Binary packing theory and the physical properties of aggregates

Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 283 ◽  
Author(s):  
KJ Coughlan ◽  
RJ Loch ◽  
WE Fox
Keyword(s):  
Physical Properties ◽  
Water Retention ◽  
Void Ratio ◽  
Wetting And Drying ◽  
Compacted Soil ◽  
Soil Mixing ◽  
Swelling Capacity ◽  
Sand Particles ◽  
Clay Percentage ◽  
Coarse To Fine

The objective of this study was to examine variations in the physical properties of non-compacted soil-sand aggregates in terms of binary packing theory. Two soils were used, a swelling black earth and a krasnozem with low swelling capacity, and aggregates with varying clay percentage were prepared by dispersing the soil, mixing with 100-50 �m sand, and wetting and drying. At lower clay percentages, void ratio with increasing clay was greater than that predicted from theory. This was attributed to clay entering between sand junctions and increasing porosity by expanding the coarse matrix. From water retention and swelling data, the transition from coarse to fine matrix occurs in both soils at about 40 % clay. In the fine particle matrix, variation of void ratio in the krasnozem aggregates was as expected from theory. In the black earth, no significant variation in void ratio occurs at clay percentages > 40%. This was attributed to porosity created around the sand particles owing to differential swelling and shrinkage. Results obtained by other workers are explained in terms of binary packing theory and the concepts developed in this paper.

scholarly journals Effect of drying temperature on physical properties of fermented dried locust bean flour

2021 ◽  
Vol 9 (1) ◽  
pp. 1-7
Author(s):  
Idowu D. O ◽  
◽  
Olaniran J. A. ◽  
Onifade T. B. ◽  
◽  
...  
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Water Retention ◽  
Final Moisture Content ◽  
Drying Temperature ◽  
Retention Ratio ◽  
Bean Flour ◽  
Swelling Capacity ◽  
Wetting Time ◽  
Locust Bean

Drying plays a major role in food processing as it reduces the activities of micro-organisms and hence preserve food from deterioration. It has been reported that drying imposes new changes to the physical properties of the product which may in turn affect its handling, packaging and usability. The present research work, therefore aimed to evaluate the effect different drying temperature on physical properties of fermented dried locust bean flour. The local fermented locust bean was dried at different temperature of 50, 60, 70, 80 and 90°C at airflow rate of 1.8 kg/min. then milled and Investigated on final moisture content, bulk density, water retention ratio, flour wetting time, and swelling capacity of the fermented dried locust bean flour. The effect of drying temperature was found to be significant (p ≤ 0.05) on all the physical properties investigated except bulky density (0.638 g/ml). As the drying temperature increased from 50 to 90°C, final moisture content decreased significantly from 5.62 to 3.52%. Whereas, water retention ratio, wetting time, swelling capacity, porosity ratio and water retention ratio increase from 1.96 to 2.5 m/g, 153 to 299 s, 2.26 to 2.44, 0.81 to 0.91 and 1.96 to 2.5 m/g respectively. These findings could prove useful in the modeling of locust bean drying and to flour millers and pelletizer who may want to use locust bean flour as a sole or composite flour for different production and application. Keywords: Fermented locust bean flour, physical properties, modeling, pelletizer, miller, drying temperature, final moisture content.

scholarly journals Biochar with Alternate Wetting and Drying Irrigation: A Potential Technique for Paddy Soil Management

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 367
Author(s):  
Ahmad Numery Ashfaqul Haque ◽  
Md. Kamal Uddin ◽  
Muhammad Firdaus Sulaiman ◽  
Adibah Mohd Amin ◽  
Mahmud Hossain ◽  
...  
Keyword(s):  
Physical Properties ◽  
Water Retention ◽  
Soil Health ◽  
Field Studies ◽  
Soil Physical Properties ◽  
Nutrient Loss ◽  
Soil Productivity ◽  
Wetting And Drying ◽  
Alternate Wetting And Drying ◽  
Growing Period

