Moisture Migration and Safe Moisture Content for Storing Grain in Bins

2021 ◽  
pp. 383-422
Author(s):  
Fuji Jian ◽  
Digvir S. Jayas
Keyword(s):  
Moisture Content ◽  
Moisture Migration

scholarly journals Computer Aided Grain Aeration Management: an Antidote to Grain Deterioration in Metal Silo

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Bayode Julius Olorunfemi ◽  
Adefemi Adekunle ◽  
Samuel Adejuyigbe
Keyword(s):  
Moisture Content ◽  
Storage Temperature ◽  
Computer Software ◽  
Air Flow Rate ◽  
Stored Grain ◽  
Power Requirement ◽  
Moisture Migration ◽  
Aeration System ◽  
The One ◽  
Grain Temperature

Aeration is very important for good grain storage as it helps to maintain uniform grain temperatures, minimizes moisture migration, and prevents quality loss of stored grain. The temperature of grain stock was monitored with the aid of temperature sensors installed inside the silo bins. Each silo contained twenty sensors located on five probes at different sections of the silo bin. Grain was received to experimented metal silos at 300C. The parameters for grain before reception were 1% broken grain, 1% mould, 1%  foreign matters, 68- 75KG/HL weight and 12% moisture content. Grain temperature rose to 450C within three weeks of storage. Temperature readings were taken in the morning and at evening times. Aeration system (fans) was operated several times, each time for long hours (≥5hours) enough to equalize temperature throughout the entire grain mass. Aeration fans were used to rapidly cool grain to 250C and then held it between 25 - 410C for over a year. The power requirement increased as air flow rate and grain depth increased. Aeration fans were controlled automatically from the operating control room while dehumidifiers were installed on the aeration fans. Loss recorded at manually operated metal silo was compared with the one from the silo monitored with computer software developed. While aeration could be used to lower grain temperature, minor changes took place on the moisture content of the grain mass. Loss was reduced to < 1% as against 5%. Aeration can be better monitored economically with the use of a computer system.

scholarly journals Moisture Migration and Control of New Embankment for Reconstruction and Expansion Project in Southern China

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Junhui Zhang ◽  
Feng Li ◽  
Ling Zeng ◽  
Junhui Peng ◽  
Le Ding ◽  
...  
Keyword(s):  
Moisture Content ◽  
Southern China ◽  
Stable State ◽  
Element Model ◽  
Capillary Barrier ◽  
Moisture Migration ◽  
Volumetric Moisture Content ◽  
The Difference ◽  
Transient Seepage ◽  
And Control

In hot and humid regions of southern China, the volumetric moisture content of the embankment after opening to traffic for a period of time reaches a stable state, and it is higher than the design value. When it was widened, the humidity gradient and exchange were formed due to the difference in moisture content between the existing and new embankment. To reveal the moisture migration of the existing and new embankment and control the rise of volumetric moisture content in new embankment, six frequency domain reflectometry sensors were installed in existing and new embankment to monitor the volumetric moisture content. A finite element model for the embankment was established and verified with the measured data. And seven numerical analyses of transient seepage in the new embankment of the cushion, cover, and partition using capillary barrier by sand were simulated. The results show that the volumetric moisture contents of the new embankment in southern China gradually increase and eventually reach an equilibrium state. The increase in water comes from the slope, the foundation, and the existing embankment. Early in the first 1∼2 years, the water mainly comes from the foundation and the existing embankment. After that, as time goes by, the water comes mostly from the slope infiltration and gradually migrates to the foundation and the existing embankment. Finally, the volumetric moisture content and the water storage gradually reach equilibrium. The volumetric moisture content of the new embankment using capillary barrier by sand at the cushion, the cover, and the partition is maintained as the construction volumetric moisture content. This combination is a very effective method to control the humidity stability of the new embankment in southern China.

scholarly journals Experimental Study on Moisture Migration of Unsaturated Loess during the Freezing Process

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hui Zhang ◽  
Tiehang Wang ◽  
Enlong Liu ◽  
Mengling Hu
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Freezing Process ◽  
Dry Density ◽  
Freezing Front ◽  
Slow Cooling ◽  
Moisture Migration ◽  
Cooling Stage ◽  
Large Size ◽  
Unsaturated Loess

