Search results for: multilayer soil strata
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3179

Search results for: multilayer soil strata

3149 Study of Buried Interfaces in Fe/Si Multilayer by Hard X-Ray Emission Spectroscopy

Authors: Hina Verma, Karine Le Guen, Renaud Dalaunay, Iyas Ismail, Vita Ilakovac, Jean Pascal Rueff, Yunlin Jacques Zheng, Philippe Jonnard

Abstract:

To the extent of our knowledge, X-ray emission spectroscopy (XES) has been applied in the soft x-ray region (photon energy ≤ 2 keV) to study the buried layers and interfaces of stacks of nanometer-thin films. Now we extend the methodology to study the buried interfaces in the hard X-ray region (i.e., ≥ five keV). The emission spectra allow us to study the interactions between elements in the buried layers from the analysis of their valence states, thereby providing sensitive information about the physical-chemical environment of the emitting element in multilayers. We exploit the chemical sensitivity of XES to study the interfaces between Fe and Si layers in the Fe/Si multilayer from the Fe Kβ₂,₅ emission spectra (7108 eV). The Fe Kβ₅ emission line results from the electronic transition from occupied 3d to 1s levels (i.e., valence to core transition) and is hence sensitive to the chemical state of emitting Fe atoms. The comparison of emission spectra recorded for Fe/Si multilayer with Fe and FeSi₂ references reveal the formation of FeSi₂ at the Fe-Si interfaces inside the multilayer stack. The interfacial thickness was calculated to be 1.4 ± 0.2 nm by taking into consideration the intensity of Fe atoms emitted from the interface and the Fe layer. The formation of FeSi₂ at the interface was further confirmed by the X-ray diffraction and X-ray photoelectron spectroscopy done on the Fe/Si multilayer. Hence, we can conclude that the XES in the hard X-ray range could be used to study multilayers and their interfaces and obtain information both qualitatively and quantitatively.

Keywords: buried interfaces, hard X-ray emission spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy

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3148 Mechanical Behavior of PVD Single Layer and Multilayer under Indentation Tests

Authors: K. Kaouther, D. Hafedh, A. Ben Cheikh Larbi

Abstract:

Various structures and compositions thin films were deposited on 100C6 (AISI 52100) steel substrate by PVD magnetron sputtering system. The morphological proprieties were evaluated using an atomic force microscopy (AFM). Vickers microindentation tests were performed with a Shimadzu HMV-2000 hardness testing machine. Hardness measurement was carried out using Jonsson and Hogmark model. The results show that the coatings topography was dominated by domes and craters. Mechanical behavior and failure modes under microindentation were depending of coatings structure and composition. TiAlN multilayer showed exception in the microindentation resistance compared to TiN single layer and TiAlN/TiAlN nanolayer. Piled structure provides an increase of failure resistance and a decrease in cracks propagation.

Keywords: PVD thin films, multilayer, microindentation, cracking, damage mechanisms

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3147 Investigating the Role of Combined Length Scale Effect on the Mechanical Properties of Ni/Cu Multilayer Structures

Authors: Naresh Radaliyagoda, Nigel M. Jennett, Rong Lan, David Parfitt

Abstract:

A series of length scale engineered multilayer material with temperature robust mechanical properties has been suggested. A range of polycrystalline copper sub-layers with the thickness varying from 1 to 25μm and buried in between two nickel layers was produced using electrodeposition dual bath technique. The structure of the multilayers was characterized using Electron Backscatter Diffraction and Scanning Electron Microscope. The interface effect on the hardness and elastic modulus was tested using Nano-indentation. Results of the grain size and layer thickness measurements, and indentation hardness have been compared. It is found that there is a combined length scale effect that improves mechanical properties in Ni/Cu multilayer structures.

Keywords: nano-indentation, size effect, multilayers, electrodeposition

Procedia PDF Downloads 118
3146 Controlling Differential Settlement of Large Reservoir through Soil Structure Interaction Approach

Authors: Madhav Khadilkar

Abstract:

