Search results for: soil moisture sensor
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4868

Search results for: soil moisture sensor

4688 Global-Scale Evaluation of Two Satellite-Based Passive Microwave Soil Moisture Data Sets (SMOS and AMSR-E) with Respect to Modelled Estimates

Authors: A. Alyaaria, b, J. P. Wignerona, A. Ducharneb, Y. Kerrc, P. de Rosnayd, R. de Jeue, A. Govinda, A. Al Bitarc, C. Albergeld, J. Sabaterd, C. Moisya, P. Richaumec, A. Mialonc

Abstract:

Global Level-3 surface soil moisture (SSM) maps from the passive microwave soil moisture and Ocean Salinity satellite (SMOSL3) have been released. To further improve the Level-3 retrieval algorithm, evaluation of the accuracy of the spatio-temporal variability of the SMOS Level 3 products (referred to here as SMOSL3) is necessary. In this study, a comparative analysis of SMOSL3 with a SSM product derived from the observations of the Advanced Microwave Scanning Radiometer (AMSR-E) computed by implementing the Land Parameter Retrieval Model (LPRM) algorithm, referred to here as AMSRM, is presented. The comparison of both products (SMSL3 and AMSRM) were made against SSM products produced by a numerical weather prediction system (SM-DAS-2) at ECMWF (European Centre for Medium-Range Weather Forecasts) for the 03/2010-09/2011 period at global scale. The latter product was considered here a 'reference' product for the inter-comparison of the SMOSL3 and AMSRM products. Three statistical criteria were used for the evaluation, the correlation coefficient (R), the root-mean-squared difference (RMSD), and the bias. Global maps of these criteria were computed, taking into account vegetation information in terms of biome types and Leaf Area Index (LAI). We found that both the SMOSL3 and AMSRM products captured well the spatio-temporal variability of the SM-DAS-2 SSM products in most of the biomes. In general, the AMSRM products overestimated (i.e., wet bias) while the SMOSL3 products underestimated (i.e., dry bias) SSM in comparison to the SM-DAS-2 SSM products. In term of correlation values, the SMOSL3 products were found to better capture the SSM temporal dynamics in highly vegetated biomes ('Tropical humid', 'Temperate Humid', etc.) while best results for AMSRM were obtained over arid and semi-arid biomes ('Desert temperate', 'Desert tropical', etc.). When removing the seasonal cycles in the SSM time variations to compute anomaly values, better correlation with the SM-DAS-2 SSM anomalies were obtained with SMOSL3 than with AMSRM, in most of the biomes with the exception of desert regions. Eventually, we showed that the accuracy of the remotely sensed SSM products is strongly related to LAI. Both the SMOSL3 and AMSRM (slightly better) SSM products correlate well with the SM-DAS2 products over regions with sparse vegetation for values of LAI < 1 (these regions represent almost 50% of the pixels considered in this global study). In regions where LAI>1, SMOSL3 outperformed AMSRM with respect to SM-DAS-2: SMOSL3 had almost consistent performances up to LAI = 6, whereas AMSRM performance deteriorated rapidly with increasing values of LAI.

Keywords: remote sensing, microwave, soil moisture, AMSR-E, SMOS

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4687 Modeling of Compaction Curves for CCA-Cement Stabilized Lateritic Soils

Authors: O. Ahmed Apampa, Yinusa, A. Jimoh

Abstract:

The aim of this study was to develop an appropriate model for predicting the compaction behavior of lateritic soils and corn cob ash (CCA) stabilized lateritic soils. This was done by first adopting an equation earlier developed for fine-grained soils and subsequent adaptation by others and extending it to modified lateritic soil through the introduction of alpha and beta parameters which are polynomial functions of the CCA binder input. The polynomial equations were determined with MATLAB R2011 curve fitting tool, while the alpha and beta parameters were determined by standard linear programming techniques using the Solver function of Microsoft Excel 2010. The model so developed was a good fit with a correlation coefficient R2 value of 0.86. The paper concludes that it is possible to determine the optimum moisture content and the maximum dry density of CCA stabilized soils from the compaction test of the unmodified soil, and recommends that this procedure is extended to other binder stabilized lateritic soils to facilitate quick decision making in roadworks.