To reveal the water-heat transfer mechanism of unsaturated loess, the effects of soil dry density (1.30 g/cm3, 1.50 g/cm3, and 1.65 g/cm3), moisture content (13.3%, 16.2%, and 19.4%), cold end temperature (−7°C, −10°C, and −13°C), and freezing mode on moisture migration in unsaturated loess in this paper are studied through indoor tests of moisture migration under the freezing action of large-size unsaturated loess. The results show that the temperature change in soil samples in the freezing process can be divided into three stages: rapid cooling stage, slow cooling stage, and stable stage. The higher the dry density, the closer the freezing front is to the cold end, with the initial moisture content having little effect on the freezing front, while the temperature at the cold end has a significant effect on the location of the freezing front. The total amount of moisture migration decreases with the increase of dry density, increases with the increase of moisture content, and increases with the decrease of cold end temperature. The freezing mode directly affects the distribution of moisture content and total amount of moisture migration in the frozen area.

Numerical Simulation of the Water-Leachate Migration in Landfill

2011 ◽  
Vol 356-360 ◽  
pp. 1244-1247
Author(s):  
Shan Shan Su ◽  
Dan He ◽  
Li Liao
Keyword(s):  
Mathematical Model ◽  
Moisture Content ◽  
Water Distribution ◽  
Leachate Recirculation ◽  
Analysis Software ◽  
Element Analysis ◽  
Land Occupation ◽  
Moisture Migration ◽  
Landfill Sites ◽  
The Mathematical Model

Recirculation is considered as an dual effective way of processing the leachate and accelerating the stabilization of landfill in many treatment because of less land occupation, low investment and simple operation. Previous researches shows that recirculation can improve microenviorment of microbial anaerobic digestion by increasing the moisture content of landfill. The mathematical model of moisture migration in the landfill was established with Multi-physics finite element analysis software in this paper. The simulation result showed that 1) moisture content would decrease to 29% with no leachate recirculation condition 2) hydraulic loads and types of recirculation both had influences on water distribution in landfill sites with leachate recirculation.

Comparison between Glaser Method and Heat, Air and Moisture Transient Model for Moisture Migration in Building Envelopes

2019 ◽  
Vol 887 ◽  
pp. 385-392 ◽  
Author(s):  
Michele Libralato ◽  
Onorio Saro ◽  
Alessandra de Angelis ◽  
Simone Spinazzè
Keyword(s):  
Moisture Content ◽  
Material Properties ◽  
Moisture Transfer ◽  
Building Envelope ◽  
Assessment Procedure ◽  
Moisture Migration ◽  
Building Envelopes ◽  
Transient Model ◽  
Percentage Difference ◽  
Real Phenomenon

The Glaser method is an assessment procedure for the risk of moisture accumulation in building mono-dimensional structures, that could be used to evaluate mould risk and interstitial condensation risk.It is based on a simplified model that does not represent the real phenomenon and its limitations are well-known qualitatively.This work provides a comparison in terms of moisture content between the Glaser method and WUFI Pro, an advanced heat, air and moisture transfer prediction tool. First the influence of material properties is evaluated on four fictitious materials walls, then six different building envelope typologies for six weather files from Central and Southern Europe are modelled to evaluate the Glaser method results.The effects of the Glaser method simplifications are quantified in terms of moisture content percentage difference.

Research on Moisture Migration Experiment of Seasonally Frozen Zone Saline Soil

2014 ◽  
Vol 1065-1069 ◽  
pp. 168-171 ◽  
Author(s):  
Cen Cen Niu ◽  
Qing Wang ◽  
Wen Hua Wang ◽  
Yan Ge Zhang ◽  
Cong Ye
Keyword(s):  
Soil Moisture ◽  
Temperature Gradient ◽  
Moisture Content ◽  
Saline Soil ◽  
Soil Salinization ◽  
Soil Freezing ◽  
Freezing Process ◽  
Moisture Migration ◽  
Before And After ◽  
Migration Experiment

Saline soil is widely distributed in Jilin seasonally frozen zone. Many engineering hazards are associated closely related to moisture migration with freezing-thawing cycles. Soil salinization in the region is mainly due to migration of soil moisture and salinity caused by the temperature gradient with soil freezing process in this area. Adopt self-developed experiment instrument for measuring the freezing experiments of saline soil in Sanzhigou. Constract and analyze the transformation of moisture content and soluble salt before and after the freeze, and quantify the moisture and salinity substance migration in the freezing process.

