992 resultados para md
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CONTENTS: Approaches to understanding pond-dike systems in Asia: the POND-LIVE project approach, by Dave Little, Marc Verdegem and Roel Bosma. The contribution of fish ponds to nutrient cycling in integrated farming systems, by P.N. Muendo, J.J. Stoorvogel and Marc Verdegem. Improving the contribution of fishfarming to livelihoods in Northeast Thailand, by Chittra Arjinkit, Roel Bosma, Danai Turongrouang. Benefits of pond-dike systems in Bangladesh, by M.S. Kabir, M.A. Wahab and Marc Verdegem. Common carp increases rohu production in farmers ponds, by Mohammad Mustafizur Rahman, Md. Abdul Wahab and Marc C.J. Verdegem. Improving pond-dike farming systems in the Mekong delta, Vietnam; the Can Tho approach, by Dang Kieu Nhan, Le Thanh Duong, Le Thanh Phong, Roel H. Bosma and Marc C.J. Verdegem. Fuzzy pathways for farm development in Vietnam, by Roel H. Bosma, Le Thanh Phong, and Dang Kieu Nhan.
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用分子动力学(MD)模拟了单晶铜的纳米压痕。提出“接触原子”方法来计算接触面积,并和实验上采用的方法进行比较,发现此方法无论是对“挤出”还是“沉陷”情况都能更准确地计算接触面积。同时也模拟了压头曲率半径对纳米压痕的影响,发现在同一压痕深度下材料纳米硬度的测量值随着压头半径的增大而变大。
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The hybrid quantum mechanics (QM) and molecular mechanics (MM) method is employed to simulate the His-tagged peptide adsorption to ionized region of nickel surface. Based on the previous experiments, the peptide interaction with one Ni ion is considered. In the QM/MM calculation, the imidazoles on the side chain of the peptide and the metal ion with several neighboring water molecules are treated as QM part calculated by "GAMESS", and the rest atoms are treated as MM part calculated by "TINKER". The integrated molecular orbital/molecular mechanics (IMOMM) method is used to deal with the QM part with the transitional metal. By using the QM/MM method, we optimize the structure of the synthetic peptide chelating with a Ni ion. Different chelate structures are considered. The geometry parameters of the QM subsystem we obtained by QM/MM calculation are consistent with the available experimental results. We also perform a classical molecular dynamics (MD) simulation with the experimental parameters for the synthetic peptide adsorption on a neutral Ni(100) surface. We find that half of the His-tags are almost parallel with the substrate, which enhance the binding strength. Peeling of the peptide from the Ni substrate is simulated in the aqueous solvent and in vacuum, respectively. The critical peeling forces in the two environments are obtained. The results show that the in-tidazole rings are attached to the substrate more tightly than other bases in this peptide.
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A post Agnes study emphasizing environmental factors...weekly sampling at eight stations from 28 June to August 30, 1972. Spatial and temporal changes in the distribution of many factors, e.g., salinity, dissolved oxygen (DO), seston, particulate carbon and nitrogen, inorganic and organic fractions of dissolved nitrogen and phosphorus, and chlorophyll a were studied and compared to earlier extensive records. Patterns shown by the present data were compared especially with a local heavy storm that occurred in the Patuxent drainage basin during July 1963. Some interesting correlations were observed in the data. (PDF has 39 pages.)
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A post-Agnes study that emphasized environmental factors was carried out on the Patuxent River estuary with weekly sampling at eight stations from 28 June t o 30 August 1972. Spatial and temporal changes in the distribution of many factors , e.g., salinity , dissolved oxygen, seston, particulate carbon and nitrogen, inorganic and organic fractions of dissolved nitrogen and phosphorus, and chlorophyll a were studied and compared t o extensive earlier records. Patterns shown by the present data were compared especially with a local heavy storm that occurred in the Patuxent drainage basin during July 1969. Estimates were made of the amounts of material contributed via upland drainage. A first approximation indicated that 14.8 x l0 (3) metric tons of seston were contributed t o the head of the estuary between 21 and 24 June. (PDF contains 46 pages)
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Editorial An increasingly secure future for wastewater-fed aquaculture in Kolkata, India? by Peter Edwards. First culture-based fisheries growth cycle in Lao PDR is overwhelmingly encouraging, by Sena De Silva. Revival of abandoned shrimp farms in Krishna District of Andhra Pradesh, by National Centre for Sustainable Aquaculture (NaCSA). Growth of forward and backward industries linked with aquaculture in Kolleru Lake area, Andhra Pradesh, India, by A. K. Roy, G. S. Saha, P. Kumaraiah and N. Sarangi Effective marketing strategies for economic viability of prawn farming in Kuttanad, India, by Ranjeet K. and B. Madhusoodana Kurup. Applications of nutritional biotechnology in aquaculture, by S.D. Singh, S.K. Nayak, M. Sekar and B.K. Behera. Some