scholarly journals RELIABILITY OF RATED ESTIMATE FOR THE GENERALIZED NON-LINEAR VOLUMETRIC MOISTURE CONTENT AND SUCTION PRESSURE RECOMMENDED FOR SEDIMENTARY GROUND

2010 ◽  
Vol 0 (2) ◽  
pp. 105-114
Author(s):  
A. B. Sitnikov ◽  
V. A. Sitnikova
Keyword(s):  
Moisture Content ◽  
Suction Pressure ◽  
Volumetric Moisture Content ◽  
Non Linear

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

2004 ◽  
Vol 22 (1) ◽  
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).

A Non-Linear Model for Sensing Moisture Content in Transformers at Reduced Time

2019 ◽  
Vol 19 (12) ◽  
pp. 4639-4646 ◽  
Author(s):  
S. Chatterjee ◽  
A. K. Pradhan ◽  
S. Dalai ◽  
S. Chakravorti ◽  
B. Chatterjee
Keyword(s):  
Moisture Content ◽  
Linear Model ◽  
Non Linear ◽  
Reduced Time

scholarly journals Influence of variation in the volumetric moisture content of the substrate on irrigation efficiency in early potato varieties

PLoS ONE ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. e0231831 ◽  
Author(s):  
Anna Jama-Rodzeńska ◽  
Amadeusz Walczak ◽  
Katarzyna Adamczewska-Sowińska ◽  
Grzegorz Janik ◽  
Izabela Kłosowicz ◽  
...  
Keyword(s):  
Moisture Content ◽  
Irrigation Efficiency ◽  
Early Potato ◽  
Potato Varieties ◽  
Volumetric Moisture Content

Field storage conditions for cattle manure to limit nitrogen losses and optimise fertiliser value

2017 ◽  
Vol 57 (10) ◽  
pp. 2148 ◽  
Author(s):  
J. Viaene ◽  
V. Nelissen ◽  
B. Vandecasteele ◽  
K. Willekens ◽  
S. De Neve ◽  
...  
Keyword(s):  
Moisture Content ◽  
Farmyard Manure ◽  
Soil Layer ◽  
Storage Conditions ◽  
N Leaching ◽  
Bulking Agents ◽  
N Losses ◽  
Mineral N ◽  
Volumetric Moisture Content ◽  
Soil Temperatures

Storage and application of cattle farmyard manure (CFM) can cause considerable environmental problems through nutrient losses to soil, water and air, if not properly handled. We investigated different storage conditions of CFM at field scale to reduce nitrogen (N) losses to the soil, meanwhile optimising the agronomical quality of the CFM. The treatments differed in terms of storage method (stockpiling, extensive composting or co-composting with bulking agents) and coverage (no cover, plastic or geotextile cover). Over the different treatments, the ammonium-N concentrations under the piles in the 0–90 cm soil layer amounted to a maximum of 4.2% of the initial manure N content. We were able to assess the relative importance of each of the two processes resulting in a higher mineral N concentration under the piles, i.e. direct leaching from the CFM to the soil on the one hand, and a smaller indirect effect of elevated soil temperatures (up to 37°C) under the piles resulting in higher N mineralisation in the top soil on the other hand. NH4+-N was the most important component of mineral N under all heaps due to limited oxygen diffusion to the soil. N leaching and end-product quality were affected by a combination of treatment option (i.e. storage and cover) and initial manure characteristics. When CFM was characterised by a low volumetric moisture content and high C : N ratio, so in case of straw-rich CFM or CFM with added bulking agents, composting led to the least N leaching and most stable end product. When CFM was characterised by a high volumetric moisture content and low C : N ratio, stockpiling and covering (plastic or geotextile) resulted in lower N leaching to the soil. Stockpiling and covering the CFM with a geotextile resulted in a more stable end product than did covering with a plastic.

