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51.
The procedure presented in this paper is a computerized methodology to generate alternate, ergonomically sound layouts of large control panels. The displays and controls are laid out on a vertical and two inclined panels taking various ergonomic design principles into account. Required input data categories, general structure of the methodology, and output reports of LAYGEN are discussed.  相似文献   
52.
A new unsymmetrical diamine monomer, 2,4‐diaminophenyl [4′‐(2′′,6′′‐diphenyl‐4′′‐pyridyl)phenyl]ether, was successfully synthesized by nucleophilic substitution of 1‐chloro‐2,4‐dinitrobenzene with 4‐(2′,6′‐diphenyl‐4′‐pyridyl) phenol. The diamine monomer was characterized by FTIR, 1H and 13C NMR, and elemental analysis techniques and used for the preparation of novel polyimides (PIs) by reaction with commercially available tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs with inherent viscosities ranged from 0.43 to 0.48 dL/g were readily soluble in many organic solvents and afforded tough and flexible films by solution casting. These polymers exhibited Tgs between 237 and 294°C, and 10% weight loss temperatures in excess of 500°C with up to 56% char yield at 600°C in air. Their maximum fluorescence emission in dilute (0.2 g/dL) NMP solution appeared at 450 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   
53.
A bionanocomposite of grafted cellulose and organo-modified clay was synthesized through solution intercalation method. For this purpose, chloromethylstyrene was grafted onto cellulose using acryloylchloride and the subsequent free radical polymerization. The synthesized cellulose-graft-polychloromethylstyrene was used as an atom transfer radical polymerization macroinitiator of acrylonitrile in the presence of CuCl/2,2′-bipyridine catalyst system, to prepare the cellulose-graft-polychloromethylstyrene-graft-polyacrylonitrile terpolymer. For preparing the modified clay, Na-montmorillonite was mixed with hexadecyl trimethyl ammonium chloride salt. Finally, cellulose-graft-polychloromethylstyrene-graft-polyacrylonitrile/organoclay bionanocomposite was prepared in CCl4 by solution intercalation method.  相似文献   
54.
This paper is providing a design and evaluation methodology for biomass utilization networks (B-NETs) planning in local areas. The methodology is an effort to integrate various exertions of many researchers as well as stakeholders in the biomass field including process technologies, local area classification and renewable energy mechanisms to design and evaluate B-NETs. The proposed design methodology has three steps: classification, problem formulation and suggesting solution methods. The core part of planning the B-NETs utilization methodology is the superstructure that is a super class model for the processes of biomass utilization networks that has to be built for the local area. The biomass utilization superstructure (BUSS) relates the biomass resources to their products, available processes, and possible future processes of utilization in static manner. Although the local area BUSS is static in nature, it shows the decision makers what kinds of B-NETs are, or can be, available in their area. It is important to note that for each super class process there exists a number of elemental technologies, or what we call unit process (UP), that can perform the job under the same condition with different processing constraint. To support the design and operation process a technological information infrastructure (TII) needs to be built to work as an information pool and simulation tool. With the support of TII and the BUSS different scenarios can be synthesized, analyzed and compared. Scenarios development enables the designer to check processing alternatives as well as biomass promotion mechanisms that fit the concerns of various stakeholders. The results of the methodology application can be given in the form of suggestions of a specific network class(es) or scenarios that can be applied in a class of localities with the same characteristics. Following to methodology configuration, a proposal for optimization methods is discussed and a case study for comparing biomass network scenarios in mountainous city is introduced.  相似文献   
55.
The objectives of this study are the correlation between the oil samples recovered from the Lower Cretaceous reservoirs and Lower and Upper Cretaceous source rocks. The investigated biomarkers of five oils indicated the oils were derived from mixed marine and terrigenous (lacustrine) organic matter and deposited under suboxic to anoxic conditions. These oils were also generated from source rocks of high thermal maturity at the peak oil window. So, based on the molecular indicators of organic source input,depositional environment and maturity parameters of oils and extracts, we can conclude that the oil recovered from Al Baraka oil field were derived from Lower Cretaceous source rocks especially KomOmbo (B) source rocks where it reached the oil window. Furthermore, we can indicate that the other lower Cretaceous formations as Abu Ballas Formation will have the opportunity to generate and expel oil at the deeper part of the basin as shown in the eastern part of the basin.  相似文献   
56.