Keywords: compaction, corn cob ash, lateritic soil, stabilization

Procedia PDF Downloads 499
4686 Significant Influence of Land Use Type on Earthworm Communities but Not on Soil Microbial Respiration in Selected Soils of Hungary

Authors: Tsedekech Gebremeskel Weldmichael, Tamas Szegi, Lubangakene Denish, Ravi Kumar Gangwar, Erika Micheli, Barbara Simon

Abstract:

Following the 1992 Earth Summit in Rio de Janeiro, soil biodiversity has been recognized globally as a crucial player in guaranteeing the functioning of soil and a provider of several ecosystem services essential for human well-being. The microbial fraction of the soil is a vital component of soil fertility as soil microbes play key roles in soil aggregate formation, nutrient cycling, humification, and degradation of pollutants. Soil fauna, such as earthworms, have huge impacts on soil organic matter dynamics, nutrient cycling, and infiltration and distribution of water in the soil. Currently, land-use change has been a global concern as evidence accumulates that it adversely affects soil biodiversity and the associated ecosystem goods and services. In this study, we examined the patterns of soil microbial respiration (SMR) and earthworm (abundance, biomass, and species richness) across three land-use types (grassland, arable land, and forest) in Hungary. The objectives were i) to investigate whether there is a significant difference in SMR and earthworm (abundance, biomass, and species richness) among land-use types. ii) to determine the key soil properties that best predict the variation in SMR and earthworm communities. Soil samples, to a depth of 25 cm, were collected from the surrounding areas of seven soil profiles. For physicochemical parameters, soil organic matter (SOM), pH, CaCO₃, E₄/E₆, available nitrogen (NH₄⁺-N and NO₃⁻-N), potassium (K₂O), phosphorus (P₂O₅), exchangeable Ca²⁺, Mg²⁺, soil moisture content (MC) and bulk density were measured. The analysis of SMR was determined by basal respiration method, and the extraction of earthworms was carried out by hand sorting method as described by ISO guideline. The results showed that there was no statistically significant difference among land-use types in SMR (p > 0.05). However, the highest SMR was observed in grassland soils (11.77 mgCO₂ 50g⁻¹ soil 10 days⁻¹) and lowest in forest soils (8.61 mgCO₂ 50g⁻¹ soil 10 days⁻¹). SMR had strong positive correlations with exchangeable Ca²⁺ (r = 0.80), MC (r = 0.72), and exchangeable Mg²⁺(r = 0.69). We found a pronounced variation in SMR among soil texture classes (p < 0.001), where the highest value in silty clay loam soils and the lowest in sandy soils. This study provides evidence that agricultural activities can negatively influence earthworm communities, in which the arable land had significantly lower earthworm communities compared to forest and grassland respectively. Overall, in our study, land use type had minimal effects on SMR whereas, earthworm communities were profoundly influenced by land-use type particularly agricultural activities related to tillage. Exchangeable Ca²⁺, MC, and texture were found to be the key drivers of the variation in SMR.

Keywords: earthworm community, land use, soil biodiversity, soil microbial respiration, soil property

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4685 Adsorption and Transformation of Lead in Coimbatore Urban Soils

Authors: K. Sivasubramanin, S. Mahimairaja, S. Pavithrapriya

Abstract:

Heavy metal pollution originating from industrial wastes is becoming a serious problem in many urban environments. These heavy metals, if not properly managed, could enter into the food chain and cause a serious health hazards in animals and humans. Industrial wastes, sewage sludge, and automobile emissions also contribute to heavy metal like Pb pollution in the urban environment. However, information is scarce on the heavy metal pollution in Coimbatore urban environment. Therefore, the current study was carried out to examine the extent of lead pollution in Coimbatore urban environment the maximum Pb concentration in Coimbatore urban environment was found in ukkadam, whose concentration in soils 352 mg kg-1. In many places, the Pb concentration was found exceeded the permissible limit of 100 mg kg-1. In laboratory, closed incubation experiment showed that the concentration of different species of Pb viz., water soluble Pb(H2O-Pb), exchangeable Pb(KNO3-Pb), organic-Pb(NaOH-Pb), and organic plus metal (Fe & Al) oxides bound-Pb(Na2 EDTA-Pb) was found significantly increased during the 15 days incubation, mainly due to biotransformation processes. Both the moisture content of soil and ambient temperature exerted a profound influence on the transformation of Pb. The results of a batch experiment has shown that the sorption data was adequately described by the Freundlich equation as indicated by the high correlation coefficients (R2= 0.64) than the Langmuir equation (R2 = 0.33). A maximum of 86 mg of Pb was found adsorbed per kilogram of soil. Consistently, a soil column experiment result had shown that only a small amount of Pb( < 1.0 µg g-1 soil) alone was found leached from the soil. This might be due to greater potential of the soil towards Pb adsorption.

