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161.
Murat Manguoglu Ahmed H. Sameh Tayfun E. Tezduyar Sunil Sathe 《Computational Mechanics》2008,43(1):73-80
We present an effective preconditioning technique for solving the nonsymmetric linear systems encountered in computation of
incompressible flows in long domains. The application category we focus on is arterial fluid mechanics. These linear systems
are solved using a nested iterative scheme with an outer Richardson scheme and an inner iteration that is handled via a Krylov
subspace method. Test computations that demonstrate the robustness of our nested scheme are presented. 相似文献
162.
Optimal Distributed Location Management in Mobile Networks 总被引:4,自引:0,他引:4
Krishnamurthi Govind Azizoğlu Murat Somani Arun K. 《Mobile Networks and Applications》2001,6(2):117-124
An important issue in the design of future Personal Communication Services (PCS) networks is the efficient management of location information. In this paper, we consider a distributed database architecture for location management in which update and query loads of the individual databases are balanced. We obtain lower bounds to the worst-case delay in locating a mobile user, to the average delay, and to the call blocking probability. We then propose a dynamic location management algorithm that meets these lower bounds. The optimality of this algorithm with respect to these three performance measures, as well as simplicity, make it an appealing candidate for distributed location management in PCS networks. 相似文献
163.
Murat Oztas Peter Rojan 《流程工业》2008,(1):56-57
通过将滤布翻转过来的方法将过滤出来的固体物质排出,这一获取高价值过滤材料的基本方法30多年来一直被成功使用,没有改变。然而现在一切似乎都在悄悄地发生着变化,本文所介绍的德国Heinkel公司第三代翻袋过滤器式离心机就印证了这种变化。 相似文献
164.
N. Maral K. Keliolu B. Arslan H. Kaya E. adrl 《Journal of Materials Processing Technology》2008,202(1-3):145-155
Succinonitrile (SCN)–7.5 wt.% carbon tetrabromide (CTB) alloy was unidirectionally solidified with a constant growth rate (V = 33 μm/s) at five different temperature gradients (G = 4.1–7.6 K/mm) and with a constant temperature gradient (G = 7.6 K/mm) at five different growth rates (V = 7.2–116.7 μm/s). The primary dendrite arm spacings, secondary dendrite arm spacings, dendrite tip radius and mushy zone depths were measured. Theoretical models for the microstructure parameters have been compared with the experimental observations, and a comparison of our results with the current theoretical models and previous experimental results have also been made. 相似文献
165.
Determination of biogenic amines in sucuk 总被引:1,自引:0,他引:1
Hüseyin Gencelep Güzin Kaban Muhammet rfan Aksu Fatih
z Mükerrem Kaya 《Food Control》2008,19(9):868-872
The biogenic amines content of sucuk (Turkish dry fermented sausage) were determined on 30 samples obtained from retail markets and butchers in Turkey. Also, pH and aw values, microbiological properties, and NPN levels of these samples were analyzed. The most important biogenic amines were tyramine (range 2.4–676 mg/kg), followed by putrescine varied from not detected to 364 mg/kg. Histamine content was under 50 mg/kg in 80% of the samples while it was over 100 mg/kg in only one sample. Tryptamine was detected in 16 of 30 samples in the range of 1.2–82.3 mg/kg.
Lactic acid bacteria, Micrococcus/Staphylococcus and Enterobacteriaceae counts of samples varied from 2.84 to 8.85 log cfu/g, <2.00 to 6.74 log cfu/g, and <2.00 to 5.04 log cfu/g, respectively. pH values were varied between 4.53 and 6.29 while water activity (aw) were measured to be between 0.761 and 0.960. NPN values were determined to be between 1.47% and 4.10%. Generally, total amine content was high in samples that had high NPN levels. 相似文献
166.
In this paper we undertake an experimental and numerical study on heat and mass transfer analysis during drying of kiwi fruits. In the experimental part, the effects of various drying conditions in terms of air velocity, temperature and relative humidity on drying characteristics of kiwi fruits are investigated. In the numerical part, the external flow and temperature fields are studied using a commercial CFD package. From these fields, the local distributions of the surface convective heat transfer coefficients for the fruits are determined to predict the local convective mass transfer coefficients through the analogy between the thermal and concentration boundary layers (known as the Chilton–Colburn analogy). In addition, the time-dependent temperature and moisture distributions for different cases are obtained using the code developed to investigate heat and mass transfer aspects inside the fruits. Numerical results are then compared with experimental data and a considerably high agreement is obtained. 相似文献
167.
