Search results for: accelerated soil erosion
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3589

Search results for: accelerated soil erosion

3229 Assessing Vertical Distribution of Soil Organic Carbon Stocks in Westleigh Soil under Shrub Encroached Rangeland, Limpopo Province, South Africa

Authors: Abel L. Masotla, Phesheya E. Dlamini, Vusumuzi E. Mbanjwa

Abstract:

Accurate quantification of the vertical distribution of soil organic carbon (SOC) in relation to land cover transformations, associated with shrub encroachment is crucial because deeper lying horizons have been shown to have greater capacity to sequester SOC. Despite this, in-depth soil carbon dynamics remain poorly understood, especially in arid and semi-arid rangelands. The objective of this study was to quantify and compare the vertical distribution of soil organic carbon stocks (SOCs) in shrub-encroached and open grassland sites. To achieve this, soil samples were collected vertically at 10 cm depth intervals under both sites. The results showed that SOC was on average 19% and 13% greater in the topsoil and subsoil respectively, under shrub-encroached grassland compared to open grassland. In both topsoil and subsoil, lower SOCs were found under shrub-encroached (4.53 kg m⁻² and 3.90 kgm⁻²) relative to open grassland (4.39 kgm⁻² and 3.67 kgm⁻²). These results demonstrate that deeper soil horizon play a critical role in the storage of SOC in savanna grassland.

Keywords: savanna grasslands, shrub-encroachment, soil organic carbon, vertical distribution

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3228 Effects of Post-Emergence Herbicides on Soil Micro-Flora and Nitrogen Fixing Bacteria in Pea Field

Authors: Ali M. Zaid, Muftah Mayouf, Yahya Said Farouj

Abstract:

The effect of post emergence herbicides on soil micro-flora and nitrogen fixing bacteria was studied in pea field. Pea (Pisum sativum) was grown and treated with one or a mixture of two of several herbicides 2 weeks after sowing. Soil samples were collected 2 weeks after herbicides application. Average number of colony forming units per gram of soil of bacteria, actinomycetes and fungi were determined. Average number of nodules per plant was obtained at the end of the growing season. The results of the study showed MCPB, Bentazon, MCPB+Fluozifop-p-butyl, Bentazon+Fluozifop-p-butyl, Metribuzin, Flouzifop-p-butyl+Metribuzin, Cycloxydin, and Sethoxydin increased the population of soil fungi, with 4 to 10 times compared with the control. The herbicides used showed no significant effects on nitrogen fixing bacteria. The effects of herbicides on soil bacteria and actinomycetes were different. The study showed the use of herbicides could influence the biological balance of soil microflora, which has an important role in soil fertility and microbial ecosystem.

Keywords: herbicides, post emergence, nitrogen fixing bacteria, environmental systems

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3227 A Study of Combined Mechanical and Chemical Stabilisation of Fine Grained Dredge Soil of River Jhelum

Authors: Adnan F. Sheikh, Fayaz A. Mir

Abstract:

After the recent devastating flood in Kashmir in 2014, dredging of the local water bodies, especially Jhelum River has become a priority for the government. Local government under the project name of 'Comprehensive Flood Management Programme' plans to undertake an increase in discharge of existing flood channels by removal of encroachments and acquisition of additional land, dredging and other works of the water bodies. The total quantity of soil to be dredged will be 16.15 lac cumecs. Dredged soil is a major component that would result from the project which requires disposal/utilization. This study analyses the effect of cement and sand on the engineering properties of soil. The tests were conducted with variable additions of sand (10%, 20% and 30%), whereas cement was added at 12%. Samples with following compositions: soil-cement (12%) and soil-sand (30%) were tested as well. Laboratory experiments were conducted to determine the engineering characteristics of soil, i.e., compaction, strength, and CBR characteristics. The strength characteristics of the soil were determined by unconfined compressive strength test and direct shear test. Unconfined compressive strength of the soil was tested immediately and for a curing period of seven days. CBR test was performed for unsoaked, soaked (worst condition- 4 days) and cured (4 days) samples.

Keywords: comprehensive flood management programme, dredge soil, strength characteristics, flood

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3226 Soil and Environmental Management Awareness as Professional Competency of the Agricultural Extension Officers for Their Plans Implementation

Authors: Muhammad Zafarullah Khan

Abstract:

Agricultural Extension Officers’ (AEOs) competency level in soil and environmental management awareness is important for interacting with farming communities of different types of soil. Questionnaire was developed for all AEOs for data collection to know the present position and needed position of competency on Likert scale from 01-05 by assigning very low (01) and very high (05). Wide gap was found in competency of suitability of various soil types for horticultural and agronomic crops and reclamation of saline soil. We observed that suitability ranking of various soil types for horticultural crops (Diff. = 1.21), agronomic crops (Diff. = 1.20) and soil borne diseases (Diff. = 1.19) were the top three important competencies where training or improvement is needed. To better fill this gap we recommend that professional qualification of AEOs should be enhanced and training opportunities should be provided to them particularly to deal with soil and environmental management awareness. Thus training opportunities may increase their competency and will add highly skilled manpower to the system for sustainable development to protect environment. It is therefore, recommended that AEOs may be provided pre and in service trainings of soil environmental management in order to equip them with a capacity to work with farming community effectively to boost the living standard of farming community and alleviate poverty for environmental protection.