Construction of a large standby reservoir was required to provide secure water supply. The new reservoir was required to be constructed at the same location of an abandoned old open pond due to space constraints. Some investigations were carried out earlier to improvise and re-commission the existing pond. But due to a lack of quantified risk of settlement from voids in the underlying limestone, the shallow foundations were not found feasible. Since the reservoir was resting on hard strata for about three-quarter of plan area and one quarter was resting on soil underlying with limestone and considerably low subgrade modulus. Further investigations were carried out to ascertain the locations and extent of voids within the limestone. It was concluded that the risk due to lime dissolution was acceptably low, and the site was found geotechnically feasible. The hazard posed by limestone dissolution was addressed through the integrated structural and geotechnical analysis and design approach. Finite Element Analysis was carried out to quantify the stresses and differential settlement due to various probable loads and soil-structure interaction. Walls behaving as cantilever under operational loads were found undergoing in-plane bending and tensile forces due to soil-structure interaction. Sensitivity analysis for varying soil subgrade modulus was carried out to check the variation in the response of the structure and magnitude of stresses developed. The base slab was additionally checked for the loss of soil contact due to lime pocket formations at random locations. The expansion and contraction joints were planned to receive minimal additional forces due to differential settlement. The reservoir was designed to sustain the actions corresponding to allowable deformation limits per code, and geotechnical measures were proposed to achieve the soil parameters set in structural analysis.

Keywords: differential settlement, limestone dissolution, reservoir, soil structure interaction

Procedia PDF Downloads 128
3145 The Aquatic Plants Community in the Owena-Idanre Section of the Owena River of Ondo State

Authors: Rafiu O. Sanni, Abayomi O. Olajuyigbe, Nelson R. Osungbemiro, Rotimi F. Olaniyan

Abstract:

The Owena River lies within the drainage basins of the Oni, Siluko, and Ogbesse rivers. The river’s immediate surroundings are covered by dense forests, interspersed by plantations of cocoa, oil palm, kolanut, bananas, and other crops. The objectives were to identify the aquatic plants community, comprising the algae and aquatic macrophytes, observe their population dynamics in relation to the two seasons and identify their economic importance, especially to the neighbouring community. The study sites were determined using a stratified sampling method. Three strata were marked out for sampling namely strata I (upstream)–5 stations, strata II (reservoir) –2 stations, and strata III (outflow) 2 stations. These nine stations were tagged st1, st2, st3…st9. The aquatic macrophytes were collected using standard methods and identified at the University of Ibadan herbarium while the algal samples were collected using standard methods for microalgae. The periphytonic species were scraped from surfaces of rocks (perilithic), sucked with large syringe from mud (epipellic), scraped from suspended logs, washed from roots of aquatic angiosperms (epiphytic), as well as shaken from other particles such as suspended plant parts. Some were collected physically by scooping floating thallus of non-microscopic multicellular forms. The specimens were taken to the laboratory and observed under a microscope with mounted digital camera for photomicrography. Identification was done using Prescott.

Keywords: aquatic plants, aquatic macrophytes, algae, Owena river

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3144 Effects of an Added Foaming Agent on Hydro-Mechanical Properties of Soil

Authors: Moez Selmi, Mariem Kacem, Mehrez Jamei, Philippe Dubujet

Abstract:

Earth pressure balance (EPB) tunnel boring machines are designed for digging in different types of soil, especially clay soils. This operation requires the treatment of soil by lubricants to facilitate the procedure of excavation. A possible use of this soil is limited by the effect of treatment on the hydro-mechanical properties of the soil. This work aims to study the effect of a foaming agent on the hydro-mechanical properties of clay soil. The injection of the foam agent in the soil leads to create a soil matrix in which they are incorporated gas bubbles. The state of the foam in the soil is scalable thanks to the degradation of the gas bubbles in the soil.

Keywords: EPB, clay soils, foam agent, hydro-mechanical properties, degradation

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3143 Influence of Antecedent Soil Moisture on Soil Erosion: A Two-Year Field Study

Authors: Yu-Da Chen, Chia-Chun Wu

Abstract:

The relationship between antecedent soil moisture content and soil erosion is a complicated phenomenon. Some studies confirm the effect of antecedent soil moisture content on soil erosion, but some deny it. Therefore, the objective of this study is to clarify such contradictions through field experiments. This study conducted two-year field observations of soil losses from natural rainfall events on runoff plots with a length of 10 meters, width of 3 meters, and uniform slope of 9%. Volumetric soil moisture sensors were used to log the soil moisture changes for each rainfall event. A total of 49 effective events were monitored. Results of this study show that antecedent soil moisture content promotes the generation of surface runoff, especially for rainfall events with short duration or lower magnitudes. A positive correlation was found between antecedent soil moisture content and soil loss per unit Rainfall-Runoff Erosivity Index, which indicated that soil with high moisture content is more susceptible to detachment. Once the rainfall duration exceeds 10 hours, the impact from the rainfall duration to soil erosion overwrites, and the effect of antecedent soil moisture is almost negligible.

