Search results for: plastic deformation
581 Evaluation of Deformation for Deep Excavations in the Greater Vancouver Area Through Case Studies
Authors: Boris Kolev, Matt Kokan, Mohammad Deriszadeh, Farshid Bateni
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Due to the increasing demand for real estate and the need for efficient land utilization in Greater Vancouver, developers have been increasingly considering the construction of high-rise structures with multiple below-grade parking. The temporary excavations required to allow for the construction of underground levels have recently reached up to 40 meters in depth. One of the challenges with deep excavations is the prediction of wall displacements and ground settlements due to their effect on the integrity of City utilities, infrastructure, and adjacent buildings. A large database of survey monitoring data has been collected for deep excavations in various soil conditions and shoring systems. The majority of the data collected is for tie-back anchors and shotcrete lagging systems. The data were categorized, analyzed and the results were evaluated to find a relationship between the most dominant parameters controlling the displacement, such as depth of excavation, soil properties, and the tie-back anchor loading and arrangement. For a select number of deep excavations, finite element modeling was considered for analyses. The lateral displacements from the simulation results were compared to the recorded survey monitoring data. The study concludes with a discussion and comparison of the available empirical and numerical modeling methodologies for evaluating lateral displacements in deep excavations.Keywords: deep excavations, lateral displacements, numerical modeling, shoring walls, tieback anchors
Procedia PDF Downloads 175580 Seismic Behavior of Suction Caisson Foundations
Authors: Mohsen Saleh Asheghabadi, Alireza Jafari Jebeli
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Increasing population growth requires more sustainable development of energy. This non-contaminated energy has an inexhaustible energy source. One of the vital parameters in such structures is the choice of foundation type. Suction caissons are now used extensively worldwide for offshore wind turbine. Considering the presence of a number of offshore wind farms in earthquake areas, the study of the seismic behavior of suction caisson is necessary for better design. In this paper, the results obtained from three suction caisson models with different diameter (D) and skirt length (L) in saturated sand were compared with centrifuge test results. All models are analyzed using 3D finite element (FE) method taking account of elasto-plastic Mohr–Coulomb constitutive model for soil which is available in the ABAQUS library. The earthquake load applied to the base of models with a maximum acceleration of 0.65g. The results showed that numerical method is in relative good agreement with centrifuge results. The settlement and rotation of foundation decrease by increasing the skirt length and foundation diameter. The sand soil outside the caisson is prone to liquefaction due to its low confinement.Keywords: liquefaction, suction caisson foundation, offshore wind turbine, numerical analysis, seismic behavior
Procedia PDF Downloads 117579 Development and Characterization of Re-Entrant Auxetic Fibrous Structures for Application in Ballistic Composites
Authors: Rui Magalhães, Sohel Rana, Raul Fangueiro, Clara Gonçalves, Pedro Nunes, Gustavo Dias
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Auxetic fibrous structures and composites with negative Poisson’s ratio (NPR) have huge potential for application in ballistic protection due to their high energy absorption and excellent impact resistance. In the present research, re-entrant lozenge auxetic fibrous structures were produced through weft knitting technology using high performance polyamide and para-aramid fibres. Fabric structural parameters (e.g. loop length) and machine parameters (e.g. take down load) were varied in order to investigate their influence on the auxetic behaviours of the produced structures. These auxetic structures were then impregnated with two types of polymeric resins (epoxy and polyester) to produce composite materials, which were subsequently characterized for the auxetic behaviour. It was observed that the knitted fabrics produced using the polyamide yarns exhibited NPR over a wide deformation range, which was strongly dependant on the loop length and take down load. The polymeric composites produced from the auxetic fabrics also showed good auxetic property, which was superior in case of the polyester matrix. The experimental results suggested that these composites made from the auxetic fibrous structures can be properly designed to find potential use in the body amours for personal protection applications.Keywords: auxetic fabrics, high performance, composites, energy absorption, impact resistance
Procedia PDF Downloads 249578 The Influence of Incorporating Coffee Grounds on Enhancing the Engineering Properties of Expansive Soils: Experimental Approach and Optimization
Authors: Bencheikh Messaouda, Aidoud Assia, Salima Boukour, Benamara Fatima Zohra, Boukhatem Ghania, Zegueur Chaouki Salah Eddine
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The utilization of waste materials in civil engineering has gained widespread attention in recent years due to their adverse effects on the environment. One such waste material is coffee grounds, a black residue generated daily across the country after coffee brewing. Instead of disposing of it, there is a growing interest in repurposing it for various agricultural and industrial applications. Utilizing coffee grounds in geotechnical engineering, such as in road embankments, presents an opportunity for its valorization. The study aims to contribute to the valorization of coffee grounds by enhancing the physical and mechanical properties of clayey soils through their incorporation at varying weight percentages (3%, 6%, 9%, 12%) as partial replacements in these soils. This not only addresses the issue of coffee ground waste but also makes a tangible contribution to sustainable development. The findings demonstrate that incorporating coffee grounds generally has positive effects on the physical and mechanical properties of clayey soil. However, the extent of these effects depends on factors such as the quantity of coffee grounds added, the particle size of the grounds, and the characteristics of the soil. Additionally, coffee grounds can improve the compression and tensile strength of clayey soil, resulting in increased stability and reduced susceptibility to deformation under external forces.Keywords: clay soil, coffee grounds, optimizing, improvement, valorization, waste
