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71.
Hydrogenated amorphous silicon oxygen alloy thin films (a-SiOx:H) were prepared on glass and crystalline silicon substrates, with two different oxygen contents: x = 0.15 and x = 0.32. The deposition was realized in an RF-PECVD reactor by using the plasma of the gas mixture SiH4 and CO2 with tunable flow rates. The optical characterization data of the single layers were received from the optical transmittance experiments. Multilayered samples were designed upon the results of the single layers. In depositing the multilayers the repetition of the a-SiO0.15:H/a-SiO0.32:H kernel-pair was used. The samples were prepared as 25-pair of λ/4 layers, 3-pair of λ/4 layers and 3-pair of λ/2 layers. The inner morphologies and nanostructural contents of the films were investigated by Small-Angle X-ray Scattering (SAXS) method. 相似文献
72.
Friction stir spot welding parameters affect the weld strength of thermoplastics, such as high density polyethylene (HDPE) sheets. The strength of a friction stir spot weld is usually determined by a lap-shear test. For maximizing the weld strength, the selection of welding parameters is very important. This paper presents an application of Taguchi method to friction stir spot welding strength of HDPE sheets. An orthogonal array, the signal to noise ratio (S/N), and the analysis of variance (ANOVA) are employed to investigate friction stir welding parameter effects on the weld strength. From the ANOVA and the S/N ratio response graphs, the significant parameters and the optimal combination level of welding parameters were obtained. Experimental results confirmed the effectiveness of the method. 相似文献
73.
Abstract: Cumin seeds might be exposed to a high level of natural bacterial contamination, and this could potentially create a public health risk besides leading to problems in exportation. Ultraviolet (UVC) and far infrared (FIR) radiation has low penetration power, and due to that, there might be no detrimental defects to the products during a possible decontamination process. Therefore, the objective of this study was to determine the effect of UVC and FIR treatment on microbial decontamination and quality of cumin seeds. For this purpose, FIR treatment at different exposure times and temperatures were applied followed by constant UVC treatment with an intensity of 10.5 mW/cm2 for 2 h. Total mesophilic aerobic bacteria of the cumin seeds were decreased to the target level of 104 CFU/g after 1.57, 2.8, and 4.8 min FIR treatment at 300, 250, and 200 °C, respectively, following a 2 h UVC treatment. Under the given conditions, a complete elimination for total yeast and molds were obtained while there were no significant changes in volatile oil content and color of the cumin seeds. Consequently, combined UVC and FIR treatment was determined to be a promising method for decontamination of the cumin seeds. Practical Application: This research attempts to apply UVC and far infrared (FIR) radiation for pasteurization of cumin seeds. The data suggested that combined UVC and FIR radiation treatments can become a promising new method for pasteurization of cumin seeds without causing any detrimental defect to the quality parameters. The results of this industry partnered (Kadioglu Baharat, Mersin, Turkey— http://www.kadioglubaharat.com ) study were already applied in industrial scale production lines. 相似文献
74.
A series of novel ZnO/polyimide composite films with different ZnO contents was prepared through incorporation hexagonal disklike ZnO particles into poly(amic acid) of the pre polymer of the polyimide. The hexagonal disklike ZnO particles with a diameter of 300-500 nm were synthesized from zinc acetate and NaOH in water with citric acid. The prepared zinc oxide-polyimide composites were characterized for their structure, morphology, and thermal behavior employing Fourier transform infrared spectroscopy, scanning electron micrograph, X-ray diffraction and thermal analysis techniques. Thermal analyses show that the ZnO particles were successfully incorporated into the polymer matrix and these ZnO/polymer composites have a good thermal stability. Scanning electron microscopy studies indicate the ZnO particles were uniformly dispersed in the polymer and they remained at the original size (300-500 nm) before immobilization. All composite films with ZnO particle contents from 1 to 5 wt% show good transparency in the visible region and luminescent properties. 相似文献
75.
Historic urban sites and traditional houses are the most important evidence of the past life style. The conservation of these traditional values in the context of conservation and revitalization of architectural heritage is in a sense the preservation of culture. The main goal of conservation is to enliven cultural properties by evaluating their architectural, historical, environmental, visual and aesthetic characteristics. These evaluation studies, which are essential in the context of conservation plans, are inevitable phases to determine the principles of the plans. This study is aimed to propose a method for the architectural evaluation phase, which is essential before conservation decisions. The proposed method is based on a gradation system. Odunpazar? district in Eski?ehir/Turkey is determined as the area to test this gradation method. It is proposed that this method explains the systematic way for evaluating architectural features belonging to historic sites whose conservation plans are to be prepared. In the study, traditional buildings are evaluated from the point of their exterior and interior architectural characteristics and classified as different value groups: A, B, C and D. This grouping will be advantageous to conservation decisions. Different technical teams may be organized to be responsible for these various value groups. As a result, a systematic approach for the determination of specialized teams and required equipment will be achieved. Thus, an accurate determination of required time and cost estimates will be realized. 相似文献
76.