Keywords: antecedent soil moisture content, soil loss, runoff coefficient, rainfall-runoff erosivity

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3142 Modeling of Daily Global Solar Radiation Using Ann Techniques: A Case of Study

Authors: Said Benkaciali, Mourad Haddadi, Abdallah Khellaf, Kacem Gairaa, Mawloud Guermoui

Abstract:

In this study, many experiments were carried out to assess the influence of the input parameters on the performance of multilayer perceptron which is one the configuration of the artificial neural networks. To estimate the daily global solar radiation on the horizontal surface, we have developed some models by using seven combinations of twelve meteorological and geographical input parameters collected from a radiometric station installed at Ghardaïa city (southern of Algeria). For selecting of best combination which provides a good accuracy, six statistical formulas (or statistical indicators) have been evaluated, such as the root mean square errors, mean absolute errors, correlation coefficient, and determination coefficient. We noted that multilayer perceptron techniques have the best performance, except when the sunshine duration parameter is not included in the input variables. The maximum of determination coefficient and correlation coefficient are equal to 98.20 and 99.11%. On the other hand, some empirical models were developed to compare their performances with those of multilayer perceptron neural networks. Results obtained show that the neural networks techniques give the best performance compared to the empirical models.

Keywords: empirical models, multilayer perceptron neural network, solar radiation, statistical formulas

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3141 Mechanical Properties of a Soil Stabilized With a Portland Cement

Authors: Ahmed Emad Ahmed, Mostafa El Abd, Ahmed Wakeb, Moahmmed Eissa

Abstract:

Soil modification and reinforcing aims to increase soil shear strength and stiffness. In this report, different amounts of cement were added to the soil to explore its effect on shear strength and penetration using 3 tests. The first test is proctor compaction test which was conducted to determine the optimal moisture content and maximum dry density. The second test was direct shear test which was conducted to measure shear strength of soil. The third experiment was California bearing ratio test which was done to measure the penetration in soil. Each test was done different amount of times using different amounts of cement. The results from every test show that cement improve soil shear strength properties and stiffness.

Keywords: soil stabilized, soil, mechanical properties of soil, soil stabilized with a portland cement

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3140 Influence of Counterface and Environmental Conditions on the Lubricity of Multilayer Graphene Coatings Produced on Nickel by Chemical Vapour Deposition

Authors: Iram Zahra

Abstract:

Friction and wear properties of multilayer graphene coatings (MLG) on nickel substrate were investigated at the macroscale, and different failure mechanisms working at the interface of nickel-graphene coatings were evaluated. Multilayer graphene coatings were produced on a nickel substrate using the atmospheric chemical vapour deposition (CVD) technique. Wear tests were performed on the pin-on-disk tribometer apparatus under dry air conditions, and using the saltwater solution, distilled water, and mineral oil lubricants and counterparts used in these wear tests were fabricated of stainless steel, chromium, and silicon nitride. The wear test parameters such as rotational speed, wear track diameter, temperature, relative humidity, and load were 60 rpm, 6 mm, 22˚C, 45%, and 2N, respectively. To analyse the friction and wear behaviour, coefficient of friction (COF) vs time curves were plotted, and the sliding surfaces of the samples and counterparts were examined using the optical microscope. Results indicated that graphene-coated nickel in mineral oil lubrication and dry conditions gave the minimum average value of COP (0.05) and wear track width ( ̴151 µm) against the three different types of counterparts. In contrast, uncoated nickel samples indicated a maximum wear track width ( ̴411 µm) and COF (0.5). Thorough investigation and analysis concluded that graphene-coated samples have two times lower COF and three times lower wear than the bare nickel samples. Furthermore, mechanical failures were significantly lower in the case of graphene-coated nickel. The overall findings suggested that multilayer graphene coatings have drastically decreased wear and friction on nickel substrate at the macroscale under various lubricating conditions and against different counterparts.

Keywords: friction, lubricity, multilayer graphene, sliding, wear

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3139 Soil Respiration Rate of Laurel-Leaved and Cryptomeria japonica Forests

Authors: Ayuko Itsuki, Sachiyo Aburatani

Abstract:

We assessed the ecology of the organic and mineral soil layers of laurel-leaved (BB-1) and Cryptomeria japonica (BB-2 and Pw) forests in the Kasugayama Hill Primeval Forest (Nara, Japan). The soil respiration rate was higher in the deeper horizons (F and H) of organic layers than in those of mineral soil layers, suggesting organic layers may be where active microbial metabolism occurs. Respiration rates in the soil of BB-1, BB-2 and Pw forests were closely similar at 5 and 10°C. However, the soil respiration rate increased in proportion to temperatures of 15°C or above. We therefore consider the activity of soil microorganisms to markedly decrease at temperatures below 10°C. At a temperature of 15°C or above, the soil respiration rate in the BB-1 organic layers was higher than in those of the BB-2 and Pw organic layers, due to differences in forest vegetation that appeared to influence several salient soil properties, particularly pH and the carbon (C) and nitrogen (N) content of the F and H horizons.

