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Showing 1 to 20 of 29 for “"LH2"”.
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Studies on the different types of LH2 complexes from the purple non-sulphur photosynthetic bacterium Rhodopseudomonas palustris strain 2.1.6
… 2.1.6, produce light harvesting antenna (LH2) with unusual absorption spectra when they are grown under low-light intensities. This ability is often related to the presence of multiple genes encoding the LH2 apoproteins. This thesis describes isolation of pure stable LH2s from …
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The Role of Hydrogen Fuel in Hard-to-Decarbonise Modes of Transport: An Energy Systems Perspective
… of electricity grid derived liquid hydrogen (LH2) fuel for these purposes is investigated. Particular focus is dedicated to: (1) the geographical, situational and design niches for which the use of LH2 is favourable within aviation and shipping; (2) the ability of LH2 to power the global …
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Removing the Quantum Barrier to Sustainable LH2 Fuel in Aviation: A Mechanistic, Process, and Environmental Life Cycle Assessment of the Ortho-Para Conversion in Liquefaction
Liquid hydrogen (LH2) is a critical energy carrier for decarbonisation, yet its production is challenged by the high energy cost and boil-off losses associated with the exothermic ortho-to-para hydrogen conversion (OPC). A fundamental trade-off exists between the energy invested during liquefaction …
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Spectroscopic Investigations of Light-Harvesting 2 Complexes from Rps. acidophila
… a prominent example, the light-harvesting 2 (LH2) antenna complexes located in the photosynthetic apparatus of anoxygenic non-sulfur purple bacteria has already provided a deep insight into how nature has developed a pigment-protein complex with highly efficient light-harvesting and energy …
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Photophysics of Biological and Synthetic Multichromophoric Systems : Spectroscopic Investigations of Bacterial Light-Harvesting Complexes and of Carbonyl-Bridged Triarylamine Derivatives
… (AuNP) and a light-harvesting complex II (LH2), another light-harvesting complex from purple bacteria, -two novel artificial light-harvesting systems, based on carbonyl-bridged triarylamines (CBTs) Different methods of optical spectroscopy and optical microscopy have been used to …
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Computational investigation of light harvesting in purple photosynthetic bacteria
… bacteria consists of light harvesting complex 2 (LH2), light harvesting complex 1 (LH1) and reaction center (RC) assembeled into a structure known as the chromatophore. The pigments embedded into the complexes in the chromatophore are placed close together and are tightly held by their surrounding …
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Understanding Ultrafast Energy Transfer across the Photosynthetic Membrane of Purple Bacteria with Near-Native Systems
… Peripheral light-harvesting complex 2 (LH2) surrounds the core light-harvesting complex 1 (LH1), which in turn encircles the reaction center (RC). Energy absorbed by LH2 is transferred to LH1 and then finally the RC, where it is converted to chemical energy through charge separation. …
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Computational investigations into two biological processes: membrane reshaping by light-harvesting proteins in the chromatophores of purple bacteria, and oligomerization and pore formation by the Hepatitis C viroporin p7
… by the light harvesting complexes LH1 and LH2. LH1 is always found surrounding the reaction center, forming LH1-RC core complexes, which may be elliptically-shaped monomers or S-shaped dimers depending on the species of bacteria. LH2 is a small ring-shaped complex which is produced to …
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Femtosekunden-Spektroskopie biologischer Systeme mittels kohärenter Kontrolle
… specifically the light harvesting complex LH2 from the photosynthetic purple bacterium Rhodopseudomonas acidophila, and the isolated carotenoid donor of the same complex. The pump-probe method using shaped excitation pulses is shown to be successful for the first time in controlling the …
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Instrument Design Optimization with Computational Methods
… density fluctuations from the liquid hydrogen (LH2) target used in the <em>Q<sub>weak</sub></em> experiment (2011-2012) are studied with Computational Fluid Dynamics (CFD) and the simulation results compared to data from the experiment. The 2.5 kW liquid hydrogen target was the highest power LH2 …
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The Safe Removal of Frozen Air from the Annulus of a Liquid Hydrogen Storage Tank
Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon …
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Photoproduction of the Φ(1020) Meson in Neutral Decay Mode γP → ΦP → K(S)K(L)P
… data of the g11a experiment collected on an LH2 target using the CLAS detectector at Hall B, TJNAF. The measured cross sections show some differences from the charged decay mode Φ → <em>K</em><sup>+</sup><em> K</em><sup>−</sup>.</p>
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On-Orbit Cryogenic Propellant Storage Optimization
… control approach documented herein minimizes LH2 boiloff to near zero boiloff in Low Earth Orbit (LEO) using only passive thermal control techniques, eliminating the need for developing complex and costly active thermal control systems. The optimal CPS system design leverages the current human …
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Developing Evaluation Measures for the Second Stage Next Generation Engine on Evolved Expendable Launch Vehicles
… (EELV), U.S. liquid propulsion, and the RL10 LH2/LOX engine to analyze tradeoffs between major requirements in new upper stage development and to provide a recommendation of evaluation measures. The results are a proactive case presenting the benefits of a new upper stage engine on EELV, a …
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Computational Investigation of Impingement Cooling for Regeneratively Cooled Rocket Nozzles
… of the Space Shuttle Main Engine (SSME) with LOX/LH2 propellants. A 1-D thermal analysis of supercritical LH2 coolant at 52.4 K and 24.8 MPa for the SSME with various nozzle wall materials, such as Stainless Steel 304 (SS 304), Inconel x-750, copper and ABS plastic, is conducted. The material …
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Computational investigations of cellular functions: Three cases on membrane morphogenesis, organization and assembly of a multi-protein complex, and the molecular origin of muscle elasticity
… membrane-bound light-harvesting proteins LH1 and LH2. LH1 directly surrounds the reaction center (RC) and, together with PufX, forms a dimeric (RC-LH1-PufX)2 protein complex known as the photosynthetic core complex. In LH2-deficient Rba . sphaeroides mutants, core complex dimers aggregate into …
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Generalized multi-commodity network flows : case studies in space logistics and complex infrastructure systems
… orbit (IMLEO) primarily because chemical (LOX/LH2) propulsion is used along with oxygen-rich ISRU. We also present one possible scenario with two "gateway" resource depots at GTO and DTO with orbital transfer vehicles (OTVs) running in the cislunar and Martian systems. Then we solve variant …
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Multi-Objective Exploration of Refueling Architecture for Sustainable Crewed and Cargo Space Transportation
… cryocoolers, the benefits of high Isp with Lox/LH2, the benefits with NRHO refueling for acceptable ΔV requirement, and positive and negative effects of reusability in mass and mission time. Furthermore, the study indicates that the number of required refueling events is more sensitive to …
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Computational study of 3D turbulent air flow in a helical rocket pump inducer
… of the swept-back leading edge. A simplified air-LH2 analogy permitted the prediction of cavitation inception in the liquid hydrogen pump, and the results obtained correspond qualitatively well with water flow visualizations. The accordance of the model with available air test data at the inlet …
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Numerical investigation of the combustion of liquid oxygen droplets in an environment of hydrogen under microgravity conditions
… to better understand the behavior of the LOX/LH2 system. This work studies the configuration of a single liquid oxygen droplet surrounded by gaseous hydrogen diluted with helium. A numerical model using OpenFOAM as well as a coupled droplet evaporation model based on combining OpenFOAM results …
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