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51.
A. I. Karayigit Y. Bulut G. Karayigit X. Querol A. Alastuey S. Vassilev 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(14):1311-1320
The Soma power plant in western Turkey consists of six 165-MW units (B1–4 and B5–6), of which the first four units (B1–4) burn Early-Middle Miocene feed coals from the lower seam in central mines (southern Soma village), and later, two units (B5–6) use Early-Middle Miocene and Upper Miocene feed coals from the lower and upper seams in Denis mines (northern Soma village). A total of 48 samples, feed coals (FCs), fly ashes (FAs) and bottom ashes (BAs), which were systematically collected once a week over an eight-week period from both group boiler units, B1–4 with 660 MW and B5–6 with 330 MW capacity from Soma power plant, have been evaluated for major and trace elements (Al, Ca, Fe, K, Mg, Mn, Na, Ti, S, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Cs, Ga, Ge, Hf, Hg, Li, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Se, Sn, Sr, Ta, Th, Tl, U, V, Y, Zn, Zr, and REEs) to get information on behavior during coal combustion. This study indicates that some elements such as Hg, Bi, Cd, As, Pb, Ge, Tl, Sn, Zn, Sb, B show enrichments in FAs relative to the BAs in both group boiler units. In addition to these, Cs, Lu, Tm, and Ga in Units B1–4 and S in Units B5–6 also have enrichments in FAs. Elements showing enrichments in BAs in both group boiler units are Ta, Mn, Nb. In addition to these, Se, Ca, Mg, Na, Fe in Units B1–4 and Cu in Units B5–6 also have enrichments in BAs. The remaining elements investigated in this study have no clear segregation between FAs and BAs. Mass balance calculations with the two methods show that some elements, S, Ta, Hg, Se, Zn, Na, Ca in Units B1–4, and Hg, S, Ta, Se, P in Units B5–6, have volatile behavior during coal combustion in the Soma power plant. This study also implies that some elements, Sb and Tb in Units B1–4 and Sb in Units B5–6, have relatively high retention effects in the combustion residues from the Soma power plant. 相似文献
52.
V. Vassilev L. Aljihmani V. Milanova T. Hristova-Vasileva 《Journal of Phase Equilibria and Diffusion》2016,37(5):524-531
The phase diagram of the (Sb2Te3)100?x –InSb x system was determined based on x-ray diffraction (XRD) analysis, differential thermal analysis (DTA), and microhardness and density measurements. An intermediate compound with composition Sb2Te3·2InSb was formed as a result of syntectic reaction, melting incongruently at 553 °C. This compound has tetragonal lattice with unit cell parameters of a = 4.3937 Å, b = 4.2035 Å, c = 3.5433 Å, α = 93.354°, and β = γ = 90°. Sb2Te3·(2 + δ)InSb (?1 ≤ δ ≤ +1) and (Sb2Te3)100?x (InSb) x (90 ≤ x ≤ 100) solid solutions exist in the investigated system, based on the intermediate compound Sb2Te3·2InSb and on InSb, respectively. Also, two invariant equilibria exist in the system, with eutectic point coordinates at compositions of x = 60 and x ≈ 85 mol% InSb and eutectic temperatures of T E = 541 and T E ≈ 501 °C, respectively. 相似文献
53.
The effect of γ-ray irradiation on the fatty acid profile of chicken meat was examined at doses of 0.5, 2.5, 5.0, 7.5, 10.0,
and 15.0 kGy by 1H-NMR spectroscopy. NMR spectral results revealed a dose-dependent effect of irradiation on the fatty acid profile. A trend
toward an increase in the amount of saturated fatty acids and a decrease in the amount of polyunsaturated fatty acids in the
triacylglycerol composition of the irradiated meat samples compared with the non-irradiated one was established with increasing
the irradiation dose. The trend of decreasing polyunsaturated fatty acyl groups was associated with a decrease in oxidative
stability of meat fat after application of γ-ray irradiation. 相似文献
54.
Numerical simulation of the buckling behaviour of masonry. The paper presents a numerical approach for the simulation and analysis of the buckling behaviour of masonry. The assumed parabolic stress‐strain function allows a realistic modelling of the composite material behaviour in compression and bending. The equilibrium is formulated in the deformed state and takes into consideration the effect of the deflections on the bearing capacity. Due to the physical nonlinearity, the stress limitations and the system modification when cracking in tension occurs, the bending stiffness becomes under loading a function of the stress state, thus leading to variable coefficients of the governing differential equation. The system solution is obtained within the frame of an iterative numeric procedure in terms of the transfer matrix method, based on the discretization of the structure into finite segments and the piecewise linearization of its parameters. 相似文献
55.