Keywords: forest soil, mineralization rate, heterotroph, soil respiration rate

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3138 pH and Temperature Triggered Release of Doxorubicin from Hydogen Bonded Multilayer Films of Polyoxazolines

Authors: Meltem Haktaniyan, Eda Cagli, Irem Erel Goktepe

Abstract:

Polymers that change their properties in response to different stimuli (e.g. light, temperature, pH, ionic strength or magnetic field) are called ‘smart’ or ‘stimuli-responsive polymers’. These polymers have been widely used in biomedical applications such as sensors, gene delivery, drug delivery or tissue engineering. Temperature-responsive polymers have been studied extensively for controlled drug delivery applications. As regard of pseudo-peptides, poly (2-alky-2-oxazoline)s are considered as good candidates for delivery systems due to their stealth behavior and nontoxicity. In order to build responsive multilayer films for controlled drug release applications from surface, Layer by layer technique (LBL) is a powerful technique with an advantage of nanometer scale control over spatial architecture and morphology. Multilayers can be constructed on surface where non-covalent interactions including electrostatic interactions, hydrogen bonding, and charge-transfer or hydrophobic-hydrophobic interactions. In the present study, hydrogen bounded multilayer films of poly (2-alky-2-oxazoline) s with tannic acid were prepared in order to use as a platform to release Doxorubicin (DOX) from surface with pH and thermal triggers. For this purpose, poly (2-isopropyl-2-oxazoline) (PIPOX) and poly (2-ethyl-2-oxazoline) (PETOX) were synthesized via cationic ring opening polymerization (CROP) with hydroxyl end groups. Two polymeric multilayer systems ((PETOX)/(DOX)-(TA) complexes and (PIPOX)/(DOX)-(TA) complexes) were designed to investigate of controlled release of Doxorubicin (DOX) from surface with pH and thermal triggers. The drug release profiles from the multilayer thin films with alterations of pH and temperature will been examined with UV-Vis Spectroscopy and Fluorescence Spectroscopy.

Keywords: temperature responsive polymers, h-bonded multilayer films, drug release, polyoxazoline

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3137 Response of Six Organic Soil Media on the Germination, Seedling Vigor Performance of Jack Fruit Seeds in Chitwan Nepal

Authors: Birendra Kumar Bhattachan

Abstract:

Organic soil media plays an important role for seed germination, growing, and producing organic jack fruits as the source of food such as vitamin A, C, and others for human health. An experiment was conducted to find out the appropriate organic soil medias to induce germination and seedling vigor of jack fruit seeds at the farm of Agriculture and Forestry University (AFU) Chitwan Nepal during June 2022 to October 2022. The organic soil medias used as treatments were as 1. soil collected under the Molingia tree; 2. soil, FYM and RH (2:1;1); 3. soil, FYM (1:1); 4. sand, FYM and RH (2:1:1), 5, sand, soil, FYM and RH (1:1:1:1) and 6. sand, soil and RH (1:2:1) under Completely Randomized Design (CRD) with four replications. Significantly highest germination of 88% was induced by soil media, followed by media of soil and FYM (!:1) i.e. 63% and the media of soil, FYM and RH (2:1;1) and the least media was sand, soil, FYM and RH (1:1:1:) to induce germination of 28%. Significantly highest seedling length of 73 cm was produced by soil media followed by the media soil, sand, and RH (1:2:1), i.e. 72 cm and the media soil, sand, FYM, and RH (1:1:1:1) and the least media was soil, FYM and RH (2:1:1) to produce 62 cm seedling length, Similarly, significantly highest seedling vigor of 6257 was produced by soil media followed by the media soil and FYM (1:1) i.e. 4253 and the least was the media sand, soil, FYM and RH (1:1:1:1) to produce seedling vigor of1916. Based on this experiment, it was concluded that soil media collected under the Moringia tree could induce the highest germinating capacity of jack fruit seeds and then seedling vigor.

