The Use of Linear Regression Relations Derived from Model and Experimental Data for Retrieval of the Water Content of Clouds from Ground-Based Microwave Measurements

Abstract. This paper deals with the simulation of microbial degradation of organic matter in soil within the pore space at a microscopic scale. Pore space was analysed with micro-computed tomography and described using a sphere network coming from a geometrical modelling algorithm. The biological model was improved regarding previous work in order to include the transformation of dissolved organic compounds and diffusion processes. We tested our model using experimental results of a simple substrate decomposition experiment (fructose) within a simple medium (sand) in the presence of different bacterial strains. Separate incubations were carried out in microcosms using five different bacterial communities at two different water potentials of −10 and −100 cm of water. We calibrated the biological parameters by means of experimental data obtained at high water content, and we tested the model without changing any parameters at low water content. Same as for the experimental data, our simulation results showed that the decrease in water content caused a decrease of mineralization rate. The model was able to simulate the decrease of connectivity between substrate and microorganism due the decrease of water content.

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Drying kinetics of ‘babassu’ mesocarp

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n10p709-714 ◽

2017 ◽

Vol 21 (10) ◽

pp. 709-714 ◽

Cited By ~ 1

Author(s):

Jhonatas C. Rosa ◽

Andreza P. Mendonça ◽

Angélica dos S. Oliveira ◽

Sylviane B. Ribeiro ◽

Andréia do R. Batista ◽

...

Keyword(s):

Experimental Data ◽

Water Content ◽

Animal Feed ◽

Coefficient Of Determination ◽

Residual Distribution ◽

Solar Dryer ◽

Error Standard Deviation ◽

Forced Air ◽

Final Water Content ◽

Best Fit

ABSTRACT ‘Babassu’ mesocarp flour has been used by the pharmaceutical, human food and animal feed industries. However, there is lack of standardization in the production, as well as absence of information on the management of the product’s quality. Thus, the objective of this study was to dry the ‘babassu’ mesocarp in forced-air oven and solar dryer, adjust different mathematical models to the experimental data, as well as to quantify the levels of proteins and crude fiber of the produced flour. The criteria for the adjustment were the coefficient of determination, magnitude of the mean relative error, standard deviation of estimate and the residual distribution trend. Drying in the shortest time occurred in oven at 60 °C (370 min), leading to water content of 4.62%, while in the solar dryer the final water content was 8.07% in 6 days. The mathematical model Two Terms showed the best fit to the experimental data for oven drying and the Midilli model showed the best fit in solar dryer. There was an increase in protein content with the drying in solar dryer and oven at 40, 50 and 60 °C (1.36, 1.33, 1.15 and 1.37%, respectively) in relation to fresh mesocarp (0.88%). Drying in both oven and solar dryer promoted increase of protein in the flour.

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CURVAS DE SECAGEM E AVALIAÇÃO DA ATIVIDADE DE ÁGUA DA BANANA PASSA

Boletim do Centro de Pesquisa de Processamento de Alimentos ◽

10.5380/cep.v22i1.1184 ◽

2004 ◽

Vol 22 (1) ◽

Cited By ~ 3

Author(s):

MILTON CANO-CHAUCA ◽

AFONSO M. RAMOS ◽

PAULO C. STRINGHETA ◽

JOSÉ ANTONIO MARQUES ◽

POLLYANNA IBRAHIM SILVA

Keyword(s):

Experimental Data ◽

Linear Regression ◽

Moisture Content ◽

Water Activity ◽

Linear Regression Analysis ◽

Sorption Isotherms ◽

Exponential Model ◽

Drying Time ◽

Non Linear ◽

Drying Curves

Curvas de secagem de banana passa foram determinadas, utilizando-se três temperaturas do ar de secagem. Os resultados indicaram que para reduzir o teor de umidade do produto até 23,5% foram necessários tempos de secagem de 51, 36 e 30 horas paras as temperaturas de 50, 60 e 70ºC, respectivamente. O modelo exponencial U/Uo = exp(-kt) foi ajustado para os dados experimentais mediante análise de regressão não-linear, encontrandose alto coeficiente de regressão linear. Determinou-se a atividade de água do produto ao longo do processo de secagem para as três temperaturas testadas. Estudou-se a correlação entre a atividade de água e o teor de umidade do produto, determinando-se as isotermas de dessorção da banana passa a 25ºC. Observou-se que a atividade de água diminuiu em função do tempo de secagem e do teor de umidade para as três temperaturas de secagem. Os dados experimentais foram ajustados mediante regressão não-linear ao modelo polinomial e a seguinte equação foi obtida: U = -1844,93 + 7293,53Aa 9515,52Aa2 + 4157,196Aa3. O ajuste mostrou-se satisfatório (R2 > 0,90). DRYING CURVES AND WATER ACTIVITY EVALUATION OF THE BANANA-PASSES Abstract Banana drying curves were determined by utilizing three drying air temperatures. The results indicated that to reduce the moisture content of the product until 23.5% it were necessary drying times of 51, 36 and 30 hours for temperatures of 50, 60 and 70ºC, respectively. The exponential model U/Uo = exp(-kt) was adjusted for the experimental data by means of non linear regression analysis, and a high coefficient of linear regression was found. The water activity of the product was determined throughout the drying process for the three tested temperatures. The correlation between the water activity and moisture content of the product was studied, and the sorption isotherms were determined at 25º C. It was observed that the water activity decreased in function to the drying time and moisture content for the three drying temperatures. The experimental data were adjusted by means of non linear regression to the polynomial model and the following equation was obtained: U = - 1844.93 + 7293.53A a 9515.52 Aa 2 + 4157.196A a 3. The final adjust was satisfactory (R2 > 0.90).