Observations on moisture migration in frozen soils

1980 ◽  
Vol 17 (1) ◽  
pp. 54-60 ◽  
Author(s):  
D. W. Mageau ◽  
N. R. Morgenstern
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Open System ◽  
Open Systems ◽  
Frozen Soil ◽  
Thermal Gradients ◽  
Cold Side ◽  
Frozen Soils ◽  
Moisture Migration ◽  
Clayey Silt

Artificially prepared, previously frozen specimens of a clayey silt have been subjected to thermal gradients under both closed and open systems. Direct observation of moisture content changes reveals that substantial amounts of water are imbibed by frozen soil under an open system. If an ice lens exists within the system, the increase in water content on the cold side of the lens is small compared with that on the warm side. Heave rate is governed primarily by the frozen fringe of soil between the warmest ice lens and the frozen–unfrozen interface.

scholarly journals Soil moisture migration model based on Flux-concentration relation under steady rainfall

2021 ◽  
Author(s):  
Lei Zhang ◽  
Gang Liu ◽  
Ming-zhi Zhao
Keyword(s):  
Moisture Content ◽  
Arbitrary Point ◽  
Constant Concentration ◽  
Moisture Migration ◽  
Migration Model ◽  
Whole Process ◽  
Volumetric Moisture Content ◽  
Long Duration ◽  
Wide Range ◽  
Flux Concentration

Abstract Moisture content distribution in soil is of great importance for understanding rainfall-induced slope failure and roadbed settlement. This study aims to develop a moisture migration model that improves the quantification of moisture content at an arbitrary point of the soil at any time for the whole process of infiltration under steady rainfall. The model was derived from the Richards' equation using the Flux-concentration relation, which was validated by numerical solutions calculated by Hydrus-1D software to evaluate the performance of the model. Results showed good accuracy and high adaptability for the moisture migration simulation of a wide range of soil types, and is applicable for short-duration and long-duration steady rainfall. Moreover, it can also reflect the stratification phenomenon for soil profile wetting by infiltration. Our analysis indicates that the flux and surface volumetric moisture content together can bound the boundary conditions of rainfall infiltration, which presents a shift from constant-flux to constant-concentration during a long-duration steady rainfall. The migration rate of the wetting front in the later stage of infiltration positively correlates with rainfall intensity under the constant-flux condition, while it finally stabilizes at Ks/(θs − θi) under the constant-concentration condition (i.e., Ks-saturated hydraulic conductivity, θs-saturated volumetric moisture content, θi-initial volumetric moisture content). HIGHLIGHT Moisture migration model was derived to improve the quantification of moisture content at an arbitrary point of the soil at any time for the whole process of infiltration under steady rainfall, which shows good accuracy and high adaptability for the moisture migration simulation of a wide range of soil types, and is applicable for short-duration and long-duration steady rainfall.

Preparation and Standardization of a Stable AHF Plasma

1968 ◽  
Vol 19 (03/04) ◽  
pp. 423-429 ◽  
Author(s):  
G. M Thelin ◽  
Keyword(s):  
Moisture Content ◽  
Primary Standard ◽  
Healthy Male ◽  
Healthy Donors ◽  
Fresh Plasma

SummaryA stable, lyophilized AHF reference plasma has been prepared from pooled plasma from at least 50 normal healthy donors and standardized against a primary standard of fresh plasma from 20 healthy male donors aged 20 to 40. Average AHF potency of a typical lot is 98.8%, and moisture content is less than 0.5%. Under storage at -25° C, this AHF reference plasma is stable for at least 18 months. It has been used in several major coagulation laboratories, and has given consistently satisfactory and reproducible results in AHF assays.

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