Proposed outflow method for the determination of the hydraulic conductivity of unsaturated porous materials

Soil Research ◽  
1966 ◽  
Vol 4 (2) ◽  
pp. 165 ◽  
Author(s):  
N Collis-George ◽  
MJ Rosenthal
Keyword(s):  
Hydraulic Conductivity ◽  
Moisture Content ◽  
Porous Materials ◽  
Curve Matching ◽  
Simple Criterion ◽  
High Moisture ◽  
Moisture Contents ◽  
Membrane Impedance ◽  
Content Range

Examination of the existing outflow methods reveals that none of the available methods consider membrane impedance without simultaneously involving subjective curve matching. A method is proposed that meets both these requirements and also allows determination of hydraulic conductivity after only small changes of moisture content; the results are therefore easier to interpret. A comparison is made between results obtained from the proposed method and from published outflow methods, as well as from the horizontal infiltration and 'air-pressure' methods. The results obtained exhibit hysteresis for both diffusivity and hydraulic conductivity as functions of moisture content. An hypothesis explaining occurrence of hysteresis in hydraulic conductivity at low moisture contents is presented. It is concluded that the proposed outflow method is experimentally suited to the dry end of the moisture content range, because of the restriction imposed at high moisture contents by the membrane impedance being large relative to the sample impedance. A simple criterion to determine the range of validity of the method is proposed.

Nutrient composition of pastoralist's raw milk of different breeds of cattle in Adamawa and Taraba states, Northeastern Nigeria

2020 ◽  
Vol 47 (2) ◽  
pp. 217-223
Author(s):  
Z. Adamu ◽  
M. B. Ardo ◽  
Y. H. Aliyara
Keyword(s):  
Moisture Content ◽  
Local Governments ◽  
Management Practices ◽  
Raw Milk ◽  
Fat Content ◽  
Ash Content ◽  
Milk Samples ◽  
Moisture Contents ◽  
Significant Difference ◽  
Content Range

This study was carried out to determine the proximate composition of raw milk produced in pastoral settlements. Six hundred pastoralists' raw milk samples were collected from 20 local governments in Adamawa and Taraba states, Nigeria. Milk samples were collected from White Fulani (WF), Red Bororo (RB) and Sokoto Gudali (SG) breeds of cattle and were analyzed for protein, fat, ash and moisture contents. The protein content ranged between 3.62±0.38% -3.95±0.11% in WF, 3.29±0.8% - 3.94±0.10% in RB and 3.31±0.27%- 3.95±0.09% in SG in Adamawa and Taraba states. The fat content ranged between 3.55±0.47% - 3.99±0.03% in WF, 3.98±0.04% - 3.98±0.06% in RB and 3.32±0.20% - 3.45±0.27% in SG. The ash content recorded was between 0.40±0.06% -0.41±0.04% in WF, 0.40±0.06% - 0.43±0.07% in RB and0.39±0.06% - 0.41±0.08% in SG, and the moisture content in Adamawa and Taraba states were between 83.52±2.07% - 84.00±0.57% in WF, 82.28±1.05% - 83.73±0.63% in RB and 82.90±1.48% - 83.56±1.35%in SG. The study from the two states revealed protein value between 3.29± 0.8% - 3.95±0.11%, fat content range of3.32±0.20% - 3.99±0.03%, ash content of between 0.39± 0.06% - 0.43±0.07% and moisture content that ranged between 82.28± 1.05% - 84.00±0.57%. Constituents of milkfrom Taraba state were higher in values than those from Adamawa sate. The statistical analysis of the results at95% confidence level showed significant difference among breeds and states. In comparison, the three breeds that resided in Adamawa state had least values, which could be attributed to herd management practices. This study showed that all the three pastoralists' breeds indicated desirable components in their milk Cross breeding with higher breeds and provision of quality feed and water may lead to better yield in all the breeds in this study.

The determination of moisture in wheat and flour: A study of “moisture testing” in water ovens and electric ovens

1928 ◽  
Vol 18 (4) ◽  
pp. 649-670 ◽  
Author(s):  
E. A. Fisher ◽  
C. R. Jones
Keyword(s):  
Moisture Content ◽  
Wheat Flour ◽  
Agricultural Products ◽  
Moisture Contents ◽  
Heated Air ◽  
Reliable Procedure ◽  
Comparative Results ◽  
Considerable Range ◽  
True Values

The nature of the problem of moisture determinations on materials such as flour and wheat is discussed shortly. It is not possible to obtain by over drying true values for moisture contents. What is sought is a convenient and reliable procedure giving strictly reproducible figures possessing full comparative value. This was the object of the work described, the main lines of which should be applicable to agricultural products of many kinds.The electrically heated air oven is the most convenient and suitable instrument for routine purposes, and comparative results show that it allows of far more reliable work than the water oven.Determinations of apparent moisture content have been made on a sample of wheat flour in electric ovens at temperatures ranging from 90° to 140° C. and for periods of heating ranging from 1 to 14 hours, the technique and number of determinations (about 400 altogether) being such that the results were suitable for statistical examination. The probable errors of single determinations were calculated for several sets of results and did not exceed 0·05 per cent. The results given show that at several temperatures, variation in time of heating over a considerable range does not affect the values obtained. In the light of these results it was possible to assess the reliability, as well as the convenience, of various possible procedures.

