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排序方式: 共有593条查询结果,搜索用时 31 毫秒
71.
Zeynep Sener E. Ertugrul Karsak 《The International Journal of Advanced Manufacturing Technology》2010,48(9-12):1173-1184
Quality function deployment (QFD) is a customer-oriented design tool for developing new or improved products and services to increase customer satisfaction. The inherent fuzziness of functional relationships between customer requirements and engineering characteristics, and among engineering characteristics in QFD modeling justifies the use of fuzzy regression. However, when linear programming is used in fuzzy regression, spread values of regression coefficients tend to approach zero. In order to overcome this problem, this paper employs a nonlinear-programming-based fuzzy regression approach to model functional relationships in product planning. Then, a fuzzy mathematical programming model is developed to determine target levels of engineering characteristics using the functional relationships obtained from fuzzy regression. Fuzzy mathematical programming model enables to account for the spread values as well as the center values of the parameter estimates of the functional relationships. A washing machine quality improvement problem is presented to illustrate the application of the proposed approach. 相似文献
72.
Zeynep Duymus Yesil Serpil Karaoglanoglu M. Samil Akyıl Nilgün Seven 《International Journal of Adhesion and Adhesives》2009,29(1):32-35
This study was carried out with the purpose of testing the bond strength of different bonding agents bonded to different substrates.Substrates consisted of cylindrical specimens of three different materials: porcelain, metal, and a porcelain–metal combination. Specimens were all 10 mm in diameter and 4 mm thick. Surfaces to be bonded were air-abraded with Al2O3 and cleaned ultrasonically in distilled water for 10 min. After the preparation of the surface was complete, three different bonding agents were applied to the central region of the substrates. Composite resin of a 3.5 mm diameter and 2 mm thick was applied. All specimens were thermocycled between 5 and 55 °C for 200 cycles with a 30-s dwell time. After thermocycling, specimens were stored at 37 °C in distilled water for an additional 7 days before being subjected to a shear load. Shear testing was conducted Hounsfield test machine.The univariate analysis of variance and the Duncan multiple comparison test were used for statistical assessment. It was found that both type of bonding agents and of substrate led to statistically significant differences in bond strength (p<0.01).It was found that the highest bond strength was produced by Clearfil and on pure alloy substrate (33.36 MPa) and the lowest bond strength in Single Bond and porcelain–alloy substrate (4.25 MPa). 相似文献
73.
Zeynep Kezer 《Architectural Design》2010,80(1):40-45
Zeynep Kezer outlines the ascendancy and development of Ankara from an obscure, central Anatolian town into a capital city that was to become the focus of the new nation state. Informed by German architectural and technological expertise, it was executed to rigorous Modernist planning principles and aesthetics, and came to represent in urban form the polarisation of pre-republican and republican Turkey. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
74.
Bomaplex Red CR-L textile dye was used in the experimental studies. Taguchi method was applied to determine optimum conditions in the removal of dye from synthetic textile wastewater. After the parameters were determined to remove Bomaplex Red CR-L dye from synthetic textile wastewater, the experimental studies were realized. The chosen experimental parameters and their ranges: HCO3- (mM), 0-39; temperature (degrees C), 18-70; ozone-air flow rate (l min-1), 5-15; the dye concentration (ppm), 200-600; particulate activated carbon (PAC) (g), 0-1.5; H2O2 (mM), 0-0056; pH, 3-12; and treatment time (min), 10-30, respectively. An orthogonal array L18 (2(1)x3(7)) for experimental plan and the smaller the better performance statistics formula were selected to define optimum conditions. The optimum conditions were found to be as follows: HCO3- (mM), 0; temperature (degrees C), 70; ozone-air flow rate (l min-1), 10; the dye concentration (ppm), 200; particulate activated carbon (PAC) (g), 1; H2O2 (mM), 0.056; pH, 12; and time (min), 20. Under these optimum conditions, it was determined that the Bomaplex Red CR-L removal efficiency from textile wastewater was 99%. 相似文献
75.
The untreated, heat- and alkali-treated Lentinus sajor-caju mycelia were used for the recovery of uranium from aqueous solutions. The effect of pH, temperature, initial concentration of UO(2)(2+) ions and contact time parameters were investigated in a batch system. The particles sizes of the fungal mycelia were ranging from 100 to 200 microm. Biosorption equilibriums were established in about 30 min and the correlation regression coefficients show that the adsorption process can be well defined by the Freundlich equation. The alkali treated form had a high biosorption capacity (378 mg/g) than those of the untreated (268 mg/g) and heat-treated fungal mycelia (342 mg/g). Optimum biosorption was observed at pH 4.5 for all the tested fungal preparations and was independent of temperature (5-35 degrees C). In addition, the polarity and surface energy of the fungal biomass film preparations were determined by contact angle measurement. The fungal biomass could be regenerated using 10mM sodium carbonate, with up to 93% recovery. The biosorbents were used in six biosorption-desorption cycles and no considerable loss in the biosorption capacity was observed. 相似文献
76.
Pb(II) and Cd(II) removal from aqueous solutions by olive cake 总被引:1,自引:0,他引:1
The removal of heavy metals from wastewater using olive cake as an adsorbent was investigated. The effect of the contact time, pH, temperature, and concentration of adsorbate on adsorption performance of olive cake for Pb(II) and Cd(II) ions were examined by batch method. Adsorption of Pb(II) and Cd(II) in aqueous solution onto olive cake was studied in single component. After establishing the optimum conditions, elution of these ions from the adsorbent surface was also examined. The optimum sorption conditions were determined for two elements. Maximum desorption of the Pb(II) and Cd(II) ions were found to be 95.92 and 53.97% by 0.5M HNO(3) and 0.2M HCl, respectively. The morphological analysis of the olive cake was performed by the scanning electron microscopy (SEM). 相似文献
77.
78.
Chawon Hwang Stephen DiPietro Kelvin Y. Xie Qirong Yang Azmi M. Celik Atta U. Khan Vladislav Domnich Scott Walck Kevin J. Hemker Richard A. Haber 《Journal of the American Ceramic Society》2019,102(8):4421-4426
Small amount of TiB2 (<5 wt%) was added into B4C through a novel method that combines the use of sputter deposition and hot pressing. Sputter deposition provided more uniform dispersion of TiB2 grains with smaller grain sizes as compared to the conventional particulate mixing. Small amount TiB2 addition demonstrated to be an effective way for improving the fracture behavior and toughness of B4C while not sacrificing its outstanding lightweight property to a large extent: 2.3 wt% TiB2 addition brought 15% improvement in indentation fracture toughness while resulting in less than 2% increase in density. The improvement can be attributed to the combination of crack impeding by TiB2 grains and crack deflection at the B4C–TiB2 interfaces. TiB2 also played as grain growth inhibitor resulting in a slight increase (2%) in Vickers hardness. Another intention of employing sputter deposition was to modify the grain boundary of B4C; however, neither formation of Ti-containing phase nor Ti segregation has been observed at grain boundaries likely due to the poor wettability of B4C. 相似文献
79.
80.
Partial spatio-temporal co-occurrence pattern mining 总被引:1,自引:0,他引:1
Mete Celik 《Knowledge and Information Systems》2015,44(1):27-49