Procedia PDF Downloads 37577 Prediction of Concrete Hydration Behavior and Cracking Tendency Based on Electrical Resistivity Measurement, Cracking Test and ANSYS Simulation
Authors: Samaila Muazu Bawa
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Hydration process, crack potential and setting time of concrete grade C30, C40 and C50 were separately monitored using non-contact electrical resistivity apparatus, a plastic ring mould and penetration resistance method respectively. The results show highest resistivity of C30 at the beginning until reaching the acceleration point when C50 accelerated and overtaken the others, and this period corresponds to its final setting time range, from resistivity derivative curve, hydration process can be divided into dissolution, induction, acceleration and deceleration periods, restrained shrinkage crack and setting time tests demonstrated the earliest cracking and setting time of C50, therefore, this method conveniently and rapidly determines the concrete’s crack potential. The highest inflection time (ti), the final setting time (tf) were obtained and used with crack time in coming up with mathematical models for the prediction of concrete’s cracking age for the range being considered. Finally, ANSYS numerical simulations supports the experimental findings in terms of the earliest crack age of C50 and the crack location that, highest stress concentration is always beneath the artificially introduced expansion joint of C50.Keywords: concrete hydration, electrical resistivity, restrained shrinkage crack, ANSYS simulation
Procedia PDF Downloads 232576 Pressure Drop Study in Moving and Stationary Beds with Lateral Gas Injection
Authors: Vinci Mojamdar, Govind S. Gupta
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Moving beds in the presence of gas flow are widely used in metallurgical and chemical industries like blast furnaces, catalyst reforming, drying, etc. Pressure drop studies in co- and counter – current conditions have been done by a few researchers. However, to the best of authours knowledge, proper pressure drop study with lateral gas injection lacks especially in the presence of cavity and nozzle protrusion inside the packed bed. The latter study is more useful for metallurgical industries for the processes such as blast furnaces, shaft reduction and, COREX. In this experimental work, a two dimensional cold model with slot type nozzle for lateral gas injection along with the plastic beads as packing material and dry air as gas have been used. The variation of pressure drop is recorded at various horizontal and vertical directions in the presence of cavity and nozzle protrusion. The study has been performed in both moving and stationary beds. Also, the experiments have been carried out in both increasing as well as decreasing gas flow conditions. Experiments have been performed at various gas flow rates and packed bed heights. Some interesting results have been reported such as there is no pressure variation in the moving bed for both the increasing and decreasing gas flow condition that is different from the stationary bed. Pressure hysteresis loop has been observed in a stationary bed.Keywords: lateral gas injection, moving bed, pressure drop, pressure hysteresis, stationary bed
Procedia PDF Downloads 303575 Validating Texture Analysis as a Tool for Determining Bioplastic (Bio)Degradation
Authors: Sally J. Price, Greg F. Walker, Weiyi Liu, Craig R. Bunt
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Plastics, due to their long lifespan, are becoming more of an environmental concern once their useful life has been completed. There are a vast array of different types of plastic, and they can be found in almost every ecosystem on earth and are of particular concern in terrestrial environments where they can become incorporated into the food chain. Hence bioplastics have become more of interest to manufacturers and the public recently as they have the ability to (bio)degrade in commercial and in home composting situations. However, tools in which to quantify how they degrade in response to environmental variables are still being developed -one such approach is texture analysis using a TA.XT Texture Analyser, Stable Microsystems, was used to determine the force required to break or punch holes in standard ASTM D638 Type IV 3D printed bioplastic “dogbones” depending on the thicknesses of them. Manufacturers’ recommendations for calibrating the Texture Analyser are one such approach for standardising results; however, an independent technique using dummy dogbones and a substitute for the bioplastic was used alongside the samples. This approach was unexpectedly more valuable than realised at the start of the trial as irregular results were later discovered with the substitute material before valuable samples collected from the field were lost due to possible machine malfunction. This work will show the value of having an independent approach to machine calibration for accurate sample analysis with a Texture Analyser when analysing bioplastic samples.Keywords: bioplastic, degradation, environment, texture analyzer
Procedia PDF Downloads 196574 Optimization of Pressure in Deep Drawing Process
Authors: Ajay Kumar Choubey, Geeta Agnihotri, C. Sasikumar, Rashmi Dwivedi
