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排序方式: 共有1219条查询结果,搜索用时 31 毫秒
51.
Eduardo Di Mauro Matteo Camaggi Nils Vandooren Caleb Bayard Jordan De Angelis Alessandro Pezzella Bill Baloukas Richard Silverwood Abdellah Ajji Christian Pellerin Clara Santato 《Polymer International》2019,68(5):984-991
In the human body, the black‐brown biopigment eumelanin blocks harmful ultraviolet (UV) radiation. In the plastics industry, additives are often added to polymers to increase their UV‐absorption properties. We herein report an assessment of the biopigment eumelanin as a nature‐inspired additive for plastics to enhance their UV absorption. Since eumelanin is produced by natural sources and is nontoxic, it is an interesting candidate in the field of sustainable plastic additives. In this work, the eumelanin‐containing films of commercial ethylene–vinyl acetate copolymer, a plastic used for packaging applications, were obtained by melt compounding and compression molding. The biopigment dispersion in the films was improved by means of the melanin free acid treatment. It was observed that eumelanin amounts as low as 0.8 wt% caused an increase of the UV absorption, up to one order of magnitude in the UVA range. We also evaluated the effect of eumelanin on the thermal stability and photostability of the films: the biopigment proved to be double‐edged, working both as UV‐absorption enhancer and photo‐prooxidant, as thermogravimetric analysis and infrared spectroscopy revealed. © 2019 Society of Chemical Industry 相似文献
52.
53.
朱聃 《武汉理工大学学报(材料科学英文版)》2012,27(5):1004-1007
This paper explores reclaimed and recycled material used in ecovillages. The models discussed in this paper include BedZED in the United Kingdom and Masdar City in the Middle East. These two communities contain features characterized by the sustainable principles of the ecovillage concept by using non-traditional building materials. The creations of more ecovillages, along with the growth of current ecovillages, play an important role in positively solvening environmental and social problems. The sustainable materials used in the ecovillages also act as a model for communities wishing to implement sustainable development. 相似文献
54.
Multiple object tracking is a fundamental subsystem of many higher level applications such as traffic monitoring, people counting, robotic vision and many more. This paper explains in details the methodology of building a robust hierarchical multiple hypothesis tracker for tracking multiple objects in the videos. The main novelties of our approach are anchor-based track initialization, prediction assistance for unconfirmed track and two virtual measurements for confirmed track. The system is built mainly to deal with the problems of merge, split, fragments and occlusion. The system is divided into two levels where the first level obtains the measurement input from foreground segmentation and clustered optical flow. Only K-best hypothesis and one-to-one association are considered. Two more virtual measurements are constructed to help track retention rate for the second level, which are based on predicted state and division of occluded foreground segments. Track based K-best hypothesis with multiple associations are considered for more comprehensive observation assignment. Histogram intersection testing is performed to limit the tracker bounding box expansion. Simulation results show that all our algorithms perform well in the surroundings mentioned above. Two performance metrics are used; multiple-object tracking accuracy (MOTA) and multiple-object tracking precision (MOTP). Our tracker have performed the best compared to the benchmark trackers in both performance evaluation metrics. The main weakness of our algorithms is the heavy processing requirement. 相似文献
55.
Edward Vine Michael Sullivan Loren Lutzenhiser Carl Blumstein Bill Miller 《Energy Efficiency》2014,7(4):627-640
The use of experiments— particularly randomized controlled trials (RCTs) where subjects are randomly assigned to treatment and control conditions—has rarely been applied to the process of improving the design of energy efficiency programs and, more fundamentally, to determining the net savings from energy efficiency programs. This paper discusses the use of experimentation in the energy efficiency program field with the hope of explaining how these experiments can be used, and identifying the barriers to their use will cause more experimentation to occur. First, a brief overview of experimental methods is presented. This discussion describes the advantages and disadvantages of conducting experiments in the context of the development and evaluation of energy efficiency programs. It then discusses barriers to the use of experimental methods (including cost and equity issues) and suggests some ways of overcoming these barriers. Finally, recommendations are made for implementing key social experiments, discussing the types of energy efficiency programs and issues that can make use of experimentation and variables that one might use for selecting treatments. 相似文献
56.
Dan A. Buzatu Willie M. Cooper Christine Summage-West John B. Sutherland Anna J. Williams Deborah A. Bass Lisa L. Smith Robert S. Woodruff Jessica M. Christman Steven Reid Randal K. Tucker Christopher J. Haney Ashfaqe Ahmed Fatemeh Rafii Jon G. Wilkes 《Food microbiology》2013
A flow cytometric method (RAPID-B™) with detection sensitivity of one viable cell of Escherichia coli serotype O157:H7 in fresh spinach (Spinacia oleracea) was developed and evaluated. The major impediment to achieving this performance was mistaking autofluorescing spinach particles for tagged target cells. Following a 5 h non-selective enrichment, artificially inoculated samples were photobleached, using phloxine B as a photosensitizer. Samples were centrifuged at high speed to concentrate target cells, then gradient centrifuged to separate them from matrix debris. In external laboratory experiments, RAPID-B and the reference method both correctly detected E. coli O157:H7 at inoculations of ca. 15 cells. In a follow-up study, after 4 cell inoculations of positives and 6 h enrichment, RAPID-B correctly identified 92% of 25 samples. The RAPID-B method limit of detection (LOD) was one cell in 25 g. It proved superior to the reference method (which incorporated real time-PCR, selective enrichment, and culture plating elements) in accuracy and speed. 相似文献
57.