Over half of the world’s population depends on rice for its calorie supply, although it consumes the highest amount of water compared to other major crops. To minimize this excess water usage, alternate wetting and drying (AWD) irrigation practice is considered as an efficient technique in which soil intermittently dried during the growing period of rice by maintaining yield compared to a flooded system. Continuous AWD may result in poor soil health caused by carbon loss, nutrient depletion, cracking, and affecting soil physical properties. Due to being a potential organic amendment, biochar has a great scope to overcome these problems by improving soil’s physicochemical properties. Biochar is a carbon enriched highly porous material and characterized by several functional groups on its large surface area and full of nutrients. However, biochar’s implication for sustaining soil physicochemical and water retention properties in the AWD irrigation systems has not been widely discussed. This paper reviews the adverse impacts of AWD irrigation on soil structure and C, N depletion; the potential of biochar to mitigate this problem and recovering soil productivity; its influence on improving soil physical properties and moisture retention; and the scope of future study. This review opined that biochar efficiently retains nutrients and supplies as a slow-release fertilizer, which may restrict preferential nutrient loss through soil cracks under AWD. It also improves soil’s physical properties, slows cracking during drying cycles, and enhances water retention by storing moisture within its internal pores. However, long-term field studies are scarce; additionally, economic evaluation is required to confirm the extent of biochar impact.

scholarly journals An Experimental Study on the Shear Behaviors of Polymer-Sand Composite Materials after Immersion

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 924 ◽  
Author(s):  
Jin Liu ◽  
Yuxia Bai ◽  
Ding Li ◽  
Qiongya Wang ◽  
Wei Qian ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Void Ratio ◽  
Dry Density ◽  
Chemical Additives ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Sand Particles ◽  
Shear Behaviors ◽  
Sand Material

Sand mixed with geotextile/fiber/cement/lime or non-traditional chemical additives to form composite materials is recognized as an effective method for improving the sand properties. In this work, the variation in properties of composite materials after immersion is reported which has rarely appeared in the literature. The focus of this study is to evaluate the shear behaviors of polymer-sand composite material after immersion with direct shear tests. Several factors which may influence the shear behaviors after immersion are analyzed. The results demonstrate that this composite material still has good shear behaviors after immersion when compared to the purely sand material. The shear behaviors are improved with an increment in the curing time, polymer content and sand dry density while there is a decrease in the shear behaviors with increasing immersion time. The interaction between sand particles and the polymer are analyzed with Scanning Electron Microscope (SEM). The polymer membranes are formed by polymer enwrapping and connected sand particles to build an elastic and viscous structure in the sand that increases the interlocking forces between sand particles and decreases the void ratio of this material. The membranes are softened in water resulting in a decrease in the shear strength. Moreover, other factors affect the shear behaviors by improving the completeness and stability of this structure.

Long-term effect of biochar on soil physical properties of agricultural soils with different textures

2021 ◽  
Author(s):  
Martin Zanutel ◽  
Sarah Garré ◽  
Charles Bielders
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Water Retention ◽  
Particle Density ◽  
Sandy Loam ◽  
Soil Physical Properties ◽  
Term Effect ◽  
Silt Loam ◽  
Long Term Effect

<p>In the context of global soil degradation, biochar is being promoted as a potential solution to improve soil quality, besides its carbon sequestration potential. Burying biochar in soils is known to effect soil physical quality in the short-term (<5 years), and the intensity of these effects depends on soil texture. However, the long-term effects of biochar remain largely unknown yet and are important to quantify given biochar’s persistency in soils. The objective of this study was therefore to assess the long-term effect of biochar on soil physical properties as a function of soil texture and biochar concentration.  For this purpose, soil physical properties (particle density, bulk density, porosity, water retention and hydraulic conductivity curves) were measured in the topsoil of three fields with former kiln sites containing charcoal more than 150 years old in Wallonia (southern Belgium).  The fields had a silt loam, loam and sandy loam texture.  Samples were collected along 3 transects in each field, from the center of the kiln sites outwards. </p><p>Particle density and bulk density slightly decreased as a function of charcoal content. Because particle density and bulk density were affected to a similar extent by charcoal content, total porosity was not affected by the presence of century-old charcoal. Regarding the soil water retention curve, charcoal affected mostly water content in the mesopore range. This effect was strongest for the sandy loam. On the other hand, the presence of century-old charcoal increased significantly the hydraulic conductivity at pF between 1.5 and 2 for the silt loam, while no effect of charcoal was observed for the loamy soil.  The study highlights a limited effect of century-old charcoal on the pore size distribution (at constant porosity) and on the resulting soil physical properties for the range of soils and charcoal concentrations investigated here.  Further research may be needed to confirm the observed trends over a wider range of soil types. </p>