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Deep-drawing operations are performed widely in industrial applications. It is very important for efficiency to achieve parts with no or minimum defects. Deep drawn parts are used in high performance, high strength and high reliability applications where tension, stress, load and human safety are critical considerations. Wrinkling is a kind of defect caused by stresses in the flange part of the blank during metal forming operations. To avoid wrinkling appropriate blank-holder pressure/force or drawbead can be applied. Now-a-day computer simulation plays a vital role in the field of manufacturing process. So computer simulation of manufacturing has much advantage over previous conventional process i.e. mass production, good quality of product, fast working etc. In this study, a two dimensional elasto-plastic Finite Element (F.E.) model for Mild Steel material blank has been developed to study the behavior of the flange wrinkling and deep drawing parameters under different Blank-Holder Pressure (B.H.P.). For this, commercially available Finite Element software ANSYS 14 has been used in this study. Simulation results are critically studied and salient conclusions have been drawn.Keywords: ANSYS, deep drawing, BHP, finite element simulation, wrinkling
Procedia PDF Downloads 446573 Development of Biodegradable Plastic as Mango Fruit Bag
Authors: Andres M. Tuates Jr., Ofero A. Caparino
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Plastics have achieved a dominant position in agriculture because of their transparency, lightness in weight, impermeability to water and their resistance to microbial attack. However, this generates a higher quantity of wastes that are difficult to dispose of by farmers. To address these problems, the project aim to develop and evaluate the biodegradable film for mango fruit bag during development. The PBS and starch were melt-blended in a twin-screw extruder and then blown into film extrusion machine. The physic-chemical-mechanical properties of biodegradable fruit bag were done following standard methods of test. Field testing of fruit bag was also conducted to evaluate its durability and efficiency field condition. The PHilMech-FiC fruit bag is made of biodegradable material measuring 6 x 8 inches with a thickness of 150 microns. The tensile strength is within the range of LDPE while the elongation is within the range of HDPE. It is projected that after thirty-six (36) weeks, the film will be totally degraded. Results of field testing show that the quality of harvested fruits using PHilMech-FiC biodegradable fruit bag in terms of percent marketable, non-marketable and export, peel color at the ripe stage, flesh color, TSS, oBrix, percent edible portion is comparable with the existing bagging materials such as Chinese brown paper bag and old newspaper.Keywords: cassava starch, PBS, biodegradable, chemical, mechanical properties
Procedia PDF Downloads 269572 Rising Velocity of a Non-Newtonian Liquids in Capillary Tubes
Authors: Reza Sabbagh, Linda Hasanovich, Aleksey Baldygin, David S. Nobes, Prashant R. Waghmare
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The capillary filling process is significantly important to study for numerous applications such as the under filling of the material in electronic packaging or liquid hydrocarbons seepage through porous structure. The approximation of the fluid being Newtonian, i.e., linear relationship between the shear stress and deformation rate cannot be justified in cases where the extent of non-Newtonian behavior of liquid governs the surface driven transport, i.e., capillarity action. In this study, the capillary action of a non-Newtonian fluid is not only analyzed, but also the modified generalized theoretical analysis for the capillary transport is proposed. The commonly observed three regimes: surface forces dominant (travelling air-liquid interface), developing flow (viscous force dominant), and developed regimes (interfacial, inertial and viscous forces are comparable) are identified. The velocity field along each regime is quantified with Newtonian and non-Newtonian fluid in square shaped vertically oriented channel. Theoretical understanding of capillary imbibition process, particularly in the case of Newtonian fluids, is relied on the simplified assumption of a fully developed velocity profile which has been revisited for developing a modified theory for the capillary transport of non-Newtonian fluids. Furthermore, the development of the velocity profile from the entrance regime to the developed regime, for different power law fluids, is also investigated theoretically and experimentally.Keywords: capillary, non-Newtonian flow, shadowgraphy, rising velocity
Procedia PDF Downloads 200571 Determination of Surface Deformations with Global Navigation Satellite System Time Series
Authors: Ibrahim Tiryakioglu, Mehmet Ali Ugur, Caglar Ozkaymak
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The development of GNSS technology has led to increasingly widespread and successful applications of GNSS surveys for monitoring crustal movements. However, multi-period GPS survey solutions have not been applied in monitoring vertical surface deformation. This study uses long-term GNSS time series that are required to determine vertical deformations. In recent years, the surface deformations that are parallel and semi-parallel to Bolvadin fault have occurred in Western Anatolia. These surface deformations have continued to occur in Bolvadin settlement area that is located mostly on alluvium ground. Due to these surface deformations, a number of cracks in the buildings located in the residential areas and breaks in underground water and sewage systems have been observed. In order to determine the amount of vertical surface deformations, two continuous GNSS stations have been established in the region. The stations have been operating since 2015 and 2017, respectively. In this study, GNSS observations from the mentioned two GNSS stations were processed with GAMIT/GLOBK (GNSS Analysis Massachusetts Institute of Technology/GLOBal Kalman) program package to create a coordinate time series. With the time series analyses, the GNSS stations’ behavior models (linear, periodical, etc.), the causes of these behaviors, and mathematical models were determined. The study results from the time series analysis of these two 2 GNSS stations shows approximately 50-80 mm/yr vertical movement.Keywords: Bolvadin fault, GAMIT, GNSS time series, surface deformations
Procedia PDF Downloads 162570 Hard Sludge Formation and Consolidation in Pressurized Water Reactor Steam Generators: An Experimental Study
Authors: R. Fernandez-Saavedra, M. B. Gomez-Mancebo, D. Gomez-Briceno