Keywords: jack fruit seed, soil media, farm yard manure, sand media, rice husk

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3136 The Effect of Raindrop Kinetic Energy on Soil Erodibility

Authors: A. Moussouni, L. Mouzai, M. Bouhadef

Abstract:

Soil erosion is a very complex phenomenon, resulting from detachment and transport of soil particles by erosion agents. The kinetic energy of raindrop is the energy available for detachment and transport by splashing rain. The soil erodibility is defined as the ability of soil to resist to erosion. For this purpose, an experimental study was conducted in the laboratory using rainfall simulator to study the effect of the kinetic energy of rain (Ec) on the soil erodibility (K). The soil used was a sandy agricultural soil of 62.08% coarse sand, 19.14% fine sand, 6.39% fine silt, 5.18% coarse silt and 7.21% clay. The obtained results show that the kinetic energy of raindrops evolves as a power law with soil erodibility.

Keywords: erosion, runoff, raindrop kinetic energy, soil erodibility, rainfall intensity, raindrop fall velocity

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3135 Soil Mass Loss Reduction during Rainfalls by Reinforcing the Slopes with the Surficial Confinement

Authors: Ramli Nazir, Hossein Moayedi

Abstract:

Soil confinement systems serve as effective solutions to any erosion control project. Various confinements systems, namely triangular, circular and rectangular with the size of 50, 100, and 150 mm, and with a depth of 10 mm, were embedded in soil samples at slope angle of 60°. The observed soil mass losses for the confined soil systems were much smaller than those from unconfined system. As a result, the size of confinement and rainfall intensity have a direct effect on the soil mass loss. The triangular and rectangular confinement systems showed the lowest and highest soil loss masses, respectively. The slopes also failed much faster in the unconfined system than in the confined slope.

Keywords: erosion control, soil confinement, soil erosion, slope stability

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3134 An Engineering Review of Grouting in Soil Improvement Applications

Authors: Mohamad Kazem Zamani, Meldi Suhatril

Abstract:

Soil improvement is one of the main concerns of each civil engineer who is working at soil mechanics and geotechnics. Grouting has been used as a powerful treatment for soil improving. In this paper, we have tried to review the grouting application base on grouts which is used and also we have tried to give a general view of grout applications and where and when can be used.

Keywords: cementious grouting, chemical grouting, soil improvement, civil engineering

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3133 Improvement in Plasticity Index and Group Index of Black Cotton Soil Using Palm Kernel Shell Ash

Authors: Patel Darshan Shaileshkumar, M. G. Vanza

Abstract:

Black cotton soil is problematic soil for any construction work. Black cotton soil contains montmorillonite in its structure. Due to this mineral, black cotton soil will attain maximum swelling and shrinkage. Due to these volume changes, it is necessary to stabilize black cotton soil before the construction of the road. For soil stabilization use of pozzolanic waste is found to be a good solution by some researchers. The palm kernel shell ash (PKSA) is a pozzolanic material that can be used for soil stabilization. Basically, PKSA is a waste material, and it is available at a cheap cost. Palm kernel shell is a waste material generated in palm oil mills. Then palm kernel shell is used in industries instead of coal for power generation. After the burning of a palm kernel shell, ash is formed; the ash is called palm kernel shell ash (PKSA). The PKSA contains a free lime content that will react chemically with the silicate and aluminate of black cotton soil and forms a C-S-H and C-A-H gel which will bines soil particles together and reduce the plasticity of the soil. In this study, the PKSA is added to the soil. It was found that with the addition of PKSA content in the soil, the liquid limit of the soil is decreased, the plastic limit of the soil is increased, and the plasticity of the soil is decreased. The group index value of the soil is evaluated, and it was found that with the addition of PKSA GI value of the soil is decreased, which indicates the strength of the soil is improved.

Keywords: palm kernel shell ash, black cotton soil, liquid limit, group index, plastic limit, plasticity index

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3132 An Approach for Multilayered Ecological Networks

Authors: N. F. F. Ebecken, G. C. Pereira

Abstract:

Although networks provide a powerful approach to the study of a wide variety of ecological systems, their formulation usually does not include various types of interactions, interactions that vary in space and time, and interconnected systems such as networks. The emerging field of 'multilayer networks' provides a natural framework for extending ecological systems analysis to include these multiple layers of complexity as it specifically allows for differentiation and modeling of intralayer and interlayer connectivity. The structure provides a set of concepts and tools that can be adapted and applied to the ecology, facilitating research in high dimensionality, heterogeneous systems in nature. Here, ecological multilayer networks are formally defined based on a review of prior and related approaches, illustrates their application and potential with existing data analyzes, and discusses limitations, challenges, and future applications. The integration of multilayer network theory into ecology offers a largely untapped potential to further address ecological complexity, to finally provide new theoretical and empirical insights into the architecture and dynamics of ecological systems.

