certain overlap between AM and SM security, the AM requires a separate and unique perspective and approach undertaken by experts with relevant domain expertise.
36 MATERIALS SCIENCE↗
Electrical design analysis and breakdown voltage test aspects of indigenously developed electrical breaks at Cryo temperatures
Electrical insulation breaks are very critical component of large-scale fusion devices employing superconducting magnets and are used to insulate electrically the coil and the cryogenic supply line (kept at ground potential). The electrical insulation of breaks consists of the composites insulations, G-10 GFRP (Glass fiber reinforced plastic), cryogenic compatible epoxy and S-glass boron free fiber in air and helium environment under vacuum. To optimize the design parameters, the detailed electrical analysis have been carried out using the electrostatic solid axi-symmetric model by COMSOL 4.1 multiphysics software for electrodes separation, electrical field strength as well as flashover phenomenon between two electrodes with composite insulator material have been analyzed at different surfaces and contours along with by varying gaps between SS electrodes. We have carried out the high voltage breakdown test (0-35) kV, insulation resistance measurement at 0-5 kV test voltage in Paschen condition of (10{sup 3} -10{sup -5}) mbar in helium gas and air environment at 300 K and 77 K experimentally on in-house developed insulation breaks. (author)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Engineering aspects of microwave diagnostics in ITER
Microwave diagnostics have potential to provide localized measurement of the electron density (ne) and temperature (Te) with good spatial (a few cm) and temporal (< 1 ms) resolutions through all phases of ITER. Development of these diagnostics is a major challenge because of severe environment, strict engineering requirements, safety issues and the need for high reliability in the measurements. Most of the diagnostic components that are placed in a high radiation environment are expected to operate in this environment for a period at least until the next planned maintenance session. This paper will cover the conceptual design of microwave diagnostics and their interface with vacuum vessel and port plugs. (author)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Improving Wind Power Market Value with Various Aspects of Diversification: Preprint
The wind generation share in many European bidding zones is already large enough to impact the market value of wind power and wind energy is getting less-than-average market price in day-ahead markets. As alternatives to investing in dedicated energy storage, there are two main ways to mitigate the decreasing market value trend, the first being different diversification measures (geographical spread, alternative wind turbine technologies, integration with solar), and the second being demand flexibility measures. Examples of these measures from some European and USA studies are given in this article, which stems from the international collaboration under IEA Wind TCP Tasks 25 and 53.
diversification↗
Influential Aspects of the Smart City
Using millions of sensors in everyday objects, smart cities will generate petabytes of data, and it will be delivered to multiple users via networks. Multi-disciplinary inter-operability is essential. We propose system engineering management, with multidisciplinary teams as an effective way to deliver real change. Their goal is to develop intelligent and integrated services through the use of digital technologies and open collaboration. We also caution that the process cannot be entirely planned ahead of time, it must be allowed to evolve. New technology will change the game (where does a 3-D printer fit into a smart city?). Municipal planning means central planning – not known for its sensitivity to reality. A successful smart city will include lots of feedback mechanisms for the citizenry.
collaboration↗
Engineering Energy-Storage Projects: Applications and Financial Aspects
Reliable engineering quality, safety, and performance are essential for a successful energy-storage project. The commercial energy-storage industry is entering its most formative period, which will impact the arc of the industry's development for years to come. Project announcements are increasing in both frequency and scale. Energy-storage systems (ESSs) are establishing themselves as a viable option for deployment across the entire electricity infrastructure as grid-connected energy-storage assets or in combination with other grid assets, such as hybrid generators. In conclusion, how the industry will evolve-in direction and degree-will depend largely on building a firm foundation of sound engineering requirements into project expectations.