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The gradual corrosion of PWR (Pressurized Water Reactor) feedwater, condensate and drain systems results in the inevitable liberation of corrosion products, principally metallic oxides, to the secondary circuit. In addition, other contaminants and impurities are introduced into the makeup water, auxiliary feedwater and by condenser leaks. All these compounds circulating in the secondary flow can eventually be transported to steam generators and be transformed into deposits on their surfaces. Deposits that accumulate on the tube sheet are known as sludge piles and when they consolidate and harden become into hard sludge. Hard sludge is especially detrimental because it favors tube deformation or denting at the top of tube sheet and further stress corrosion cracking (SCC). These failures affect the efficiency of nuclear power plants. In a recent work, a model for the formation and consolidation of hard sludge has been formulated, highlighting the influence of aluminum and silicon compounds in the initial formation of hard sludge. In this work, an experimental study has been performed in order to get a deeper understanding of the behavior of Al and Si species in hard sludge formation and consolidation. For this purpose, the key components of hard sludge (magnetite, aluminum and/or silicon sources) have been isothermally autoclaved in representative secondary circuit conditions during one week, and the resulting products have been chemically and structurally characterized by XRF and XRD techniques, respectively.Keywords: consolidation, hard sludge, secondary circuit, steam generator
Procedia PDF Downloads 186569 The Effect of Arbitrary Support Conditions on the Static Behavior of Curved Beams Using the Finite Element Method
Authors: Hossein Mottaghi T., Amir R. Masoodi
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This study presents a finite curved element for analyzing the static behavior of curved beams within the elastic range. The objective is to enhance accuracy while reducing the number of elements by incorporating first-order shear deformations of Timoshenko beams. Initially, finite element formulations are developed by considering polynomial initial functions for axial, shear, and rotational deformations for a three-node element. Subsequently, nodal interpolation functions for this element are derived, followed by the construction of the element stiffness matrix. To enable the utilization of the stiffness matrix in the static analysis of curved beams, the constructed matrix in the local coordinates of the element is transformed to the global coordinate system using the rotation matrix. A numerical benchmark example is investigated to assess the accuracy and effectiveness of this method. Moreover, the influence of spring stiffness on the rotation of the endpoint of a clamped beam is examined by substituting each support reaction of the beam with a spring. In the parametric study, the effect of the central angle of the beam on the rotation of the beam's endpoint in a cantilever beam under a concentrated load is examined. This research encompasses various mechanical, geometrical, and boundary configurations to evaluate the static characteristics of curved beams, thus providing valuable insights for their analysis and examination.Keywords: curved beam, finite element method, first-order shear deformation theory, elastic support
Procedia PDF Downloads 44568 Numerical Analysis of Bearing Capacity of Caissons Subjected to Inclined Loads
Authors: Hooman Dabirmanesh, Mahmoud Ghazavi, Kazem Barkhordari
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A finite element modeling for determination of the bearing capacity of caissons subjected to inclined loads is presented in this paper. The model investigates the uplift capacity of the caisson with varying cross sectional area. To this aim, the behavior of the soil is assumed to be elasto-plastic, and its failure is controlled by Modified Cam-Clay failure criterion. The simulation takes into account the couple analysis. The approach is verified using available data from other research work especially centrifuge data. Parametric studies are subsequently performed to investigate the effect of contributing parameters such as aspect ratio of the caisson, the loading rate, the loading direction angle, and points where the external load is applied. In addition, the influence of the caisson geometry is taken into account. The results show the bearing capacity of the caisson increases with increasing the taper angle. Hence, the pullout capacity will increase using the same material. In addition, the bearing capacity of caissons strongly depends on the suction that is generated at tip and in sealed surface on top of caisson. Other results concerning the influencing factors will be presented.Keywords: aspect ratio, finite element method, inclined load, modified Cam clay, taper angle, undrained condition
Procedia PDF Downloads 253567 Evolution of Gravity Flap Structures in the Southern Central Atlas of Tunisia. Example: Northern of Orbata Anticline (Ben Zannouch Structure)
Authors: Soulef Amamria, Mohamed Sadok Bensalem, Mohamed Ghanmi
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Several works found in the fold-and-thrust belt area of the southern central atlas of Tunisia, which were often related with tectonic shortening, are, in fact, related to superficial gravity structures. These gravitational collapse structures have developed in the northern flank of jebel Orbata. These include rock-slides, rock falls, wrinkle folds, slip sheets, and flaps. The Gravity collapse structures of ben zannouch are parallel to the major thrust of Bou Omrane between Orbata and El Ong structures. The thrust activity of Bou Omrane associated to the important paleo-slope to the south and plastic lithology (incompetent marly and gypsum layers) facilitates the development of the Ben Zannouch Flap structure. The definition in the first time of gravitional collapse structures in Tunisia, particularly in the northern flank of Jebel Orbata, is controlled by three principal structural conditions: the fragmentation of the landslide surfaces, the lithology, and the topography. Other regional factors can be distinguished in the southern-central Tunisian Atlas as the seismity activity of the Gafsa fault and the wetter conditions during the postglacial period.Keywords: collapse structure, flap structure, gravity structures, thrust activity