57.
This study was aimed at engineering photocrosslinkable azithromycin (AZ)-laden gelatin methacryloyl fibers via electrospinning to serve as a localized and biodegradable drug delivery system for endodontic infection control. AZ at three distinct amounts was mixed with solubilized gelatin methacryloyl and the photoinitiator to obtain the following fibers: GelMA+5%AZ, GelMA+10%AZ, and GelMA+15%AZ. Fiber morphology, diameter, AZ incorporation, mechanical properties, degradation profile, and antimicrobial action against Aggregatibacter actinomycetemcomitans and Actinomyces naeslundii were also studied. In vitro compatibility with human-derived dental pulp stem cells and inflammatory response in vivo using a subcutaneous rat model were also determined. A bead-free fibrous microstructure with interconnected pores was observed for all groups. GelMA and GelMA+10%AZ had the highest fiber diameter means. The tensile strength of the GelMA-based fibers was reduced upon AZ addition. A similar pattern was observed for the degradation profile in vitro. GelMA+15%AZ fibers led to the highest bacterial inhibition. The presence of AZ, regardless of the concentration, did not pose significant toxicity. In vivo findings indicated higher blood vessel formation, mild inflammation, and mature and thick well-oriented collagen fibers interweaving with the engineered fibers. Altogether, AZ-laden photocrosslinkable GelMA fibers had adequate mechanical and degradation properties, with 15%AZ displaying significant antimicrobial activity without compromising biocompatibility.  相似文献   
58.
  总被引:1,自引:0,他引:1  
A novel experimental technique, that combines high-speed imaging and digital image correlation techniques, has been developed and applied to investigate the high-rate deformation behavior of aluminum sheet during electro-hydraulic forming (EHF). Aluminum alloy AA5182-O sheets (1 mm thick and ∼152 mm diameter) were EHF deformed by high-energy (up to ∼21 kJ) pressure-pulse and the time-evolution of sheet-displacement, velocity, strain and strain-rate quantified. The data shows that different locations on the sheet undergo unique deformation history that is not apparent from the conventional post-mortem strain measurement (using etched circle/grid pattern) approach. Under the experimental conditions used in this work, the sheets were formed into domes and the maximum strain-rate observed was ∼664/s. Further, this maximum strain-rate was observed at an off-apex location and was ∼2.5 times greater than the maximum strain-rate at the dome apex. The maximum velocity observed was ∼100 m/s and the velocity-time data showed evidence of pressure-wave reverberations during the forming process. We believe that knowledge of such time-evolution of sheet deformation is necessary for a better understanding and accurate modeling of sheet formability that has often been reported to exceed quasi-static forming limits under high-rate forming conditions.  相似文献   
59.
  总被引:1,自引:0,他引:1  
Non-isothermal DSC thermograms were obtained for the ternary Se90Te10−xSnx (x = 2, 4, 6 and 8) chalcogenide glasses in order to determine the melting temperature Tm, glass transition temperature Tg, onset Tc and peak Tp temperatures of crystallization. These temperatures were utilized to investigate the thermal stability through the calculations of temperature difference (Tc − Tg), the glass transition activation energy Et, the parameter S and the average value of crystallization rate factor 〈Kp〉. In addition, the glass forming ability was estimated by the criteria of reduced glass transition temperature, Trg and Hruby parameter HR. The fragility index m for the present glasses was determined in order to see whether these materials are obtained from strong or fragile glass-forming liquid. Results reveal that, both thermal stability and glass forming ability exhibit a maximum at x = 4 at.% of Sn. Meanwhile, the prepared glasses were obtained from strong glass-forming liquid as evident from the fragility index calculations. The compositional dependence of the above parameters was discussed on the basis of Philips and Thorpe topological model and the critical composition occurs at an average coordination number 〈r〉 = 2.16 but not 2.40. This is due to the formation of iono-covallent bonds when the glass doped with heavy elements like Sn.  相似文献   
60.
A survey of current safety practices in the design of residential buildings in Saudi Arabia identified deficiencies in governance and design procedures. A systematic safety compliance checklist was developed to address these deficiencies incorporating existing local safety instructions and international safety codes and standards. Checklist use is intended to ensure compliance with minimal safety requirements in the design of residential buildings.  相似文献   
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