Physical Properties Effect on Stress-Strain Behavior of Wheat En Masse—Part 11. Constitutive Elastoplastic Parameter Dependence on Initial Bulk Density and Moisture Content

1989 ◽  
Vol 32 (1) ◽  
pp. 0203-0209 ◽  
Author(s):  
Q. Zhang ◽  
Y. Li ◽  
V. M. Puri ◽  
H. B. Manbeck
2016 ◽  
Vol 824 ◽  
pp. 100-107 ◽  
Author(s):  
Alena Struhárová

Bulk density and moisture content are factors that significantly affect the physical properties of autoclaved aerated concrete (AAC) including thermal conductivity and other thermo-technical characteristics. This article shows the results of measurements of compressive strength, capillary absorption, water absorption and porosity of AAC (ash on fluidized fly ash) at different bulk density and also the results of thermal conductivity of AAC at different bulk density and variable moisture content of the material. The thermo-technical properties were measured using the Isomet 2104, a portable measuring device. Acquired results demonstrate dependence of physical properties including thermal conductivity of AAC on bulk density and moisture content. The reliability and accuracy of the method of measuring was also shown.


2011 ◽  
Vol 6 (No. 2) ◽  
pp. 73-82 ◽  
Author(s):  
S.E. Obalum ◽  
J.C. Nwite ◽  
J. Oppong ◽  
C.A. Igwe ◽  
T. Wakatsuki

One peculiar feature of the inland valleys abundant in West Africa is their site-specific hydrology, underlain mainly by the prevailing landforms and topography. Development and management of these land resources under the increasingly popular sawah (a system of bunded, puddled and levelled rice field with facilities for irrigation and drainage) technology is a promising opportunity for enhancing rice (Oryza sativa L.) production in the region. Information on the variations in selected soil physical properties as influenced by the prevailing landforms may serve as a useful guide in site selection. This is of practical importance since majority of the inland valleys are potentially unsuitable for sawah development and most farmers in the region are of low technical level. Three landforms (river levee, elevated area and depressed area) were identified within a sawah field located in an inland valley at Ahafo Ano South District of Ghana. Each of these landforms was topsoil-sampled along on identified gradient (top, mid and bottom slope positions). Parameters determined included particle size distribution, bulk density, total porosity and field moisture content. The soil is predominantly clayey. There were no variations in the particle size distribution among the slope positions in the river levee. Overall, the river levee had lower silt content than the elevated and the depressed landforms. The bulk density, total porosity, and gravimetric moisture content indicated relative improvements only in the depressed area in the order, bottom &gt; mid &gt; top slope. Irrespective of slope position, the three landforms differed in these parameters in the order, depressed &gt; river levee &gt; elevated. The sand fraction impacted negatively on the silt fraction and bulk density of the soil, both of which controlled the soil moisture status. Despite the fairly low silt content of the soil, the silt fraction strongly influenced the gravimetric moisture content (R<sup>2</sup> = 0.80). So too did the soil bulk density on the gravimetric moisture content (R<sup>2</sup> = 0.90). It is concluded that: (1) since the landforms more prominently influenced the measured parameters than the slope positions, the former should take pre-eminence over the latter in soil suitability judgment; (2) with respect to moisture retention, variations in silt fraction and bulk density of this and other clayey inland-valley soils should be used as guide in site selection for sawah development.


Author(s):  
P. C. Vengaiah ◽  
S. Kaleemullah ◽  
M. Madhava ◽  
A. Mani ◽  
B. Sreekanth

Some physical properties of palmyrah fruit were investigated in this study. The average values of major, medium, minor and geometric mean diameters of fresh whole palmyrah fruit were 11.54,10.45, 9.85 and 10.64 cm respectively at 47.34 % (w.b) moisture content whereas that of palmyrah nut were 8.59, 7.35, 4.99 and 6.79 cm respectively at 8% (w.b) moisture content. Sphericity, surface area and aspect ratio were found to be 91.94%, 359.17 cm2 and 0.90 for fruit and whereas that of nut were 79.19%, 145.16 cm2 and 0.86 respectively. The average mass of the individual palmyrah fruit and nut was 927.78 and 248.10 g whereas bulk density was 525.92 and 693.0 kg/m3 respectively. The coefficient of static friction on mild steel, glass and plywood surfaces were 0.27, 0.21 and 0.25 for palmyrah fruit and 0.36, 0.28 and 0.27 for nut respectively. The angle of repose of palmyrah fruit and nut were 30.77 and 44.03 respectively.