Keywords: professional competency, agricultural extension officers, soil and environmental management awareness, plans implementation

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3225 Soil Moisture Regulation in Irrigated Agriculture

Authors: I. Kruashvili, I. Inashvili, K. Bziava, M. Lomishvili

Abstract:

Seepage capillary anomalies in the active layer of soil, related to the soil water movement, often cause variation of soil hydrophysical properties and become one of the main objectives of the hydroecology. It is necessary to mention that all existing equations for computing the seepage flow particularly from soil channels, through dams, bulkheads, and foundations of hydraulic engineering structures are preferable based on the linear seepage law. Regarding the existing beliefs, anomalous seepage is based on postulates according to which the fluid in free volume is characterized by resistance against shear deformation and is presented in the form of initial gradient. According to the above-mentioned information, we have determined: Equation to calculate seepage coefficient when the velocity of transition flow is equal to seepage flow velocity; by means of power function, equations for the calculation of average and maximum velocities of seepage flow have been derived; taking into consideration the fluid continuity condition, average velocity for calculation of average velocity in capillary tube has been received.

Keywords: seepage, soil, velocity, water

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3224 Evaluation of the Skid Resistance of Asphalt Concrete Made of Local Low-Performance Aggregates Based on New Accelerated Polishing Machine

Authors: Saci Abdelhakim Ferkous, Khedoudja Soudani, Smail Haddadi

Abstract:

This paper presents the results of a laboratory experimental study that explores the skid resistance of asphalt concrete mixtures made of local low-performance aggregates by partially replacing sand with olive mill waste (OMW). OMW was mixed with aggregates using a dry process by replacing sand with contents of 5%, 7%, 10% and 15%. The mechanical performances of the mixtures were evaluated using the Marshall and Duriez tests. A modified accelerated polishing machine was used as polishing equipment, and a British pendulum tester (BPT) was used to test the skid resistance of the samples. Finally, texture parameter analysis was performed using scanning electron microscopy (SEM) and Mountains Map software to assess the effect of OMW on the friction coefficient evolution. Using a distinct road wheel for a modified version of an accelerated polishing machine, which is normally used to determine the polished stone value of aggregates, the results showed that the addition of OMW up to 10% conferred a better skid resistance in comparison to normal asphalt concrete. The presence of olive mill waste in the mixture until 15% guarantees a gain of 22%-29% in skid resistance after polishing compared with the reference mix. Indeed, from texture parameter analysis, it was observed that there was differential wear of the lightweight aggregates (OMW) compared to the other aggregates during the polishing process, which created a new surface microtexture that had new peaks and led to a good level of friction compared to the mixtures without OMW. In general, it was found that OMW is a promising modifier for asphalt mixtures with both engineering and economic merits.

Keywords: skid resistance, olive mill waste, polishing resistance, accelerated polishing machine, local materials, sustainable development.

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3223 Evaluation of Ecological Resilience in Mountain-plain Transition Zones: A Case Study of Dujiangyan City, Chengdu

Authors: Zhu Zhizheng, Huang Yong, Li Tong

Abstract:

In the context of land and space development and resource environmental protection. Due to its special geographical location, mountain-plain transition zones are limited by many factors such as topography, mountain forest protection, etc., and their ecology is also more sensitive, with the characteristics of disaster susceptibility and resource gradient. Taking Dujiangyan City, Chengdu as an example, this paper establishes resilience evaluation indicators on the basis of ecological suitability evaluation through the analysis of current situation data and relevant policies: water conservation evaluation, soil and water conservation evaluation, biodiversity evaluation, soil erosion sensitivity evaluation, etc. Based on GIS spatial analysis, the ecological suitability and resilience evaluation results of Dujiangyan city were obtained by disjunction operation. The ecological resilience level of Dujiangyan city was divided into three categories: high, medium and low, with an area ratio of 50.81%, 16.4% and 32.79%, respectively. This paper can provide ideas for solving the contradiction between man and land in the mountain-plain transition zones, and also provide a certain basis for the construction of regional ecological protection and the delineation of three zones and three lines.

Keywords: urban and rural planning, ecological resilience, dujiangyan city, mountain-plain transition zones

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3222 The Effect of the Combination of Mouthwash and Saliva Substitutes on Tooth Erosion: An in Vitro Study

Authors: Young-Eun Jang, Mi-Hye Ma, Yemi Kim

Abstract:

As the elderly population increases, the number of patients complaining of dry mouth is also increasing. Elderly people often use mouthwash to prevent periodontal disease. Mouthwash and saliva substitutes with low pH were reported to be able to cause enamel erosion. To the best of our knowledge, there have been no studies showing the effect of mouthwash on patients using saliva substitutes. Therefore, the purpose of this study was to evaluate the effect of the use of mouthwash in combination with saliva substitutes on tooth erosion using a quantitative light-induced fluorescence-digital (QLF-D) system. A total of 96 bovine specimens were embedded in putty blocks and randomly allocated to the following groups with n = 12 each: Group 1, application of mouthwash; Group 2, application of saliva substitutes; Group 3, application of saliva substitutes in combination with mouthwash; and control group, application of saline. The bovine samples were eroded using a demineralization solution and then saliva substitutes and mouthwash were applied according to the groups for 2 weeks. For saliva substitutes, three different products were used; Oasis (Oasis Consumer Health, Cleveland, OH, USA), Xeromia solution (Osstem Pharma Co., Seoul, Korea), and Drymund gel (Dong-A Pharma Co., Seoul, Korea). The pH values of the saliva substitutes were determined using a pH meter. Loss of enamel and root dentin was measured using the QLF-D system immediately after demineralization on the 3rd, 7th, and 14th days. The data were analyzed using repeated measures ANOVA followed by Tukey’s post hoc tests (p < 0.05). Mineral loss in enamel and root dentin was detected when mouthwash and saliva substitutes were used alone, respectively (p < 0.05). Also, when mouthwash was used with saliva substitutes, the mineral loss was observed in enamel and root dentin (p < 0.05). The use of Xeromia and Drymund gel increased mineral loss of enamel significantly compared to the use of Oasis (p < 0.05). However, when Drymund gel and Xeromia were used in combination with mouthwash, mineral loss of enamel was significantly reduced compared to when they were used alone (p < 0.05). The pH values of Drymund gel, Xeromia, Oasis, and mouthwash were 5.5, 5.52, 6.2, and 6.37, respectively. Based on these results, it can be concluded that the use of mouthwash with a higher pH value than that of saliva substitutes could help patients suffering from xerostomia avoid the risk of dental erosion.