Keywords: lead pollution, adsorption, transformation, heavy metal pollution

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4684 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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4683 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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4682 Effects of Dimensional Sizes of Mould on the Volumetric Shrinkage Strain of Lateric Soil

Authors: John E. Sani, Moses George

Abstract:

The paper presents the result of a laboratory study carried out on lateritic soil to determine the effects of dimensional size on the volumetric shrinkage strain (VSS) using three mould sizes i.e. split former mould, proctor mould and California bearing ratio (CBR) mould at three energy levels; British standard light (BSL), West African standard (WAS) and British standard heavy (BSH) respectively. Compactions were done at different molding water content of -2 % to +6 % optimum moisture content (OMC). At -2% to +2% molding water content for the split former mould the volumetric shrinkage strain met the requirement of not more than 4% while at +4% and +6% only the WAS and BSH met the requirement. The proctor mould and the CBR mould on the other hand gave a lower value of volumetric shrinkage strain in all compactive effort and the values are lower than the 4% safe VSS value.

Keywords: lateritic soil, volumetric shrinkage strain, molding water content, compactive effort

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4681 Failure Analysis of Khaliqabad Landslide along Mangla Reservoir Rim

Authors: Fatima Mehmood, Khalid Farooq

Abstract:

After the Mangla dam raising in 2010, the maximum reservoir impoundment level of 378.5 m SPD (Survey of Pakistan Datum) was achieved in September 2014. The reservoir drawdown was started on September 29, 2014 and a landslide occurred on Mirpur-Kotli Road near Khaliqabad on November 27, 2014. This landslide took place due to the failure of a slope along the reservoir rim. This study was undertaken to investigate the causative factors of Khaliqabad landslide. Site visits were carried out for recording the field observations and collection of the soil samples. The soil was subjected to different laboratory tests for the determination of index and engineering properties. The shear strength tests were performed at various levels of density and degrees of saturation. These soil parameters were used in an integrated SEEP-SLOPE/W analysis to obtain the drop in factor of safety with time and reservoir drawdown. The results showed the factor of safety dropped from 1.28 to 0.85 over a period of 60 days. The ultimate reduction in the shear strength of soil due to saturation with the simultaneous removal of the stabilizing effect of reservoir caused the disturbing forces to increase, and thus failure happened. The findings of this study can serve as a guideline for the modeling of the slopes experiencing rapid drawdown scenario with the consideration of more realistic distribution of soil moisture/ properties across the slope

Keywords: geotechnical investigation, landslide, reservoir drawdown, shear strength, slope stability

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4680 Studying the Moisture Sources and the Stable Isotope Characteristic of Moisture in Northern Khorasan Province, North-Eastern Iran

Authors: Mojtaba Heydarizad, Hamid Ghalibaf Mohammadabadi

Abstract:

Iran is a semi-arid and arid country in south-western Asia in the Middle East facing intense climatological drought from the early times. Therefore, studying the precipitation events and the moisture sources and air masses causing precipitation has great importance in this region. In this study, the moisture sources and stable isotope content of precipitation moisture in three main events in 2015 have been studied in North-Eastern Iran. HYSPLIT model backward trajectories showed that the Caspian Sea and the mixture of the Caspian and Mediterranean Seas are dominant moisture sources for the studied events. This showed the role of cP (Siberian) and Mediterranean (MedT) air masses. Stable isotope studies showed that precipitation events originated from the Caspian Sea with lower Sea Surface Temperature (SST) have more depleted isotope values. However, precipitation events sourced from the mixture of the Caspian and the Mediterranean Seas (with higher SST) showed more enriched isotope values.

Keywords: HYSPLIT, Iran, Northern Khorasan, stable isotopes

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4679 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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4678 Data Clustering in Wireless Sensor Network Implemented on Self-Organization Feature Map (SOFM) Neural Network

Authors: Krishan Kumar, Mohit Mittal, Pramod Kumar

Abstract:

Wireless sensor network is one of the most promising communication networks for monitoring remote environmental areas. In this network, all the sensor nodes are communicated with each other via radio signals. The sensor nodes have capability of sensing, data storage and processing. The sensor nodes collect the information through neighboring nodes to particular node. The data collection and processing is done by data aggregation techniques. For the data aggregation in sensor network, clustering technique is implemented in the sensor network by implementing self-organizing feature map (SOFM) neural network. Some of the sensor nodes are selected as cluster head nodes. The information aggregated to cluster head nodes from non-cluster head nodes and then this information is transferred to base station (or sink nodes). The aim of this paper is to manage the huge amount of data with the help of SOM neural network. Clustered data is selected to transfer to base station instead of whole information aggregated at cluster head nodes. This reduces the battery consumption over the huge data management. The network lifetime is enhanced at a greater extent.

