258 research outputs found

    Underwater Vehicles

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    For the latest twenty to thirty years, a significant number of AUVs has been created for the solving of wide spectrum of scientific and applied tasks of ocean development and research. For the short time period the AUVs have shown the efficiency at performance of complex search and inspection works and opened a number of new important applications. Initially the information about AUVs had mainly review-advertising character but now more attention is paid to practical achievements, problems and systems technologies. AUVs are losing their prototype status and have become a fully operational, reliable and effective tool and modern multi-purpose AUVs represent the new class of underwater robotic objects with inherent tasks and practical applications, particular features of technology, systems structure and functional properties

    Large space structures and systems in the space station era: A bibliography with indexes

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    Bibliographies and abstracts are listed for 1372 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1990 and June 30, 1990. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

    Large space structures and systems in the space station era: A bibliography with indexes

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    Bibliographies and abstracts are listed for 1219 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1990 and December 31, 1990. The purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

    Space station systems: A bibliography with indexes

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    This bibliography lists 967 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future space station

    Technology for large space systems: A bibliography with indexes (supplement 13)

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    This bibliography lists 399 reports, articles and other documents introduced into the NASA scientific and technical information system between January 1, 1985 and June 30, 1985. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

    A whispering gallery mode based biosensor platform for single enzyme analysis

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    Enzymes catalyze most of the biochemical reactions in our cells. The functionality of enzymes depends on their dynamics starting from small bond vibrations in the fs timescale to large domain motions in the microsecond-millisecond timescale. Understanding the precise and rapid positioning of atoms within a catalytic site by an enzyme’s molecular movements is crucial for understanding biomolecular processes and for realizing synthetic biomolecular machines in the longer term. Hence, sensors capable of studying enzymes over a wide range of amplitudes and timescale and ideally one enzyme at a time are required. Many capable single-molecule techniques have been established in the past three decades, each with its pros and cons. This thesis presents the development of one such single-molecule sensor. The sensor is based on plasmonically enhanced whispering gallery mode resonators and is capable of studying enzyme kinetics and large-scale dynamics over the timescale of ns-seconds. Unlike fluorescence techniques which require labeling of the enzymes with dyes, the technique presented in this work detects single enzymes immobilized on the surface of plasmonic gold nanoparticles. A fast, low-noise, lock-in method is utilized to extract sensor signals in the microsecond timescale. Using a model enzyme, the ability of the sensor to detect conformational fluctuations of single enzymes is shown. Further, the thermodynamics of the enzyme is studied and the relevant thermodynamic parameters are extracted from the single-molecule data. Additionally, we extract the heat capacity changes associated with the enzyme using the single-molecule data. The sensor system presented in this thesis in the future could enable a fast, real-time, rapid throughput, lab-on-chip sensor system for studying single enzymes for both research and clinical use.Engineering and Physical Sciences Research Council (EPSRC)Engineering and Physical Sciences Research Council (EPSRC

    Orbital research centrifuge. Experiment performance options and cost, volume 3. Space shuttle compatible Experiment Performance Options (EPOS)

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    Cost comparisons and experiment performance options for space shuttle orbital research centrifug

    Applications of Tethers in Space: Workshop Proceedings, Volume 2

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    Topics addressed include: tethered orbital transfer vehicle operations, Centaur and Shuttle tether technology; tethered constellations, gravitational effects; Shuttle continuous open wind tunnel; optimal control laws, electrodynamic tether technology; and space station facilities

    Characterization and exploitation of protein ligand interactions for structure based drug design

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    Most characterised protein-small molecule interactions that display a change in heat capacity (\bigtriangleupCp) occur with a negative \bigtriangleupCp value. This is often attributed to solvent reorganisation from reduction in solvent accessible apolar surface area accompanying complex formation. Positive \bigtriangleupCp values have not been widely reported and could typically be attributed to an increased solvent accessible apolar surface area, desolvation of polar surface area or structural transitions in the biomolecular complex. Heat shock protein-90 (Hsp90) is one of the abundant and important molecular ATP-dependent chaperones. The N-terminal domain of Hsp90 contains ATP/ADP binding site, where Hsp90-ADP interactions proceed with a large positive \bigtriangleupCp of 2.35 ± 0.46 kJ·mol-1·K-1. Interestingly geldanamycin, an Hsp90 inhibitor which binds to the same N-Hsp90-ADP/ATP binding site, interacts with a negative \bigtriangleupCp of -0.39 ± 0.04 kJ·mol-1·K-1. The semi-empirical correlation of the solvent accessible surface area change does not match well with the observed \bigtriangleupCp. This prompted us to investigate various factors affecting the thermodynamics of protein-small molecule binding including varying buffers, differing salt concentration, altering pH, substitution of different metal cations and performing interactions in heavy water. Molecular dynamics simulation and NMR studies have allowed us to disregard structural changes of N-Hsp90-ADP molecule from giving rise to positive \bigtriangleupCp. From a combination of these calorimetric, simulation and structural studies we have gathered a considerable body of evidence suggesting that the change in accessible surface area, ionic interactions and resultant desolvation of water molecules from the surface of a Mg2+ ion can contribute substantially to a positive \bigtriangleupCp. We conclude that this unique result appears to come from extensive disruption of the tightly bound water molecules present around Mg2+-ADP after binding to Hsp90, which then gives rise to a positive \bigtriangleupCp. In addition to these findings, the thermodynamics of 18 structurally related CDK2 inhibitors were investigated using ITC. CDK2 is a member of cyclin dependent kinases implicated in eukaryotic cell cycle progression and control. This investigation showed that even conservative changes in small molecule structure can reveal large variation in thermodynamic signature, while simple concepts such as van der Waals interactions, steric hindrance, and hydrophobicity are insufficient to explain it

    Sliding Mode Control

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    The main objective of this monograph is to present a broad range of well worked out, recent application studies as well as theoretical contributions in the field of sliding mode control system analysis and design. The contributions presented here include new theoretical developments as well as successful applications of variable structure controllers primarily in the field of power electronics, electric drives and motion steering systems. They enrich the current state of the art, and motivate and encourage new ideas and solutions in the sliding mode control area
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