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排序方式: 共有1640条查询结果,搜索用时 218 毫秒
1.
Multidimensional Systems and Signal Processing - In medical Image processing, the chief objective is to detect Neoplasm effectively. Neoplasm is basically a sort of abnormal excessive cell growth... 相似文献
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In this article, a theoretical model for predicting the equilibrium morphology of gas–liquid Janus droplets was built. Based on this model, the effects of bubble radius and volume ratio on morphology change was systematically studied. The increase of bubble radius causes the two parts (bubble and oil drop) in Janus droplets tend to merge while the impact of volume ratio is complicated. When volume ratio increases, these two parts firstly tend to merge, then gradually separate. The accuracy of this model was verified by experimental results. 相似文献
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Kara D. Fong Helen K. Bergstrom Bryan D. McCloskey Kranthi K. Mandadapu 《American Institute of Chemical Engineers》2020,66(12):e17091
The theory of transport phenomena in multicomponent electrolyte solutions is presented here through the integration of continuum mechanics, electromagnetism, and nonequilibrium thermodynamics. The governing equations of irreversible thermodynamics, including balance laws, Maxwell's equations, internal entropy production, and linear laws relating the thermodynamic forces and fluxes, are derived. Green–Kubo relations for the transport coefficients connecting electrochemical potential gradients and diffusive fluxes are obtained in terms of the flux–flux time correlations. The relationship between the derived transport coefficients and those of the Stefan–Maxwell and infinitely dilute frameworks are presented, and the connection between the transport matrix and experimentally measurable quantities is described. To exemplify the application of the derived Green–Kubo relations in molecular simulations, the matrix of transport coefficients for lithium and chloride ions in dimethyl sulfoxide is computed using classical molecular dynamics and compared with experimental measurements. 相似文献
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Fabiana Helen Santos Luana Elisa Siqueira Giselle Pereira Cardoso Gustavo Molina Franciele Maria Pelissari 《应用聚合物科学杂志》2021,138(35):50887
The increasing use of non-biodegradable materials and the difficulty in recycling most of the available packaging have been pushing the development of biodegradable packaging. In this study, the potential uses of agroindustrial wastes to produce biodegradable films with antioxidant capacity were investigated. Starch films were produced by casting method using bran from jaboticaba peel, mango peel, and broccoli stalk. The influence of the concentration or type of bran in the properties of the films was evaluated through a central composite design. The results were analyzed by response surface and desirability function. Except for elongation and water solubility, the fitted equations were predictive in all studied properties. The films prepared from a higher concentration of mango peel exhibited better antioxidant capacity, while the broccoli stalk had no significant effect on antioxidant properties. The optimal formulation of the film (2.8% of jaboticaba peel and 20.0% of mango peel) and their predicted response variables (0.8 MPa for tensile strength, 40.0 MPa for Young's modulus, 4.5 mg/ml for IC50, and 41.6% for inhibition percentage) were defined according to the results. The optimization was satisfactory and the film presented high antioxidant capacity and moderate mechanical properties, proving to be an alternative to replace plastic packaging. 相似文献
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Neal C House WA Jarvie HP Neal M Hill L Wickham H 《The Science of the total environment》2005,344(1-3):107-128
Variations in phosphorus (P) concentrations in an agriculturally impacted river draining a Chalk aquifer and an associated canal in the west of the Thames Basin, southern England are examined and linked to agricultural and sewage sources and within river/canal process controls. The study area comprises the River Dun, the adjacent River Kennet and the Kennet and Avon (K&A) Canal. Large seasonal variations are observed for soluble reactive phosphorus (SRP) and dissolved silicon (Si) with low concentrations in the spring and summer times when biological activity is high. The K&A Canal shows the largest SRP and Si concentration declines. This reflects high biological activity coupled with higher temperatures and higher water residence times. The extent of SRP removal is examined in relation to organic (uptake/release with phytoplankton growth/decay) and, to a lesser extent, inorganic (SRP coprecipitation with calcite) mechanisms. Boron (B) is used as a tracer of sewage sources. Agricultural inputs of both dissolved and particulate P (PP) can be important particularly under conditions where the catchment is wet and near surface/overland flow is important: sewage treatment works effluent and septic tank discharges to groundwater also probably provide a major component of the SRP occurring within the water column. The canal, and to a lesser extent the river, acts as sink for P in sewage effluent sources due to the high biological activity especially during the spring and summer. The aquifer probably acts as a major sink for agricultural and septic tank inputs of P. 相似文献
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A series of chlorination studies were carried out on natural and artificial sea-water. It was determined that both the forward and back titration procedures accurately described the two phases of chlorine losses in sea-water: a rapid initial loss followed by a continuous loss at a sharply reduced rate. The order of adding the iodide and buffer reagents was found to be crucial in affecting the rapid initial loss. The initial loss was found to reach a saturation level that varied widely between natural sea-water samples and appeared to be related to a true organic demand. In contrast, the second phase was difficult to explain. Losses continued over 10 day periods and were pronounced in both natural and artificial sea-water containing bromide. In the absence of bromide, long term losses in artificial sea-water were greatly reduced, indicating that the lost applied chlorine was associated with the bromine chemical system in sea-water. The fate of the lost chlorine was not determined and the untitratable halogen compounds must remain suspect as potential biocides. 相似文献
10.
Lewis Base Additives Improve the Zeolite Ferrierite‐Catalyzed Synthesis of Isostearic Acids 下载免费PDF全文
Helen L. Ngo 《Journal of the American Oil Chemists' Society》2015,92(4):613-619
Isostearic acids (IA) are highly utilized for industrial purposes especially in the area of biolubricants, such as cosmetics and slip additives for polyolefin and related copolymer films. This study was designed to develop a zeolitic catalysis process for efficient IA production through isomerization of fatty acids. The process utilized zeolite protonated Ferrierite with a small amount of base additive to neutralize (i.e., poison) the acidic sites on the external surfaces of the zeolite particles to prevent side reactions. Of the six base additives examined, the proton sponge combined with the zeolite protonated Ferrierite was found to be the most effective for this isomerization. With only 0.5 wt% proton sponge additive to 5.0 wt% Ferrierite, the dimers were successfully suppressed from 20.6 wt% yield to 2.42 wt% with an IA yield of 83.4 wt% and a 98 % conversion. 相似文献