ChemInform Abstract: REACTIONS OF HALOMETHANES IN THE VAPOR PHASE. PART 4. THE REACTIONS OF IMIDAZOLES WITH CHLOROFORM AT 500°C, AND A COMPARISON WITH THEIR LIQUID-PHASE REACTIONS WITH TRICHLOROACETATE ION OR HEXACHLOROACETONE AND BASE

1980 ◽  
Vol 11 (38) ◽  
Author(s):  
R. E. BUSBY ◽  
M. A. KHAN ◽  
M. R. KHAN ◽  
J. PARRICK ◽  
C. J. G. SHAW ◽  
...  
Keyword(s):  
Author(s):  
Vedanth Srinivasan ◽  
Abraham J. Salazar ◽  
Kozo Saito

A new unsteady cavitation event tracking model is developed for predicting vapor dynamics occurring in multi-dimensional incompressible flows. The procedure solves incompressible Navier-Stokes equations for the liquid phase with an additional vapor transport equation for the vapor phase. The model tracks regions of liquid vaporization and applies compressibility effects to compute the local variation in speed of sound using the Homogeneous Equilibrium Model (HEM) assumptions. The variation of local cell density as a function of local pressure is used to construct the source term in the vapor fraction transport equation. The novel Cavitation-Induced-Momentum-Defect (CIMD) correction methodology developed in this study serves to account for cavitation inception and collapse events as relevant momentum source terms in the liquid phase momentum equations. Effects of vapor phase accumulation and diffusion are incorporated by detailed relaxation models. A modified RNG K-ε model, including the effects of compressibility in the vapor regions, is employed for modeling turbulence effects. Turbulent kinetic energy and dissipation contributions from the vapor regions are integrated with the liquid phase turbulence using relevant source terms. Numerical simulations are carried out using a Finite Volume methodology available within the framework of commercial CFD software code Fluent v.6.2. Simulation results are in qualitative agreement with experiments for unsteady cloud cavitation behavior in planar nozzle flows. Multitude of mechanisms such as formation of vortex cavities, vapor cluster shedding and coalescence, cavity pinch off are sharply captured by the supplemented vapor transport equation. Our results concur with previously established theories concerning sheet and cloud cavitation such as the re-entrant jet motion, cavity closure and the impact of adverse pressure gradients on cavitation dynamics.


1989 ◽  
Author(s):  
W. Davis ◽  
H. Cochran ◽  
J. Leitnaker
Keyword(s):  

1928 ◽  
Vol 1 (2) ◽  
pp. 208-210
Author(s):  
Stanley Francis Birch

Abstract OF THE numerous methods available for the preparation of butadiene in the laboratory, those described by Thiele and by Ostromuislenskii are probably the most convenient. Both, however, suffer from the disadvantages which usually characterize operations at comparatively high temperatures; the exact conditions are difficult to find, the process is long and tedious, and finally involves the separation of the required material from a complex mixture. It has long been known that butadiene occurs in the various products obtained when oils are heated to a high temperature. Caventou first isolated butadiene in the form of its tetrabromide from illuminating gas, and Armstrong and Miller definitely established the presence of butadiene in the liquid obtained by compressing oil gas. The work of numerous later investigators has confirmed their results and has shown that the more drastic the heat treatment to which the oil is submitted the greater is the tendency for butadiene to be formed. For this reason vapor-phase cracking of petroleum, which is carried out at a much higher temperature than liquid-phase cracking, yields products specially rich in butadiene.


2002 ◽  
Vol 124 (33) ◽  
pp. 9684-9685 ◽  
Author(s):  
Igor V. Koptyug ◽  
Alexander V. Kulikov ◽  
Anna A. Lysova ◽  
Valery A. Kirillov ◽  
Valentin N. Parmon ◽  
...  

1984 ◽  
Vol 56 (3) ◽  
pp. 710-712 ◽  
Author(s):  
D. P. Wilt ◽  
R. F. Karlicek ◽  
K. E. Strege ◽  
W. C. Dautremont‐Smith ◽  
N. K. Dutta ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Daming Gao ◽  
Hui Zhang ◽  
Peter Lücking ◽  
Hong Sun ◽  
Jingyu Si ◽  
...  

Vapor-liquid equilibrium (VLE) data for the strongly associated ternary system methanol + water + ethanoic acid and the three constituent binary systems have been determined by the total pressure-temperature-liquid-phase composition-molar excess enthalpy of mixing of the liquid phase (p, T, x, HmE) for the binary systems using a novel pump ebulliometer at 101.325 kPa. The vapor-phase compositions of these binary systems had been calculated from Tpx and HmE based on the Q function of molar excess Gibbs energy through an indirect method. Moreover, the experimental T, x data are used to estimate nonrandom two-liquid (NRTL), Wilson, Margules, and van Laar model parameters, and these parameters in turn are used to calculate vapor-phase compositions. The activity coefficients of the solution were correlated with NRTL, Wilson, Margules, and van Laar models through fitting by least-squares method. The VLE data of the ternary system were well predicted from these binary interaction parameters of NRTL, Wilson, Margules, and van Laar model parameters without any additional adjustment to build the thermodynamic model of VLE for the ternary system and obtain the vapor-phase compositions and the calculated bubble points.


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