Keywords: artificial neural network, data clustering, self organization feature map, wireless sensor network

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4677 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

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4676 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

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4675 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

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4674 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

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4673 Identification of Suitable Rainwater Harvesting Sites Using Geospatial Techniques with AHP in Chacha Watershed, Jemma Sub-Basin Upper Blue Nile, Ethiopia

Authors: Abrha Ybeyn Gebremedhn, Yitea Seneshaw Getahun, Alebachew Shumye Moges, Fikrey Tesfay

Abstract:

Rainfed agriculture in Ethiopia has failed to produce enough food, to achieve the increasing demand for food. Pinpointing the appropriate site for rainwater harvesting (RWH) have a substantial contribution to increasing the available water and enhancing agricultural productivity. The current study related to the identification of the potential RWH sites was conducted at the Chacha watershed central highlands of Ethiopia which is endowed with rugged topography. The Geographic Information System with Analytical Hierarchy Process was used to generate the different maps for identifying appropriate sites for RWH. In this study, 11 factors that determine the RWH locations including slope, soil texture, runoff depth, land cover type, annual average rainfall, drainage density, lineament intensity, hydrologic soil group, antecedent moisture content, and distance to the roads were considered. The overall analyzed result shows that 10.50%, 71.10%, 17.90%, and 0.50% of the areas were found under highly, moderately, marginally suitable, and unsuitable areas for RWH, respectively. The RWH site selection was found highly dependent on a slope, soil texture, and runoff depth; moderately dependent on drainage density, annual average rainfall, and land use land cover; but less dependent on the other factors. The highly suitable areas for rainwater harvesting expansion are lands having a flat topography with a soil textural class of high-water holding capacity that can produce high runoff depth. The application of this study could be a baseline for planners and decision-makers and support any strategy adoption for appropriate RWH site selection.

Keywords: runoff depth, antecedent moisture condition, AHP, weighted overlay, water resource

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4672 A Bio-Inspired Approach for Self-Managing Wireless Sensor and Actor Networks

Authors: Lyamine Guezouli, Kamel Barka, Zineb Seghir

Abstract:

Wireless sensor and actor networks (WSANs) present a research challenge for different practice areas. Researchers are trying to optimize the use of such networks through their research work. This optimization is done on certain criteria, such as improving energy efficiency, exploiting node heterogeneity, self-adaptability and self-configuration. In this article, we present our proposal for BIFSA (Biologically-Inspired Framework for Wireless Sensor and Actor networks). Indeed, BIFSA is a middleware that addresses the key issues of wireless sensor and actor networks. BIFSA consists of two types of agents: sensor agents (SA) that operate at the sensor level to collect and transport data to actors and actor agents (AA) that operate at the actor level to transport data to base stations. Once the sensor agent arrives at the actor, it becomes an actor agent, which can exploit the resources of the actors and vice versa. BIFSA allows agents to evolve their genetic structures and adapt to the current network conditions. The simulation results show that BIFSA allows the agents to make better use of all the resources available in each type of node, which improves the performance of the network.

Keywords: wireless sensor and actor networks, self-management, genetic algorithm, agent.

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4671 Major Mechanisms of Atmospheric Moisture Transport and Their Role in Precipitation Extreme Events in the Amazonia

Authors: Luis Gimeno, Rosmeri da Rocha, Raquel Nieto, Tercio Ambrizzi, Alex Ramos, Anita Drumond

Abstract:

The transport of moisture from oceanic sources to the continents represents the atmospheric branch of the water cycle, forming the connection between evaporation from the ocean and precipitation over the continents. In this regard two large scale dynamical/meteorological structures appear to play a key role, namely Low Level Jet (LLJ) systems and Atmospheric Rivers (ARs). The former are particularly important in tropical and subtropical regions; the latter is mostly confined to extratropical regions. A key question relates to the anomalies in the transport of moisture observed during natural hazards related to extremes of precipitation (i.e., drought or wet spells). In this study we will be focused on these two major atmospheric moisture transport mechanisms (LLJs and ARs) and its role in precipitation extreme events (droughts and wet spells) in the Amazonia paying particular attention to i) intensification (decreasing) of moisture transport by them and its role in wet spells (droughts), and ii) changes in their positions and occurrence with associated flooding and wet spells.