Author(s):  
Ryszard Oleszczuk ◽  
Milena Truba

Abstract The analysis of some physical properties of drained peat-moorsh soil layers. The paper presents the results of measurements of some physical properties for 14 drained fen peat-moorsh layers (degree of decomposition, bulk density, particle density, porosity and saturated moisture content). The soil samples were taken from north- -east, central and east part of Poland. These areas were drained in order to use as a grassland and meadows. The article presents obtained data of selected physical properties from several drained peatlands in Poland and shows the comparison of established results with relevant data published in literature.


2021 ◽  
Vol 15 (2) ◽  
pp. 216
Author(s):  
Yonodius Paskalis Bay ◽  
Nina Yulianti ◽  
Suparno Suparno ◽  
Fengky Florante Adji ◽  
Zafrullah Damanik ◽  
...  

Indonesia has the largest peat area in the tropical zone, which estimated about 21 million ha, with a percentage of 70% of the peat area in Southeast Asia and 50% of the world's tropical peatlands. This study aims to evaluate the physical properties of soil in each layer of soil and land cover in inland peat swamp forests in LAHG in Central Kalimantan. The research used the profile method (minipit) measuring 120 cm x 120 cm. Each location is given 3 plots on 2 (two) land cover  namely forest and burnt area. The research location is in LAHG. This research was conducted in July-December 2020. Samples were analyzed at the Banjarbaru Research and Development Laboratory. The parameters observed were bulk density, moisture content, fiber content, soil color, infiltration, and hydraulic conductivity. The research data were analyzed statistically by means of regression and correlation analysis. The results showed that the study of the physical properties of inland peat soil in the forest had bulk density ranging from 0.10 to 0.15 g / cm-3, moisture content 541.18-910.00%, fiber content 8-40%, infiltration -0 , 58-29.27 ml / hour, hydraulic conductivity 2.4-66.6 cm / hour with reddish black soil color. Whereas on burnt land, bulk density ranged from 0.10 to 0.15 g / cm-3, moisture content was 500.00-916.67%, fiber content was 12-52%, infiltration was -3.19-60.99 ml. / hr, hydraulic conductivity 2.4-30.6 cm / hr with dark black soil color. The study relationship pattern shows positive and negative.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 48
Author(s):  
Dorota Dukarska ◽  
Tomasz Rogoziński ◽  
Petar Antov ◽  
Lubos Kristak ◽  
Jakub Kmieciak

The properties of particleboards and the course of their manufacturing process depend on the characteristics of wood particles, their degree of fineness, geometry, and moisture content. This research work aims to investigate the physical properties of wood particles used in the particleboard production in dependence on their moisture content. Two types of particles currently used in the production of three-layer particleboards, i.e., microparticles (MP) for the outer layers of particleboards and particles for the core layers (PCL), were used in the study. The particles with a moisture content of 0.55%, 3.5%, 7%, 10%, 15%, and 20% were tested for their poured bulk density (ρp), tapped bulk density (ρt), compression ratio (k), angle of repose (αR), and slippery angle of repose (αs). It was found that irrespective of the fineness of the particles, an increase in their moisture content caused an increase in the angle of repose and slippery angle of repose and an increase in poured and tapped bulk density, while for PCL, the biggest changes in bulk density occurred in the range up to 15% of moisture content, and for MP in the range above 7% of moisture content, respectively. An increase in the moisture content of PCL in the range studied results in a significant increase in the compression ratio from 47.1% to 66.7%. The compression ratio of MP increases only up to 15% of their moisture content—a change of value from 47.1% to 58.7%.