Recycled fiber treated with NaOH/urea aqueous solution: effects on physical properties of paper sheets and on hornification

2018 ◽  
Vol 33 (4) ◽  
pp. 651-660 ◽  
Author(s):  
Yingju Miao ◽  
Yunfei Zhi ◽  
Heng Zhang ◽  
Ying Chen ◽  
Shaoyun Shan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Physical Properties ◽  
Water Retention ◽  
Crystalline Region ◽  
Cellulose Film ◽  
Reinforced Concrete Structure ◽  
Water Retention Value ◽  
Fiber Network ◽  
Urea Aqueous Solution ◽  
Intramolecular Hydrogen

Abstract Hydrogen bonding among fiber microfibrils is the primary cause of fiber hornification, wherein NaOH/urea aqueous solution precooled to −13 °C can disassemble inter- and intramolecular hydrogen bonds. Whether hornified fibers treated with this process can significantly improve fiber swelling ability and physical properties of the resulting paper sheets remains a problem. In this investigation, the 6th cycle fiber was pretreated with this procedure, and the water retention value of the fiber before and after treatment and the physical properties of the resulting paper sheets were studied. The results indicate that the lignin decline, complete swelling of flat fiber, filling of cellulose film between the interfiber network, and decreasing crystalline region all contribute to the increase in water retention value. The water retention value of repaired fiber is equivalent to that of virgin pulp, and hornification reverses by 89 %. In addition, the cellulose film filling among the fiber network constructs a similar reinforced concrete structure, which causes the tear, burst, and tensile index of the resulting paper sheets to increase by 145 %, 98 %, and 43 %, respectively.

scholarly journals Sensitivity analysis of point and parametric pedotransfer functions for estimating water retention of soils in Algeria

SOIL ◽  
2016 ◽  
Vol 2 (4) ◽  
pp. 647-657 ◽  
Author(s):  
Sami Touil ◽  
Aurore Degre ◽  
Mohamed Nacer Chabaca
Keyword(s):  
Water Retention ◽  
Sensitivity Analyses ◽  
Pedotransfer Functions ◽  
Sand Fraction ◽  
Significant Difference ◽  
Point Pressure ◽  
Input Variables ◽  
Clay Percentage ◽  
Different Sources ◽  
Linear Regressions

Abstract. Improving the accuracy of pedotransfer functions (PTFs) requires studying how prediction uncertainty can be apportioned to different sources of uncertainty in inputs. In this study, the question addressed was as follows: which variable input is the main or best complementary predictor of water retention, and at which water potential? Two approaches were adopted to generate PTFs: multiple linear regressions (MLRs) for point PTFs and multiple nonlinear regressions (MNLRs) for parametric PTFs. Reliability tests showed that point PTFs provided better estimates than parametric PTFs (root mean square error, RMSE: 0.0414 and 0.0444 cm3 cm−3, and 0.0613 and 0.0605 cm3 cm−3 at −33 and −1500 kPa, respectively). The local parametric PTFs provided better estimates than Rosetta PTFs at −33 kPa. No significant difference in accuracy, however, was found between the parametric PTFs and Rosetta H2 at −1500 kPa with RMSE values of 0.0605 cm3 cm−3 and 0.0636 cm3 cm−3, respectively. The results of global sensitivity analyses (GSAs) showed that the mathematical formalism of PTFs and their input variables reacted differently in terms of point pressure and texture. The point and parametric PTFs were sensitive mainly to the sand fraction in the fine- and medium-textural classes. The use of clay percentage (C %) and bulk density (BD) as inputs in the medium-textural class improved the estimation of PTFs at −33 kPa.

scholarly journals Investigation of the Potential Use of Curauá Fiber for Reinforcing Mortars