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Effect of Common Impurities on the Phase Behavior of Carbon-Dioxide-Rich Systems: Minimizing the Risk of Hydrate Formation and Two-Phase Flow

SPE Journal ◽

10.2118/123778-pa ◽

2011 ◽

Vol 16 (04) ◽

pp. 921-930 ◽

Cited By ~ 31

Author(s):

Antonin Chapoy ◽

Rod Burgass ◽

Bahman Tohidi ◽

J. Michael Austell ◽

Charles Eickhoff

Keyword(s):

Experimental Data ◽

Carbon Dioxide ◽

Phase Behavior ◽

Water Content ◽

Thermodynamic Model ◽

Two Phase Flow ◽

Hydrate Formation ◽

Experimental Methodology ◽

Phase Flow ◽

Two Phase

Summary Carbon dioxide (CO2) produced by carbon-capture processes is generally not pure and can contain impurities such as N2, H2, CO, H2 S, and water. The presence of these impurities could lead to challenging flow-assurance issues. The presence of water may result in ice or gas-hydrate formation and cause blockage. Reducing the water content is commonly required to reduce the potential for corrosion, but, for an offshore pipeline system, it is also used as a means of preventing gas-hydrate problems; however, there is little information on the dehydration requirements. Furthermore, the gaseous CO2-rich stream is generally compressed to be transported as liquid or dense-phase in order to avoid two-phase flow and increase in the density of the system. The presence of impurities will also change the system's bubblepoint pressure, hence affecting the compression requirement. The aim of this study is to evaluate the risk of hydrate formation in a CO2-rich stream and to study the phase behavior of CO2 in the presence of common impurities. An experimental methodology was developed for measuring water content in a CO2-rich phase in equilibrium with hydrates. The water content in equilibrium with hydrates at simulated pipeline conditions (e.g., 4°C and up to 190 bar) as well as after simulated choke conditions (e.g., at -2°C and approximately 50 bar) was measured for pure CO2 and a mixture of 2 mol% H2 and 98 mol% CO2. Bubblepoint measurements were also taken for this binary mixture for temperatures ranging from -20 to 25°C. A thermodynamic approach was employed to model the phase equilibria. The experimental data available in the literature on gas solubility in water in binary systems were used in tuning the binary interaction parameters (BIPs). The thermodynamic model was used to predict the phase behavior and the hydrate-dissociation conditions of various CO2-rich streams in the presence of free water and various levels of dehydration (250 and 500 ppm). The results are in good agreement with the available experimental data. The developed experimental methodology and thermodynamic model could provide the necessary data in determining the required dehydration level for CO2-rich systems, as well as minimum pipeline pressure required to avoid two-phase flow, hydrates, and water condensation.

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EXPLORATION OF INTERCALATED KAOLINITE CLAY FOR THE UPTAKE OF BASIC DYE BY ADSORPTION − EQUILIBRIUM, KINETICS AND THERMODYNAMIC STUDIES

Journal of Chemical Society of Nigeria ◽

10.46602/jcsn.v46i1.590 ◽

2021 ◽

Vol 46 (1) ◽

Author(s):

C. E. Chigbundu ◽

K. O. Adebowale

Keyword(s):

Experimental Data ◽

Linear Regression ◽

Goodness Of Fit ◽

Linear Regression Analysis ◽

Dye Adsorption ◽

Batch Adsorption ◽

Sem Images ◽

Kaolinite Clay ◽

Non Linear ◽

The Impact

Dyes are complex and sensitive organic chemicals which exposes microbial populations, aquatic lives and other living organisms to its toxic effects if their presence in water bodies or industrial effluents are not properly handled. This work therefore, comparatively studied the adsorption efficiencies of natural raw kaolinite (NRK) clay adsorbent and dimethyl sulphoxide (DMSO) faciley intercalated kaolinite clay (DIK) adsorbent for batch adsorption of Basis Red 2 (BR2) dye. The impact of varying the contact time, temperature and other operating variables on adsorption was also considered. The two adsorbents were characterized using SEM images, FTIR and XRD patterns. Linear and non-linear regression analysis of different isotherm and kinetic models were used to describe the appropriate fits to the experimental data. Error analysis equations were also used to measure the goodness-of-fit. Langmuir isotherm model best described the adsorption as being monolayer on homogenous surfaces while Kinetic studies showed that Elovich model provides the best fit to experimental data. The adsorption capacities of NRK and DIK adsorbents for the uptake of BR2 were 16.30 mg/g and 32.81 mg/g, respectively (linear regression) and 19.30 mg/g and 30.81 mg/g, respectively (non-linear regression). The thermodynamic parameter, ∆G showed that BR2 dye adsorption onto the adsorbents were spontaneous. DIK adsorbent was twice efficient compared with NRK for the uptake of BR2 dye.

