The moisture content-equilibrium relative humidity relationships of five varieties of Canadian wheat and of candle rapeseed at different temperatures

Pixton, S.W.; Henderson, Sylvia

doi:10.1016/0022-474x(81)90004-7

Cited by 21 publications

(5 citation statements)

References 3 publications

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“…EXPERIMENTAL DESORPTION EQUILIBRIUM DATA, produced by some of the authors or retrieved from the literature, were used to put together a representative data bank. Foods considered and the corresponding data sources were: almonds (Pixton and Henderson, 1979), apples (Nuncs, 1984), corn meal (Wolf et al, 1973;Labuza et al, 198.5), potatoes (Crapiste and Rotstein, 1986), rice (Wolf et al, 1973;Aguerre et al, 1983) and wheat (Pixton and Henderson, 1981). The data bank was used to evaluate the predictive quality of the correlations presented in this work as compared with other cor- relations.…”

Section: Methodsmentioning

confidence: 99%

A New Water Sorption Equilibrium Expression for Solid Foods based on Thermodynamic Considerations

Ratti

Crapiste

Rotstein³

1989

Journal of Food Science

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Solution thermodynamics was used to derive a new semitheoretical expression to represent sorptional equilibrium in food products having both temperature and water content as independent variables. A number of correlations have been studied and compared with the proposed equation using different requirements, necessary for their application in mathematical modeling and engineering calculations. These criteria were their capabilities to fit the experimental data, to evaluate the derivatives and the heat of sorption, and to predict the behavior at high moistures. On this basis, it was concluded that the present expression provided an accurate description of the sorptional behavior for many food systems.

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Section: Methodsmentioning

confidence: 99%

A New Water Sorption Equilibrium Expression for Solid Foods based on Thermodynamic Considerations

Ratti

Crapiste

Rotstein³

1989

Journal of Food Science

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“…Equilibrium RH was calculated using the Chung-Pfost equation (ASAE Standards, 2003) for two different grain moisture contents (10% and 12% w.b.). Chung-Pfost equation constants were determined for moisture adsorption data in Pixton and Henderson (1981) However, all moisture contents cited herein are w.b. The input temperature for the Chung-Pfost equation is T eff , which is not known in advance; thus, the iterative procedure in step 3 was used.…”

Section: Calculation Of the Effective Temperaturementioning

confidence: 99%

“…Durum Wheat Correction [a] Soft Wheat Correction [b] 15°C [a] Data source: Pixton and Henderson (1981). [b] Data source: ASAE Standards (2003).…”

Section: Humidity (%)mentioning

confidence: 99%

Climatic Humidity Effects on Controlled Summer Aeration in the Hard Red Winter Wheat Belt

Akdoğan¹,

Casada²

2006

Transactions of the ASABE

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Aeration is an inexpensive way to improve grain storage conditions, but it can be difficult to implement immediately after harvest in much of the hard red winter (HRW) wheat belt due to high ambient temperatures. High nighttime relative humidity worsens this problem because the heat of condensation released during adsorption reduces aeration cooling, but the magnitude of this humidity effect is not well documented. A procedure was developed to calculate effective temperature (T eff), which coupled dry-bulb temperature (T db), wet-bulb temperature (T wb), and grain moisture content to predict the actual final grain temperature after aeration. Hourly historical weather data were used to determine the available aeration hours below 24°C from mid-July through early August in Kansas, Oklahoma, Texas, eastern New Mexico, and eastern Colorado, along with nearby portions of surrounding states. Grain cooling was highly influenced by humidity. Actual available aeration hours averaged approximately 78% less during the periods studied compared to calculations based on T db alone. Airflow rates higher than 0.1 m 3 /min/t were found necessary to achieve sufficient grain cooling for the summer in Texas, Oklahoma, and southeastern Kansas.

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“…Using EMC relationships to measure MC in bulk grain, Pixton and Henderson (1981) found small varietal differences between EMC/ERH (equilibrium relative humidity) relationships for five Canadian wheats. Differences were only significant at low MC.…”

mentioning

confidence: 95%

Accuracy of Grain Moisture Content Prediction Using Temperature and Relative Humidity Sensors

Uddin¹,

Armstrong²,

Zhang³

2006

Applied Engineering in Agriculture

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Grain temperature and moisture content (MC) are considered to be principal factors for safe storage of grain. Continuous monitoring of temperatures within grain masses is relatively easy using thermocouples, but monitoring of MC is limited by availability of sensors. However, temperature and relative humidity (RH) can be used to predict grain MC based on equilibrium moisture content (EMC) equations such as the Modified Henderson, Chung-Pfost, or Oswin. These models are limited to quasi-static thermodynamic conditions but do provide a method to predict MC with commercial sensors. Error analysis was performed using EMC relationships for wheat to determine the error in grain MC prediction due to sensor error. EMC prediction errors were found to be +0.25% to +0.65% MC db between the RH ranges of 20% to 70% RH. At higher RH levels, prediction error increased substantially. Sensor error was set to +2% RH and +0.45C, for the error analysis. The sensor error was adopted from a commercial sensor that could be potentially used for a cabled monitoring system. At higher levels of sensor error (+3% RH, +0.45C and +4% RH, +0.45C), prediction error increased from +0.38% to +0.96% MC db and from +0.65% to +1.29% MC db , respectively, for the same RH range. Prediction error due to sensor error was found to be of the same magnitude as the standard errors of regression models developed for wheat. Measurements of sensor accuracy were also performed and accuracy was found to be within or better than rated manufacturer specifications for RH but temperature accuracy was less than rated accuracy.

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The moisture content-equilibrium relative humidity relationships of five varieties of Canadian wheat and of candle rapeseed at different temperatures

Cited by 21 publications

References 3 publications

A New Water Sorption Equilibrium Expression for Solid Foods based on Thermodynamic Considerations

A New Water Sorption Equilibrium Expression for Solid Foods based on Thermodynamic Considerations

Climatic Humidity Effects on Controlled Summer Aeration in the Hard Red Winter Wheat Belt

Accuracy of Grain Moisture Content Prediction Using Temperature and Relative Humidity Sensors

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