Keywords: saliva substitute, mouthwash, tooth erosion, dry mouth

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3221 Experimental Study of Geotextile Effect on Improving Soil Bearing Capacity in Aggregate Surfaced Roads

Authors: Mahdi Taghipour Masoumi, Ali Abdi Kordani, Mahmoud Nazirizad

Abstract:

Geosynthetics utilization plays an important role in the construction of highways with no additive layers, such as asphalt concrete or cement concrete, or in a subgrade layer which affects the bearing capacity of unbounded layers. This laboratory experimental study was carried out to evaluate changes in the load bearing capacity of reinforced soil with these materials in highway roadbed with regard to geotextile properties. California Bearing Ratio (CBR) test samples were prepared with two types of soil: Clayey and sandy containing non-reinforced and reinforced soil. The samples comprised three types of geotextiles with different characteristics (150, 200, 300 g/m2) and depths (H= 5, 10, 20, 30, 50, 100 mm), and were grouped into two forms, one-layered and two-layered, based on the sample materials in order to perform defined tests. The results showed that the soil bearing characteristics increased when one layer of geotextile was used in clayey and sandy samples reinforced by geotextile. However, the bearing capacity of the soil, in the presence of a geotextile layer material with depth of more than 30 mm, had no remarkable effect. Furthermore, when the two-layered geotextile was applied in material samples, although it increased the soil resistance, it also showed that through the addition of a number or weights of geotextile into samples, the natural composition of the soil changed and the results are unreliable.

Keywords: reinforced soil, geosynthetics, geotextile, transportation capacity, CBR experiments

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3220 Soil Surface Insect Diversity of Tobacco Agricultural Ecosystem in Imogiri, Bantul District of Yogyakarta Special Region, Indonesia

Authors: Martina Faika Harianja, Zahtamal, Indah Nuraini, Septi Mutia Handayani, R. C. Hidayat Soesilohadi

Abstract:

Tobacco is a valuable commodity that supports economic growth in Indonesia. Soil surface insects are important components that influence productivity of tobacco. Thus, diversity of soil surface insects needs to be studied in order to acquire information about specific roles of each species in ecosystem. This research aimed to study the soil surface insect diversity of tobacco agricultural ecosystem in Imogiri, Bantul District of Yogyakarta Special Region, Indonesia. Samples were collected by pitfall-sugar bait trap in August 2015. Result showed 5 orders, 8 families, and 17 genera of soil surface insects were found. The diversity category of soil surface insects in tobacco agricultural ecosystem was poor. Dominant genus was Monomorium with dominance index score 0.07588. Percentages of insects’ roles were omnivores 43%, detritivores 24%, predators 19%, and herbivores 14%.

Keywords: diversity, Indonesia, soil surface insect, tobacco

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3219 Influence of Alccofine on Semi-Light Weight Concrete under Accelerated Curing and Conventional Curing Regimes

Authors: P. Parthiban, J. Karthikeyan

Abstract:

This paper deals with the performance of semi-light weight concrete, prepared by using wood ash pellets as coarse aggregates which were improved by partial replacement of cement with alccofine. Alccofine is a mineral admixture which contains high glass content obtained through the process of controlled granulation. This is finer than cement which carries its own pozzolanic property. Therefore, cement could be replaced by alccofine as 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, and 70% to enhance the strength and durability properties of concrete. High range water reducing admixtures (HRWA) were used in these mixes which were dosed up to 1.5% weight of the total cementitious content (alccofine & cement). It also develops the weaker transition zone into more impermeable layer. Specimens were subjected in both the accelerated curing method as well as conventional curing method. Experimental results were compared and reported, in that the maximum compressive strength of 32.6 MPa was achieved on 28th day with 30% replacement level in a density of 2200 kg/m3 to a conventional curing, while in the accelerated curing, maximum compressive strength was achieved at 40% replacement level. Rapid chloride penetration test (RCPT) output results for the conventional curing method at 0% and 70% give 3296.7 and 545.6 coulombs.