Keywords: ecological networks, multilayered networks, sea ecology, Brazilian Coastal Area

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3131 Soil Salinity Mapping using Electromagnetic Induction Measurements

Authors: Fethi Bouksila, Nessrine Zemni, Fairouz Slama, Magnus Persson, Ronny Berndasson, Akissa Bahri

Abstract:

Electromagnetic sensor EM 38 was used to predict and map soil salinity (ECe) in arid oasis. Despite the high spatial variation of soil moisture and shallow watertable, significant ECe-EM relationships were developed. The low drainage network efficiency is the main factor of soil salinization

Keywords: soil salinity map, electromagnetic induction, EM38, oasis, shallow watertable

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3130 Corellation between Soil Electrical Resistivity and Metal Corrosion Based on Soil Types for Structure Designs

Authors: L. O. A. Oyinkanola, J.A. Fajemiroye

Abstract:

Soil resistivity measurements are an important parameter employed in the designing earthing installations. Thus, The knowledge of soil resistivity with respect to how it varies with related parameters such as moisture content, Temperature and depth at the intended site is very vital to determine how the desired earth resistance value can be attained and sustained over the life of the installation with the lowest cost and effort. The relationship between corrosion and soil resistivity has been investigated in this work. Varios soil samples: Sand, Gravel, Loam, Clay and Silt were collected from different spot within the vicinity.

Keywords: Corrosion, resistivity, clay, hydraulic conductivity

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3129 Assessment of Soil Salinity through Remote Sensing Technique in the Coastal Region of Bangladesh

Authors: B. Hossen, Y. Helmut

Abstract:

Soil salinity is a major problem for the coastal region of Bangladesh, which has been increasing for the last four decades. Determination of soil salinity is essential for proper land use planning for agricultural crop production. The aim of the research is to estimate and monitor the soil salinity in the study area. Remote sensing can be an effective tool for detecting soil salinity in data-scarce conditions. In the research, Landsat 8 is used, which required atmospheric and radiometric correction, and nine soil salinity indices are applied to develop a soil salinity map. Ground soil salinity data, i.e., EC value, is collected as a printed map which is then scanned and digitized to develop a point shapefile. Linear regression is made between satellite-based generated map and ground soil salinity data, i.e., EC value. The results show that maximum R² value is found for salinity index SI 7 = G*R/B representing 0.022. This minimal R² value refers that there is a negligible relationship between ground EC value and salinity index generated value. Hence, these indices are not appropriate to assess soil salinity though many studies used those soil salinity indices successfully. Therefore, further research is necessary to formulate a model for determining the soil salinity in the coastal of Bangladesh.

Keywords: soil salinity, EC, Landsat 8, salinity indices, linear regression, remote sensing

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3128 Matric Suction Effects on Behavior of Unsaturated Soil Slope

Authors: Mohsen Mousivand, Hesam Aminpour

Abstract:

Soil slopes are usually located above the groundwater level that are largely unsaturated. It is possible that unsaturated soil of slope has expanded or collapsed as a result of wetting by rain or other factor that this type of soil behavior can cause serious problems including human and financial damage. The main factor causing this difference in behavior of saturated and unsaturated state of soil is matric suction that is created by interface of the soil and water in the soil pores. So far theoretical studies show that matric suction has important effect on the mechanical behavior of soil although the impact of this factor on slope stability has not been studied. This paper presents a numerical study of effect of matric suction on slope stability. The results of the study indicate that safety factor and stability of soil slope increase due to an increasing of matric suction and in view of matric suction leads to more accurate results and safety factor.

Keywords: slope, unsaturated soil, matric suction, stability

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3127 Development of an IoT System for Smart Crop Production

Authors: Oyenike M. Olanrewaju, Faith O. Echobu, Aderemi G. Adesoji, Emmy Danny Ajik, Joseph Nda Ndabula, Stephen Lucas

Abstract:

Nutrients are required for any soil with which plants thrive to improve efficient growth and productivity. Amongst these nutrients required for proper plant productivity are nitrogen, phosphorus and potassium (NPK). Due to factors like leaching, nutrients uptake by plants, soil erosion and evaporation, these elements tend to be in low quantity and the need to replenish them arises. But these replenishment of soil nutrients cannot be done without a timely soil test to enable farmers to know the amount of each element in short quantity and evaluate the amount required to be added. Though wet soil analysis is good but it comes with a lot of challenges ranging from soil test gargets availability to the technical knowledge of how to conduct such soil test by the common farmer. Internet of things test kit was developed to fill in the gaps created by wet soil analysis, as it can test for N, P, K, soil temperature and soil moisture in a given soil at the time of test. In this implementation, sample test was carried out within 0.2 hectares of land divided into smaller plots. The kits perform adequately well as the range of values obtained across the segments were within a very close range.