Procedia PDF Downloads 82566 Idealization of Licca-Chan and Barbie: Comparison of Two Dolls across the Pacific
Authors: Miho Tsukamoto
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Since the initial creation of the Barbie doll in 1959, it became a symbol of US society. Likewise, the Licca-chan, a Japanese doll created in 1967, also became a Japanese symbolic doll of Japanese society. Prior to the introduction of Licca-chan, Barbie was already marketed in Japan but their sales were dismal. Licca-chan (an actual name: Kayama Licca) is a plastic doll with a variety of sizes ranging from 21.0 cm to 29.0 cm which many Japanese girls dream of having. For over 35 years, the manufacturer, Takara Co., Ltd. has sold over 48 million dolls and has produced doll houses, accessories, clothes, and Licca-chan video games for the Nintendo DS. Many First-generation Licca-chan consumers still are enamored with Licca-chan, and go to Licca-chan House, in an amusement park with their daughters. These people are called Licca-chan maniacs, as they enjoy touring the Licca-chan’s factory in Tohoku or purchase various Licca-chan accessories. After the successful launch of Licca-chan into the Japanese market, a mixed-like doll from the US and Japan, a doll, JeNny, was later sold in the same Japanese market by Takara Co., Ltd. in 1982. Comparison of these cultural iconic dolls, Barbie and Licca-chan, are analyzed in this paper. In fact, these dolls have concepts of girls’ dreams. By using concepts of mythology of Jean Baudrillard, these dolls can be represented idealized images of figures in the products for consumers, but at the same time, consumers can see products with different perspectives, which can cause controversy.Keywords: Barbie, dolls, JeNny, idealization, Licca-chan
Procedia PDF Downloads 266565 Investigation of Crack Formation in Ordinary Reinforced Concrete Beams and in Beams Strengthened with Carbon Fiber Sheet: Theory and Experiment
Authors: Anton A. Bykov, Irina O. Glot, Igor N. Shardakov, Alexey P. Shestakov
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This paper presents the results of experimental and theoretical investigations of the mechanisms of crack formation in reinforced concrete beams subjected to quasi-static bending. The boundary-value problem has been formulated in the framework of brittle fracture mechanics and has been solved by using the finite-element method. Numerical simulation of the vibrations of an uncracked beam and a beam with cracks of different size serves to determine the pattern of changes in the spectrum of eigenfrequencies observed during crack evolution. Experiments were performed on the sequential quasistatic four-point bending of the beam leading to the formation of cracks in concrete. At each loading stage, the beam was subjected to an impulse load to induce vibrations. Two stages of cracking were detected. At the first stage the conservative process of deformation is realized. The second stage is an active cracking, which is marked by a sharp change in eingenfrequencies. The boundary of a transition from one stage to another is well registered. The vibration behavior was examined for the beams strengthened by carbon-fiber sheet before loading and at the intermediate stage of loading after the grouting of initial cracks. The obtained results show that the vibrodiagnostic approach is an effective tool for monitoring of cracking and for assessing the quality of measures aimed at strengthening concrete structures.Keywords: crack formation, experiment, mathematical modeling, reinforced concrete, vibrodiagnostics
Procedia PDF Downloads 297564 Characterization and Nanostructure Formation of Banana Peels Nanosorbent with Its Application
Authors: Opeyemi Atiba-Oyewo, Maurice S. Onyango, Christian Wolkersdorfer
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Characterization and nanostructure formation of banana peels as sorbent material are described in this paper. The transformation of this agricultural waste via mechanical milling to enhance its properties such as changed in microstructure and surface area for water pollution control and other applications were studied. Mechanical milling was employed using planetary continuous milling machine with ethanol as a milling solvent and the samples were taken at time intervals between 10 h to 30 h to examine the structural changes. The samples were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red (FTIR), Transmission electron microscopy (TEM) and Brunauer Emmett and teller (BET). Results revealed three typical structures with different deformation mechanisms and the grain-sizes within the range of (71-12 nm), nanostructure of the particles and fibres. The particle size decreased from 65µm to 15 nm as the milling progressed for a period of 30 h. The morphological properties of the materials indicated that the particle shapes becomes regular and uniform as the milling progresses. Furthermore, particles fracturing resulted in surface area increment from 1.0694-4.5547 m2/g. The functional groups responsible for the banana peels capacity to coordinate and remove metal ions, such as the carboxylic and amine groups were identified at absorption bands of 1730 and 889 cm-1, respectively. However, the choice of this sorbent material for the sorption or any application will depend on the composition of the pollutant to be eradicated.Keywords: characterization, nanostructure, nanosorbent, eco-friendly, banana peels, mechanical milling, water quality
Procedia PDF Downloads 278563 Influence of Produced Water Mixed With Crude Oil on the Geotechnical Properties of Sandy Soil
Authors: Khalifa Abdunaser