Keywords: Alccofine, compressive strength, RCPT, wood ash pellets

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3218 Different Tools and Complex Approach for Improving Phytoremediation Technology

Authors: T. Varazi, M. Pruidze, M. Kurashvili, N. Gagelidze, M. Sutton

Abstract:

The complex phytoremediation approach given in the presented work implies joint application of natural sorbents, microorganisms, natural biosurfactants and plants. The approach is based on using the natural mineral composites, microorganism strains with high detoxification abilities, plants-phytoremediators and natural biosurfactants for enhancing the uptake of intermediates of pollutants by plant roots. In this complex strategy of phytoremediation technology, the sorbent serves to uptake and trap the pollutants and thus restrain their emission in the environment. The role of microorganisms is to accomplish the first stage biodegradation of organic contaminants. This is followed by application of a phytoremediation technology through purposeful planting of selected plants. Thus, using of different tools will provide restoration of polluted environment and prevention of toxic compounds’ dissemination from hotbeds of pollution for a considerable length of time. The main idea and novelty of the carried out work is the development of a new approach for the ecological safety. The wide spectrum of contaminants: Organochlorine pesticide – DDT, heavy metal –Cu, oil hydrocarbon (hexadecane) and wax have been used in this work. The presented complex biotechnology is important from the viewpoint of prevention, providing total rehabilitation of soil. It is unique to chemical pollutants, ecologically friendly and provides the control of erosion of soils.

Keywords: bioremediation, phytoremediation, pollutants, soil contamination

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3217 Soil Quality Response to Long-Term Intensive Resources Management and Soil Texture

Authors: Dalia Feiziene, Virginijus Feiza, Agne Putramentaite, Jonas Volungevicius, Kristina Amaleviciute, Sarunas Antanaitis

Abstract:

The investigations on soil conservation are one of the most important topics in modern agronomy. Soil management practices have great influence on soil physico-chemical quality and GHG emission. Research objective: To reveal the sensitivity and vitality of soils with different texture to long-term antropogenisation on Cambisol in Central Lithuania and to compare them with not antropogenised soil resources. Methods: Two long-term field experiments (loam on loam; sandy loam on loam) with different management intensity were estimated. Disturbed and undisturbed soil samples were collected from 5-10, 15-20 and 30-35 cm depths. Soil available P and K contents were determined by ammonium lactate extraction, total N by the dry combustion method, SOC content by Tyurin titrimetric (classical) method, texture by pipette method. In undisturbed core samples soil pore volume distribution, plant available water (PAW) content were determined. A closed chamber method was applied to quantify soil respiration (SR). Results: Long-term resources management changed soil quality. In soil with loam texture, within 0-10, 10-20 and 30-35 cm soil layers, significantly higher PAW, SOC and mesoporosity (MsP) were under no-tillage (NT) than under conventional tillage (CT). However, total porosity (TP) under NT was significantly higher only in 0-10 cm layer. MsP acted as dominant factor for N, P and K accumulation in adequate layers. P content in all soil layers was higher under NT than in CT. N and K contents were significantly higher than under CT only in 0-10 cm layer. In soil with sandy loam texture, significant increase in SOC, PAW, MsP, N, P and K under NT was only in 0-10 cm layer. TP under NT was significantly lower in all layers. PAW acted as strong dominant factor for N, P, K accumulation. The higher PAW the higher NPK contents were determined. NT did not secure chemical quality within deeper layers than CT. Long-term application of mineral fertilisers significantly increased SOC and soil NPK contents primarily in top-soil. Enlarged fertilization determined the significantly higher leaching of nutrients to deeper soil layers (CT) and increased hazards of top-soil pollution. Straw returning significantly increased SOC and NPK accumulation in top-soil. The SR on sandy loam was significantly higher than on loam. At dry weather conditions, on loam SR was higher in NT than in CT, on sandy loam SR was higher in CT than in NT. NPK fertilizers promoted significantly higher SR in both dry and wet year, but suppressed SR on sandy loam during usual year. Not antropogenised soil had similar SOC and NPK distribution within 0-35 cm layer and depended on genesis of soil profile horizons.

Keywords: fertilizers, long-term experiments, soil texture, soil tillage, straw

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3216 Bearing Capacity of Sulphuric Acid Content Soil

Authors: R. N. Khare, J. P. Sahu, Rajesh Kumar Tamrakar

Abstract:

Tests were conducted to determine the property of soil with variation of H2SO4 content for soils under different stage. The soils had varying amounts of plasticity’s ranging from low to high plasticity. The unsaturated soil behavior was investigated for different conditions, covering a range of compactive efforts and water contents. The soil characteristic curves were more sensitive to changes in compaction effort than changes in compaction water content. In this research paper two types of water (Ground water Ph =7.9, Turbidity= 13 ppm; Cl =2.1mg/l and surface water Ph =8.65; Turbidity=18.5; Cl=1mg/l) were selected of Bhilai Nagar, State-Chhattisgarh, India which is mixed with a certain type of soil. Results shows that by the presence of ground water day by day the particles are becoming coarser in 7 days thereafter its size reduces; on the other hand by the presence of surface water the courser particles are disintegrating, finer particles are accumulating and also the dry density is reduces. Plasticity soils retained the smallest water content and the highest plasticity soils retained the highest water content at a specified suction. In addition, soil characteristic for soils to be compacted in the laboratory and in the field are still under process for analyzing the bearing capacity. The bearing capacity was reduced 2 to 3 times in the presence of H2SO4.

