Soil deformation observations in a vertisol under field traffic

Soil Research ◽  
1995 ◽  
Vol 33 (5) ◽  
pp. 817 ◽  
Author(s):  
DM Bakker ◽  
RJ Davis

A procedure based on the point grid method has been used to measure and visualize soil deformation resulting from tyre loads in a controlled traffic system. Several tests were performed in an irrigated heavy clay soil under various moisture conditions and two different geometries of the wheel tracks, recessed and elevated. This represented normal working conditions and illustrated that significant deformations were occurring. Deformations increased with moisture content and the number of passes. From the point grid displacements, bulk density changes were calculated which corresponded with the measured increases in density obtained from cores. Large displacements were observed when the soil was trafficked at high moisture content with little corresponding increase in bulk density. Soil structural degradation resulting from trafficking this soil at high moisture content should therefore be seen as a different process, such as a change in the orientation of clay particles or porosity of natural aggregates, rather than an increase in bulk density. Significant differences between vertical and horizontal displacements were found for the various tests. Increases in horizontal displacements were contributed to an increase in the degree of saturation. The recessed wheel tracks increased horizontal displacements due to the geometry of the wheel tracks.

1976 ◽  
Vol 86 (3) ◽  
pp. 567-571 ◽  
Author(s):  
P. T. Gooderham

Untimely ploughing and rotavation of a silt loam soil was found to increase bulk density, and mechanical resistance to a needle penetrometer probe, and to reduce air porosity. These effects were not found deeper than 8 cm, although measurements with a 13 mm field penetrometer probe indicated some increase in mechanical resistance down to 30 cm. The effect of untimely cultivations on soil conditions was small when compared with the effect of loosening by hand digging. This treatment reduced substantially the bulk density and mechanical resistance; it increased air porosity and moisture content of the subsoil. Although measurements of mechanical resistance with the laboratory penetrometer were 2·4 times those of the field penetrometer, there was nevertheless good correlation between measurements.


2018 ◽  
Vol 10 (2) ◽  
pp. 63-74 ◽  
Author(s):  
I Dewa Gede Putra Prabawa

The purposes of this research were to study the ieffects of biomass moisture content and process temperature on the quality of biopellet derived from rubber seed shell and bamboo ater (Gigantochloa atter). The biomass was conditioned at different moisture contents (6, 12, 14, 16, 18, and 20% w/w), and the biopelet was produced at a pressure of 597,24 kg/cm2 with various process temperatures (100, 125, 150, 175, and 200oC). The results showed that the properties of produced biopellets were significantly affected by the variation of moisture content and process temperature. High moisture content of biomass could increase the moisture content of biopellet while the calorific value and ash content decreased. With the increase in process temperatures, calorific value and ash increased whereas the moisture content of biopellet decreased. Mechanical durability was enhanced with the increase inthe moisture content of biomass, starting from 6% to 18%;and was improved with the increase in the process temperatures, starting from 100oC to 175oC. However, the bulk density of biopellet increased with the increase inthe moisture content of biomass, starting from 6% to 16%, and was improved with the increase in the process temperatures from 100oC to 150oC. The best quality of biopellet was produced  in the biomass moisture content of 16% and the process temperature of 150oC. That biopellet had mechanical durability of 99.16%, calorific value of 4,402 cal/g, bulk density of 1,157 kg/m3, moisture content of 6.71%, ash of 1.19%, nitrogen of 0.15%, Sulphur of 0.013%, and chlorine of <0.1 ppm. That biopellet quality met European standards (EN 14961-2).


2017 ◽  
Vol 12 (3) ◽  
pp. 400 ◽  
Author(s):  
Valdiney Cambuy Siqueira ◽  
Flávio Meira Borém ◽  
Guilherme Euripedes Alves ◽  
Eder Pedroza Isquierdo ◽  
Afonso Celso Ferreira Pinto ◽  
...  

Objetivou-se, com o presente trabalho, propor um novo método de processamento e secagem, assim como avaliar o comportamento dos grãos submetidos a este processo, por meio da taxa de redução de água e do ajuste de diferentes modelos matemáticos aos dados experimentais da secagem. Os frutos colhidos no estágio maduro foram divididos em três lotes. O primeiro foi seco continuamente à temperatura de 40±1 °C. O segundo consiste na secagem do café natural até os teores de água de 0,56±0,02, 0,41±0,02, 0,28±0,02 e 0,20±0,02 decimal (base seca, b.s.), seguido de beneficiamento e secagem contínua nas temperaturas de 35±1 ºC e 40±1 ºC. O terceiro lote correspondeu à secagem contínua do café descascado e desmucilado na temperatura de 40±1 °C. Em todos os lotes, a secagem foi encerrada quando os grãos atingiram o teor de água de 0,12±0,05 (b.s.). Aos dados experimentais da secagem foram ajustados dez modelos matemáticos utilizados para representação da secagem dos produtos agrícolas. Além da representação da cinética de secagem foi avaliada a taxa de redução de água dos grãos. Conclui-se que a taxa de redução de água é maior para a temperatura de secagem de 40±1 °C, especialmente para maiores teores de água. O tempo total de secagem do café beneficiado com alto teor de água é expressivamente reduzido, quando comparado ao tempo de secagem completa do café natural. O modelo de Midilli descreve satisfatoriamente a cinética de secagem do café beneficiado.


2014 ◽  
Vol 124 ◽  
pp. 267-274 ◽  
Author(s):  
Seung-Hyun Moon ◽  
In-Soo Ryu ◽  
Seung-Jae Lee ◽  
Tae-In Ohm

2020 ◽  
Vol 67 (2) ◽  
pp. 73-77
Author(s):  
Zarife Bajraktari-Gashi ◽  
Muharrem Zabeli ◽  
Behram Halilaj

AbstractDuring 1984–1997, the ferronickel plant in Drenas used iron-nickel ore from the mines of the Republic of Kosovo: Glavica and Çikatove (Dushkaje and Suke) mines. However, during the years 2007–2017, when the plant started operating from the cessation of production, which was from 1998 to 2007, some types of iron-nickel ores from different countries began to be used, starting from iron-nickel ores from Kosovo, iron-nickel ores from Albania, ores from Indonesia, ores from the Philippines, ores from Guatemala, ores from Turkey and ores from Macedonia. The ore composition, however, is mainly oxide-laterite ore. Iron-nickel ores in the plant are characterised by high moisture content, a very important factor influencing the process of scraping the charge in rotary kilns and presenting in general. Among the iron-nickel ore used in the ferronickel plant, the ores from Albania are characterised due to their low moisture content when compared with the other ores as well as the high content of iron oxides, which affect the temperature rise inside the furnaces, as the iron ores play an important role in the pre-casting process in rotary kilns.


2014 ◽  
Vol 23 (2) ◽  
pp. 89-95
Author(s):  
J. A. Okhuoya ◽  
S. O. Itaman

In a fungal suryey of sawn timbers in scattared localities in Benin City, fungal species isolated were mainly members of <i>Hyphomycetes</i>, with few <i>Ascomycetes</i> and<i> Basidiomycetes</i>. Cellulolytic abilities of isolates were determined and found to be highest in a basidiomycete, <i>Pleurotus ostreatus</i>. The high incidence of these isolates was traced to the poor ventillation in the shades where the timbers arę sold and the high moisture content of timber before display for sale.


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