An industrial ethane thermal cracking reactor was modeled assuming a molecular mechanism for the reaction kinetics coupled with material, energy, and momentum balances of the reactant-product flow along the reactor. To carry out the multi-objective optimization for two objectives such as conversion and ethylene selectivity, the elitist non-dominated sorting genetic algorithm was used. The Paret...

~~'he t hermal conductivity of CO 2 has been m.easured in a coaxia l cyl inder cell as a fu nctIO n of pressure over a range of t emperatures from 3.66 to 75.26 °C. P ar Licular attention was given to t he measurement s from 1 to 9 deg C above t he cri tical t emperature at pressures closely spaced to i nclude t he crit ical density. The t hermal co ndu ctivity of CO2(0) near t he cri tical poi...

A description is given of an apparatus used for determining the t hermal conductivities o f solids in t he temperature range 4° K to 300° K. The apparatus is especially suited to the determination of thermal conductivity over a la rge temperature interval , enabling coverage of t he temperatures between t he normal boil ing points of liquefied gases. Illustrati ve results are given for an insul...

The efficiency of the application of high-emissivity coatings on the furnace walls in steam cracking technology can only be evaluated on the asis of a description of radiative heat transfer distinguishing between the frequency bands. To this end, a non-grey gas radiation model based on he exponential wide band model (EWBM) has been developed and applied in the context of three-dimensional CFD s...

A bstra ct . When one compares t he time evolution of two spin configura tions subjected to the same t hermal noise, domains appea r of ident ical and opposite spins . We st udy these domains and their growt h for three magnetic systems in two dime nsions: ferromagnet, spin glass, and non-symmetric spin glass. For Ierromagnet s, t hese distan ce associated domains are very similar to the magnet...

Failure of hollow trees in urban areas is a worldwide concern, and it can be caused by different mechanisms, i.e. bending stresses or flattening-related failures. Here we derive a new analytical expression for predicting the bending moment for tangential cracking, and compare the breaking moment of various failure modes, including Brazier buckling, tangential cracking, shear failure and convent...

m 0 7 r m a d s a t p f t u 4,4*-Diphenyltetrathiafulvalene (DPTTF) capped gold nanoarticles of 3to 5-nm diameter have been prepared and their hermal stability has been investigated by variable temperature T–IR spectroscopy. The DPTTF molecules at the cluster surface ndergo charge-transfer complexation with C60 to form Au/ PTTF.C60. Direct evidence of complexation is observed in the -ray photoe...

A laboratory investigation on a scaled model of a landACT: l ti n a scaled o l f ­ fill liner was conducted to provide data regarding the occurrence l i e e and extent of desiccation cracking of prototype liners. The crack t t of desi t e li rs. intensity factor, CIF, was introduced as a descriptor of the extent of t f , , as i tr as f the extent of surficial cracking. CIF is defmed as the rati...

Polybutadiene and a co poly mer consisting of 76.5 percent butadiene and 23 .5 percent of styrene were investigated as to t he rates of t heir t hermal degradation . The ra tes for polybu tadiene indicated an act iv:ttion energy of 60 kilocalories per mole. The copolym er had very high init ial rates of degradation, followed by a rapid cirop, so t hat it wa~ not possible to obtain a reliab le a...