Keywords: droughts, wet spells, amazonia, LLJs, atmospheric rivers

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4670 Seismic Soil-Pile Interaction Considering Nonlinear Soil Column Behavior in Saturated and Dry Soil Conditions

Authors: Mohammad Moeini, Mehrdad Ghyabi, Kiarash Mohtasham Dolatshahi

Abstract:

This paper investigates seismic soil-pile interaction using the Beam on Nonlinear Winkler Foundation (BNWF) approach. Three soil types are considered to cover all the possible responses, as well as nonlinear site response analysis using finite element method in OpenSees platform. Excitations at each elevation that are output of the site response analysis are used as the input excitation to the soil pile system implementing multi-support excitation method. Spectral intensities of acceleration show that the extent of the response in sand is more severe than that of clay, in addition, increasing the PGA of ground strong motion will affect the sandy soil more, in comparison with clayey medium, which is an indicator of the sensitivity of soil-pile systems in sandy soil.

Keywords: BNWF method, multi-support excitation, nonlinear site response analysis, seismic soil-pile interaction

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4669 Cooking Attributes of Rice Stored under Varying Temperature and Moisture Regimes

Authors: Lakshmi E. Jayachandran, Manepally Rajkumar, Pavuluri Srinivasa Rao

Abstract:

The objective of this research was to study the changes in eating quality of rice during storage under varying temperature and moisture regimes. Paddy (IR-36) with high amylose content (27%) was stored at a temperature range between 10 to 40°C and moisture content from 9 to 18% (d.b.) for 6 months. Drastic changes in color and parameters representing cooking qualities, cooked rice texture, and surface morphology occurred after 4 months of storage, especially at elevated temperature conditions. Head rice yield was stable throughout the storage except at extreme conditions of temperature and moisture content. Yellowing of rice was prominent at combinations of high temperature and moisture content, both of which had a synergistic effect on the b* values of rice. The cooking time, length expansion ratio and volume expansion ratio of all the rice samples increased with prolonged storage. The texture parameter, primarily, the hardness, cohesiveness, and adhesiveness of cooked rice samples were higher following storage at elevated temperature. Surface morphology was also significantly affected in stored rice as compared to fresh rice. Storage of rice at 10°C with a grain moisture content of 10% for 2 months gave cooked rice samples with good palatability and minimal cooking time. The temperature was found to be the most prominent storage parameter for rough rice, followed by moisture content and storage duration, influencing the quality of rice.

Keywords: rice, cooking quality, storage, surface morphology

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4668 The Effect of Soil Binder and Gypsum to the Changes of the Expansive Soil Shear Strength Parameters

Authors: Yulia Hastuti, Ratna Dewi, Muhammad Sandi

Abstract:

Many methods of soil stabilization that can be done such as by mixing chemicals. In this research, stabilization by mixing the soil using two types of chemical admixture, those are gypsum with a variation of 5%, 10%, and 15% and Soil binder with a concentration of 20 gr / lot of water, 25 gr / lot of water, and 30 gr / lot of water aimed to determine the effect on the soil plasticity index values and comparing the value of shear strength parameters of the mixture with the original soil conditions using a Triaxial UU test. Based on research done shows that with increasing variations in the mix, then the value of plasticity index decreased, which was originally 42% (very high degree of swelling) becomes worth 11.24% (lower Swelling degree) when a mixture of gypsum 15% and 30 gr / Lt water soil binder. As for the value shear, strength parameters increased in all variations of mixture. Admixture with the highest shear strength parameter's value is at 15% the mixture of gypsum and 20 gr / litre of water of soil binder with the 14 day treatment period, which has enhanced the cohesion value of 559.01%, the friction angle by 1157.14%. And a shear strength value of 568.49%. It can be concluded that the admixture of gypsum and soil binder correctly, can increase the value of shear strength parameters significantly and decrease the value of plasticity index of the soil.

Keywords: expansive soil, gypsum, soil binder, shear strength

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4667 Experimental Investigation of Soil Corrosion and Electrical Resistance in Depth by Geoelectrical Method

Authors: Seyed Abolhassan Naeini, Maedeh Akhavan Tavakkoli

Abstract:

Determining soil engineering properties is essential for geotechnical problems. In addition to high cost, invasive soil survey methods can be time-consuming, so geophysical methods can be an excellent choice to determine soil characteristics. In this study, geoelectric investigation using the Wenner arrangement method has been used to determine the amount of soil corrosion in soil layers in a project site as a case study. This study aims to assess the degree of corrosion of soil layers to a depth of 5 meters and find the variation of soil electrical resistance versus depth. For this purpose, the desired points in the study area were marked and specified, and all withdrawals were made within the specified points. The collected data have been processed by standard and accepted methods, and the results have been presented in the form of calculation tables and curves of electrical resistivity with depth.