2009 ◽  
Vol 55 (No. 4) ◽  
pp. 165-169 ◽  
Author(s):  
M.C. Ndukwu

The research looked at some selected physical properties of <I>Brachystegia eurycoma</I>, such as axial dimension, roundness, sphericity, surface area, bulk density, solid density, porosity, and volume which are essential in the design and construction of the processing and handling equipments of <I>Brachystegia eurycoma</I>. All the above physical properties measured showed some deviations from the average values which is typical of agricultural biomaterials. Solid density showed the highest deviation of 4.04 g/mm<sup>3</sup> while the volume showed the least deviation of 0.01 mm<sup>3</sup> when compared to those of other physical properties. The angle of repose increased with the increase in the moisture content with a coefficient of determination of 0.98.


2016 ◽  
Vol 44 (2) ◽  
Author(s):  
Shrikant Baslingappa Swami ◽  
N.J. Thakor A.M. Gawai

<p>The physical properties, viz., geometric diameter, surface area, sphericity, volume, bulk density, true density and angle of repose was measured for  four  cashew varieties <em>viz</em>., <em>Vengurle 1, Vengurle 3, Vengurle 4</em>  and <em>Vengurle 7</em> at different moisture content (15 to 87% db). For <em>Vengurle</em> 1 as the moisture content increased, the physical properties i.e., geometric mean diameter, volume, surface area, true density and angle of repose increased from 20.8 to 22.1 mm, 3485 to 4416 mm<sup>3</sup>, 1355 to 1540 mm<sup>2</sup>, 984 to 1030 kg m<sup>-3</sup> and 32 to 37˚, respectively. The sphericity and bulk density decreased from 74.2 to 71.4 per cent and 490 to 418 kg m<sup>-3</sup> respectively. For <em>Vengurle 3</em> geometric mean diameter, volume, surface area, true density and angle of repose increased from 27.2 to 28.6 mm, 7912 to 9169 mm<sup>3</sup>, 2320 to 2567 mm<sup>2</sup>, 1020 to 1048 kg m<sup>-3</sup> and 33 to 35.5˚, respectively. The sphericity and bulk density decreased from 75.5 to 75.2 per cent and 531 to 470 kg m<sup>-3</sup> respectively. For <em>Vengurle 4</em> the geometric mean diameter, volume, surface area, true density and angle of repose increased from 21.0 to 24.1mm, 3362 to 5113 mm<sup>3</sup>, 1391 to 1828 mm<sup>2</sup>, 970 to 1030 kg m<sup>-3</sup> and 32.5 to 38˚,  respectively. The sphericity and bulk density decreased from 65.8 to 66.8 per cent, 517 to 462 kg m<sup>-3</sup>, respectively. For <em>Vengurle 7</em> the geometric mean diameter, volume, surface area, true density and angle of repose increased from 24.2 to 24.9 mm, 5102 to 5547 mm<sup>3</sup>, 1840 to 1941 mm<sup>2</sup>, 998 to 1045 kg m<sup>-3</sup> and 33 to 38˚, respectively. The sphericity and bulk density decreased from 65.4 to 65.8 per cent, 518 to 438 kg m<sup>-3</sup>, respectively.</p>


Author(s):  
Elton A. S. Martins ◽  
André L. D. Goneli ◽  
Cesar P. Hartmann Filho ◽  
Munir Mauad ◽  
Valdiney C. Siqueira ◽  
...  

ABSTRACT Safflower is an oil crop and its oil can be used for food and industrial purposes. However, there is little information about the physical properties of these grains, which is important for the planning and execution of post-harvest stages. Thus, this study was carried out with the aim of evaluating the effect of drying on the main physical properties of safflower grains. Safflower grains were harvested with an initial moisture content of approximately 0.445 decimal d.b. (dry basis) and subjected to drying in an oven with forced air circulation at 40 °C, until the grains reached a final moisture content of 0.073 ± 0.008 decimal d.b. During the drying, bulk density and true density, porosity, thousand-grain mass, circularity, sphericity, projected and surface area, and surface-volume ratio were measured. Based on these results, it is concluded that all gravimetric and geometrical characteristics of safflower grains were reduced due to the reduction of moisture content, except for the surface-volume ratio.


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