Johan Oppen David L. Woodruff 《International Transactions in Operational Research》2009,16(5):627-640
Algorithms that search for good solutions to optimization problems present a trace of current best objective values over time. We describe an empirical study of parametric models of this progression that are both interesting as ways to characterize the search progression compactly and useful as means of predicting search behavior. In our computational experiments, we give examples of a variety of problems and algorithms where we are able to use the parametric models to make predictions of performance that cross instances and instance sizes. 相似文献
58.
Sorour Alotaibi Mihir Sen Bill Goodwine K. T. Yang 《Numerical Heat Transfer, Part A: Applications》2013,63(3):229-244
The temperature control of outlet air by changing the water flow rate in a single-pass waterto-air cross-flow heat exchanger is investigated. The conservation laws are applied to finite control volumes and an implicit formulation is used for transient numerical solutions. Conjugate forced convection heat transfer from the tube is solved to calculate the temperatures of the air and water coming out of the heat exchanger. In the simulations the outlet air temperature is controlled by changing the water flow rate entering the heat exchanger using a proportional-integral (PI) controller. The range of controllability of the heat exchanger was studied first. Then disturbances in the form of step changes in the inlet air temperature, the air flow rate, and the set point temperature were separately introduced. The effects of the limiting-condition constraints and different control parameters on controlling the outlet air temperature are presented. The results show that the control behavior can be simulated numerically and that this control methodology is effective within limits. 相似文献
59.
Judith Yates Maryann Wulff Andrew Beer Bill Mudd Tu Yong David Wesney 《Urban Policy and Research》2013,31(4):415-424
This article identifies issues around the Auckland Region's strategy for urban intensification and discusses the ensuing policy implications. Medium density housing forms an important element of the strategy for growth management. Implications for its success are primarily drawn from research into a major housing development in Waitakere City. It is argued that for ideological, political and technical reasons the strategy could be easily undermined. The article also suggests that something of a paradigm shift is underway in urban planning. 相似文献
60.
A new approach to the creation of design tools is proposed that addresses the real information needs of designers in the early stages of design of non-residential buildings. Traditional simplified design tools are typically too limited to be of much use, even in conceptual design. The proposal is to provide access to the power of detailed simulation tools at a stage in design when little is known about the final building, but at a stage also when the freedom to explore options is greatest and the ability to improve the design is greatest. The concept of the building performance sketch forms the basis of the proposed design tool. It was derived from consultation with design analysis teams as part of the development of the COMFEN tool for fenestration design. Tools like COMFEN are explored to understand how they were shaped by consultation and how requests from these teams for real-world relevance might shape such tools in the future. The simulation process can effectively utilize some of the as-built, as-occupied and as-managed lessons on behaviours and technical outcomes from the Post-occupancy Evaluation (PoE) of buildings. Il est proposé pour la création des outils de conception une nouvelle approche répondant aux véritables besoins d'information des concepteurs dans les premières phases de conception des bâtiments non résidentiels. Les outils de conception simplifiée traditionnels sont habituellement trop limités pour être très utiles, même en design conceptuel. Ce qui est proposé est de pouvoir accéder à la puissance d'outils de simulation détaillée à un stade de la conception où l'on sait encore peu de choses concernant le bâtiment final, mais également à un stade auquel la liberté d'exploration des options possibles comme la capacité d'amélioration de la conception sont les plus grandes. Le concept du schéma de performance du bâtiment constitue la base de l'outil de conception proposé. Il découle de la consultation des équipes chargées de l'analyse de la conception dans le cadre du développement de l'outil COMFEN de conception du fenêtrage. Des outils tels que COMFEN sont examinés afin de comprendre comment ils ont été modelés par la consultation et comment les demandes de ces équipes en termes de pertinence réelle pourraient façonner ces outils à l'avenir. Le processus de simulation peut tirer efficacement parti de certaines des leçons, conformes à l'exécution, à l'occupation et à la gestion, en matière de comportements et de résultats techniques, retirées de l'Evaluation Après Occupation des bâtiments. modèles d'information du bâtiment?bâtiments?processus de conception?outils de conception?début de conception?efficacité énergétique?retour d'information?simulation des performances?évaluation après occupation 相似文献