Synthesis and characterization of a Zr‐containing silicate‐based epoxy‐functional polymer nanocomposite system 下载免费PDF全文
As a continuation of efforts to explore the potential of certain types of polymer nanocomposites to be successful candidates as dental restoration/adhesion materials, a Zr‐containing and organically modified silicate‐based material system with epoxy functionality was prepared by use of a sol–gel synthesis method, and UV light‐ and visible light (VL)‐curing processes. Comparative influences of the synthesis and processing parameters on the mechanical, thermal, and microstructural/nanostructural properties of the system were detailed. Zr‐containing species proved to more effectively catalyze the epoxy polymerization/crosslinking reactions than those containing Ti. Incorporation of Zr into the nanocomposite network led to significantly advanced mechanical properties. An elastic (Young's) modulus value of 23 MPa was achieved. The system with relatively high Zr content was successfully obtained, which also had higher thermal stability. Overall observations and results suggested that Zr content, and the UV light‐ or VL‐curing process could be capitalized on to modify the structure, and to improve the final properties of these material systems, which indicated a prospective opportunity for this material system to be utilized in dental restoration/adhesion applications. POLYM. ENG. SCI., 55:792–798, 2015. © 2014 Society of Plastics Engineers 相似文献
168.
Carolin Braun Eduard Spuling Niklas B. Heine Murat Cakici Martin Nieger Stefan Brse 《Advanced Synthesis \u0026amp; Catalysis》2016,358(10):1664-1670
Pyridyl‐substituted [2.2]paracyclophanes build a multifunctional structural motif that is useful in material chemistry, catalysis and for luminescent structures. Nonetheless, there is still a lack of general methods for the synthesis of these structures tolerating easily accessible bromides as well as different isomeric pyridyl groups. Hence the coupling of functionalized [2.2]paracyclophanes with various substituted and functionalized pyridyl derivatives was achieved using Stille, Suzuki and Kumada coupling conditions. Hereby the Stille coupling of a [2.2]paracyclophane is presented as a versatile reaction for the formation of heteromeric [2.2]paracyclophane‐containing biaryl structures.
169.
A copolymer of 4‐methoxybenzyl methacrylate and isobornyl methacrylate was synthesized by atom transfer radical polymerization. The structure of poly(4‐methoxybenzyl methacrylate‐co‐isobornyl methacrylate) was confirmed by means of Fourier transform infrared, 1H‐NMR, and 13C‐NMR techniques. The molecular weight distribution values of the copolymer were determined with gel permeation chromatography. The number‐average molecular weight and polydispersity index values of poly(4‐methoxybenzyl methacrylate‐co‐isobornyl methacrylate) were found to be 12,500 and 1.5, respectively. The kinetics of the thermal degradation of the copolymer was investigated with thermogravimetric analysis at different heating rates. The activation energy values obtained with the Kissinger, Flynn–Wall–Ozawa, and Tang methods were determined to be 166.38, 167.54, and 167.47 kJ/mol, respectively. Different integral and differential methods were used, and the results were compared with these values. Doyle approximation was also used for comparing the experimental results to master plots. An analysis of the experimental results suggested that the reaction mechanism was an R1 deceleration type in the conversion range studied. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
170.
Boehmite/multi-wall carbon nanotube (MWCNT) composite powders were prepared by hydrothermal processing. Starting chemical of aluminum acetate powders (2Al(OH)(C2H3O2)2) and MWCNTs were mixed for the formation of stoichiometric boehmite powders in an attempt to synthesize MWCNT-reinforced boehmite nano-powders via hydrothermal synthesis at 200 °C for 2 h. Kinetically stable suspensions of MWCNT–boehmite composite powders were prepared and subsequently electrophoretic deposition (EPD) was applied to obtain complex shape products in the form of micro-gears. It is shown that the EPD technique is a powerful tool to manufacture small components in a short time. Detail TEM observations also indicated that hydrothermal processing provides an ideal environment to obtain homogeneous mixtures of MWCNT–boehmite powders due to effective surface functionalization of MWCNTs under hydrothermal conditions. 相似文献