Search results for "Simple equation"
showing 4 items of 4 documents
Influence d'humidité de l'air sur le séchage d'une goutte déposée sur une surface solide et sur la destruction microbienne.
2017
International audience; This study was carried out in order to develop experimental methodology using a camera to monitor the evolution of the surface of a liquid droplet deposited on a solid surface composed of polypropylene. The droplet was exposed to various ambient relative humidity conditions (11.3%, 43.2%, 68.9% and 75.5%). Two types of liquid were investigated: distilled water and water containing nutritive substances (salmon “juice”). At 11.3% relative humidity, it takes 40% longer to evaporate a water droplet (initial weight 0.36 g, volume 360 μL, radius 6.5 × 10−3 m) than a salmon “juice” droplet (3.66 h for distilled water, 2.83 h for salmon “juice”). In the case of the distilled…
The accuracy of calculated base excess in blood.
2002
Most equations used for calculation of the base excess (BE, mmol/l) in human blood are based on the fundamental equation derived by Siggaard-Andersen and called the Van Slyke equation: BE = Z x [[cHCO3-(P) - C7.4 HCO3-(P)] + beta x (pH -7.4)]. In simple approximation, where Z is a constant which depends only on total hemoglobin concentration (cHb, g/dl) in blood, three equations were tested: the ones proposed by Siggaard-Andersen (SA), the National Committee for Clinical Laboratory Standards (NCCLS) or Zander (ZA). They differ only slightly in the solubility factor for carbon dioxide (alphaCO2, mmol/l x mmHg) and in the apparent pK(pK'), but more significantly in the plasma bicarbonate conc…
Schmelz- und kristallisationserscheinungen bei makromolekularen substanzen. II. Haupt- und nachkristallisation aus der unterkühlten schmelze von 4,6-…
1960
Mit einer Dichtewaage werden Kristallisationsisothermen von 4,6-Polyurethan aufgenommen. Nach einer Beschreibung der Apparatur werden die Mesergebnisse im Temperaturbereich oberhalb 163°C und uber Kristallisationszeiten von zehn Minuten bis zu zwei Tagen mitgeteilt. Zur Deutung der Kristallisationsisothermen wird zwischen Haupt- und Nachkristallisation unterschieden. Die Hauptkristallisation wird als Wachstum morphologischer Strukturen verstanden und die Nachkristallisation als langsame Verbesserung des masigen mittleren Ordnungsgrades innerhalb dieser Strukturen. Die Hauptkristallisation wird im Sinne von AVRAMI, EVANS und MORGAN ausgewertet. Fur die systematischen Abweichungen von der AVR…
Reconsidering TOF calculation in the transformation of epoxides and CO2 into cyclic carbonates
2020
Abstract The combination of Lewis acids and Lewis bases, currently defined as catalysts and co-catalysts (or promoter) respectively, in the reaction between epoxides and CO2 to give cyclic carbonates, is discussed, starting from examples in which the Lewis base was used in larger amount with respect to the Lewis acid. In these cases, turnover frequency (TOF) values have been usually calculated taking into account solely the amount of the Lewis acid employed. The occurrence of two distinct reaction pathways, one catalysed by the sole Lewis base and the other one catalysed by the Lewis acid/Lewis base couple, in which the Lewis acid alone does not play a catalytic role, should bring researche…