Keywords: Wenner array, geoelectric, soil corrosion, electrical soil resistance

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4666 Care: A Cluster Based Approach for Reliable and Efficient Routing Protocol in Wireless Sensor Networks

Authors: K. Prasanth, S. Hafeezullah Khan, B. Haribalakrishnan, D. Arun, S. Jayapriya, S. Dhivya, N. Vijayarangan

Abstract:

The main goal of our approach is to find the optimum positions for the sensor nodes, reinforcing the communications in points where certain lack of connectivity is found. Routing is the major problem in sensor network’s data transfer between nodes. We are going to provide an efficient routing technique to make data signal transfer to reach the base station soon without any interruption. Clustering and routing are the two important key factors to be considered in case of WSN. To carry out the communication from the nodes to their cluster head, we propose a parameterizable protocol so that the developer can indicate if the routing has to be sensitive to either the link quality of the nodes or the their battery levels.

Keywords: clusters, routing, wireless sensor networks, three phases, sensor networks

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4665 Effect of Various Tillage Systems on Soil Compaction

Authors: Sushil Kumar, Mukesh Jain, Vijaya Rani, Vinod Kumar

Abstract:

The prime importance of tillage is that it prepares the land where the seed easily germinate and later the plant can well establish. Using different types of equipments driven manually or by powered, machines make the soil suitable to place the seeds into the desirable depth. Moreover, tillage loosens the compacted layers. Heavy equipment and tillage implements can cause damage to the soil structure. Effect of various tillage methods on soil compaction was studied in Rabi season of 2013-14 at village Ladwa, Hisar, Haryana (India). The experiments studied the effect of six tillage treatments i.e. no tillage or zero tillage (T1), tillage with rotavator (T2), disc harrow (T3), rotavator + sub soiler (T4), disc harrow + sub soiler (T5) and power harrow (T6) on soil compaction. Soil compaction was measured before tillage and after sowing at 0, 30, 60 and 90 days after sowing. No change in soil resistance was recorded before and after no tillage treatment. Maximum soil resistance was found in zero tillage followed by disc harrow up to 150 mm soil depth. Minimum soil resistance was found in rotavator immediately after the tillage treatment. However, the soil resistance approached the same level as it had been before the tillage after the soil strata where the implement cannot reach.

Keywords: tillage, no tillage, rotavator, subsoiler, compaction

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4664 Study on the Thermal Conductivity about Porous Materials in Wet State

Authors: Han Yan, Jieren Luo, Qiuhui Yan, Xiaoqing Li

Abstract:

The thermal conductivity of porous materials is closely related to the thermal and moisture environment and the overall energy consumption of the building. The study of thermal conductivity of porous materials has great significance for the realization of low energy consumption building and economic construction building. Based on the study of effective thermal conductivity of porous materials at home and abroad, the thermal conductivity under a variety of different density of polystyrene board (EPS), plastic extruded board (XPS) and polyurethane (PU) and phenolic resin (PF) in wet state through theoretical analysis and experimental research has been studied. Initially, the moisture absorption and desorption properties of specimens had been discussed under different density, which led a result indicates the moisture absorption of four porous materials all have three stages, fast, stable and gentle. For the moisture desorption, there are two types. One is the existence of the rapid phase of the stage, such as XPS board, PU board. The other one does not have the fast desorption, instead, it is more stabilized, such as XPS board, PF board. Furthermore, the relationship between water content and thermal conductivity of porous materials had been studied and fitted, which figured out that in the wake of the increasing water content, the thermal conductivity of porous material is continually improving. At the same time, this result also shows, in different density, when the same kind of materials decreases, the saturated moisture content increases. Finally, the moisture absorption and desorption properties of the four kinds of materials are compared comprehensively, and it turned out that the heat preservation performance of PU board is the best, followed by EPS board, XPS board, PF board.

