INFLUENCE OF DRYING-WETTING CYCLES ON THE COMPRESSIBILITY OF CLAY SOILS IN THE COMMUNE OF HOUEYOGBE

2021 ◽  
Vol 10 (5) ◽  
pp. 1-12
Keyword(s):  
Soil Sample ◽  
Laboratory Study ◽  
Clay Soil ◽  
Clay Soils ◽  
Extreme Conditions ◽  
Soil Suction ◽  
Consolidation Pressure ◽  
Compressibility Index ◽  
Experimental Laboratory ◽  
Number Of Cycles

This article presents the results of an experimental laboratory study carried out with the odometer and the Richards press on a class A3 clay soil sample that had undergone drying-wetting cycles. These tests allowed us to analyze in fine the influence of the drying-wetting cycles on the compressibility and suction behavior of the soil object of our study. This study reveals that the drying-wetting cycles have a certain influence on clay soils. Indeed, the compressibility index of the soil increases while the swelling index decreases according to the cycles; the pre-consolidation pressure and the oedometric modulus show a more or less constant variation; the permeability of the soil increases clearly when the number of cycles increases. Soil suction decreases as the number of drying-wetting cycles increases under extreme conditions.

scholarly journals Use of Biopolymers in the Stabilization of Clay Soils

2021 ◽  
Vol 16 (2) ◽  
pp. 37-53
Author(s):  
Idoui Imane ◽  
Rehab Bekkouche Souhila ◽  
Benzaid Riad ◽  
Berdi Inas
Keyword(s):  
Wheat Straw ◽  
Clay Soil ◽  
Agricultural Waste ◽  
Clay Soils ◽  
Construction Sites ◽  
The Sustainable Development ◽  
Treatment Techniques ◽  
Compressibility Index ◽  
Compressive Strength Test ◽  
Proctor Test

Abstract The treatment and stabilization of soils make it possible to recycle materials on construction sites in preparation for the installation of a final covering or the construction of a road network. In road geotechnics, various materials such as lime, cement, and pozzolans were used as additions to stabilize clay soils. In recent years, bio-polymers and bacteria are of increasing interest to researchers in the field of stabilization and improvement of the physico-mechanical and chemical characteristics of clay soils. Currently, in place of traditional clay treatment techniques and to minimize environmental problems, natural fibrous waste is being used increasingly and spectacularly. Several studies on biotechnological engineering applications already exist, such as the use of vegetation, algae, bacteria, enzymes, and biopolymers. The northern Algerian region where the urban tissue does not stop expanding contains significant potential in terms of wheat straw, which represents a very present agricultural waste. So, there is a local interest in the sustainable development of several regions known to produce wheat. This study is interested in investigating the effect of wheat straw on the stabilization of swelling clay soil. In order to improve the physico-mechanical characteristics of clay soils, a series of laboratory tests (Atterberg limit, Proctor test, direct shear test, Oedometer test, and unconfident compressive strength test) were carried out on reconstituted clay soil with defined initial properties through numerous analyses (e.g., XRD and XRF) and then treated with different vegetable fiber content. The results indicate that there is an improvement in the compressibility characteristics of the treated soil, a remarkable decrease in the swelling index and the compressibility index respectively with increasing percentages of wheat straw.

scholarly journals Distribution and Restricted Vertical Movement of Nematodes in a Heavy Clay Soil

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 221
Author(s):  
Oliver Knox ◽  
Katherine Polain ◽  
Elijha Fortescue ◽  
Bryan Griffiths
Keyword(s):  
Soil Sample ◽  
Crop Rotation ◽  
Clay Soil ◽  
Vertical Movement ◽  
Plant Roots ◽  
Clay Soils ◽  
Nematode Control ◽  
Sample Depth ◽  
Heavy Clay ◽  
Chemical Availability

A large part of Australia’s broad acre irrigation industry, which includes cotton, is farmed on heavy clay Vertosols. Recent changes in nematicide chemical availability, changes in rotations and the observation of the reniform nematode in central Queensland has highlighted that we need to improve our understanding of nematodes in these soils. We undertook preliminary investigations into distribution by depth under a cotton-cotton and cotton-maize rotation as well as vertical movement experiments in microcosms to better understand nematode distribution and movement in heavy clay soils. Analysis revealed that field populations decreased with soil sample depth, but there were also differences between rotations. In microcosm experiments, vertical movement of nematodes in these heavy clay soils was restricted, even in the presence of plant roots and moisture, both of which were hypothesised to improve nematode migration. The results imply that crop rotation currently remains a plausible option for nematode control, and that we still have a lot to learn about the ecology of nematode populations in Vertosols.