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This study investigated the effects of oil contamination due to pro-duced water leaks that created lakes decades ago, as well as the extent of its im-pact on altering the geotechnical characteristics of the soil, which could act as a barrier to groundwater access The concentration of total petroleum hydrocarbons (TPH), which is the main component in the contaminated soil, was measured using a variety of analyses. Additionally, some extensive laboratory tests were performed to examine the effects on the soil's geotechnical properties, including particle size distribution, shear strength, consistency limits, specific gravity, and permeability coefficient. A clear decrease in TPH concentration was observed with increasing depth, and it is expected to end within only a few meters. It was found that there is a signifi-cant effect of this pollutant on the size of the soil particles, which led to them be-coming coarser than the uncontaminated soil particles. Moreover, it causes a de-crease in fluid and plastic boundaries, as well as an increase in cohesion between soil particles. However, the angle of internal friction decreases with the increase in the content of petroleum hydrocarbons in the soil samples. It came to light that determining the permeability coefficient as one of the physical characteristics of the most important factors responsible for the passage of pollutants in the groundwater, as it showed an obvious reduction in the permeability, which is the main reason dealt as an obstacle to the arrival of oil pollutants to the groundwater.Keywords: TPH, specific gravity, oil lake, Libya
Procedia PDF Downloads 86562 Waste Management in a Hot Laboratory of Japan Atomic Energy Agency – 3: Volume Reduction and Stabilization of Solid Waste
Authors: Masaumi Nakahara, Sou Watanabe, Hiromichi Ogi, Atsuhiro Shibata, Kazunori Nomura
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In the Japan Atomic Energy Agency, three types of experimental research, advanced reactor fuel reprocessing, radioactive waste disposal, and nuclear fuel cycle technology, have been carried out at the Chemical Processing Facility. The facility has generated high level radioactive liquid and solid wastes in hot cells. The high level radioactive solid waste is divided into three main categories, a flammable waste, a non-flammable waste, and a solid reagent waste. A plastic product is categorized into the flammable waste and molten with a heating mantle. The non-flammable waste is cut with a band saw machine for reducing the volume. Among the solid reagent waste, a used adsorbent after the experiments is heated, and an extractant is decomposed for its stabilization. All high level radioactive solid wastes in the hot cells are packed in a high level radioactive solid waste can. The high level radioactive solid waste can is transported to the 2nd High Active Solid Waste Storage in the Tokai Reprocessing Plant in the Japan Atomic Energy Agency.Keywords: high level radioactive solid waste, advanced reactor fuel reprocessing, radioactive waste disposal, nuclear fuel cycle technology
Procedia PDF Downloads 150561 A Finite Elements Model for the Study of Buried Pipelines Affected by Strike-Slip Fault
Authors: Reza Akbari, Jalal MontazeriFashtali, PeymanMomeni Taromsari
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Pipeline systems, play an important role as a vital element in reducing or increasing the risk of earthquake damage and vulnerability. Pipelines are suitable, cheap, fast, and safe routes for transporting oil, gas, water, sewage, etc. The sepipelines must pass from a wide geographical area; hence they will structurally face different environmental and underground factors of earthquake forces’ effect. Therefore, structural engineering analysis and design for this type of lines requires the understanding of relevant parameters behavior and lack of familiarity with them can cause irreparable damages and risks to design and execution, especially in the face of earthquakes. Today, buried pipelines play an important role in human life cycle, thus, studying the vulnerability of pipeline systems is of particular importance. This study examines the behavior of buried pipelines affected by strike-slip fault. Studied fault is perpendicular to the tube axis and causes stress and deformation in the tube by sliding horizontally. In this study, the pipe-soil interaction is accurately simulated, so that one can examine the large displacements and strains, nonlinear material behavior and contact and friction conditions of soil and pipe. The results can be used for designing buried pipes and determining the amount of fault displacement that causes the failure of the buried pipes.Keywords: pipe lines , earthquake , fault , soil-fault interaction
Procedia PDF Downloads 447560 Capillary Wave Motion and Atomization Induced by Surface Acoustic Waves under the Navier-Slip Condition at the Wall
Authors: Jaime E. Munoz, Jose C. Arcos, Oscar E. Bautista, Ivan E. Campos
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The influence of slippage phenomenon over the destabilization and atomization mechanisms induced via surface acoustic waves on a Newtonian, millimeter-sized, drop deposited on a hydrophilic substrate is studied theoretically. By implementing the Navier-slip model and a lubrication-type approach into the equations which govern the dynamic response of a drop exposed to acoustic stress, a highly nonlinear evolution equation for the air-liquid interface is derived in terms of the acoustic capillary number and the slip coefficient. By numerically solving such an evolution equation, the Spatio-temporal deformation of the drop's free surface is obtained; in this context, atomization of the initial drop into micron-sized droplets is predicted at our numerical model once the acoustically-driven capillary waves reach a critical value: the instability length. Our results show slippage phenomenon at systems with partial and complete wetting favors the formation of capillary waves at the free surface, which traduces in a major volume of liquid being atomized in comparison to the no-slip case for a given time interval. In consequence, slippage at the wall possesses the capability to affect and improve the atomization rate for a drop exposed to a high-frequency acoustic field.Keywords: capillary instability, lubrication theory, navier-slip condition, SAW atomization
Procedia PDF Downloads 150559 Bio-Based Polyethylene/Rice Starch Composite Prepared by Twin Screw Extruder
Authors: Waris Piyaphon, Sathaphorn O-Suwankul, Kittima Bootdee, Manit Nithitanakul
