Kinetics of Moisture-Induced Hydrolysis in Powder Blends Stored at and below the Deliquescence Relative Humidity: Investigation of Sucrose−Citric Acid Mixtures

2010 ◽  
Vol 58 (22) ◽  
pp. 11716-11724 ◽  
Author(s):  
Kaho Kwok ◽  
Lisa J. Mauer ◽  
Lynne S. Taylor
Keyword(s):  
Citric Acid ◽  
Relative Humidity ◽  
Powder Blends ◽  
Deliquescence Relative Humidity ◽  
Kinetics Of

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.

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 Сitric acid influence on electroreduction processes in low concentrated Cu(NO3)2 solutions

2017 ◽  
Vol 5 (2) ◽  
pp. 136-143
Author(s):  
Alla Pravda ◽  
Vasil Larin
Keyword(s):  
Citric Acid ◽  
Ph Value ◽  
Reduction Reaction ◽  
Copper Electrodeposition ◽  
Nitrate Ions ◽  
Low Concentrations ◽  
Physico Chemical ◽  
Influence Of Ph ◽  
Kinetics Of ◽  
Cathode Reduction

Physico-chemical regularities citric acid influence on processes of copper and nitrate-ions reduction in low concentrated nitrate solutions were established. An influence of pH value on inhibitor action of low concentrations of the additive according to cathode reduction reaction of nitrate-ions, on kinetics of copper electrodeposition, on structure of the precipitates obtained was shown. Polarization measurements show us changes of copper electrodeposition at introduction of citric acid in Cu(NO3)2 solution. By the methods of traced elements and extraction into aqueous phase the reversible inclusion complexes into electrolytic copper, was established that proves participation of complexes in cathode process.

Effect of Relative Humidity on the Corrosion Kinetics of HSLA and Low Carbon Steels

CORROSION ◽  
1984 ◽  
Vol 40 (10) ◽  
pp. 507-511 ◽  
Author(s):  
S. Tosto ◽  
G. Brusco
Keyword(s):  
Relative Humidity ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Corrosion Kinetics ◽  
Kinetics Of

scholarly journals Phytochemical Molecules from the Decarboxylation of Gomphrenins in Violet Gomphrena globosa L.—Floral Infusions from Functional Food

2020 ◽  
Vol 21 (22) ◽  
pp. 8834
Author(s):  
Natalia Drobnicka ◽  
Katarzyna Sutor ◽  
Agnieszka Kumorkiewicz-Jamro ◽  
Aneta Spórna-Kucab ◽  
Michał Antonik ◽  
...  
Keyword(s):  
Citric Acid ◽  
High Resolution Mass Spectrometry ◽  
Potential Health ◽  
Gomphrena Globosa ◽  
Brewing Process ◽  
Health Promoting ◽  
The Stability ◽  
Kinetics Of ◽  
Derivatives Of

Herein, the generation of decarboxylated derivatives of gomphrenin pigments exhibiting potential health-promoting properties and the kinetics of their extraction during tea brewing from the purple flowers of Gomphrena globosa L. in aqueous and aqueous citric acid solutions were investigated. Time-dependent concentration monitoring of natural gomphrenins and their tentative identification was carried out by LC-DAD-ESI-MS/MS. The high content of acylated gomphrenins and their principal decarboxylation products, 2-, 15-, 17-decarboxy-gomphrenins, along with minor levels of their bidecarboxylated derivatives, were reported in the infusions. The identification was supported by the determination of molecular formulas of the extracted pigments by liquid chromatography coupled with high-resolution mass spectrometry (LCMS-IT-TOF). The influence of plant matrix on gomphrenins’ stability and generation of their derivatives, including the extraction kinetics, was determined by studying the concentration profiles in the primary and diluted infusions. Isolated and purified acylated gomphrenins from the same plant material were used for the preliminary determination of their decarboxylated derivatives. The acylated gomphrenins were found to be more stable than nonacylated ones. Citric acid addition had a degradative influence on natural gomphrenins mainly during the longer tea brewing process (above 15 min); however, the presence of plant matrix significantly increased the stability for betacyanins’ identification.

Drying of Rough Rice in Oven: An Experimental Study

2015 ◽  
Vol 365 ◽  
pp. 77-81 ◽  
Author(s):  
J.V. Silva ◽  
E.M.A. Pereira ◽  
T.H.F. Andrade ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Experimental Study ◽  
Relative Humidity ◽  
Moisture Content ◽  
Product Quality ◽  
Air Temperature ◽  
Drying Rate ◽  
Rough Rice ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Mechanical Movement

This paper aims to present an experimental study of rough rice (BRSMG CONAI cultivar) drying by using a stationary method. The grain was dried in an oven with air mechanical movement under controlled conditions of velocity, temperature and relative humidity. In order to obtain balanced moisture content, the samples studied were kept at 40 and 70°C. Results of the drying and heating kinetics of the grain during the process are shown and analyzed. It was found that higher drying rate and lower time for drying as higher air temperature (70°C) is used. It can be concluded that the reduction of the moisture content of the grain, is considered very complex and, depending on the method and drying conditions, can substantially provokes breaking and cracks, which reduces final product quality.

scholarly journals   Copper release kinetics: Effect of two extractants and wheat (Triticum aestivum L.) rhizosphere

2012 ◽  
Vol 58 (No. 10) ◽  
pp. 471-476 ◽  
Author(s):  
H.R. Motaghian ◽  
A.R. Hosseinpur
Keyword(s):  
Citric Acid ◽  
Release Kinetics ◽  
Calcareous Soils ◽  
Triticum Aestivum L ◽  
First Order ◽  
Rhizosphere Soils ◽  
Copper Release ◽  
Successive Extraction ◽  
The Mean ◽  
Kinetics Of

The greenhouse experiment was performed to determine Cu release characteristics in the bulk and the rhizosphere of some calcareous soils using rhizobox. The kinetics of Cu release in the bulk and the rhizosphere soils were determined by successive extraction with diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA) and 10 mmol/L citric acid in a period of 1 to 504 h at 25 ± 1°C. The results of kinetics study showed that Cu extracted using DTPA-TEA in the rhizosphere soils was significantly (P < 0.01) lower than the bulk soils, while Cu extracted using citric acid in the rhizosphere soils was significantly (P < 0.01) higher than the bulk soils. The mean of released Cu after 504 h using DTPA-TEA were 8.59 and 7.46 mg/kg in the bulk and the rhizosphere soils, respectively. The mean release of Cu after 504 h using citric acid was 14.73 and 16.05 mg/kg in the bulk and the rhizosphere soils, respectively. Release kinetics of Cu in two extractants conformed fairly well to parabolic diffusion, power function, and first order equations. The results of correlation analysis illustrated that a significant correlation between Cu desorption after 504 h with citric acid and Cu concentration in wheat was found (r = 0.96 and r = 0.90 in the rhizosphere and the bulk soils, respectively, P < 0.01). Therefore, application of 10 mmol/L citric acid extractant would be recommended in the future study on the kinetics of release of Cu in calcareous soils.  

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