Keywords: soil compaction, H2SO4, soil water, water conditions

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3215 Dynamic Study on the Evaluation of the Settlement of Soil under Sea Dam

Authors: Faroudja Meziani, Amar Kahil

Abstract:

In order to study the variation in settlement of soil under a dyke dam, the modelisation in our study consists of applying an imposed displacement at the base of the mass of soil (consisting of a saturated sand). The imposed displacement follows the evolution of acceleration of the earthquake of Boumerdes 2003 in Algeria. Moreover, the gravity load is taken into consideration by taking account the specific weight of the materials constituting the dyke. The results obtained show that the gravity loads have a direct influence on the evolution of settlement, especially at the center of the dyke where these loads are higher.

Keywords: settlement, dynamic analysis, rockfill dam, effect of earthquake, soil dynamics

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3214 Investigating the Potential of Spectral Bands in the Detection of Heavy Metals in Soil

Authors: Golayeh Yousefi, Mehdi Homaee, Ali Akbar Norouzi

Abstract:

Ongoing monitoring of soil contamination by heavy metals is critical for ecosystem stability and environmental protection, and food security. The conventional methods of determining these soil contaminants are time-consuming and costly. Spectroscopy in the visible near-infrared (VNIR) - short wave infrared (SWIR) region is a rapid, non-destructive, noninvasive, and cost-effective method for assessment of soil heavy metals concentration by studying the spectral properties of soil constituents. The aim of this study is to derive spectral bands and important ranges that are sensitive to heavy metals and can be used to estimate the concentration of these soil contaminants. In other words, the change in the spectral properties of spectrally active constituents of soil can lead to the accurate identification and estimation of the concentration of these compounds in soil. For this purpose, 325 soil samples were collected, and their spectral reflectance curves were evaluated at a range of 350-2500 nm. After spectral preprocessing operations, the partial least-squares regression (PLSR) model was fitted on spectral data to predict the concentration of Cu and Ni. Based on the results, the spectral range of Cu- sensitive spectra were 480, 580-610, 1370, 1425, 1850, 1920, 2145, and 2200 nm, and Ni-sensitive ranges were 543, 655, 761, 1003, 1271, 1415, 1903, 2199 nm. Finally, the results of this study indicated that the spectral data contains a lot of information that can be applied to identify the soil properties, such as the concentration of heavy metals, with more detail.

Keywords: heavy metals, spectroscopy, spectral bands, PLS regression

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3213 Geotechnical Investigation of Soil Foundation for Ramps of Dawar El-Tawheed Bridge in Jizan City, Kingdom of Saudi Arabia

Authors: Ali H. Mahfouz, Hossam E. M. Sallam, Abdulwali Wazir, Hamod H. Kharezi

Abstract:

The soil profile at site of the bridge project includes soft fine grained soil layer located between 5.0 m to 11.0 m in depth, it has high water content, low SPT no., and low bearing capacity. The clay layer induces high settlement due to surcharge application of earth embankment at ramp T1, ramp T2, and ramp T3 especially at heights from 9m right 3m. Calculated settlement for embankment heights less than 3m may be accepted regarding Saudi Code for soil and foundation. The soil and groundwater at the project site comprise high contents of sulfates and chlorides of high aggressively on concrete and steel bars, respectively. Regarding results of the study, it has been recommended to use stone column piles or new technology named PCC piles as soil improvement to improve the bearing capacity of the weak layer. The new technology is cast in-situ thin wall concrete pipe piles (PCC piles), it has economically advantageous and high workability. The technology can save time of implementation and cost of application is almost 30% of other types of piles.

Keywords: soft foundation soil, bearing capacity, bridge ramps, soil improvement, geogrid, PCC piles

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3212 Statistical Assessment of Models for Determination of Soil–Water Characteristic Curves of Sand Soils

Authors: S. J. Matlan, M. Mukhlisin, M. R. Taha

Abstract:

Characterization of the engineering behavior of unsaturated soil is dependent on the soil-water characteristic curve (SWCC), a graphical representation of the relationship between water content or degree of saturation and soil suction. A reasonable description of the SWCC is thus important for the accurate prediction of unsaturated soil parameters. The measurement procedures for determining the SWCC, however, are difficult, expensive, and time-consuming. During the past few decades, researchers have laid a major focus on developing empirical equations for predicting the SWCC, with a large number of empirical models suggested. One of the most crucial questions is how precisely existing equations can represent the SWCC. As different models have different ranges of capability, it is essential to evaluate the precision of the SWCC models used for each particular soil type for better SWCC estimation. It is expected that better estimation of SWCC would be achieved via a thorough statistical analysis of its distribution within a particular soil class. With this in view, a statistical analysis was conducted in order to evaluate the reliability of the SWCC prediction models against laboratory measurement. Optimization techniques were used to obtain the best-fit of the model parameters in four forms of SWCC equation, using laboratory data for relatively coarse-textured (i.e., sandy) soil. The four most prominent SWCCs were evaluated and computed for each sample. The result shows that the Brooks and Corey model is the most consistent in describing the SWCC for sand soil type. The Brooks and Corey model prediction also exhibit compatibility with samples ranging from low to high soil water content in which subjected to the samples that evaluated in this study.