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Starch from rice was used as a filler in low density polyethylene in preparation of low density polyethylene/rice starch composite. This study aims to prepare LDPE/rice starch composites. Glycerol (GC) was used as a plasticizer in order to increase dispersion and reduce agglomeration of rice starch in low density polyethylene (LDPE) matrix. Low density polyethylene grafted maleic anhydride (LDPE-g-MA) was used as a compatibilizer to increase the compatibility between LDPE and rice starch. The content of rice starch was varied between 10, 20, and 30 %wt. Results indicated that increase of rice starch content reduced tensile strength at break, elongation, and impact strength of composites. LDPE-g-MA showed positive effect on mechanical properties which increased in tensile strength and impact properties as well as compatibility between rice starch and LDPE matrix. Moreover, the addition of LDPE-g-MA significantly improved the impact strength by 50% compared to neat composite. The incorporation of GC enhanced the processability of composite. Introduction of GC affected the viscosity after blending by reducing the viscosity at all shear rate. The presence of plasticizer increased the impact strength but decreased the stiffness of composite. Water absorption of the composite was increased when plasticizer was added.Keywords: composite material, plastic starch composite, polyethylene composite, PE grafted maleic anhydride
Procedia PDF Downloads 200558 Mycoplasmas and Pathogenesis in Preventive Medicine
Authors: Narin Salehiyan
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The later sequencing of the complete genomes of Mycoplasma genitalium and M. pneumoniae has pulled in significant consideration to the atomic science of mycoplasmas, the littlest self-replicating living beings. It shows up that we are presently much closer to the objective of defining, in atomic terms, the complete apparatus of a self-replicating cell. Comparative genomics based on comparison of the genomic cosmetics of mycoplasmal genomes with those of other microbes, has opened better approaches of looking at the developmental history of the mycoplasmas. There's presently strong hereditary bolster for the speculation that mycoplasmas have advanced as a department of gram-positive microbes by a handle of reductive advancement. Amid this prepare, the mycoplasmas misplaced significant parcels of their ancestors’ chromosomes but held the qualities basic for life. In this way, the mycoplasmal genomes carry a tall rate of preserved qualities, incredibly encouraging quality comment. The critical genome compaction that happened in mycoplasmas was made conceivable by receiving a parasitic mode of life. The supply of supplements from their has clearly empowered mycoplasmas to lose, amid advancement, the qualities for numerous assimilative forms. Amid their advancement and adjustment to a parasitic mode of life, the mycoplasmas have created different hereditary frameworks giving a profoundly plastic set of variable surface proteins to avoid the have safe framework.Keywords: mycoplasma, plasma, pathogen, genome
Procedia PDF Downloads 59557 Determination of Bisphenol A and Uric Acid by Modified Single-Walled Carbon Nanotube with Magnesium Layered Hydroxide 3-(4-Methoxyphenyl)Propionic Acid Nanocomposite
Authors: Illyas Md Isa, Maryam Musfirah Che Sobry, Mohamad Syahrizal Ahmad, Nurashikin Abd Azis
Abstract:
A single-walled carbon nanotube (SWCNT) that has been modified with magnesium layered hydroxide 3-(4-methoxyphenyl)propionic acid nanocomposite was proposed for the determination of uric acid and bisphenol A by square wave voltammetry. The results obtained denote that MLH-MPP nanocomposites enhance the sensitivity of the voltammetry detection responses. The best performance is shown by the modified carbon nanotube paste electrode (CNTPE) with the composition of single-walled carbon nanotube: magnesium layered hydroxide 3-(4-methoxyphenyl)propionic acid nanocomposite at 100:15 (% w/w). The linear range where the sensor works well is within the concentration 1.0 10-7 – 1.0 10-4 and 3.0 10-7 – 1.0 10-4 for uric acid and bisphenol A respectively with the limit of detection of 1.0 10-7 M for both organics. The interferences of uric acid and bisphenol A with other organic were studied and most of them did not interfere. The results shown for each experimental parameter on the proposed CNTPE showed that it has high sensitivity, good selectivity, repeatability and reproducibility. Therefore, the modified CNTPE can be used for the determination of uric acid and bisphenol A in real samples such as blood, plastic bottles and foods.Keywords: bisphenol A, magnesium layered hydroxide 3-(4-methoxyphenyl)propionic acid nanocomposite, Nanocomposite, uric acid
Procedia PDF Downloads 206556 Thermo-Mechanical Approach to Evaluate Softening Behavior of Polystyrene: Validation and Modeling
Authors: Salah Al-Enezi, Rashed Al-Zufairi, Naseer Ahmad
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A Thermo-mechanical technique was developed to determine softening point temperature/glass transition temperature (Tg) of polystyrene exposed to high pressures. The design utilizes the ability of carbon dioxide to lower the glass transition temperature of polymers and acts as plasticizer. In this apparatus, the sorption of carbon dioxide to induce softening of polymers as a function of temperature/pressure is performed and the extent of softening is measured in three-point-flexural-bending mode. The polymer strip was placed in the cell in contact with the linear variable differential transformer (LVDT). CO2 was pumped into the cell from a supply cylinder to reach high pressure. The results clearly showed that full softening point of the samples, accompanied by a large deformation on the polymer strip. The deflection curves are initially relatively flat and then undergo a dramatic increase as the temperature is elevated. It was found that increasing the pressure of CO2 causes the temperature curves to shift from higher to lower by increment of about 45 K, over the pressure range of 0-120 bars. The obtained experimental Tg values were validated with the values reported in the literature. Finally, it is concluded that the defection model fits consistently to the generated experimental results, which attempts to describe in more detail how the central deflection of a thin polymer strip affected by the CO2 diffusions in the polymeric samples.Keywords: softening, high-pressure, polystyrene, CO₂ diffusions