Impacts of forage grazing and cultivation on near-surface relative compaction

1999 ◽  
Vol 79 (3) ◽  
pp. 465-471 ◽  
Author(s):  
D. A. Twerdoff ◽  
D. S. Chanasyk ◽  
E. Mapfumo ◽  
M. A. Naeth ◽  
V. S. Baron
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Grazing Intensity ◽  
Depth Interval ◽  
Curvilinear Relationship ◽  
Research Station ◽  
Hordeum Vulgare L ◽  
Near Surface ◽  
Volumetric Moisture Content ◽  
Relative Compaction

The study was conducted at the Lacombe Research Station, Alberta, on an Orthic Black Chernozem of loam to silt loam texture to investigate grazing impacts and cultivation on near-surface soil compaction. Four forages, smooth bromegrass (Bromus inermis Leyss 'Carlton'), meadow bromegrass (Bromus riparius Rhem 'Paddock'), a mixture of triticale (X Triticosecale Wittmack 'Pika') and barley (Hordeum vulgare L. AC Lacombe), and triticale were used for the study. Each forage species was subjected to heavy, medium and light intensity grazing. Measurements of bulk density and volumetric moisture content for the 0- to 10-cm depth interval were conducted using a surface moisture-density probe between spring 1994 and fall 1996. Relative compaction was calculated as the actual bulk density expressed as a percentage of the Proctor maximum density. Relative compaction values for all treatments and that for the benchmark were less than 90%, which is considered critical for limiting plant growth. Cultivation reduced bulk density under annual forages by only 3% and lowered it under heavy grazed annual treatments most. Regression analysis conducted on the dependence of bulk density to cumulative cow-days indicated a curvilinear relationship. Bulk density increased more rapidly with increasing cumulative cow-days for annuals compared to perennials. From a management perspective, adopting intensive rotational grazing systems for perennial and annual forages may not cause any serious surface compaction problems for soils in this area. Key words: Annuals, bulk density, cow-days, grazing intensity, perennials, volumetric moisture content

The Spatial Simulation of Soil Volumetric Moisture Content in Different Growth Stages of Peanut

2012 ◽  
Vol 10 (1) ◽  
pp. 155-161
Author(s):  
Yujian Yang ◽  
Shubo Wan ◽  
Jianhua Zhu ◽  
Zhicheng Wang
Keyword(s):  
Moisture Content ◽  
Growth Stages ◽  
Spatial Simulation ◽  
Volumetric Moisture Content ◽  
Different Growth Stages

Use of Time Domain Reflectometry to Estimate Moisture and Density of Unbound Road Materials: Laboratory Calibration and Field Investigation

2017 ◽  
Vol 2655 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Habibullah Bhuyan ◽  
Alexander Scheuermann ◽  
Didier Bodin ◽  
Rolf Becker
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Time Domain ◽  
Voltage Drop ◽  
Base Material ◽  
Field Investigation ◽  
Time Domain Reflectometry ◽  
Pavement Performance ◽  
Dry Density ◽  
Volumetric Moisture Content

Soil moisture content and dry density of unbound granular pavement materials are important properties for compaction control that influence pavement performance under cyclic loading. Under these loading conditions, increasing moisture content can accelerate significant changes in density. Time domain reflectometry (TDR) is a method for measuring the moisture content and density of soils with rod probe sensors. This paper introduces new calibration functions for TDR measurements using these rod probe sensors embedded in the soil. TDR measurements were taken in the laboratory for a typical road base material at two basically different conditions: at constant moisture content with different dry densities and at constant dry density with different moisture contents. In this study, a relationship was developed between the voltage drop occurring for the passage of an electromagnetic wave through the soil and the bulk density. The permittivity of the soil sample obtained from the travel time of TDR signals was used to calculate the volumetric moisture content. Finally, the gravimetric moisture content was obtained from the volumetric moisture content and bulk density relationship. For the validation of the calibration functions, rod probe sensors were installed in a road to obtain in situ moisture content and density under field conditions. Laboratory results indicate that the calibration functions are independent of moisture and density, and the field test shows the applicability of the method. The newly developed calibration functions allow for the monitoring of the long-term pavement performance, leading to a better understanding of the time-dependent evolution of, for example, rutting of roads.

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