Keywords: soil-water characteristic curve (SWCC), statistical analysis, unsaturated soil, geotechnical engineering

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3211 Physical and Chemical Properties during Home Composting of Municipal Organic Solid Waste in Jordan and Production of Organic Fertilizer

Authors: Munir Rusan

Abstract:

Municipal waste management (MWM) represents a cornerstone in the effort to preserve the environment, which guarantees a healthy living environment for communities. MWM is directly affected by population growth and population density, urbanization, and tourism. In Jordan, MWM is currently managed by transferring and dumping waste into landfills. Landfills are mostly saturated and cannot receive any more waste. Besides, the organic waste, which accounts for 50% of municipal waste, will be naturally fermented in the landfills creating an unpleasant odor and emits greenhouse gases as well as generate organic leachates that are harmful to the environment. Organic waste can be aerobically composted and generate organic fertilizer called compost. Compost is very beneficial to soil and plant growth and, in general, to the ecosystem. Home composting is very common in most developed countries, but unfortunately, in developing countries such as Jordan, such an approach is not practiced and is not even socially well acceptable. The objective of this study was to evaluate the physical and chemical properties of home composting materials and to produce compost for further use as a soil amendment. The effect of compost soil application on the soil-plant system was evaluated. The soil application of the compost resulted in enhancing soil organic matter and soil N, P, and K content. The plant growth was also improved quantitatively and qualitatively. It was concluded that composting of municipal organic solid waste and soil application of the compost has a significant positive impact on the environment and soil-plant productivity.

Keywords: composting, organic solid waste, soil, plant

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3210 Consolidation Behavior of Lebanese Soil and Its Correlation with the Soil Parameters

Authors: Robert G. Nini

Abstract:

Soil consolidation is one of the biggest problem facing engineers. The consolidation process has an important role in settlement analysis for the embankments and footings resting on clayey soils. The settlement amount is related to the compression and the swelling indexes of the soil. Because the predominant upper soil layer in Lebanon is consisting mainly of clay, this layer is a real challenge for structural and highway engineering. To determine the effect of load and drainage on the engineering consolidation characteristics of Lebanese soil, a full experimental and synthesis study was conducted on different soil samples collected from many locations. This study consists of two parts. During the first part which is an experimental one, the Proctor test and the consolidation test were performed on the collected soil samples. After it, the identifications soil tests as hydrometer, specific gravity and Atterberg limits are done. The consolidation test which is the main test in this research is done by loading the soil for some days then an unloading cycle was applied. It takes two weeks to complete a typical consolidation test. Because of these reasons, during the second part of our research which is based on the analysis of the experiments results, some correlations were found between the main consolidation parameters as compression and swelling indexes with the other soil parameters easy to calculate. The results show that the compression and swelling indexes of Lebanese clays may be roughly estimated using a model involving one or two variables in the form of the natural void ratio and the Atterberg limits. These correlations have increasing importance for site engineers, and the proposed model also seems to be applicable to a wide range of clays worldwide.

Keywords: atterberg limits, clay, compression and swelling indexes, settlement, soil consolidation

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3209 Accelerated Aging of Photopolymeric Material Used in Flexography

Authors: S. Mahovic Poljacek, T. Tomasegovic, T. Cigula, D. Donevski, R. Szentgyörgyvölgyi, S. Jakovljevic

Abstract:

In this paper, a degradation of the photopolymeric material (PhPM), used as printing plate in the flexography reproduction technique, caused by accelerated aging has been observed. Since the basis process for production of printing plates from the PhPM is a radical cross-linking process caused by exposing to UV wavelengths, the assumption was that improper storage or irregular handling of the PhPM plate can change the surface and structure characteristics of the plates. Results have shown that the aging process causes degradation in the structure and changes in the surface of the PhPM printing plate.

Keywords: aging process, artificial treatment, flexography, photopolymeric material (PhPM)

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3208 Nickel and Chromium Distributions in Soil and Plant Influenced by Geogenic Sources

Authors: Mohamad Sakizadeh, Fatemeh Mehrabi Sharafabadi, Hadi Ghorbani

Abstract:

Concentrations of Cr and Ni in 97 plant samples (belonged to eight different plant species) and the associated soil groups were considered in this study. The amounts of Ni in soil groups fluctuated between 26.8 and 36.8 mgkg⁻¹ whereas the related levels of chromium ranged from 67.7 to 94.3mgkg⁻¹. The index of geoaccumulation indicated that 87 percents of the studied soils for chromium and 98.8 percents for nickel are located in uncontaminated zone. The results of Mann-Whitney U-test proved that agricultural practices have not significantly influenced the values of Ni and Cr. In addition, tillage had also little impact on the Ni and Cr transfer in the surface soil. Ni showed higher accumulation and soil-to-plant transfer factor compared with that of chromium in the studied plants. There was a high similarity between the accumulation pattern of Cr and Fe in most of the plant species.

Keywords: bioconcentration factor, chromium, geoaccumulation index, nickel

Procedia PDF Downloads 328
3207 Improvement of Deficient Soils in Nigeria Using Bagasse Ash - A Review

Authors: Musa Alhassan, Alhaji Mohammed Mustapha

Abstract:

Review of studies carried out on the use of bagasse ash in the improvement of deficient soils in Nigeria, with emphasis on lateritic and black cotton soils is presented. Although, the bagasse ash is mostly used as additive to the conventional soil stabilizer (cement and lime), the studies generally showed improvement of geotechnical properties of the soils either modified or stabilized with the ash. This showed the potentials of using this agricultural waste (bagasse ash) in the improvement of geotechnical properties of deficient soils. Thus suggesting that using this material at large scale level, in geotechnical engineering practice could help in the provision of stable and durable structures, reduce cost of soil improvement and also reduces environmental nuisance caused by the unused waste in Nigeria

Keywords: bagasse ash, black cotton soil, deficient soil, laterite, soil improvement

