Sorption Kinetics of Toluene in Humin under Two Different Levels of Relative Humidity

2002 ◽  
Vol 31 (3) ◽  
pp. 970-978 ◽  
Author(s):  
Yang-hsin Shih ◽  
Shian-chee Wu
Keyword(s):  
Relative Humidity ◽  
Sorption Kinetics ◽  
Kinetics Of ◽  
Different Levels

scholarly journals On the mechanism of water vapour sorption from unsaturated atmospheres by ticks

1997 ◽  
Vol 200 (10) ◽  
pp. 1491-1498 ◽  
Author(s):  
K Gaede ◽  
W Knülle
Keyword(s):  
Relative Humidity ◽  
Water Vapour ◽  
Adsorbed Water ◽  
Salivary Secretion ◽  
Sorption Kinetics ◽  
Measurement Range ◽  
Water Vapour Sorption ◽  
Critical Equilibrium ◽  
Kinetics Of ◽  
Water Vapour Uptake

The nascent salivary secretion of 41 partly dehydrated and unfed adult female Amblyomma variegatum, 5­8 months post-ecdysis, during water vapour uptake at 93.5 % relative humidity and 20 °C, had an osmolality of between 298.6 and 769.7 mosmol kg-1 (mean ± s.d. 470.3±85.8 mosmol kg-1). This range would allow water vapour uptake at relative humidities of approximately 98­99 %, but it would not suffice for lower relative humidities down to 80­85 %, the critical equilibrium humidity of A. variegatum. At this relative humidity (85 %), an osmolality of 9796 mosmol kg-1 is required for water vapour uptake. It is proposed that hydrophilic cuticle in the hypostome could play a role in water condensation and that the slightly hyperosmotic secretion of the agranular alveoli of the salivary glands might alter the water affinity at the adsorbing cuticle surface and release the adsorbed water. The water-enriched secretion would then be drawn into the mouth by the powerful suction of the pharynx. This hypothetical hydrophilic cuticle component of water vapour uptake in A. variegatum merits closer investigation. The sorption kinetics of A. variegatum support an additional 'osmotic' component of water vapour uptake at humidities near saturation. A nanolitre osmometer particularly suited to sample volumes smaller than 5 nl was developed. This device does not require the transfer of fluid after collection, and its measurement range is extended beyond the 5 osmol kg-1 that can be measured using commercial apparatus.

Modeling of sorption kinetics of U(VI) micro-quantities nanostructured materials with anatase mesoporous structures

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Veniamin Zheleznov ◽  
Aleksey Golikov ◽  
Tatiana Sokolnitskaya ◽  
Sergey Ivannikov
Keyword(s):  
Nanostructured Materials ◽  
Sorption Kinetics ◽  
Uranyl Ion ◽  
Competitive Sorption ◽  
Hydroxyl Groups ◽  
Complex Ions ◽  
The Stability ◽  
Kinetics Of ◽  
Mesoporous Structures ◽  
Ionic Forms

Abstract The sorption kinetics of uranyl ions micro-quantities from fluoride solutions by nanostructured materials with anatase mesoporous structures has been studied. Using the model of competitive sorption of ions and positively charged complexes of uranyl ion on deprotonated hydroxyl groups of an anatase, kinetic curves of changes in the ratio of ionic forms of uranium in solution were calculated. Modeling was carried out under the assumption of a two-stage mechanism of uranium complex ions sorption. The modeling considered the influence of the uranyl ion carbonate complexes formation. The shift in equilibrium among ionic forms of uranyl correlates with the stability of the complexes in solution.

Oxygen Absorption Kinetics of Sheets and Films Containing a Commercial Iron-based Oxygen Scavenger

2009 ◽  
Vol 15 (2) ◽  
pp. 159-168 ◽  
Author(s):  
M.J. Galotto ◽  
S.A. Anfossi ◽  
A. Guarda
Keyword(s):  
Relative Humidity ◽  
Kinetic Parameters ◽  
Oxygen Absorption ◽  
Absorption Kinetics ◽  
Oxygen Scavenger ◽  
Arrhenius Behavior ◽  
Oxygen Scavengers ◽  
Iron Based ◽  
Empirical Growth ◽  
Kinetics Of

Absorption kinetics of three different forms of the same iron-based oxygen scavenger were studied. Oxygen scavengers were used as pellet, sheet, and film materials. Two scavenger concentrations were used for sheet and film forms. Scavenger samples were analyzed at 75 or 100% relative humidities and stored at 5, 15, and 25°C. Oxygen concentration in the headspace was measured as a function of time. Absorption kinetics was best described by the Chapman-Richards empirical growth model rather than by a first-order reaction. Arrhenius behavior was observed for variations in the final absorption rate with temperature. Absorption capacities, final absorption rates, and activation energies were evaluated and discussed. Scavenger concentration, relative humidity, and temperature effects on kinetic parameters were studied for each experimental condition. Temperature was the most important factor that affected kinetic parameters. At the relative humidity levels studied, any important effect on kinetic parameters was not observed, except on absorption capacities.

The effect of post-harvest storage on the weight of Golden Delicious apples

2021 ◽  
Vol 13 (2) ◽  
pp. 7-11
Author(s):  
Salma Kassebi ◽  
Péter Korzenszky
Keyword(s):  
Relative Humidity ◽  
Storage Temperature ◽  
Extended Period ◽  
Food Products ◽  
Significant Loss ◽  
Loss Of Weight ◽  
Ambient Storage ◽  
Golden Delicious ◽  
Different Levels ◽  
Careful Management

Apples, like other fruits, are exposed to stress during their growth and development in the field, also during harvest and the postharvest environment (processing, storage, and transportation). The refrigeration system allows for bulk handling of food products from harvest to market, ensuring that food products are maintained in their freshness and integrity for an extended period through careful management of storage temperature and humidity. This study investigated the effects of storage on the weight loss of apples (Golden Delicious fruits harvested at maturity), under refrigerated conditions at a temperature of 5±0.5°C and relative humidity of 82% and under ambient storage at a temperature of 25 ±0.5 °C and relative humidity of 60 %, over 3 months. The findings revealed that the two groups of apples experienced weight reduction at different levels. Apples placed at cold storage presented a loss of weight between 3.31g and 4.49g; however, apples stored at ambient temperature showed a significant loss of weight between 21.9g and 31.76g.

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