Keywords: Internet of Things, soil nutrients, test kit, soil temperature

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3126 Heavy Metal Reduction in Plant Using Soil Amendment

Authors: C. Chaiyaraksa, T. Khamko

Abstract:

This study investigated the influence of limestone and sepiolite on heavy metals accumulation in the soil and soybean. The soil was synthesized to contaminate with zinc 150 mg/kg, copper 100 mg/kg, and cadmium 1 mg/kg. The contaminated soil was mixed with limestone and sepiolite at the ratio of 1:0, 0:1, 1:1, and 2:1. The amount of soil modifier added to soil was 0.2%, 0.4%, and 0.8%. The metals determination was performed on soil both before and after soybean planting and in the root, shoot, and seed of soybean after harvesting. The study was also on metal translocate from root to seed and on bioaccumulation factor. Using of limestone and sepiolite resulted in a reduction of metals accumulated in soybean. For soil containing a high concentration of copper, cadmium, and zinc, a mixture of limestone and sepiolite (1:1) was recommended to mix with soil with the amount of 0.2%. Zinc could translocate from root to seed more than copper, and cadmium. From studying the movement of metals from soil to accumulate in soybean, the result was that soybean could absorb the highest amount of cadmium, followed by zinc, and copper, respectively.

Keywords: heavy metals, limestone, sepiolite, soil, soybean

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3125 Effects of Multilayer Coating of Chitosan and Polystyrene Sulfonate on Quality of ‘Nam Dok Mai No.4’ Mango

Authors: N. Hadthamard, P. Chaumpluk, M. Buanong, P. Boonyaritthongchai, C. Wongs-Aree

Abstract:

Ripe ‘Nam Dok Mai’ mango (Mangifera indica L.) is an important exported fruit of Thailand, but rapidly declined in the quality attributes mainly by infection of anthracnose and stem end rot diseases. Multilayer coating is considered as a developed technique to maintain the postharvest quality of mangoes. The utilization of alternated coating by matching oppositely electrostatic charges between 0.1% chitosan and 0.1% polystyrene sulfonate (PSS) was studied. A number of the coating layers (layer by layer) were applied on mature green ‘Nam Dok Mai No.4’ mangoes prior to storage at 25 oC, 65-70% relative humidity (RH). There were significant differences in some quality attributes of mangoes coated by 3½ layers, 4½ layers and 5½ layers. In comparison to coated mangoes, uncoated fruits were higher in weight loss, total soluble solids, respiration rate, ethylene production and disease incidence except the titratable acidity. Coating fruit at 3½ layers exhibited the ripening delay and reducing disease infection without off flavour. On the other hand, fruit coated with 5½ layers comprised the lowest acceptable score, caused by exhibiting disorders from fermentation at the end of storage. As a result, multilayer coating between chitosan and PSS could effectively maintain the postharvest quality of mango, but number of coating layers should be thoroughly considered.

Keywords: multilayer, chitosan, polystyrene sulfonate, Nam Dok Mai No.4

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3124 Applying Massively Parallel Sequencing to Forensic Soil Bacterial Profiling

Authors: Hui Li, Xueying Zhao, Ke Ma, Yu Cao, Fan Yang, Qingwen Xu, Wenbin Liu

Abstract:

Soil can often link a person or item to a crime scene, which makes it a valuable evidence in forensic casework. Several techniques have been utilized in forensic soil discrimination in previous studies. Because soil contains a vast number of microbiomes, the analyse of soil microbiomes is expected to be a potential way to characterise soil evidence. In this study, we applied massively parallel sequencing (MPS) to soil bacterial profiling on the Ion Torrent Personal Genome Machine (PGM). Soils from different regions were collected repeatedly. V-region 3 and 4 of Bacterial 16S rRNA gene were detected by MPS. Operational taxonomic units (OTU, 97%) were used to analyse soil bacteria. Several bioinformatics methods (PCoA, NMDS, Metastats, LEfse, and Heatmap) were applied in bacterial profiles. Our results demonstrate that MPS can provide a more detailed picture of the soil microbiomes and the composition of soil bacterial components from different region was individualistic. In conclusion, the utility of soil bacterial profiling via MPS of the 16S rRNA gene has potential value in characterising soil evidences and associating them with their place of origin, which can play an important role in forensic science in the future.