scholarly journals Breakage Susceptibility of Wheat and Triticale Seeds Related to Moisture Content and Impact Energy

2012 ◽  
Vol 45 (3) ◽  
pp. 5-13
Author(s):  
F. Shahbazi ◽  
A Dowlatshah ◽  
S. Valizadeh
Keyword(s):  
Moisture Content ◽  
Impact Energy ◽  
Mechanical Damage ◽  
Moisture Contents ◽  
Seed Damage ◽  
Significant Difference ◽  
Impact Energies ◽  
The Impact ◽  
Content Range ◽  
Wheat Seeds

Abstract Mechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quantity of seeds. Seed damage result in lower grain value, storability problem, and reduced seed germination and seedling vigor and subsequent yield of crops. The objective of this research was to determine the effects of moisture content and impact energy on the breakage susceptibility of wheat and triticale seeds. The experiments were conducted at five moisture contents of 7.5, 12, 17, 22 and 27% w.b. and at the impact energies of 0.05 and 0.1 J. The percentage of breakage of both wheat and triticale seeds increased as impact energy increased. The analysis of variance showed that there was a significant difference between breakage susceptibility of wheat and triticale seeds at the 1% probability level. Triticale seeds had more breakage than wheat seeds. For both wheat and triticale seeds as the moisture content of the seeds increased, the amount of the percentage breakage of seeds decreased as a polynomial. The average values of percentage breakage of wheat seeds decreased from 43.81 to 19.88% as the moisture content increased from 7.5 to 27%. Over this same moisture content range the percentage breakage of triticale seeds varied from 81.34 to 37.77%. Below the moisture contents of 17% for the wheat and 22% for the triticale the percentage breakage of seeds increased dramatically.

scholarly journals STORAGE OF TRUE POTATO SEED

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 577c-577
Author(s):  
Noël Pallais
Keyword(s):  
Moisture Content ◽  
Seed Dormancy ◽  
Potato Seed ◽  
True Potato Seed ◽  
Seedling Vigor ◽  
High Moisture ◽  
Seed Moisture Content ◽  
Moisture Contents ◽  
Seed Moisture

True potato seed of Atzimba × 104.12LB (intermediate dormancy) was dried to seed moisture contents ranging from 3.85 to 12.5% (dry wt basis) and was stored for 2 years at 30, 15 and 5°C. Seed was tested for various germination and seedling vigor criteria at 4 month intervals. Seed dormancy and viability were better preserved at seed moisture levels below 7% and as temperature decreased. High moisture (>9%) was lethal to seed stored at 30°C. TPS should be stored at <5% seed moisture content. Under this condition seed dormancy in the genotype studied was lost after about 12 months at 30°C.

scholarly journals Determination of soil moisture by neutron scattering.

1956 ◽  
Vol 4 (1) ◽  
pp. 111-113
Author(s):  
P. Mortier ◽  
M. De Boodt
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Neutron Scattering ◽  
Counting Rate ◽  
Clay Soils ◽  
Moisture Contents ◽  
Rate Versus ◽  
Improved Accuracy ◽  
Slow Neutrons

Curves of counting rate versus moisture content are presented, for sand, loam and clay soils, using (i) a 1000 me Ra-Be source surrounded by a small rigid indium cylinder acting as detector of slow neutrons and (ii) two co-axial Cd cylinders protecting the indium detector. Improved accuracy in the region of low moisture contents was obtained with (ii). (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Effect of tillage practices at different levels of soil moisture on some soil properties and maize productivity

2020 ◽  
Vol 5 (01) ◽  
pp. 1-15
Author(s):  
Abdel-Aal M. H.
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Moisture Content ◽  
Soil Properties ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Conventional Tillage ◽  
No Tillage ◽  
Tillage Practices ◽  
Moisture Contents

A field experiment was carried out during the early summer seasons of 2018, at Agricultural Research Centre (ARC) Giza, Egypt. This study aims to examine the effect of three tillage treatments under three different moisture contents on some soil properties and on maize crop production. The experiments included three moisture contents of (MC1, 27.2 %), (MC2, 15.4 %) and (MC3, 7.2 %); as well as three tillage treatments, no-tillage control (NT), minimum tillage (MT) and conventional tillage (CT). The experimental was laid out in split-split plot design with four replications. The results showed that, there was significant effect of tillage at different moisture levels on soil physical and chemical properties. It was also indicated that the effect of tillage practices was significantly on soil bulk density, total porosity, hydraulic conductivity and moisture constants, where the conventional tillage at soil moisture level 15.4% (MC2) helped in improving soil bulk density, hydraulic conductivity and total porosity. Soil organic C, cations exchange capacity CEC, available N, P and K were improved in the soil surface layer of NT and decreased with depth. Clod mean weight diameter of soil was improved with 15.4-% of soil moisture content regardless of tillage depth and enhanced root proliferation by increasing density roots compared with minimum and no tillage in maize plant. The grain yields of maize were improving more under conventional tillage at moisture content 15.4% compared with other treatments. It was found that plant height and roots value increased by using conventional tillage compared with other tillage treatments.