Keywords: porous materials, thermal conductivity, moisture content, transient hot-wire method

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4663 Effect Different Moisture States of Surface-treated Recycled Concrete Aggregate on Properties of Fresh and Hardened Concrete

Authors: Sallehan Ismail, Mahyuddin Ramli

Abstract:

This study examined the properties of fresh and hardened concretes as influenced by the moisture state of the coarse recycled concrete aggregates (RCA) after surface treatment. Surface treatment was performed by immersing the coarse RCA in a calcium metasilicate (CM) solution. The treated coarse RCA was maintained in three controlled moisture states, namely, air-dried, oven-dried, and saturated surface-dried (SSD), prior to its use in a concrete mix. The physical properties of coarse RCA were evaluated after surface treatment during the first phase of the experiment to determine the density and the water absorption characteristics of the RCA. The second phase involved the evaluation of the slump, slump loss, density, and compressive strength of the concretes that were prepared with different proportions of natural and treated coarse RCA. Controlling the moisture state of the coarse RCA after surface treatment was found to significantly influence the properties of the fresh and hardened concretes.

Keywords: moisture state, recycled concrete aggregate, surface treatment

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4662 Metagenomic Assessment of the Effects of Genetically Modified Crops on Microbial Ecology and Physicochemical Properties of Soil

Authors: Falana Yetunde Olaitan, Ijah U. J. J, Solebo Shakirat O.

Abstract:

Genetically modified crops are already phenomenally successful and are grown worldwide in more than eighteen countries on more than 67 million hectares. Nigeria, in October 2018, approved Bacillus thuringiensis (Bt) cotton and maize; therefore, the need to carry out environmental risk assessment studies. A total of 15 4L octagonal ceramic pots were filled with 4kg of soil and placed on the bench in 2 rows of 10 pots each and the 3rd row of 5 pots, 1st-row pots were used to plant GM cotton seeds, while the 2nd-row pots were used for non-GM cotton seeds and the 3rd row of 5 pots served as control, all in the screen house. Soil samples for metagenomic DNA extraction were collected at random and at the monthly interval after planting at a distance of 2mm from the plant’s root and at a depth of 10cm using a sterile spatula. Soil samples for physicochemical analysis were collected before planting and after harvesting the GM and non-GM crops as well as from the control soil. The DNA was extracted, quantified and sequenced; Sample 1A (DNA from GM cotton Soil at 1st interval) gave the lowest sequence read with 0.853M while sample 2B (DNA from GM cotton Soil at 2nd interval) gave the highest with 5.785M, others gave between 1.8M and 4.7M. The samples treatment were grouped into four, Group 1 (GM cotton soil from 1 to 3 intervals) had between 800,000 and 5,700,000 strains of microbes (SOM), Group 2 (non GM cotton soil from 1 to 3 intervals) had between 1,400,600 and 4,200,000 SOM, Group 3 (control soil) had between 900,000 and 3,600,000 SOM and Group 4 (initial soil) had between 3,700,000 and 4,000,000 SOM. The microbes observed were predominantly bacteria (including archaea), fungi, dark matter alongside protists and phages. The predominant bacterial groups were the Terrabacteria (Bacillus funiculus, Bacillus sp.), the Proteobacteria (Microvirga massiliensis, sphingomonas sp.) and the Archaea (Nitrososphaera sp.), while the fungi were Aspergillus fischeri and Fusarium falciforme. The comparative analysis between groups was done using JACCARD PERMANOVA beta diversity analysis at P-value not more than 0.76 and there was no significant pair found. The pH for initial, GM cotton, non-GM cotton and control soil were 6.28, 6.26, 7.25, 8.26 and the percentage moisture was 0.63, 0.78, 0.89 and 0.82, respectively, while the percentage Nitrogen was observed to be 17.79, 1.14, 1.10 and 0.56 respectively. Other parameters include, varying concentrations of Potassium (0.46, 1,284.47, 1,785.48, 1,252.83 mg/kg) and Phosphorus (18.76, 17.76, 16.87, 15.23 mg/kg) were recorded for the four treatments respectively. The soil consisted mainly of silt (32.09 to 34.66%) and clay (58.89 to 60.23%), reflecting the soil texture as silty – clay. The results were then tested with ANOVA at less than 0.05 P-value and no pair was found to be significant as well. The results suggest that the GM crops have no significant effect on microbial ecology and physicochemical properties of the soil and, in turn, no direct or indirect effects on human health.

