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11.
For Anatolian earthquakes, there are insufficient strong motion data from rock sites to model an attenuation relationship
for Turkey. This necessitates the use of records from soil sites, which are significantly affected by amplification. In order
to include soil site data in the attenuation analyses, boreholes were drilled at 64 recording stations on soil sites. After
removing the effects of soil amplification, rock site and soil site data were combined to establish an attenuation relationship.
Various models were tested through regression analyses using moment magnitude, epicentral distance and threshold peak horizontal
ground acceleration. A new attenuation relationship is modeled for Turkey. 相似文献
12.
The research goal of this study is to produce suitable scaffolds for tissue engineering applications. Different ratios of polyvinyl alcohol (PVA)/starch (90:10, 70:30, 50:50) and crosslinking methods have been used to prepare cryogels. Chemically crosslinked cryogels were synthesized using glutaraldehyde as the crosslinking agent. For the physically crosslinked cryogels, sodium dodecyl sulfate was used during cryogelation as the foaming agent. Chemical structure and pore morphology were demonstrated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). Swelling ratio and degradation profile of the scaffolds were also determined. 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide assay and SEM were used to investigate the biocompatibility of the scaffolds and cell morphology. Genotoxicity test was performed to show DNA fragmentation. The overall results demonstrated that PVA/starch cryogels could have potentially appealing application as scaffolds for tissue engineering applications and additives affect the architecture and characteristic properties of the cryogels. 相似文献
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Emine Ubay Cokgor Gulsum Emel Zengin Didem Okutman Tas Seda Oktay Clifford Randall Derin Orhon 《Canadian Metallurgical Quarterly》2006,132(1):68-74
This study investigates the potential of primary sludge fermentation for the generation of readily biodegradable substrate. Experimental evaluation indicates that uncontrolled fermentation converted 22% of the initial volatile suspended solids in the sludge into soluble biodegradable chemical oxygen demand (COD). More than 85% of the soluble COD generated was associated with the formation of short chain volatile fatty acids (VFAs). The recoverable fraction of the fermented sludge supernatant may potentially increase the biodegradable COD content of the primary effluent by 5%. The VFA composition predominantly involved acetic and propionic acids as reported in the literature. Due to the high VFA content, activated sludge Model No. 1 could not predict the COD fractionation in the primary sludge; activated sludge Model No. 3 provided a better interpretation of the oxygen uptake profile through initial storage of the VFAs in the sludge. 相似文献
15.
This study proposes to use genetic algorithms for defining the topic boundaries in search of engine transaction logs. Users are interested in multiple topics during a search session, and genetic algorithms are used in this study to determine whether a search engine user has changed topics during a session. Sample data logs from FAST and Excite search engines were analyzed. The findings show that genetic algorithms are fairly successful in identifying topic continuations and shifts in search engine transaction logs. 相似文献
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Seda Bekin Acar Mustafa Ozcelik Tamer Uyar Mehmet Atilla Tasdelen 《Iranian Polymer Journal》2017,26(6):405-411
A series of hybrid networks based on polyhedral oligomeric silsesquioxane (POSS) were prepared by thiol-epoxy click reaction using commercially available octakis-glycidyl-POSS (G-POSS), trimethylolpropane triglycidyl ether, and trimethylolpropane tris(3-mercaptopropionate) as monomers. The click reaction was simply catalyzed by lithium hydroxide which proceeded readily at ambient conditions in very good yields. The incorporation of G-POSS into the network was clearly determined by transmission electron microscopy, FTIR, and 1H-NMR spectroscopy techniques performed with a model study using 1-butane thiol and G-POSS molecules. The homogeneous distribution of G-POSS up to 5 wt% in the hybrid network was apparently confirmed by morphological investigations. By increasing G-POSS content higher than 5 wt%, the heterogeneous dispersion of G-POSS was determined from the tensile strength measurements. The significant decrease in tensile strength was possible due to the agglomeration of G-POSS. On the other hand, thermal properties of hybrid networks were compared together by thermogravimetric analyses, where all samples exhibited one-step degradation in the range of 220–500 °C. The thermal decomposition of hybrid network led to complete degradation of the organic part and favored the formation of stable carbonaceous and inorganic residues as char. Thus, the char yields of hybrid networks were increased to 6.2, 7.8, 10.1, 12.7, and 15.1% by G-POSS loadings from 0 to 15 wt%. This improvement was also a proof of the incorporation of G-POSS into the hybrid networks that resulted in high heat-resistant POSS-based hybrid networks compared to a sample without G-POSS. 相似文献
18.
A GIS-Based Optimization Framework for Competitive Multi-Facility Location-Routing Problem 总被引:1,自引:1,他引:0
In a dynamic market setting, firms need to quickly respond to shifting demographics and economic conditions. In this paper,
we investigate the problem of determining the optimum set of locations for a firm, which operates a chain of facilities under
competition. We consider the objective of maximizing profit, defined as gross profit margin minus logistics costs. We propose
a location-routing model where revenue is realized according to probabilistic patronization of customers and routing costs
are incurred due to vehicles serving the open facilities from a central depot. We propose a hybrid heuristic optimization
methodology for solving this model. The optimal locations are searched for by a Genetic Algorithm while an integrated Tabu
Search algorithm is employed for solving the underlying vehicle routing problem. The solution approach is tested on a real
dataset of a supermarket chain. The results show that the location decisions made by the proposed methodology lead to increased
market share and profit margin, while keeping logistics costs virtually unchanged. Finally, we present a GIS-based framework
that can be used to store, analyze and visualize all data as well as model solutions in geographic format. 相似文献
19.
FA Atik GJ Lopes Filho Mde M Linhares J Seda Neto NS Mansur 《Canadian Metallurgical Quarterly》1998,116(4):1781-1783
The authors report a case of a 25 year old Brazilian man with a history of crampy abdominal pain in the left iliac fossa for 2 weeks, abdominal distention, mucous diarrhea and anorexia. The patient presented signs of hemodynamic instability and a hard mass palpated in the left iliac fossa presented peritoneal irritation. At laparotomy, fecal peritonitis and a punched-out perforation of the midsigmoid colon were found. A left hemicolectomy was performed with terminal colostomy. Specimen examination revealed a thickened rectosigmoid wall, narrow lumen and multiple mucosal polyps. Microscopically, chronic granulomatous colitis with Schistosoma mansoni eggs confirmed the etiology. To the authors' knowledge, this is the first case of obstruction complicated with perforation due to mansoni schistosomiasis reported in the literature. 相似文献
20.