Studies on the use of mutagenic agents in plant breeding. II. The effects of dose and seed moisture content on mutation production in Lupinus angustifolius by X-Rays

1965 ◽  
Vol 16 (3) ◽  
pp. 301 ◽  
Author(s):  
JS Gladstones ◽  
CM Francis
Keyword(s):  
Moisture Content ◽  
Mutation Rate ◽  
Lupinus Angustifolius ◽  
Mutation Rates ◽  
X Rays ◽  
High Moisture ◽  
Seed Moisture Content ◽  
Moisture Contents ◽  
Seed Moisture ◽  
Wet Weight

Seeds of Lupinus angustifolius were given X-ray doses of 2.5, 5, 10, and 20 kr at each of 12 moisture contents ranging from 6.1 to 18.1 % (wet weight basis). Various measures of injury were recorded in the X1 generation, and the types and rates of mutations in the X2. At moisture contents below 16%, total mutation rates were closely correlated with X1 injury. Injury and mutation rate decreased with increasing moisture up to 11–12% moisture, and thereafter remained at a constant minimum up to 16%. Between 16 and 18% moisture there was again an increase in X1 injury, but not in mutation rate. Between 6 and 12 % moisture, a linear relationship was found between moisture content and the logarithm of the dose required to cause a given level of injury or mutation. A possible mechanism for such a pattern of protection is discussed. Lethal mutations increased as a proportion of all mutations as dose and mutation rate increased. There were also proportionately more lethals at high moisture contents than in lower moisture treatments giving the same mutation rates. It is concluded that lethal and seedling chlorophyll-deficient mutations could be misleading when used as indicators of total and viable mutation rates, and that, contrary to the conclusions of some previous authors, no advantage is likely to be gained in practical breeding work from irradiating at high seed moisture contents.

scholarly journals Hydraulic Properties of Baled Switchgrass and Miscanthus

2018 ◽  
Vol 61 (3) ◽  
pp. 1145-1155
Author(s):  
Drew F. Schiavone ◽  
Michael D. Montross
Keyword(s):  
Hydraulic Conductivity ◽  
Moisture Content ◽  
Hydraulic Properties ◽  
Biomass Conversion ◽  
Initial Moisture Content ◽  
Variable Density ◽  
High Solids ◽  
Moisture Contents ◽  
Percentage Points ◽  
Infiltration Tests

Abstract. This study characterized the hydraulic properties within baled switchgrass ( L., variety Alamo) and miscanthus (×), thereby enabling a better understanding of moisture changes in baled biomass during on-farm storage and/or high-solids bioconversion. Fully saturated bales were drained by gravity, and the moisture content was determined over 60 h. The average initial moisture content ranged between 55.9% and 71.9% (w.b.) for switchgrass and between 60.5% and 73.9% (w.b.) for miscanthus bales depending on the dry bale density. As the bale drained by gravity, rapid leaching of water was observed within the first 0.1 h, with a reduction in moisture content of 7.3 and 7.0 percentage points (w.b.) for switchgrass and miscanthus, respectively. Leaching then continued at a steady rate until termination of the experiment, with further reductions of 4.3 and 4.4 percentage points (w.b.) for switchgrass and miscanthus, respectively. Final moisture contents after 60 h ranged from 45.8% to 58.3% for switchgrass and from 48.7% to 60% for miscanthus, with the higher moisture contents observed in the lowest density bales. Hydraulic conductivity tests were carried out with bales of switchgrass and miscanthus with a constant head system. The average saturated hydraulic conductivity ranged between 0.103 and 0.616 cm s-1 for baled switchgrass and between 0.219 and 0.658 cm s-1 for baled miscanthus depending on the bale density. The matric suction of baled switchgrass was also assessed at variable densities and moisture contents using the contact filter paper method. The van Genuchten parameters were found to range between 0.235 and 0.270 m-1 for a and between 5.415 and 10.345 for n, depending on the density. Infiltration tests were also carried out on baled switchgrass at variable densities and moisture contents using a minidisk infiltrometer. The curve-fitting parameters of Philip’s two-term equation ranged between 0.086 × 10-6 and 0.779 × 10-6 cm s-1 for C1 and between 0.200 and 5.805 × 10-6 cm s-1/2 for C2, depending on the density and moisture content. The unsaturated hydraulic conductivity ranged between 0.019 and 0.272 cm s-1, while sorptivity ranged between 0.048 and 2.103 cm s-1/2, depending on the density and moisture content. These results provide data required to evaluate water flow through variable-density rectangular bales and indicate a potential to remove end-products of biomass conversion from baled biomass. Keywords: Biomass, Bioprocessing, Flushing, High solids.

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