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Velocity of radio waves in glaciers as an indicator of their hydrothermal state, structure and regime

Journal of Glaciology ◽

10.3189/s0022143000016038 ◽

1993 ◽

Vol 39 (132) ◽

pp. 373-384 ◽

Cited By ~ 8

Author(s):

Yu. Ya. Macheret ◽

M. Yu. Moskalevsky ◽

E.V. Vasilenko

Keyword(s):

Experimental Data ◽

Radio Wave ◽

Water Content ◽

Low Frequency ◽

Wide Angle ◽

Radio Waves ◽

State Structure ◽

Mountain Ridge ◽

Wave Velocities

AbstractThe results of measurements of radio-wave velocities (RWV) by wide-angle reflection (WAR) methods in the temperate Abramov Glacier in the Alai Mountain Ridge and the “two-layered” sub-polar Fridtjovbreen and Hansbreen on Svalbard using a low-frequency (2–13 MHz) radar are considered and discussed. The experimental data obtained and the data from the literature show that the values of RWV could be a good indicator of the hydrothermal state of glaciers. As such, these data enable the identification of cold, temperate and transitional (two-layered) glaciers, and can be used for estimation of the water content in glaciers and changes in the hydrothermal state.

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A Soil Water Characteristic Curve Model Considering Urea Concentration

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.798-799.157 ◽

2013 ◽

Vol 798-799 ◽

pp. 157-160

Author(s):

You Le Wang ◽

Dong Fang Tian ◽

Gai Qing Dai ◽

Yao Ruan ◽

Lang Tian

Keyword(s):

Experimental Data ◽

Water Content ◽

Soil Water ◽

Exponential Function ◽

Characteristic Curve ◽

Urea Concentration ◽

Exponential Functions ◽

Valuable Data ◽

Soil Water Characteristic Curve ◽

Curve Model

A new soil water characteristic curve (SWCC) model considering urea concentration is presented in the paper. Two assumptions are used to obtain the model. One is SWCC which could be described by exponential functions in the experiments. Another is relationship between the parameters of exponential functions and urea concentration which is linear based on experimental data. In the research, we have carried out some experiments of SWCC and obtained some valuable data which could affect urea concentration. By using linear fitting, an exponential function between water content and suction and urea concentration is established.

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Study on Diffusion Processes of Water and Proton in PEM Using Molecular Dynamics Simulation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.704-705.1266 ◽

2011 ◽

Vol 704-705 ◽

pp. 1266-1272 ◽

Cited By ~ 3

Author(s):

Lei Chen ◽

Wen Quan Tao

Keyword(s):

Experimental Data ◽

Molecular Dynamics ◽

Water Content ◽

Diffusion Processes ◽

Calculation Model ◽

Dynamics Simulation ◽

Water Molecules ◽

Hydrogen Ions ◽

Model Cell ◽

Dynamics Calculation

In this paper a molecular dynamics calculation model for the Nafion 117 membrane is constructed by Materials Studio (MS) software platform to study its micro-structure and transport properties. Based on the calculation model, cell structures of different water content of Nafion 117 membrane are obtained and the predicted density values of simulated cell are in good agreement with experimental data. Meanwhile, the diffusion processes of water molecules and hydrogen ions in the membrane are studied, respectively. The predicted diffusion coefficients of both water molecules and hydrogen ions increase with the water content, which agrees well with the variation trend of experimental data. The reasons for the deviation between numerical results and the experiment values in literature are analyzed.

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Kinetic Model with Effect of Water Content for Enzyme-Catalyzed Citronellyl Laurate Esterification Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.284-287.423 ◽

2013 ◽

Vol 284-287 ◽

pp. 423-428 ◽

Cited By ~ 3

Author(s):

Siti Asyura Zulkeflee ◽

Suhairi Abd Sata ◽

Norashid Aziz

Keyword(s):

Experimental Data ◽

Kinetic Model ◽

Water Content ◽

Model Development ◽

Initial Water Content ◽

Initial Water ◽

Effect Of Water ◽

Proposed Model ◽

Optimal Value ◽

Influence Of Water

A kinetic model with effect of water content for enzyme-catalyzed citronellyl laurate was developed. These models incorporate the combined influences of established kinetics model with the function model on the effect of initial water content with kinetic parameters. The model development was carried out by performing a linear and nonlinear regression based on the behavior of the kinetic parameter profiles and validated with experimental data. Using the developed models, the influence of water content towards the enzyme-catalyzed initial rate of reaction was theoretically explained. It has been shown that the proposed model have good agreement between experimental data and intends to capture the effect of water content towards the conversion of ester. With this model, the optimal value of initial water content for this process could be estimated.

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