25 ENERGY STORAGE↗
Implementational Aspects for the Characterization of Low-Inertia in Power Systems
The replacement of conventional generating units with non-conventional renewable energy resources impacts the stability of the power system. While the general goal of supplying demand could be achieved from both generation resources, inverter-based energy resources are different from traditional synchronous machines in the sense that they do not inherently provide inertia to the system. The latter obviously worsen the system ability to maintain the balance between supply and demand after certain contingencies such as generator outages. With high integration of renewable-based generation resources, there is a reduction in total system inertia, which could lead to systems with less time to react for frequency restoration in case of such unexpected unit failures. While conceptually it is true, there is a missing gap in the field of power system stability community in terms of test-bed power systems for characterizing low-inertia conditions. In this paper, a framework for low-inertia power systems is presented. The purpose of the test-bed is to establish an environment for testing and conducting research on power systems experiencing low-inertia issues. The frequency nadir, the rate of change of frequency, and the under-frequency load shedding scheme are used as a measure of the healthiness of power grids.
Baquedano-Aguilar, Mario D.↗
Effect of Rod Material on the Impedance Behavior of Small Aspect Ratio Rod Pinches.
Abstract not provided.
Harper-Slaboszewicz, Victor Jozef↗
Epidermal jasmonate perception is sufficient for all aspects of jasmonate‐mediated male fertility in Arabidopsis
Summary Jasmonate ( JA ) signaling is essential for several environmental responses and reproductive development in many plant species. In Arabidopsis thaliana , the most obvious phenotype of JA biosynthetic and perception mutants is profound sporophytic male sterility characterized by failure of stamen filament elongation, severe delay of anther dehiscence and pollen inviability. The site of action of JA in the context of reproductive development has been discussed, but the ideas have not been tested experimentally. To this end we used targeted expression of a COI 1‐ YFP transgene in the coi1‐1 mutant background. As COI 1 is an essential component of the JA co‐receptor complex, the null coi1‐1 mutant is male sterile due to lack of JA perception. We show that expression of COI 1‐ YFP in the epidermis of the stamen filament and anther in coi1 mutant plants is sufficient to rescue filament elongation, anther dehiscence and pollen viability. In contrast, filament expression alone or expression in the tapetum do not restore dehiscence and pollen viability. These results demonstrate that epidermal JA perception is sufficient for anther function and pollen viability, and suggest the presence of a JA ‐dependent non‐autonomous signal produced in the anther epidermis to synchronize both anther dehiscence and pollen maturation.
Jewell, Jeremy B.↗
Structural and growth aspects of electron beam physical vapor deposited NiO-CeO{sub 2} nanocomposite films
Deposition of composite materials as thin film by electron beam physical vapor deposition technique (EB-PVD) still remains as a challenge. Here, the authors report the deposition of NiO-CeO{sub 2} (30/70 wt. %) composites on quartz substrate by EB-PVD. Two NiO-CeO{sub 2} nanocomposite targets—one as green compact and the other after sintering at 1250 °C—were used for the deposition. Though the targets varied with respect to physical properties such as crystallite size (11–45 nm) and relative density (44% and 96%), the resultant thin films exhibited a mean crystallite size in the range of 20–25 nm underlining the role of physical nature of deposition. In spite of the crystalline nature of the targets and similar elemental concentration, a transformation from amorphous to crystalline structure was observed in thin films on using sintered target. Postannealing of the as deposited film at 800 °C resulted in a polycrystalline structure consisting of CeO{sub 2} and NiO. Deposition using pure CeO{sub 2} or NiO as target resulted in the preferential orientation toward (111) and (200) planes, respectively, showing the influence of adatoms on the evaporation and growth process of NiO-CeO{sub 2} composite. The results demonstrate the influence of electron beam gun power on the adatom energy for the growth process of composite oxide thin films.
36 MATERIALS SCIENCE↗
Plasma etching of high aspect ratio features in SiO 2 using Ar/C 4 F 8 /O 2 mixtures: A computational investigation
Not provided.
Materials Science↗
Key aspects of sub-nanometer deterministic ion beam figuring for synchrotron hard x-ray mirror fabrication
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36 MATERIALS SCIENCE↗