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991.
E. Tel A. Kaplan A. Aydın S. Özkorucuklu H. Büyükuslu G. Yıldırım 《Journal of Fusion Energy》2010,29(4):312-316
Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology,
there is still a long way to go to penetrate commercial fusion reactors to the energy market. Tritium self-sufficiency must
be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater
than 1.05. So, working out the systematics of (n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various
nuclei at different energies. In this study, (n,xt) reactions for some target nuclei as 16O, 27Al, 59Co and 209Bi have been investigated up to 45 MeV incident neutron energy. In the calculations of the triton emission spectra, the pre-equilibrium
and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the
literature. 相似文献
992.
Repeated dehydriding-hydriding cycles of ball-milled nanocrystalline MgH2 was carried out in a Sieverts’-type apparatus. In order to characterize the microstructural changes during a complete MgH2 → Mg → MgH2 transformation, the fourth desorption and subsequent absorption were interrupted at different hydrogenation stages. Convolutional multiple whole profile fitting procedure of the corresponding X-ray diffractograms was applied to reveal the evolution of microstructural parameters during the sorption cycle, such as average coherent domain size and crystallite size distribution. Complementary analysis of lattice parameters was also carried out. In this paper we demonstrate that analysing solely the evolution of microstructural parameters during cycling leads to similar rate-controlling mechanisms obtained by sorption kinetic measurements. 相似文献
993.
Stina Svensson Gunilla Borgefors Ingela Nystrm 《Journal of Visual Communication and Image Representation》1999,10(4):379
In many applications thinning of objects is of great interest. We here present a skeletonization algorithm that is based on the idea of iteratively thinning the distance transform of an object layer by layer until either an anchor-point is reached or the connectivity breaks. Our algorithm is general in the sense that any metric and any connectivity can be used. Also, it is based on ideas that are not specific for 2D. The properties of the resulting skeletons are evaluated according to the “Lee–Lam–Suen properties.” 相似文献
994.
Magnus Hanson Anders Grd Pavel Krakhmalev Sture Hogmark Jens Bergstrm 《Lubrication Science》2008,14(3):147-158
Two test methods often used to simulate the tribological performance of forming tool materials are compared in this investigation through an evaluation of the friction and wear properties of four tool steels in dry sliding. One test (slider‐on‐flat‐surface (SOFS)) utilises a vertical disc sliding on a horizontal flat test surface, and the other (load scanner (LS) tests) utilises two crossed cylindrical rods. The test conditions were selected as equal as possible for the two tests, and the following conclusions are made. Somewhat unexpectedly, the friction and wear results differed substantially between the two tests. The SOFS test showed a better potential to evaluate wear resistance since one test sample is in continuous contact with the other. The LS test can generate higher contact pressures since the two rods contact each other in an unworn condition throughout the whole test stroke. LS indicate that two hard and smooth tool steels tested against each other generally give low friction and good galling resistance. The two hard couples tested sustained the highest loads without any detectable surface damage. For the same combinations of hard steels, SOFS gave a higher friction due to the wear of the disc. The carbides in the disc material resist wear better than the matrix and will consequently wear the disc by abrasion, which adds to the friction. The above conclusions are drawn from a rather limited examination using only one set of test parameters. In fact, the two tests are both very flexible as to the way they can be used, and they both have advantages and limitations in tribological studies. They should rather be considered complementary than competitive. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
995.
In this paper we describe how behavioral responses of carbon dioxide (CO2) tax increases are accounted for in tax revenue estimation in Sweden. The rationale for developing a method for this is a mix between that a CO2 tax is a primary climate policy tool aiming to reduce CO2 emissions and that the CO2 tax generates sizable tax revenues. 相似文献
996.
Ömer Güler Mustafa Boyrazlı Öyküm Başgöz Bayram Bostancı 《Canadian Metallurgical Quarterly》2017,56(3):349-359
Tea wastes are rich in carbon, nitrogen and potassium but poor in phosphorus, which signifies that they can also be used to reduce metal oxides after they are carbonised. The tea wastes were carbonised at the first stage. The sample, which was put into a ladle with screw cap, was carbonised in a muffle furnace at 400, 500, 600, 700 and 800°C for 30, 60, 90, 120, 240, 360, 720 and 1440?min. It was determined that carbon and sulphur contents of the sample carbonised at 800°C for 1440?min were 94.68 and 0.05%, respectively. Calorific value of the same sample was 8652?cal?g?1. It was found that with increasing temperature, carbon ratio of the carbonised samples increased and their sulphur ratio decreased from 0.39 to 0.05%. The carbonised structure was subjected to the milling process as the second stage. In the milling process, particle size of the carbon-rich sample was brought into nano size and the structure acquired the energy, required for the third stage. The amorphous carbon structure obtained after the milling process was subjected to annealing process at 1400°C as the third stage. As a result of these processes, carbon nanotubes (CNTs), carbon nano-onion structures and amorphous carbon structures were determined in the structure. 相似文献
997.
998.
The solubility of vanadium oxide in the SiO2–CaO–VOX system was investigated as a function of basicity (CaO/SiO2) at a fixed temperature of 1600°C and oxygen partial pressure of 10?10?atm. Formed phases and microstructures of saturated samples were identified with SEM–EDS analysis and XRD. Maximum solubility of vanadium oxide was between 15 and 20% independent of basicity. Pure karelianite (V2O3) was formed in all samples at saturation of vanadium oxide. The morphology of karelianite changed with the change in basicity in the slag, where needles or threads were formed for slags with basicity B2?=?0.54 and B2?=?0.67 and stars or dendritic patterns were formed with basicity B2?=?1.0 and B2?=?1.22. Wollastonite (CaSiO3) was also formed in the slags with star or dendritic patterns. 相似文献
999.
Karin M. Almgren E. Kristofer Gamstedt Fredrik Berthold Mikael Lindstrm 《Polymer Composites》2009,30(12):1809-1816
Effects of butantetracarboxylic acid (BTCA) modification, choice of matrix, and fiber volume fraction on hygroexpansion of wood fiber composites have been investigated. Untreated reference wood fibers and BTCA‐modified fibers were used as reinforcement in composites with matrices composed of polylactic acid (PLA), polypropylene (PP), or a mixture thereof. The crosslinking BTCA modification reduced the out‐of‐plane hygroexpansion of PLA and PLA/PP composites, under water‐immersed and humid conditions, whereas the swelling increased when PP was used as matrix material. This is explained by difficulties for the BTCA‐modified fibers to adhere to the PP matrix. Fiber volume fraction was the most important parameter as regards out‐of‐plane hygroexpansion, with a high‐fiber fraction leading to large hygroexpansion. Fiber‐matrix wettability during processing and consolidation also showed to have a large impact on the dimensional stability and moisture uptake. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers 相似文献
1000.
A parallel algorithm for reordering the eigenvalues in the real Schur form of a matrix is presented and discussed. Our novel approach adopts computational windows and delays multiple outside‐window updates until each window has been completely reordered locally. By using multiple concurrent windows the parallel algorithm has a high level of concurrency, and most work is level 3 BLAS operations. The presented algorithm is also extended to the generalized real Schur form. Experimental results for ScaLAPACK‐style Fortran 77 implementations on a Linux cluster confirm the efficiency and scalability of our algorithms in terms of more than 16 times of parallel speedup using 64 processors for large‐scale problems. Even on a single processor our implementation is demonstrated to perform significantly better compared with the state‐of‐the‐art serial implementation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献