Keywords: genetically modified crop, microbial ecology, physicochemical properties, metagenomics, DNA, soil

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4661 Characterization of Carbon/Polyamide 6,6 (C/PA66) Composite Material for Dry and Wet Conditions

Authors: Tariq Bashir, Muhammad Waseem Tahir, Ulf Stigh, Behnaz Baghaie, Mikael Skrifvars

Abstract:

Absorption of moisture may cause many problems in a composite material, such as delamination, degradation of the strength and increase in the weight. For small coupons, the increase in weight may be negligible, however, for large structures increase in weight due to moisture absorption may be quite significant. Polyamides (PA6, PA66) absorb more moisture as compared to other thermoplastics. There are many parameters which affect the moisture absorption of the composite material for example temperature, pressure, type of matrix and fibers, thickness of the material and relative humidity (RH) etc. So, it is utmost important to investigate the impact of moisture on PA66 based composites which can be done by characterizing the mechanical properties of composite materials both for dry and wet conditions. In this study, laminates of C/PA66 composite are manufactured by first heating the commingled material in conventional oven at a temperature of 220 °C followed by pressing in a manual hot press for 20 minutes with preheated platen at 220 °C. To observe the moisture absorption of the composite, coupons of the material were placed in a climate chamber at five different conditions 0, 25, 50, 75 and 100% RH for 24 hours. Five specimens were used for each condition. These coupons were weighed before placing in the climate chamber and just after removing from the chamber to observe the moisture absorption of the material. The mechanical characterization such as tensile strength, flexural modulus, impact strength and DMTA of C/PA66 material are performed at 0, 50 and 100 % RH. The work is going on for the testing of the material and results will be presented in full paper.

Keywords: Carbon/Polyamide 66 composites, structural composites, mechanical characterizations, wet and dry conditions

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4660 Compost Bioremediation of Oil Refinery Sludge by Using Different Manures in a Laboratory Condition

Authors: O. Ubani, H. I. Atagana, M. S. Thantsha

Abstract:

This study was conducted to measure the reduction in polycyclic aromatic hydrocarbons (PAHs) content in oil sludge by co-composting the sludge with pig, cow, horse and poultry manures under laboratory conditions. Four kilograms of soil spiked with 800 g of oil sludge was co-composted differently with each manure in a ratio of 2:1 (w/w) spiked soil:manure and wood-chips in a ratio of 2:1 (w/v) spiked soil:wood-chips. Control was set up similar as the one above but without manure. Mixtures were incubated for 10 months at room temperature. Compost piles were turned weekly and moisture level was maintained at between 50% and 70%. Moisture level, pH, temperature, CO2 evolution and oxygen consumption were measured monthly and the ash content at the end of experimentation. Bacteria capable of utilizing PAHs were isolated, purified and characterized by molecular techniques using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), amplification of the 16S rDNA gene using the specific primers (16S-P1 PCR and 16S-P2 PCR) and the amplicons were sequenced. Extent of reduction of PAHs was measured using automated soxhlet extractor with dichloromethane as the extraction solvent coupled with gas chromatography/mass spectrometry (GC/MS). Temperature did not exceed 27.5O°C in all compost heaps, pH ranged from 5.5 to 7.8 and CO2 evolution was highest in poultry manure at 18.78 µg/dwt/day. Microbial growth and activities were enhanced. Bacteria identified were Bacillus, Arthrobacter and Staphylococcus species. Results from PAH measurements showed reduction between 77 and 99%. The results from the control experiments may be because it was invaded by fungi. Co-composting of spiked soils with animal manures enhanced the reduction in PAHs. Interestingly, all bacteria isolated and identified in this study were present in all treatments, including the control.

Keywords: bioremediation, co-composting, oil refinery sludge, PAHs, bacteria spp, animal manures, molecular techniques

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4659 Highly Linear and Low Noise AMR Sensor Using Closed Loop and Signal-Chopped Architecture

Authors: N. Hadjigeorgiou, A. C. Tsalikidou, E. Hristoforou, P. P. Sotiriadis

Abstract:

During the last few decades, the continuously increasing demand for accurate and reliable magnetic measurements has paved the way for the development of different types of magnetic sensing systems as well as different measurement techniques. Sensor sensitivity and linearity, signal-to-noise ratio, measurement range, cross-talk between sensors in multi-sensor applications are only some of the aspects that have been examined in the past. In this paper, a fully analog closed loop system in order to optimize the performance of AMR sensors has been developed. The operation of the proposed system has been tested using a Helmholtz coil calibration setup in order to control both the amplitude and direction of magnetic field in the vicinity of the AMR sensor. Experimental testing indicated that improved linearity of sensor response, as well as low noise levels can be achieved, when the system is employed.

Keywords: AMR sensor, closed loop, memory effects, chopper, linearity improvement, sensitivity improvement, magnetic noise, electronic noise

Procedia PDF Downloads 339