Atomic Energy of Canada Limited

About: Atomic Energy of Canada Limited is a company organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Neutron & Zirconium alloy. The organization has 4845 authors who have published 4826 publications receiving 102951 citations.

The Segregated Approach to Predicting Viscous Compressible Fluid Flows

Abstract: The SIMPLE method of Patankar and Spalding and its variants such as SIMPLER, SIMPLEC and SIMPLEX are segregated methods for solving the discrete algebraic equations representing the equations of motion for an incompressible fluid flow. The present paper presents the extension of these methods to the solution of compressible fluid flows within the context of a generalized segregated approach. To provide a framework for better understanding the segregated approach to solving viscous compressible fluid flows an interpretation of the role of pressure in the numerical method is presented. With this interpretation it becomes evident that the linearization of the equation for mass conservation and the approach used to solve the linearized algebraic equations representing the equations of motion are important in determining the performance of the numerical method. The relative performance of the various segregated methods are compared for several subsonic and supersonic compressible fluid flows.Copyright © 1986 by ASME

Spin dynamics and the Haldane gap in the spin-1 quasi-one-dimensional antiferromagnet CsNiCl 3

Abstract: A full description of a series of spin-wave measurements in ${\mathrm{CsNiCl}}_{3}$ in the three-dimensional (3D) and one-dimensional (1D) phases and their analysis to provide the first experimental evidence for the Haldane gap is presented. Neutron scattering experiments were performed on a single crystal of ${\mathrm{CsNiCl}}_{3}$ with both (h,0,l) and (h,h,l) as the scattering plane. The order parameter in both 3D phases was measured and the spin-wave dispersion determined in the lower phase. The spin-wave spectrum calculated from a dynamic susceptibility method was compared with the experimental response in the lower 3D phase to obtain the following values for the exchange and anisotropy constants: J=0.345\ifmmode\pm\else\textpm\fi{}0.008 THz, J'=0.0060\ifmmode\pm\else\textpm\fi{}0.005 THz, and D=-0.0130\ifmmode\pm\else\textpm\fi{}0.0015 THz. These parameters confirm that ${\mathrm{CsNiCl}}_{3}$ in its disordered phase is a good approximation to a one-dimensional Heisenberg antiferromagnet. In the 1D phase the gap frequency for an isolated chain of ${\mathrm{Ni}}^{2+}$ ions is found to be 0.32 THz close to the gap estimated in finite-chain calculations. The results constitute experimental support for the Haldane conjecture that the excitations of integer-spin chains, unlike half-integer--spin chains, exhibit an apparent anisotropy that arises not from the underlying isotropic Hamiltonian, but from many-body effects.

Radiosensitization of mammalian cells by p-nitroacetophenone. 3. Effectiveness of nitrobenzene analogues.

Abstract: SummaryNitrobenzene analogues of p-nitroacetophenone (PNAP) have been tested on Chinese-hamster cells for their ability to sensitize hypoxic cells to x-rays. Seven compounds which are more effective than PNAP at a given non-toxic concentration are reported. One of these, 1-(2,4-dinitrophenyl)pyridinium chloride (DNPC), approaches the nitrofuran class of radiosensitizers in effectiveness. A correlation between cellular radiosensitization and drug electron affinity is examined for its usefulness in predicting radiosensitizing potential of compounds in the nitrobenzene series.