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Showing papers by "Applied Science Private University published in 1983"


Journal ArticleDOI
TL;DR: In this article, the sintering behavior of commercial and high purity RBSN with and without MgO and Y2O3 additions has been studied by high temperature dilatometry with nitrogen overpressure.
Abstract: The sintering behaviour of commercial and high purity RBSN with and without MgO and Y2O3 additions has been studied by high temperature dilatometry with nitrogen overpressure. Activation energies for densification are in the region 500 to 600 kJ mol−1. Commercial RBSN shows some shrinkage and α-β Si3N4 conversion without addition. High purity RBSN retains 74%αSi3N4 after 1 h at 1750° C and shows only 0.2% linear shrinkage. The effect of calcium, aluminium and iron impurities was examined. The densification curves obtained with MgO as additive show a transient expansion in the early stages of sintering which is associated with the gas overpressure. In the absence of a powder bed, decomposition was impracticably high. Both a powder bed and nitrogen overpressure were needed to suppress decomposition.

15 citations


Journal ArticleDOI
TL;DR: The proposed approach takes into account such factors as nonlinearity of cost functions, reliability requirements of every cluster, provides least-cost network configuration by an appropriate selection of flow routing strategies, and capacities of all links with their acceptable delays.

8 citations


Journal ArticleDOI
TL;DR: The copolymerization of the cis-and trans-piperylene isomers with maleic anhydride in the presence of a peroxide catalyst yields identical equimolar, alternating copolymers which, according to 13 C-NMR analyses, have transmethyl group conformation and trans -1,4 unsaturation.

4 citations


Journal ArticleDOI
TL;DR: In this paper, the authors developed comprehensive scenarios for the startup and shutdown of fusion plants and investigated physics and engineering requirements and design constraints and their implications, focusing on the impact of such considerations on the operation of tandem mirror fusion reactors (TMR's).
Abstract: With the maturity of conceptual fusion reactor designs it is important to develop comprehensive scenarios for the startup and shutdown of fusion plants and to investigate physics and engineering requirements and design constraints and their implications. The authors then focus on the impact of such considerations on the operation of tandem mirror fusion reactors (TMR's). Brief examples from both the fission and conventional power industries are discussed. TMR plant operation is divided into an initial commissioning phase and four subsequent generic phases: (1) Phase IA: cold shutdown; (2) Phase IB: hot shutdown; (3) Phase II: system testing, plasma startup and standby power operation; (4) Phase III: staged power operation; and (5) Phase IV: rated power operation. Power ascention through these phases is explained in terms of the operation of two major systems: (1) the plasma technology and support system, and (2) the heat transport system. Physics and engineering constraints, subsystem interactions, and design implications are discussed throughout the paper using the Mirror Advanced Reactor Study (MARS) as the specific example.

4 citations


Journal ArticleDOI
TL;DR: In the above paper, the purpose of Theorem 1 was to reduce the number of feasible query trees by determining the optimal positions of unary operations in a given query tree by assuming the processing cost of a unary operation is independent of the volume of input data.
Abstract: In the above paper1, Theorem 1 is not true in general. The purpose of Theorem 1 was to reduce the number of feasible query trees by determining the optimal positions of unary operations in a given query tree. In fact, Theorem I is true only if the processing cost of a unary operation is independent of the volume of input data.

1 citations