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Transfer Conditions (transfer + condition)

Distribution by Scientific Domains
Polymers and Materials Science40%
Chemistry40%

Selected Abstracts

ChemInform Abstract: Palladium-Catalyzed Allylic Alkylation of tert-Butyl(diphenylmethylene)-glycinate with Simple Allyl Esters under Chiral Phase Transfer Conditions.

CHEMINFORM, Issue 47 2001
Guoshu Chen
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Quenching with fluid jets

MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 5-6 2009
S. Schuettenberg
Verzugskompensation; Distortion Engineering; Jetabschreckung; Flüssigkeitsabschreckung Abstract The quenching process within the heat treatment of workpieces can be optimized by applying locally adapted quenching conditions. Locally variable heat transfer conditions at the workpiece surface are realizable by impressing and regulation of adjustable flexible flow fields on the basis of arrays for jet flow impingings on surfaces inside the quenching media. With use of these adapted jet fields it is possible to generate spatially and or timewise varying quenching conditions with high cooling intensities for a systematic locally heat transfer during the quenching process. For the analysis of workpiece distortion activated by heat treatment, the heat transfer and hardening process by quenching in adapted flexible flow fields is modelwise described. By controlled quenching with liquid media, the quenching intensities can be increased for specific local hardening results on massive workpieces. By that, the heat treatment process and the quenching result can be affected and optimized by controlling the boiling process and the establishing of the rewetting front on the workpiece surface. Abschrecken mit Flüssigkeitsjets Der Abschreckprozess bei der Wärmebehandlung von Werkstücken kann durch die Aufprägung lokaler Abschreckbedingungen optimiert werden. Lokal variable Wärmeübergangsbedingungen an der Werkstückoberfläche sind hier innerhalb des Abschreckmediums durch die Aufprägung und Regelung flexibler Strömungsfelder auf der Grundlage von Jetfeldern mit Prallströmungen auf die Oberflächen möglich. Mit der Anwendung dieser angepassten Jetfelder ist es möglich, räumlich und zeitlich variable Abschreckbedingungen mit hohen Kühlintensitäten für einen gezielten, lokalen Wärmeübergang während des Abschreckprozesses zu generieren. Zur Analyse des durch die Wärmebehandlung aktivierten Bauteilverzugs wird der Härteprozess durch Abschreckung in angepassten, flexiblen Strömungsfeldern modellmäßig beschrieben. Durch gesteuertes Abschrecken mit flüssigen Medien können die Abschreckintensitäten für bestimmte lokale Härteergebnisse an massiven Werkstücken erhöht werden. Damit kann das Abschreckergebnis durch die Steuerung des Siedeprozesses und des Verlaufs der Wiederbenetzungsfront an der Werkstückoberfläche beeinflusst und optimiert werden. [source]

Industrial solidification processes in polybutene-1.

POLYMER ENGINEERING & SCIENCE, Issue 1 2003
Part I, quiescent melts
In the first paper of this series the principles for solidification of crystallizable polymers under heat transfer conditions are discussed for the case of the absence of flow. For industrial polymers, which, in general, are forced to crystallize at large undercoolings, the pertinent kinetic data are extremely rare. In the present paper the growth speeds of spherulites and the number of nuclei per unit volume are presented as functions of temperature for two industrial polybutene-1 grades. [source]

Minimum Wetting Rates for Falling Films on Stainless Steel

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1-2 2006
K. R. Morison
The minimum wetting rate is defined as the minimum mass flowrate per unit circumference that is required to maintain of complete falling film of liquid on a surface. In this work minimum wetting rates in a 48 mm i.d. stainless steel tube were determined jor water, 50% sucrose solution, and reconstituted skim milk under isothermal and heat transfer conditions. It was found that initial distribution of the liquid at the top of the tube was critically important. The minimum wetting rates under isothermal and heat transfer conditions ranged from 0.22 kg m,1 s,1 for 50% sucrose at 20% to 0.12 kg m,1 s,1 for water az 70°C. Nearly all rates decreased with temperature. Equations in the literature did not accurately predict the results obtained. [source]

Kinetic modeling of light limitation and sulfur deprivation effects in the induction of hydrogen production with Chlamydomonas reinhardtii: Part I. Model development and parameter identification

BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2009
Swanny Fouchard
Abstract Chlamydomonas reinhardtii is a green microalga capable of turning its metabolism towards H2 production under specific conditions. However this H2 production, narrowly linked to the photosynthetic process, results from complex metabolic reactions highly dependent on the environmental conditions of the cells. A kinetic model has been developed to relate culture evolution from standard photosynthetic growth to H2 producing cells. It represents transition in sulfur-deprived conditions, known to lead to H2 production in Chlamydomonas reinhardtii, and the two main processes then induced which are an over-accumulation of intracellular starch and a progressive reduction of PSII activity for anoxia achievement. Because these phenomena are directly linked to the photosynthetic growth, two kinetic models were associated, the first (one) introducing light dependency (Haldane type model associated to a radiative light transfer model), the second (one) making growth a function of available sulfur amount under extracellular and intracellular forms (Droop formulation). The model parameters identification was realized from experimental data obtained with especially designed experiments and a sensitivity analysis of the model to its parameters was also conducted. Model behavior was finally studied showing interdependency between light transfer conditions, photosynthetic growth, sulfate uptake, photosynthetic activity and O2 release, during transition from oxygenic growth to anoxic H2 production conditions. Biotechnol. Bioeng. 2009;102: 232,245. © 2008 Wiley Periodicals, Inc. [source]