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21.
Concurrent programs that embed specifications of synchronizations in the body of their component are difficult to extend and modify. Small changes in a concurrent program, particularly changes in the interactions among components, may require re-implementation of a large number of components. Even specifications of components cannot be reused easily. This paper presents a concurrent program composition mechanism in which both specification and implementation of computations and interactions are completely separated. Separation of specifications and implementations facilitates extensions and modifications of programs by allowing one to separately change the implementations of computations and interactions. It also supports their reusability. The paper also describes the design and implementation of a concurrent object-oriented programming language based on this model, including a compiler for the language, and reports on the execution behavior of programs written in the language. 相似文献
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Large amount of literature is presently available on the topic of scour around uniform piers and its control. However, relatively fewer studies have been carried out so far on the topic of flow field and scour around compound piers. The state of art on the topic of flow structure and scour around circular compound piers is presented herein. The available literature reveals that variations in foundation and pier geometry significantly affect the maximum depth of scour and its temporal variation. In case of compound piers the scour depth is highly sensitive to the change in elevation of the top surface of the foundation well. As compared to uniform piers, a reduction is observed in maximum depth of scour around compound pier when the top surface of the well is kept below the general level of river bed. These observations however are yet to be quantified. Results from an experimental study on flow field around the compound piers are also presented. 相似文献
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Raju Kocharekar 《Information Systems Management》2004,21(2):22-30
In today's world of “co-opetition” among organizations, where one organization competes and cooperates simultaneously with business partners, all organizations must have IT architectures that are nimble and flexible. This article takes a look at one important aspect in achieving a flexible IT architecture: access management of information resources over the Web. It describes an access management architecture that can change as business does and recommends how best to implement this nimble architecture. 相似文献
25.
D. Pamu G.L. Narayana Rao K.C. James Raju 《Science and Technology of Advanced Materials》2013,14(6):469-476
The effect of CuO on the sintering temperature, microstructure and microwave dielectric properties of (Zr0.8Sn0.2)TiO4 (ZST) modified with 1 wt% of ZnO has been investigated. Microwave dielectric properties of ZST ceramics are measured from cryogenic to room temperatures (15–290 K). Crystallite sizes of sintered ZST ceramics as derived from XRD are in the 30–50 nm range. The addition of CuO effectively reduced the sintering temperature to 1300 1C, possibly due to liquid-phase effects. Addition of CuO did not cause any secondary phases up to 1.5 wt% of CuO. The dielectric constant (εr) and temperature coefficient of resonant frequency (εf) of ZST ceramics do not significantly vary with temperature, whereas the unloaded quality factor (Qu) changes noticeably. It is found that the Qu factor of the sample without CuO decreased with increase in temperature, whereas the samples with addition of CuO up to 1.0 wt% showed less dependence on temperature. The Qu factor of CuO-free ZST is 15,000 and that of ZST with 0.5 wt% of CuO is 11,800 at 15 K. The Qu factor while measured at room temperature ranged between 2900 and 7000. Efforts were made to understand whether the increase in Qu factor at both cryogenic and room temperatures is the result of intrinsic or extrinsic factors. 相似文献
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R. Floriano S. Deledda B.C. Hauback D.R. Leiva W.J. Botta 《International Journal of Hydrogen Energy》2017,42(10):6810-6819
In this study, powder mixtures of MgH2 + 2 mol.% X, with X = Nb, Nb2O5, NbF5, Fe, Fe2O3, FeF3, were processed by mechanical milling at liquid nitrogen temperature (cryomilling). The effect of additives on crystalline structure, thermal properties and hydrogen storage properties of the mixtures were investigated. Morphological investigations indicated a heterogeneous particle size distribution of the powder mixtures and a fine dispersion of additive particles (FeF3) in the MgH2 matrix. High resolution synchrotron radiation X-ray diffraction (SR-XRD) data followed by Rietveld refinements showed a significant reduction on crystallite size for the samples containing fluorides (11 nm) in comparison with the pure MgH2 sample (29 nm). This was related to the mechanical behavior of fluorides during milling with MgH2, which act as a lubricant, dispersing and/or cracking agent during milling, and thus helping to further reduce MgH2 particle size. DSC analysis revealed that fluorides (NbF5, FeF3) are much more effective than oxides (Nb2O5, Fe2O3) and the transition metals (Nb and Fe), respectively, in reduction the desorption temperature. Furthermore, Nb2O5 is more efficient than Fe2O3. Finally, the best results for desorption kinetics were observed for the fluorides: NbF5 and FeF3 (equivalent effect and consistent to the DSC analysis) followed by the oxides: Nb2O5, Fe2O3 and Nb. The addition of Fe was not efficient in comparison with the pure cryomilled sample. 相似文献
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Kishore K Jena Tapan K Rout Ramanuj Narayan Kothapalli V S N Raju 《Polymer International》2012,61(7):1101-1106
(Hyperbranched polyurethane‐urea)/[(3‐aminopropyl)triethoxysilane]‐ZnO (HBPUU‐APTES‐ZnO) hybrid coatings were synthesized using an inexpensive mixing technique by varying the APTES‐modified ZnO concentration. The mechanical and surface properties of the hybrid coating films were studied and compared with unmodified and modified ZnO. The corrosion, solvent and abrasion resistance show significant enhancement in HBPUU‐APTES‐ZnO hybrids and their properties are increased with increasing APTES‐ZnO concentration. This hybrid coating has opened up an opportunity for automotive topcoat application. Copyright © 2012 Society of Chemical Industry 相似文献
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