Procedia PDF Downloads 385
3206 Sustainable Underground Structures Through Soil-Driven Bio-Protection of Concrete

Authors: Abdurahim Abogdera, Omar Hamza, David Elliott

Abstract:

The soil bacteria can be affected by some factors such as pH, calcium ions and Electrical conductivity. Fresh concrete has high pH value, which is between 11 and 13 and these values will be prevented the bacteria to produce CO₂ to participate with Calcium ions that released from the concrete to get calcite. In this study we replaced 15% and 25% of cement with Fly ash as the fly ash reduce the value of the pH at the concrete. The main goal of this study was investigated whether bacteria can be used on the soil rather than in the concrete to avoid the challenges and limitations of containing bacteria inside the concrete. This was achieved by incubating cracked cement mortar specimens into fully saturated sterilized and non-sterilized soil. The crack sealing developed in the specimens during the incubation period in both soil conditions were evaluated and compared. Visual inspection, water absorption test, scanning electron microscopy (SEM), and Energy Dispersive X-ray (EDX) were conducted to evaluate the healing process.

Keywords: pH, calcium ions, MICP, salinity

Procedia PDF Downloads 87
3205 Impact of Fly Ash on Soil Quality in Semi-Arid Region

Authors: Anjuri Srivastava, Akhouri Nishant Bhanu

Abstract:

Soil is a natural material with a distinctive form. It is regarded to be a natural source of nutrients and minerals for plants. It meets many of our needs through the crops, trees, and inhabited places that have grown on or underneath it. Productive and rich soil plays a crucial role in both its wealth and well-being. If any external substance changes the soil's composition, it directly impacts the plant that was grown in that soil. If the soil is deficient in one or more essential components, fly ash can be utilized as fertilizer by incorporating it into the soil. This can also increase the porosity of the soil. Fly ash has a sufficient concentration of essential components to promote the growth of plants. The high concentration of elements in fly ash, including C, Na, K, Fe, and Zn, increases crop yields. Hazardous compounds harm plant life as soon as they get into the soil. The US Environmental Protection Agency and other regulatory agencies have found it as non-hazardous. By employing fly ash as a potential fertilizer supplement for degraded soils, the problem of disposing of solid waste can be partially handled. Fly ash's rapid growth can slow down mineralization because it contains a higher proportion of harmful heavy metals. The chemical characteristics, inclusion ratio, and composting process of fly ash have a significant impact on the fly ash compost’s potential to improve soil nutrition. Research institutions and regulatory agencies have been thoroughly investigating fly ash for a long time. Guard cells on plant leaves that accumulate fly ash trigger the regulatory system. Fly ash increases both chemical and physical damage at certain humidity levels. The lengthy sowing period is caused by the high levels of fly ash in the soil, which also slows down seedling germination and growth. For the sake of human health, it is crucial to consider the bioaccumulation of dangerous heavy metals and their necessary concentrations in plant tissues and soil.

Keywords: soil, fly ash, plant, fertilizer, composts

Procedia PDF Downloads 66
3204 Service Life Study of Polymers Used in Renovation of Heritage Buildings and Other Structures

Authors: Parastou Kharazmi

Abstract:

Degradation of building materials particularly pipelines causes environmental damage during renovation or replacement and is a time consuming and costly process. Rehabilitation by polymer composites is a solution for renovation of degraded pipeline in heritage buildings and other structures which are less costly, faster and causes less damage to the environment; however, it is still not clear for how long these materials can perform as expected in the field and working condition. To study their service life, two types of composites based on Epoxy and Polyester resins have been evaluated by accelerated exposure and field exposure. The primary degradation agent used in accelerated exposure has been cycling temperature with half of the tests performed in presence of water. Thin films of materials used in accelerated testing were prepared in laboratory by using the same amount of material as well as technique of multi-layers application used in majority of the field installations. Extreme intensity levels of degradation agents have been used only to evaluate materials properties and as also mentioned in ISO 15686, are not directly correlated with degradation mechanisms that would be experienced in service. In the field exposure study, the focus has been to identify possible failure modes, causes, and effects. In field exposure, it has been observed that there are other degradation agents present which can be investigated further such as presence of contaminants and rust before application which prevents formation of a uniform layer of polymer or incompatibility between dissimilar materials. This part of the study also highlighted the importance of application’s quality of the materials in the field for providing the expected performance and service life. Results from extended accelerated exposure and field exposure can help in choosing inspection techniques, establishing the primary degradation agents and can be used for ageing exposure programs with clarifying relationship between different exposure periods and sites.

Keywords: building, renovation, service life, pipelines

Procedia PDF Downloads 171
3203 Formulation of Extended-Release Ranolazine Tablet and Investigation Its Stability in the Accelerated Stability Condition at 40⁰C and 75% Humidity

Authors: Farzad Khajavi, Farzaneh Jalilfar, Faranak Jafari, Leila Shokrani

Abstract:

Formulation of Ranolazine in the form of extended-release tablet in 500 mg dosage form was performed using Eudragit L100-55 as a retarding agent. Drug-release profiles were investigated in comparison with the reference Ranexa extended-release 500 mg tablet. F₂ and f₁ were calculated as 64.16 and 8.53, respectively. According to Peppas equation, the release of drug is controlled by diffusion (n=0.5). The tablets were put into accelerated stability conditions (40 °C, 75% humidity) for 3 and 6 months. The dissolution release profiles and other physical and chemical characteristics of the tablets confirmed the robustness and stability of formulation in this condition.