Procedia PDF Downloads 122555 A Case Study on the Collapse Assessment of the Steel Moment-Frame Setback High-Rise Tower
Authors: Marzie Shahini, Rasoul Mirghaderi
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This paper describes collapse assessments of a steel moment-frame high-rise tower with setback irregularity, designed per the 2010 ASCE7 code, under spectral-matched ground motion records. To estimate a safety margin against life-threatening collapse, an analytical model of the tower is subjected to a suite of ground motions with incremental intensities from maximum considered earthquake hazard level to the incipient collapse level. Capability of the structural system to collapse prevention is evaluated based on the similar methodology reported in FEMA P695. Structural performance parameters in terms of maximum/mean inter-story drift ratios, residual drift ratios, and maximum plastic hinge rotations are also compared to the acceptance criteria recommended by the TBI Guidelines. The results demonstrate that the structural system satisfactorily safeguards the building against collapse. Moreover, for this tower, the code-specified requirements in ASCE7-10 are reasonably adequate to satisfy seismic performance criteria developed in the TBI Guidelines for the maximum considered earthquake hazard level.Keywords: high-rise buildings, set back, residual drift, seismic performance
Procedia PDF Downloads 256554 Preparation and Characterization of Bioplastic from Sorghum Husks
Authors: Hannatu Abubakar Sani, Abubakar Umar Birnin Yauri, Aliyu Muhammad, Mujahid Salau, Aminu Musa, Hadiza Adamu Kwazo
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The increase in the global population and advances in technology have made plastic materials to have wide applications in every aspect of life. However, the non-biodegradability of these petrochemical-based materials and their increasing accumulation in the environment has been a threat to the planet and has been a source of environmental concerns and hence, the driving force in the search for ‘green’ alternatives for which agricultural waste remains the front liner. Sorghum husk, an agricultural waste with potentials as a raw material in the production of bioplastic, was used in this research to prepare bioplastic using sulphuric acid-catalyzed acetylation process. The prepared bioplastic was characterized by X-ray diffraction and Fourier transform infrared spectroscopy (FTIR), and the structure of the prepared bioplastic was confirmed. The Fourier transform infrared spectroscopy (FTIR) spectra of the product displayed the presence of OH, C-H, C=O, and C-O absorption peaks. The bioplastic obtained is biodegradable and is affected by acid, salt, and alkali to a lesser extent. Other tests like solubility and swelling studies were carried out to ensure the commercial properties of these bioplastic materials. Therefore, this revealed that new bioplastics with better environmental and sustainable properties could be produced from agricultural waste, which may have applications in many industries.Keywords: agricultural waste, bioplastic, characterization, Sorghum Husk
Procedia PDF Downloads 148553 Unusual High Origin and Superficial Course of Radial Artery: A Case Report with Embryological Explanation
Authors: Anasuya Ghosh, Subhramoy Chaudhury
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During routine cadaveric dissection at gross anatomy lab of our institution, a radial artery was found with unusual origin and superficial course. Normally the radial artery takes its origin as one of the terminal branches of brachial artery at the level of the neck of radius. It usually lies along the lateral border of fore arm deep to the brachioradialis muscle. While dissecting a 72-year-old Caucasian female cadaver, it was found that the right sided radial artery originated from the upper part of brachial artery of arm, 2 cm below the lower border of teres major muscle, from the lateral aspect of brachial artery. Then the radial artery superficially crossed the brachial artery and median nerve from lateral to medial direction and rested superficially at the cubital fossa. Embryologically, it can be explained as a failure of disappearance, or abnormal persistence of some insignificant embryonic vessels may give rise to this kind of vascular anomalies. As radial artery is one of the most important upper limb arteries, its variation and related complications are clinically significant. This unusual origin and course of radial artery should be kept in mind by all healthcare providers including surgeons and radiologists during routine venipuncture, orthopedic and plastic surgeries of arm, coronary angiographic procedures in radial approach etc. to prevent unwanted complications.Keywords: brachial artery anomalies, brachio-radial artery, high origin radial artery, superficial radial artery
Procedia PDF Downloads 322552 Finite Difference Based Probabilistic Analysis to Evaluate the Impact of Correlation Length on Long-Term Settlement of Soft Soils
Authors: Mehrnaz Alibeikloo, Hadi Khabbaz, Behzad Fatahi
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Probabilistic analysis has become one of the most popular methods to quantify and manage geotechnical risks due to the spatial variability of soil input parameters. The correlation length is one of the key factors of quantifying spatial variability of soil parameters which is defined as a distance within which the random variables are correlated strongly. This paper aims to assess the impact of correlation length on the long-term settlement of soft soils improved with preloading. The concept of 'worst-case' spatial correlation length was evaluated by determining the probability of failure of a real case study of Vasby test fill. For this purpose, a finite difference code was developed based on axisymmetric consolidation equations incorporating the non-linear elastic visco-plastic model and the Karhunen-Loeve expansion method. The results show that correlation length has a significant impact on the post-construction settlement of soft soils in a way that by increasing correlation length, probability of failure increases and the approach to asymptote.Keywords: Karhunen-Loeve expansion, probability of failure, soft soil settlement, 'worst case' spatial correlation length
Procedia PDF Downloads 161