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21.
An optical emission spectroscopy (OES) method has been used to measure the concentration above the melt of some radioelements,
137Cs, 60Co and 106Ru during the vitrification of radioactive wastes by thermal plasma. This method allows the study of non homogeneous optically
thin plasmas exhibiting a symmetry plane without sophisticated tomographic systems. Local plasma temperatures above the melt
have been evaluated using measured relative intensities of spectral lines of the plasma-forming gas. Radioelement concentrations
in the plasma are deduced from the intensity ratio of the radioelement–gas spectral lines. A computer model is used to simulate
the volatility of 137Cs, 60Co and 106Ru, during the treatment of radioactive wastes by thermal plasma. This model is based on the calculation of system composition
using the free enthalpy minimization method, coupled with the equation of mass transfer at the reactional interface. In this
study, the OES measurements and the computer model allowed the determination of this radioelement volatility depending on
the parameters like plasma current, and the nature of atmosphere furnace. The results of the model are compared to those obtained
by OES measurements. 相似文献
22.
In this paper, we study the identical parallel machine scheduling problem with a planned maintenance period on each machine to minimize the sum of completion times. This paper is a first approach for this problem. We propose three exact methods to solve the problem at hand: mixed integer linear programming methods, a dynamic programming based method and a branch-and-bound method. Several constructive heuristics are proposed. A lower bound, dominance properties and two branching schemes for the branch-and-bound method are presented. Experimental results show that the methods can give satisfactory solutions. 相似文献
23.
Imed Zaguia 《Order》2011,28(3):465-479
We prove that if a finite (3 + 1)-free ordered set of height two has the fixed point property, then it is dismantlable by irreducibles. We provide an example of a finite (3 + 1)-free ordered set of height three with the fixed point property and no irreducible elements. We characterize the minimal automorphic ordered sets which are respectively (3 + 1)-free, (2 + 2)-free and N-free. 相似文献
24.
In this paper we are interested in the study of the dynamic behavior of a planar flexible slider–crank mechanism with clearance. Simulation and experimental tests were carried out for this goal. For the simulation tests, we have built the model under the software ADAMS. We used a contact model based on the so called Impact-function. An experimental set-up was designed and built to achieve some experimental validations. The presented results show that, in the presence of clearance, the mechanism responses were greatly influenced. The motion is characterized by the occurrence of three phases: a free motion, a continuous contact motion and an impact motion. In this paper, both the case of the mechanism with rigid link and the case with flexible link were studied. It is shown that in the presence of clearance, the coupler flexibility has a role of suspension for the mechanism. 相似文献
25.
Imed Basdouri 《Algebras and Representation Theory》2013,16(1):35-50
We investigate the first cohomology space associated with the embedding of the Lie Orthosymplectic superalgebra $\mathfrak{osp}(n|2)$ on the (1,n)-dimensional superspace ?1|n in the Lie superalgebra $ \mathcal{S}\Psi\mathcal{DO}(n)$ of superpseudodifferential operators with smooth coefficients, where n?=?0, 1, 2. Following Ovsienko and Roger, we give erxplicit expressions of the basis cocycles. 相似文献
26.
We show that there are four infinite prime graphs such that every infinite prime graph with no infinite clique embeds one
of these graphs. We derive a similar result for infinite prime posets with no infinite chain or no infinite antichain. 相似文献
27.
Imed Zaguia 《Order》2008,25(3):267-279
The purpose of this paper is to investigate how the fixed point property and its negation behave when a covering relation
is added to the order. We prove that every finite ordered set which is not totally ordered and which is dismantlable by retractables,
respectively by irreducibles, has an upper cover (in its extension lattice) which is also dismantlable by retractables, respectively
by irreducibles. We also provide examples of finite ordered sets having the fixed point property so that none of their upper
covers has the fixed point property.
Part of this work was done while the author was visiting Brandon University. The author thanks M. Roddy for his hospitality
and financial support. 相似文献
28.
29.
Given Ω bounded open regular set of ${\mathbb{R}^2}$ , ${q_1,\ldots, q_K \in \Omega}$ , ${\varrho : \Omega \longrightarrow [0,+\infty)}$ a regular bounded function and ${V: \Omega \longrightarrow [0,+\infty)}$ a bounded fuction. We give a sufficient condition for the model problem $$(P):\qquad-{\Delta}u -{\lambda}\varrho(x)|{\nabla}u|^2 = \varepsilon^{2}V(x)e^u$$ to have a positive weak solution in Ω with u = 0 on ?Ω, which is singular at each q i as the parameters ${\varepsilon}$ and λ tend to 0, essentially when the set of concentration points q i and the set of zeros of V are not necessarily disjoint. 相似文献
30.