A Vassilev J Yamauchi T Kotani C Prives ML Avantaggiati J Qin Y Nakatani 《Canadian Metallurgical Quarterly》1998,2(6):869-875
PCAF histone acetylase is found in a complex with more than 20 associated polypeptides. Here we report cloning and characterization of the 400 kDa PCAF-associated factor referred to as PAF400. PAF400 is almost identical to TRRAP, which binds to c-Myc and E2F, and has significant sequence similarities to the ATM superfamily including FRAP, ATM, ATR, and the catalytic subunit of DNA-PK. Remarkably, PAF400 and FRAP share sequence similarity in broad regions that cover 80% of the entire PAF400 sequence. However, unlike the other members of the ATM superfamily, PAF400 is not a protein kinase as judged from the lack of kinase motif and autophosphorylation activity. We discuss the possibility that PAF400 may play a role in signaling of DNA damage to p53 by stimulation of p53 acetylation. 相似文献
56.
57.
Vassil S. Vassilev Subhash C. Narula & Vassil G. Gouljashki 《International Transactions in Operational Research》2001,8(4):367-380
We present a learning-oriented interactive reference direction algorithm for solving multi-objective convex nonlinear integer programming problems. At each iteration the decision-maker (DM) sets his/her preferences as aspiration levels of the objective functions. The modified aspiration point and the solution found at the previous iteration define the reference direction. Based on the reference direction, we formulate a mixed-integer scalarizing problem with specific properties. By solving this problem approximately, we find one or more integer solutions located close to the efficient surface. At some iteration (usually at the last iteration), the DM may want to solve the scalarizing problem to obtain an exact (weak) efficient solution. Based on the proposed algorithm, we have developed a research-decision support system that includes one exact and one heuristic algorithm. Using this system, we illustrate the proposed algorithm with an example, and report some computational results. 相似文献
58.
Vassil Kriakov George Kollios Alex Delis 《The VLDB Journal The International Journal on Very Large Data Bases》2009,18(3):739-764
Contemporary applications continuously modify large volumes of multidimensional data that must be accessed efficiently and,
more importantly, must be updated in a timely manner. Single-server storage approaches are insufficient when managing such
volumes of data, while the high frequency of data modification render classical indexing methods inefficient. To address these
two problems we introduce a distributed storage manager for multidimensional data based on a Cluster-of-Workstations. The
manager addresses the above challenges through a set of mechanisms that, through selective on-line data reorganization, collectively
maintain a balanced load across a cluster of workstations. With the help of both a highly efficient and speedy self-tuning
mechanism, based on a new data structure called stat-index, as well as a query aggregation and clustering algorithm, our storage manager attains short query response times even
in the presence of massive modifications and highly skewed access patterns. Furthermore, we provide a data migration cost
model used to determine the best data redistribution strategy. Through extensive experimentation with our prototype, we establish
that our storage manager can sustain significant update rates with minimal overhead. 相似文献
59.
Metal complexes of poly(2-N,N-dimethylaminoethyl) methacrylate
were prepared by complex-forming with aqueous solutions of salts of FeSO4.2H2O;
CoCl2.6H2O; CuCl2.2H2O;
VOSO4.5H2O; Na2MoO4.2H2O
and Na2WO4.2H2O. The catalytic activity
of the complexes was studied in the oxidation of cyclohexene as a model reaction. The activities of
the complexes synthesized towards the reaction of cyclohexene epoxidation can be arranged by the following
order: PDMAEM-MoO2
2+> PDMAEM-VO2+
> PDMAEM-WO2
2+> PDMAEM-Co2+
> PDMAEM-Fe3+> PDMAEM-Cu2+. The complexes
catalyzing the homolytic decomposition of tert-butylhydroperoxide increased
the maximum yield of 2-cyclohexene-1-ol and 2-cyclohexene-1-on. The yield of cyclohexene oxide and 2-cyclohexene-1-ol
were 58% and 13%, respectively. 相似文献
60.
A new 3-dB power divider for millimeter-wavelengths 总被引:2,自引:0,他引:2
Vassilev V. Belitsky V. Urbain D. Kovtonyuk S. 《Microwave and Wireless Components Letters, IEEE》2001,11(1):30-32
This paper presents a new type of 3-dB power divider that achieves wideband, low-loss, and symmetric power division. In the paper, we discuss the design considerations and present results of measurements at 10 and 100 GHz. The power divider symmetry is examined as a function of the termination loads mismatch. The simplicity of the presented divider makes it very suitable for application at millimeter and submillimeter bands. The predicted and the measured performance are in very good agreement 相似文献