technical and management aspects of catfish hatcheries in Hong Ngu district, Dong Thap province, Vietnam, by H. P. Hung, N. T. T. An, N. V. Trieu, D. T. Yen, U. Na-Nakorn, Thuy T. T. Nguyen. Nodavirus: An emerging threat to freshwater prawn farming, by Biju Sam Kamalam, J., Saravanan, S. and Ajith Stalin, J.L. Asia-Pacific Marine Finfish Aquaculture Network Magazine: Asian seabass farming: Brainstorming workshop and training in India. Comparative study for broodstock management of grey mullet (Mugil cephalus L.) in cages and earthen ponds with hormone treatment, by Nani Gopal Das, Md. Shahadat Hossain, Sushanta Bhattacharjee and Prabal Barua. Cultivation of gilthead sea bream (Sparus auratus L.) in low saline inland water of the southern part of Israel desert, by Samuel Appelbaum and A. Jesu Arockia Raj. Mariculture development opportunities in SE Sulawesi, Indonesia, by La Ode M. Aslan, Hotman Hutauruk, Armen Zulham,Irwan Effendy, Mhummaed Atid, Michael Phillips, Lars Olsen, Brendan Larkin, Sena S De Silva, Geoff Gooley. Improved hatchery and grow-out technology for marine finfish. NACA Newsletter
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Molecular dynamics (MD) simulation is employed to study the bio-adhesion in F1 ATP molecular motor. Histidine-peptide is widely used as linkage in micro systems because of its strong binding strength to metals. This paper focuses on the adhesion between a synthetic peptide containing 6xHis-tag (Gly-Gly-Lys-Gly-Gly-Lys-Gly-Gly-His-His-His-His-His-His) and metal substrate, which is used to define the position of the F1 ATP molecular motor on the metal substrate. It is shown that the binding strength between histidine and nickel substrate is the strongest, while that of copper is smaller and that of gold substrate is the smallest. From the result of simulation, we find that the stability of adhesion between histidine and the metal substate result of the ringed structure in histidine.
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Cohesive zone characterizations of the interface between metal film and ceramic substrate at micro- and nano-scales are performed in the present research. At the nano-scale, a special potential for special material interface (Ag/MgO) is adopted to investigate the interface separation mechanism by using MD simulation, and stress-separation relationship will be obtained. At the micro-scale, peeling experiment is performed for the Al film/Al2O3 substrate system with an adhesive layer at the interface. Adhesive is a mixture of epoxy and polyimide with mass ratio 1:1, by which a brittle cohesive property is obtained. The relationships between energy release rate, the film thickness and the adhesive layer thickness are measured during the steady-state peeling. The experimental result has a similar trend as modeling result for a weak adhesion interface case.
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By applying for molecular dynamics (MD) simulation and Griffith fracture criterion, the brittle behavior of crack extension of mode I type is investigated. The critical stress intensity factor (SIF)K-Ic(MD) of crack extension is calculated, and the evolution of atoms near crack tip is observed. It is found that K-Ic(MD) is in good agreement with the Griffith ftacture criterion K-Ic(Griffith).
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Hurricane Isabel made landfall as a Category 2 Hurricane on 18 September 2003, on the North Carolina Outer Banks between Cape Lookout and Cape Hatteras, then coursed northwestward through Pamlico Sound and west of Chesapeake Bay where it downgraded to a tropical storm. Wind damage on the west and southwest shores of Pamlico Sound and the western shore of Chesapeake Bay was moderate, but major damage resulted from the storm tide. The NOAA, National Ocean Service, National Centers for Coastal Ocean Sciences, Center for Coastal Fisheries and Habitat Research at Beaufort, North Carolina and the Center for Coastal Environmental Health and Biomedical Research Branch at Oxford, Maryland have hurricane preparedness plans in place. These plans call for tropical storms and hurricanes to be tracked carefully through NOAA National Weather Service (NWS) watches, warnings, and advisories. When a hurricane watch changes to a hurricane warning for the areas of Beaufort or Oxford, documented hurricane preparation plans are activated. Isabel exacted some wind damage at both Beaufort and Oxford. Storm tide caused damage at Oxford, where area-wide flooding isolated the laboratory for many hours. Storm tide also caused damage at Beaufort. Because of their geographic locations on or near the open ocean (Beaufort) or on or near large estuaries (Beaufort and Oxford), storm tide poses a major threat to these NOAA facilities and the safety of federal employees. Damage from storm surge and windblown water depends on the track and intensity of a storm. One tool used to predict storm surge is the Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model of the NWS, which provides valuable surge forecasts that aid in hurricane preparation.