Keywords: drug release, extended-release tablet, ranolazine, stability

Procedia PDF Downloads 127
3202 Evaluation of Shear Strength Parameters of Rudsar Sandy Soil Stabilized with Waste Rubber Chips

Authors: R. Ziaie Moayed, M. Hamidzadeh

Abstract:

The use of waste rubber chips not only can be of great importance in terms of the environment, but also can be used to increase the shear strength of soils. The purpose of this study was to evaluate the variation of the internal friction angle of liquefiable sandy soil using waste rubber chips. For this purpose, the geotechnical properties of unmodified and modified soil samples by waste lining rubber chips have been evaluated and analyzed by performing the triaxial consolidated drained test. In order to prepare the laboratory specimens, the sandy soil in part of Rudsar shores in Gilan province, north of Iran with high liquefaction potential has been replaced by two percent of waste rubber chips. Samples have been compressed until reaching the two levels of density of 15.5 and 16.7 kN/m3. Also, in order to find the optimal length of chips in sandy soil, the rectangular rubber chips with the widths of 0.5 and 1 cm and the lengths of 0.5, 1, and 2 cm were used. The results showed that the addition of rubber chips to liquefiable sandy soil greatly increases the shear resistance of these soils. Also, it can be seen that decreasing the width and increasing the length-to-width ratio of rubber chips has a direct impact on the shear strength of the modified soil samples with rubber chips.

Keywords: improvement, shear strength, internal friction angle, sandy soil, rubber chip

Procedia PDF Downloads 124
3201 Environmentally Friendly KOH and NH4OH-KOH Pulping of Rice Straw

Authors: Omid Ghaffarzadeh Mollabashi, Sara Khorshidi, Hossein Kermanian Seyed, Majid Zabihzadeh

Abstract:

The main problem that hinders the intensive use of non-wood raw materials in papermaking industry is the environmental pollution caused by black liquor. As a matter of fact, black liquor of nonwood pulping is discharged to the environment due to the lack of recovery. Traditionally, NaOH pulping produces Na-based black liquor that may increase soil erosion and reduce soil permeability. With substitution of KOH/NH4OH with NaOH as the cooking liquor, K and N can act as a soil fertilizer while offering an environmentally acceptable disposal alternative. For this purpose, rice straw samples were pulped under the following conditions; Constant factors were: straw weight: 100 gram (based on oven dry), liquor to straw ratio 7:1 and maximum temperature, 170 and 180 ºC. Variable factors for KOH cooks were: KOH dosage of 14, 17 and %20 on oven dry of straw and times at maximum temperature of 60 and 90 minutes. For KOH-NH4OH cooks, KOH dosage of 5 and %10 and NH4OH dosage of 25 and %35, both based as oven dry of straw were applied. Besides, time at maximum temperature was 90 minutes. Yield ranges of KOH and KOH-NH4OH pulp samples were obtained from 37.28 to 48.62 and 45.63 to 48.08 percent, respectively. In addition, Kappa number ranged from 21.91 to 29.85 and 55.15 to 56.25, respectively. In comparison with soda, soda-AQ, cold soda, kraft, EDA (dissolving), De-Ethylene Glycol (dissolving), burst and tensile index for KOH pulp was more in similar cooking condition. With an exception of soda pulps, tear index of the mentioned pulp is more than all compared treatments. Therefore, it can be resulted that KOH pulping method is an appropriate choice for making paper of the rice straw. Also, compared to KOH-NH4OH, KOH pulping method is more appropriate choice because of better pulping results.

Keywords: environmentally friendly process, rice straw, NH4OH-KOH pulping, pulp properties

Procedia PDF Downloads 243
3200 Sustainable Improvement in Soil Properties and Maize Performance by Organic Fertilizers at Different Levels

Authors: Shahid Iqbal, Haroon Z. Khan, Muhammad Arif

Abstract:

A sustainable agricultural system involving the improvement in soil properties and crop performance cannot be developed without organic fertilizer use. The effects of poultry manure compost (PMC) and pressmud compost (PrMC) at different levels on improving the soil properties and maize performance has not been yet described by any study comprehensively. Thus, field experiments (2011 and 2012) were conducted at Agronomy Research Area, University of Agriculture Faisalabad (31°26'5" N and 73°4'6" E) in sandy loam soil to determine the improvement in soil properties and maize performance due to application of PMC and PrMC each at five different levels (2, 4, 6, 8 and 10 t ha-1). A control (unamended) treatment was also included for comparison. The results indicated that performance of PMC levels was superior to PrMC levels. Increasing both composts levels improved soil properties, maize growth, and stover yield. Results showed that during both years’ highest rates of PMC i.e. 10 and 8 t ha-1 improved the soil properties: ECe, pH, inorganic N, OM, and WHC higher than other treatments. While, 10 and 8 t PMC ha-1 also significantly increased leaf area index (LAI), crop growth rate (CGR) and net assimilation rate (NAR), and stover yield. Similarly, 10 and 8 t PMC ha-1 also improved the grain protein content, but contrarily, grain oil was lowest for 10 and 8 t ha-1 PMC during both years. Moreover, in both years highest gross and net income, and benefit cost ratio was also achieved by 10 and 8 t ha-1 PMC. It is concluded that PMC at rate of 10 and 8 t ha-1 sustainably improved soil properties and maize performance.

Keywords: compost, soil, maize, growth, yield

Procedia PDF Downloads 332