Keywords: bacterial profiling, forensic, massively parallel sequencing, soil evidence

Procedia PDF Downloads 531
3123 The Effect of Soil Fractal Dimension on the Performance of Cement Stabilized Soil

Authors: Nkiru I. Ibeakuzie, Paul D. J. Watson, John F. Pescatore

Abstract:

In roadway construction, the cost of soil-cement stabilization per unit area is significantly influenced by the binder content, hence the need to optimise cement usage. This research work will characterize the influence of soil fractal geometry on properties of cement-stabilized soil, and strive to determine a correlation between mechanical proprieties of cement-stabilized soil and the mass fractal dimension Dₘ indicated by particle size distribution (PSD) of aggregate mixtures. Since strength development in cemented soil relies not only on cement content but also on soil PSD, this study will investigate the possibility of reducing cement content by changing the PSD of soil, without compromising on strength, reduced permeability, and compressibility. A series of soil aggregate mixes will be prepared in the laboratory. The mass fractal dimension Dₘ of each mix will be determined from sieve analysis data prior to stabilization with cement. Stabilized soil samples will be tested for strength, permeability, and compressibility.

Keywords: fractal dimension, particle size distribution, cement stabilization, cement content

Procedia PDF Downloads 184
3122 Soil Reinforcement by Fibers Using Triaxial Compression Test

Authors: Negadi Kheira, Arab Ahmed, Kamal Elbokl Mohamed, Setti Fatima

Abstract:

In order to evaluate influences of roots on soil shear strength, monotonic drained and undrained triaxial laboratory tests were carried out on reconstituted specimens at various confining pressure (σc’=50, 100, 200, 300, 400 kPa) and a constant relative density (Dr = 50%). Reinforcement of soil by fibrous roots is crucial for preventing soil erosion and degradation. Therefore, we investigated soil reinforcement by roots of acacia planted in the area of Chlef where shallow landslides and slope instability are frequent. These roots were distributed in soil in two forms: vertically and horizontally. The monotonic test results showed that roots have more impacts on the soil shear strength than the friction angle, and the presence of roots in soil substantially increased the soil shear strength. Also, the results showed that the contribution of roots on the shear strength mobilized increases with increase in the confining pressure.

Keywords: soil, monotonic, triaxial test, root fiber, undrained

Procedia PDF Downloads 383
3121 Experimental Simulation of Soil Boundary Condition for Dynamic Studies

Authors: Omar S. Qaftan, T. T. Sabbagh

Abstract:

This paper studies the free-field response by adopting a flexible membrane container as soil boundary for experimental shaking table tests. The influence of the soil container boundary on the soil behaviour and the dynamic soil properties under seismic effect were examined. A flexible container with 1/50 scale factor was adopted in the experimental tests, including construction, instrumentation, and determination of the results of dynamic tests on a shaking table. Horizontal face displacements and accelerations were analysed to determine the influence of the container boundary on the performance of the soil. The outputs results show that the flexible boundary container allows more displacement and larger accelerations. The soil in a rigid wall container cannot deform as similar as the soil in the real field does. Therefore, the response of flexible container tested is believed to be more reliable for soil boundary than that in the rigid container.

Keywords: soil, seismic, earthquake, interaction

Procedia PDF Downloads 270
3120 Maximum Power Point Tracking for Small Scale Wind Turbine Using Multilayer Perceptron Neural Network Implementation without Mechanical Sensor

Authors: Piyangkun Kukutapan, Siridech Boonsang

Abstract:

The article proposes maximum power point tracking without mechanical sensor using Multilayer Perceptron Neural Network (MLPNN). The aim of article is to reduce the cost and complexity but still retain efficiency. The experimental is that duty cycle is generated maximum power, if it has suitable qualification. The measured data from DC generator, voltage (V), current (I), power (P), turnover rate of power (dP), and turnover rate of voltage (dV) are used as input for MLPNN model. The output of this model is duty cycle for driving the converter. The experiment implemented using Arduino Uno board. This diagram is compared to MPPT using MLPNN and P&O control (Perturbation and Observation control). The experimental results show that the proposed MLPNN based approach is more efficiency than P&O algorithm for this application.

Keywords: maximum power point tracking, multilayer perceptron netural network, optimal duty cycle, DC generator

Procedia PDF Downloads 299