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21.
Gerard E. Lenain Herbert A. McKinstry Dinesh K. Agrawal 《Journal of the American Ceramic Society》1985,68(9):224-C
The X-ray diffraction pattern for potassium-zirconium phosphate is significantly improved when the material is prepared by the sol-gel route rather than the powder method. Peaks at high, low, and intermediate angles are presented and compared for the two methods. It is assumed that the more nearly homogeneous mixing of the elements in the sol-gel process is responsible for the significant improvement in crystallinity. 相似文献
22.
CoMo and NiMo supported Al2O3 catalysts have been investigated for hydrotreating of model molecule as well as industrial feedstock. Activity studies were carried out for thiophene and SRGO hydrodesulfurization (HDS) in an atmospheric pressure and batch reactor respectively. These activities on sulfided catalysts were evaluated as a function of promoter content [M/(M + Mo) = 0.30, 0.34, 0.39; M = Co or Ni] using fixed (ca. 8 wt.%) molybdenum content. The promoted catalysts were characterized by textural properties, XRD, and temperature programmed reduction (TPR). TPR spectra of the Co and Ni promoter catalysts showed that Ni promotes the easy reduction of Mo species compared with Co. With the variation of promoter content NiMo catalyst was found to be superior to CoMo catalyst for gas oil HDS, while at low-promoter content the opposite trend was observed for HDS of thiophene. The behavior was attributed to the several reaction mechanisms involved for gas oil HDS. A nice relationship was obtained for hydrodesulfurized gas oil refractive index (RI) and aromatic content, which corresponds to the Ni hydrogenation property. 相似文献
23.
A series of novel copolymer superabsorbents based on monomer acrylamide (AM), potassium methacrylate (KMA), and 2‐hydroxyethyl methacrylate (HEMA) were prepared by copolymerization using ammonium persulfate (APS) as an initiator and N,N‐methylenebisacrylamide (MBA) as a crosslinking agent. The synthetic variables (the monomer concentration, crosslinker concentration, and initiator concentration) were also studied. The experimental results of superabsorbent polymers (SAPs) show a better absorbency in both water and NaCl solutions. The copolymers were characterized by IR spectroscopy. The water retention in the soil was enhanced using the above superabsorbents. The use of SAPs for the growth of groundnut plants was also investigated. SAPs can be considered for water‐managing materials for agriculture and horticulture purposes in desert and drought‐prone areas. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1795–1801, 2002 相似文献
24.
T. Chandrasekhara Rao G. Lakshminarayana N. B. L. Prasad S. Jagan Mohan Rao G. Azeemoddin D. Atchyuta Ramayya S. D. Thirumala Rao 《Journal of the American Oil Chemists' Society》1984,61(9):1472-1473
The seeds and extracted oils ofCarissa spinarum (Apocynaceae), (I),Leucaena leucocephala (Leguminosae) (II) andPhysalis minima (Solanaceae) (III) were analyzed for characteristics and compositions. The seeds of I, II and III contained 22.4, 6.4 and
40.0% oil and 10.1, 27.6 and 17.9% protein, respectively. The oils of I, II and III had, respectively, iodine values 70.1,
113.5 and 122.5; saponification values 186, 188 and 189; unsaponifiable matter 5.2, 2.5 and 0.8%, and the following fatty
acid compositions (area %): palmitic 12.6, 14.2, 10.5; stearic 7.6, 6.1, 8.6; oleic 72.7, 20.1, 17.3; linoleic 5.2, 53.8,
61.4; linolenic 0.9, 1.8, 0.0, and arachidic 1.0, 2.3, 0.0. II contained 1.7% lignoceric acid. III contained small amounts
of hexadecenoic (0.1%), epoxy (0.6%) and hydroxy (1.5%) fatty acids. 相似文献
25.
Ashwin S. Dhabale Rutuja Dive Mohan V. Aware Shantanu Das 《Asian journal of control》2015,17(6):2143-2152
In this paper a new algorithm is presented to calculate the poles and zeros to approximate a fractional order (FO) differintegral (s±α,α∈(0,1)) by a rational function on a finite frequency band ω∈(ωl,ωh). The constant phase property of the FO differintegral is the basis for development of the algorithm. Interlacing of real poles and zeros is used to achieve the constant phase. The calculations are done using the asymptotic Bode phase plot. A brief investigation is made to get a good approximation for the Bode phase plot. Two design parameters are introduced to keep the average phase close to the desired phase angle and to keep the error within the allowed bounds. A study is done to empirically understand the relationship between the error and the design parameters. The results thus obtained help in the further calculations. The algorithm is computationally simple and inexpensive, and gives a fairly good approximation of fractance frequency response on the specified frequency band. 相似文献
26.
27.
Design of Barrages with Genetic Algorithm Based Embedded Simulation Optimization Approach 总被引:2,自引:2,他引:0
Raj Mohan Singh 《Water Resources Management》2011,25(2):409-429
Barrages are hydraulic structures constructed across rivers to divert flow into irrigation canals or power generation channels.
The most of these structures are founded on permeable foundation. The optimum cost of these structures is nonlinear function
of factors that cause the seepage forces under the structure. There is, however, no procedure to ascertain the basic barrage
parameters such as depth of sheet piles or cutoffs and the length and thickness of floor in a cost–effective manner. In this
paper, a nonlinear optimization formulation (NLOF), which consists of an objective function of minimizing total cost, is solved
using genetic algorithm (GA). The mathematical model that represents the subsurface flow is embedded in the NLOF. The applicability
of the approach has been illustrated with a typical example of barrage profile. The results obtained in this study shows drastic
cost savings when the proposed NLOF is solved using GA than that of using classical optimization technique and conventional
method. A parametric analysis has also been performed to study the effect of varying soil and hydrological conditions on design
parameters and on over all cost. 相似文献
28.
29.
We advocate the use of quickly‐adjustable, computer‐controlled color spectra in photography, lighting and displays. We present an optical relay system that allows mechanical or electronic color spectrum control and use it to modify a conventional camera and projector. We use a diffraction grating to disperse the rays into different colors, and introduce a mask (or LCD/DMD) in the optical path to modulate the spectrum. We analyze the trade‐offs and limitations of this design, and demonstrate its use in a camera, projector and light source. We propose applications such as adaptive color primaries, metamer detection, scene contrast enhancement, photographing fluorescent objects, and high dynamic range photography using spectrum modulation. 相似文献
30.
ICCD: Interactive Continuous Collision Detection between Deformable Models Using Connectivity-Based Culling 总被引:1,自引:0,他引:1
Tang Min Curtis Sean Yoon Sung-Eui Manocha Dinesh 《IEEE transactions on visualization and computer graphics》2009,15(4):544-557
We present an interactive algorithm for continuous collision detection between deformable models. We introduce multiple techniques to improve the culling efficiency and the overall performance of continuous collision detection. First, we present a novel formulation for continuous normal cones and use these normal cones to efficiently cull large regions of the mesh as part of self-collision tests. Second, we introduce the concept of “procedural representative triangles” to remove all redundant elementary tests between nonadjacent triangles. Finally, we exploit the mesh connectivity and introduce the concept of “orphan sets” to eliminate redundant elementary tests between adjacent triangle primitives. In practice, we can reduce the number of elementary tests by two orders of magnitude. These culling techniques have been combined with bounding volume hierarchies and can result in one order of magnitude performance improvement as compared to prior collision detection algorithms for deformable models. We highlight the performance of our algorithm on several benchmarks, including cloth simulations, N-body simulations, and breaking objects. 相似文献