Fibers ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 69
Author(s):  
Afonso R. G. de Azevedo ◽  
Sergey Klyuev ◽  
Markssuel T. Marvila ◽  
Nikolai Vatin ◽  
Nataliya Alfimova ◽  
...  
Keyword(s):  
Water Retention ◽  
Natural Fibers ◽  
Northern Region ◽  
Technological Properties ◽  
Wetting And Drying ◽  
Air Content ◽  
Naoh Solution ◽  
Potential Use ◽  
Reference Mixture ◽  
Curauá Fiber

Curauá is a bromeliad of Amazonian origin, present in some states in the northern region of Brazil and in other countries in South America. Its natural fibers have several technological advantages for application in composite materials. The objective of this research was to investigate the potential of using the fiber of Curauá as a reinforcement element in mortars for wall covering. Mortars were made with a 1:1:6 ratio (cement:lime:sand) in relation to their mass, evaluating the effect of adding 1%, 2% and 3% of Curauá fiber natural and fiber treated in NaOH solution in relation to the mass of cement, compared to the reference mixture (0%). Technological properties such as consistency, water retention and incorporated air content, compressive strength, water absorption and durability in wetting and drying cycles were evaluated. The results showed that the addition of the Curauá fiber causes an improvement in the mechanical properties of mortars, and at levels of addition 3% or more, it causes problems of workability and incorporation of air into the dough, thus, the fiber addition in 2% presented better results for application in coating mortars, in relation a Brazilian norm, even improving the durability of external coatings.

scholarly journals Physical Properties and Consumer Evaluation of Cocoa Bean Shell-Functionalized Biscuits Adapted for Diabetic Consumers by the Replacement of Sucrose with Tagatose

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 814 ◽  
Author(s):  
Olga Rojo-Poveda ◽  
Letricia Barbosa-Pereira ◽  
David Orden ◽  
Caroline Stévigny ◽  
Giuseppe Zeppa ◽  
...  
Keyword(s):  
Physical Properties ◽  
Structural Properties ◽  
Water Retention ◽  
Consumer Acceptance ◽  
Cocoa Bean ◽  
Total Dietary Fiber ◽  
Consumer Evaluation ◽  
Lower Solubility ◽  
Interesting Possibility ◽  
Physicochemical And Structural Properties

The cocoa bean shell (CBS), a by-product of the cocoa industry, has been reported to be rich in fiber and polyphenols, which could contribute to reducing the metabolism of sugars and glucose adsorption. The production of CBS-based biscuits in which sucrose is replaced with tagatose (a low-glycemic sugar with prebiotic properties), benefiting diabetic consumers, is proposed. Six prototype biscuits were produced using sucrose, tagatose, and CBS powder at 0%, 10%, and 20% as a wheat flour replacement. Biscuits were studied in terms of fiber content, and those with 10% and 20% CBS showed to contain 5.66% and 8.70–8.71% of total dietary fiber, respectively. Moreover, the physicochemical and structural properties of the biscuits were studied to evaluate their differences due to the use of sucrose and tagatose combined with CBS. Significant effects mainly caused by the reducing nature and lower solubility of tagatose with respect to sugar, and the water retention capacities of CBS were observed. Finally, the biscuits were evaluated by performing a consumer acceptance evaluation, and their perceptible sensorial differences were studied by performing a Napping® sensory characterization. CBS-based biscuits represent an interesting possibility for cocoa by-product revalorization, although an optimized recipe is recommended, especially when employing tagatose.

A note on the capillary rise of water in soils

1919 ◽  
Vol 9 (4) ◽  
pp. 396-399 ◽  
Author(s):  
Bernard A. Keen
Keyword(s):  
Physical Properties ◽  
Capillary Rise ◽  
Historical Review ◽  
Compacted Soil ◽  
Properties Of Soil

Very diverse views are expressed on the height to which water can rise in soils under the forces of capillarity. Alway and MacDole in the course of a brief historical review, point out that these estimates range from two or three feet only, to as much as two or three kilometres, although the majority do not exceed 200 feet. Most of the investigators who advance a high value for the capillary rise are careful to point out that in all probability the movement of water in this case would be exceedingly slow, owing to the excessive friction in the minute capillary spaces. Actual experiments on the rise of water in tubes of compacted soil result in low values, which are in all probability exceeded in the field. Warington in his book Physical Properties of Soil gives a typical table showing the results of Loughridgeb for Californian soils.

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