The differential attenuation coefficients for total scattering have been measured using the Si(Li) detector at photon excitation energy of 59.5 keV for Fe2O3, Y2O3, Nb2O5, SeO2, Sb2O5 and BaO compounds at seven angles ranging from 60° to 120° at intervals of 10°. The obtained results have been compared with relativistic and non-relativistic theoretical values. 相似文献
77.
İ Bakirtaş 《International Journal of Engineering Science》1984,22(4):347-359
The problem of a rigid punch on an elastic half plane with orthotropic and non-homogeneous material is considered. The axes of orthotropy are chosen to coincide with the Cartesian coordinate system in which one axis is parallel to the edge of the half plane and the other is perpendicular to it. Non-homogeneity is introduced in both directions of orthotropy as continuous functions along these directions. Using the Fourier Transform Technique, the mixed boundary value problem is reduced to a singular integral equation which is solved numerically. The formulation of the problem is obtained for a rigid punch with arbitrary shape. 相似文献
78.
İnci Türk Toğrul 《International Journal of Food Science & Technology》2010,45(6):1146-1152
In this work, heat and moisture transport occurred during drying of black grapes in a laboratory dryer were investigated. In the experiments, the air was passed through the chamber at a variety of flow rates (0.5, 0.75, 1.0 and 1.25 m s?1) and temperatures (40, 50, 60 and 70 °C). Thermal and moisture diffusivities were determined. The possibility of expressing the moisture removal from the grapes was searched with the fourteen one‐layer drying models selected from the literature. Among all the models, the Page model was found the best for explaining the experimental results. The effects of the drying temperature and air velocity on the constants and coefficients of Page model and diffusivities were also investigated by multiple combinations of the different equations as the linear, power, logarithmic, exponential, polynomial, inverse polynomial and Arrhenius type by non‐ linear regression analyses. Models obtained were also analysed statistically using t‐test, RMSE, MBE and χ2. 相似文献
79.
M. Çağil Akkaya Serkan Emik Gamze Güçlü Tülin Banu İyim Saadet Özgümüş 《应用聚合物科学杂志》2009,114(2):1150-1159
In this study, Acrylic acid (AA)/2‐acrylamido‐2‐methlypropane sulfonic acid (AMPS) hydrogels were prepared by free radical polymerization in aqueous solutions of AA, AMPS, and N,N‐methylenebisacrylamide (NMBA) as crosslinker. Potassium persulfate (PPS)/potassium bisulfide (PBS) were used as initiator and accelerator pair. The water absorption capacities and dye adsorption properties of the hydrogels were investigated. Adsorption properties of the hydrogels were evaluated by depending on different adsorption conditions such as different initial dye concentration and contact time. The concentrations of the dyes were determined using UV/Vis Spectrophotometer at wavelength 530 nm for safranine T (ST) and 622 nm for brilliant cresyl blue (BCB). Adsorption kinetic studies showed that pseudo‐first order kinetic model is suitable to explain the adsorption kinetic data of the hydrogels. Langmuir and Freundlich isotherm models were used to describe adsorption data. The result revealed that the adsorption of basic dyes onto hydrogels fit very well both Langmuir and Freundlich isotherms. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
80.
Imine coupled phenolic monomers containing carbazole unit were synthesized in four steps. The monomers were polymerized via oxidative polycondensation by air as oxidant in an aqueous alkaline medium at 50°C. The structures of compounds were confirmed by ultraviolet–visible (UV–vis), Fourier transform infrared, and 1H‐ and 13C‐NMR techniques. The conductivity measurements of these polymers were made by the four‐point probe technique and iodine was used as doping agent. The highest occupied molecular orbital, the lowest unoccupied molecular orbital, and electrochemical and optical band gap values were calculated by the results of the UV–vis and the cyclic voltammetry measurement, respectively. The number‐average molecular weight, weight‐average molecular weight, and polydispersity index values were determined by the size exclusion chromatography technique. Also, thermal behavior of these polymers was determined by thermogravimetric/differential thermal analysis measurements in a N2 atmosphere between 20 and 1000°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献