When Apologies for Injustice Matter

2008 ◽  
Vol 13 (4) ◽  
pp. 239-247 ◽  
Author(s):  
David De Cremer ◽  
Barbara C. Schouten
Keyword(s):  
Laboratory Study ◽  
Interaction Effect ◽  
Interactive Effect ◽  
Cross Sectional ◽  
Fairness Perceptions ◽  
Organizational Survey ◽  
Experimental Laboratory

The present research examined the idea that the effectiveness of apologies on promoting fairness perceptions depends on how meaningful and sincere the apology is experienced. More precisely, it was predicted that apologies are more effective when they are communicated by an authority being respectful to others. A study using a cross-sectional organizational survey showed that an apology (relative to giving no apology) revealed higher fairness perceptions, but only so when the authority was respectful rather than disrespectful. In a subsequent experimental laboratory study the same interaction effect (as in Study 1) on fairness perceptions was found. In addition, a similar interaction effect also emerged on participants’ self-evaluations in terms of relational appreciation (i.e., feeling valued and likeable). Finally, these self-evaluations accounted (at least partly) for the interactive effect on fairness perceptions.

scholarly journals Licorice (Glycyrrhiza glabra (Linnaeus, 1753)) roots aqueous extract and some additives against Bactrocera zonata (Saunders, 1841) (Diptera: Tephritidae)

2021 ◽  
Vol 90 (2 - Ahead of print) ◽  
pp. 70-85
Author(s):  
Mervat Abdel-Moneauim Mostafa El-Genaidy ◽  
Mohamed Abd El-Aziz Mohamed Hindy ◽  
Nehad Abdel-Hameed Soliman
Keyword(s):  
Aqueous Extract ◽  
Sandy Soil ◽  
Clay Soil ◽  
Mineral Oil ◽  
Glycyrrhiza Glabra ◽  
Clay Soils ◽  
Insecticidal Effect ◽  
Bactrocera Zonata ◽  
Light Mineral ◽  
Petroleum Oil

Peach fruit fly, Bactrocera zonata (Saunders, 1841) is a destructive polyphagous pest threatening the horticultural production in Egypt. Licorice, Glycyrrhiza glabra (Linnaeus, 1753) is a plant growing in Egypt and many other countries and famous for saponins groups that have insecticidal effect against broad spectrum of insect pests. In the present study, the insecticidal effect of licorice roots aqueous extract (LRAE), petroleum oil, KZ light mineral oil 96% (EC), water and an emulsion (1/4 L LRAE + ¼ L petroleum oil + ½ L KZ light oil 96% (EC)) treatments in a ratio 1 L: 29 L water were used in Matabi® sprayer of 30 L capacity against B. zonata pupae in sandy and clay soils. In sandy and clay soils LRAE reduced B. zonata population by 74.44% and 87.55% while petroleum oil, KZ light mineral oil 96% (EC) prevented flies emergence (100% reduction). Water treatment suppressed B. zonata population by 78.61% in sandy soil but caused 100% population reduction in clay soil. The emulsion reduced B. zonata population by 96.94% in sandy soil and 100% in clay soil. The best method for application of the emulsion was to spray as one target spray technique for eight seconds that was sufficient to obtain suitable coverage on soil with spray speed 1.2 km / hour. The persistence of the emulsion that highly reduced B. zonata larval populations was 3.5 and 4.5 days in sandy and clay soils, respectively. The flies emerged from B. zonata pupae treated with the emulsion neither feed nor move naturally. The histological studies showed that these flies suffered changes in the eyes, labellum, muscles and midgut tissues that were different from the emerged control treatment flies.

scholarly journals An Experimental Study on the Effect of Tire Powder on the Geotechnical Properties of Clay Soils

2018 ◽  
Vol 4 (3) ◽  
pp. 594 ◽  
Author(s):  
Davood Akbarimehr ◽  
Esmael Aflaki
Keyword(s):  
Clay Soil ◽  
Geotechnical Properties ◽  
Atterberg Limits ◽  
Clay Soils ◽  
Positive Effects ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Problematic Soils ◽  
Geotechnical Problems ◽  
Comprehensive Study

With respect to the increasing production of tire wastes, the use of these wastes as an additive in civil engineering has always gained attentions of researchers due to their positive effects on material properties and reduction of environmental problems. Clay soils, as problematic soils, have always caused geotechnical problems including high Atterberg limits and consequently low workability. Tire powder, as one of the products of tire wastes, lacks clay cohesion and it can be effective in altering the plasticity of clay soils. As no comprehensive study has been conducted in this regard specifically on Tehran clay soil yet, this research studies experimentally the effect of adding different percentages of tire powder to clay soil at the Atterberg limits of clay soils with two different types of plasticity. More over according to previous studies, the effect of tire powder on other geotechnical properties of clay soils and the advantages and disadvantages of using tire powder in clay soils are discussed. The results indicate that addition of tire powder to clay soils has positive effects on reducing the Atterberg limits, increasing efficiency, and improving resistance, permeability, swelling reduction, and settlement properties, and reducing soil density and it can be used as an additive in improving clay soils.

scholarly journals Investigation on a Bangladeshi isolate Bacillus aryabhattai for promising biotechnological applications

2018 ◽  
Vol 7 (2) ◽  
pp. 33-45
Author(s):  
Mohammad Shahedur Rahman ◽  
Rasheda Banu ◽  
Ripa Moni ◽  
Nazmul Islam ◽  
Mastura Khatun Ruma ◽  
...  
Keyword(s):  
Soil Sample ◽  
Extracellular Enzymes ◽  
Extreme Conditions ◽  
Biotechnological Applications ◽  
Optimum Temperature ◽  
First Report ◽  
Bacillus Aryabhattai ◽  
Physico Chemical ◽  
Chemical Studies

A new isolate was investigated from soil sample collected from Shahrasti upazilla of Chandpur district of Bangladesh. Based on the physico-chemical studies the strain was identified as gram positive Bacilli. Moleculer characterization of the strain was identified as Bacillus aryabhattai which is the first report in Bangladesh. The strain can survive in extreme conditions of salt, temperature and pH. This strain was further characterized and screened for the ability to produce useful enzymes. The optimum temperature for growth and production of these enzymes was within the temperature range 35oC to 40oC. The pH was found to be 7 for its growth and production of different enzymes when investigated over 48 h of incubation. The isolate produced various extracellular enzymes such as α-amylases, cellulases, β-glucosidases, lipases and proteases. The findings of this study provide useful information of the new strain that has potential biotechnological applications. Jahangirnagar University J. Biol. Sci. 7(2): 33-45, 2018 (December)

Influence of 3 Kinds of Organic Fertilizers on the Degradation of p, p′-DDT in Clay under Flooding Conditions

2014 ◽  
Vol 1010-1012 ◽  
pp. 610-613
Author(s):  
Xiao Deng ◽  
Chun Yuan Wu ◽  
Yi Li ◽  
Jing Kun Liu ◽  
Qin Fen Li
Keyword(s):  
Activated Sludge ◽  
Clay Soil ◽  
Organic Fertilizers ◽  
Chicken Manure ◽  
Pot Experiment ◽  
Clay Soils ◽  
Manure Compost ◽  
Degradation Rates ◽  
Cassava Residue ◽  
Degradation Effect

Using pot experiment to study the influence of three organic fertilizers of chicken manure compost (CM), activated sludge (AS) and cassava residue compost (CR) on the degradation of p, p'-DDT in clay soil under flooding conditions. The results showed that the two kinds of organic fertilizers of AS and CM could effectively accelerate the degradation of p, p'-DDT in clay soils, and the degradation effect was the best when adding 2% CM or 3% AS in clay soil. However, the influence of CR on the degradation of p, p'-DDT was not obvious. The degradation rates of P, P′-DDT in the treatment on adding 1% AS were from zero to 7.4% higher than that of 1% CM. The degradation rates of P, P′-DDT in the treatment on adding 2% AS were from zero to 11.3% higher than that of 2% CM. The degradation rates of P, P′-DDT in the treatment on adding 3% AS were from 8.3% to 27.4% higher than that of 3% CM. which indicated that AS is more conducive to the degradation of p, p'-DDT in the clay.

The effects of cement and natural zeolite additives on problematic clay soils

2013 ◽  
Vol 20 (4) ◽  
pp. 395-405 ◽  
Author(s):  
Murat Turkoz ◽  
Pinar Vural
Keyword(s):  
Natural Zeolite ◽  
Clay Soil ◽  
Expansive Soils ◽  
Chemical Properties ◽  
Soil Samples ◽  
Clay Soils ◽  
Engineering Structures ◽  
Significant Strength ◽  
Strength Tests ◽  
Physical And Chemical

AbstractDispersive and expansive soils are considered problematic, and these soil properties cause serious problems for many engineering structures. For many years, comprehensive studies have been carried out with the aim of improving the swelling and dispersive qualities of soils by using additives. Each feature in the literature associated with the improvement of the dispersive and swell properties of clay soil with additives was separately evaluated. In this study, the effect of cement and natural zeolite additives on the characteristics of dispersibility and swelling potential of clay soils were investigated. A fixed percentage of cement (3%) plus different percentages of natural zeolite (1%, 3%, 6%, 10%, 15%, and 20%) were mixed with four different clay soil samples. In this context, first, the physical and chemical properties of the soil samples were determined. Next, the swell percentage, swell pressure, crumb, pinhole and unconfined compressive strength tests at different curing times were performed on samples with and without the additive by compressing the sample to achieve particular compaction characteristics. Significant strength value increases depended on curing time, and the properties were improved with the mixture of cement and zeolite additives, depending on the sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) values of clay soil samples with different plasticity characteristics that exhibit dispersive and swell properties. This study not only showed that a mixture of cement and zeolite additives improved the dispersive and swell properties of clay soil samples with four different plasticity characteristics, depending on their SAR and ESP values, but also significant increases in strength values were observed.

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