Search results for: plastic wastes
1052 Determination of Brominated Flame Retardants In Recycled Plastic Toys Using Thermal Desorption GC/MS
Authors: Athena Nguyen, Rojin Belganeh
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In recycling plastics industries, waste plastics are converted into monomers and other useful molecules by chemical reactions. Thermal energy generated by incineration is recovered when waste plastics melt. During the process, Flame retardants containing products get in, and brominated flame retardants (BFRs) are often used to reduce the flammability of products. Some of the originally formulated brominated flame retardants additives are restricted by the RoHS Directive, such as PBDE and PBB. The determination of BFRs other than those restricted by the RoHS directive is required. Frontier Lab developed a pyrolyzer based on the vertical micro-furnace design. The multi-mode pyrolyzer with different modes of operations, including evolve gas analysis (EGA), flash pyrolysis, thermal desorption, heart cutting, allows users to choose among the techniques for their analysis purposes. The method requires very little sample preparation. The first step is to perform an EGA using temperature programs. This technique provides information about the thermal temperature behaviors of the sample. The EGA thermogram is then used to determine the next steps in the analysis process. In this presentation, with an Optimal thermal temperature zone identified based on EGA thermogram, thermal desorption GC/MS is a chosen technique for the determination of brominated flame retardants in recycled plastic toys. Five types of general-purpose brominated flame retardants other than those restricted by the RoHS Directive are determined by the standard addition method.Keywords: gas chromatography/mass spectrometry, pyrolysis, pyrolyzer, thermal desorption-GC/MS
Procedia PDF Downloads 1811051 Alternative Energy and Carbon Source for Biosurfactant Production
Authors: Akram Abi, Mohammad Hossein Sarrafzadeh
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Because of their several advantages over chemical surfactants, biosurfactants have given rise to a growing interest in the past decades. Advantages such as lower toxicity, higher biodegradability, higher selectivity and applicable at extreme temperature and pH which enables them to be used in a variety of applications such as: enhanced oil recovery, environmental and pharmaceutical applications, etc. Bacillus subtilis produces a cyclic lipopeptide, called surfactin, which is one of the most powerful biosurfactants with ability to decrease surface tension of water from 72 mN/m to 27 mN/m. In addition to its biosurfactant character, surfactin exhibits interesting biological activities such as: inhibition of fibrin clot formation, lyses of erythrocytes and several bacterial spheroplasts, antiviral, anti-tumoral and antibacterial properties. Surfactin is an antibiotic substance and has been shown recently to possess anti-HIV activity. However, application of biosurfactants is limited by their high production cost. The cost can be reduced by optimizing biosurfactant production using cheap feed stock. Utilization of inexpensive substrates and unconventional carbon sources like urban or agro-industrial wastes is a promising strategy to decrease the production cost of biosurfactants. With suitable engineering optimization and microbiological modifications, these wastes can be used as substrates for large-scale production of biosurfactants. As an effort to fulfill this purpose, in this work we have tried to utilize olive oil as second carbon source and also yeast extract as second nitrogen source to investigate the effect on both biomass and biosurfactant production improvement in Bacillus subtilis cultures. Since the turbidity of the culture was affected by presence of the oil, optical density was compromised and no longer could be used as an index of growth and biomass concentration. Therefore, cell Dry Weight measurements with applying necessary tactics for removing oil drops to prevent interference with biomass weight were carried out to monitor biomass concentration during the growth of the bacterium. The surface tension and critical micelle dilutions (CMD-1, CMD-2) were considered as an indirect measurement of biosurfactant production. Distinctive and promising results were obtained in the cultures containing olive oil compared to cultures without it: more than two fold increase in biomass production (from 2 g/l to 5 g/l) and considerable reduction in surface tension, down to 40 mN/m at surprisingly early hours of culture time (only 5hr after inoculation). This early onset of biosurfactant production in this culture is specially interesting when compared to the conventional cultures at which this reduction in surface tension is not obtained until 30 hour of culture time. Reducing the production time is a very prominent result to be considered for large scale process development. Furthermore, these results can be used to develop strategies for utilization of agro-industrial wastes (such as olive oil mill residue, molasses, etc.) as cheap and easily accessible feed stocks to decrease the high costs of biosurfactant production.Keywords: agro-industrial waste, bacillus subtilis, biosurfactant, fermentation, second carbon and nitrogen source, surfactin
Procedia PDF Downloads 2941050 Comparative Assessment of Finite Element Methodologies for Predicting Post-Buckling Collapse in Stiffened Carbon Fiber-Reinforced Plastic (CFRP) Panels
Authors: Naresh Reddy Kolanu
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The stability and collapse behavior of thin-walled composite structures, particularly carbon fiber-reinforced plastic (CFRP) panels, are paramount concerns for structural designers. Accurate prediction of collapse loads necessitates precise modeling of damage evolution in the post-buckling regime. This study conducts a comparative assessment of various finite element (FE) methodologies employed in predicting post-buckling collapse in stiffened CFRP panels. A systematic approach is adopted, wherein FE models with various damage capabilities are constructed and analyzed. The study investigates the influence of interacting intra- and interlaminar damage modes on the post-buckling response and failure behavior of the stiffened CFRP structure. Additionally, the capabilities of shell and brick FE-based models are evaluated and compared to determine their effectiveness in capturing the complex collapse behavior. Conclusions are drawn through quantitative comparison with experimental results, focusing on post-buckling response and collapse load. This comprehensive evaluation provides insights into the most effective FE methodologies for accurately predicting the collapse behavior of stiffened CFRP panels, thereby aiding structural designers in enhancing the stability and safety of composite structures.Keywords: CFRP stiffened panels, delamination, Hashin’s failure, post-buckling, progressive damage model
Procedia PDF Downloads 311049 Destructive and Nondestructive Characterization of Advanced High Strength Steels DP1000/1200
Authors: Carla M. Machado, André A. Silva, Armando Bastos, Telmo G. Santos, J. Pamies Teixeira
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Advanced high-strength steels (AHSS) are increasingly being used in automotive components. The use of AHSS sheets plays an important role in reducing weight, as well as increasing the resistance to impact in vehicle components. However, the large-scale use of these sheets becomes more difficult due to the limitations during the forming process. Such limitations are due to the elastically driven change of shape of a metal sheet during unloading and following forming, known as the springback effect. As the magnitude of the springback tends to increase with the strength of the material, it is among the most worrisome problems in the use of AHSS steels. The prediction of strain hardening, especially under non-proportional loading conditions, is very limited due to the lack of constitutive models and mainly due to very limited experimental tests. It is very clear from the literature that in experimental terms there is not much work to evaluate deformation behavior under real conditions, which implies a very limited and scarce development of mathematical models for these conditions. The Bauschinger effect is also fundamental to the difference between kinematic and isotropic hardening models used to predict springback in sheet metal forming. It is of major importance to deepen the phenomenological knowledge of the mechanical and microstructural behavior of the materials, in order to be able to reproduce with high fidelity the behavior of extension of the materials by means of computational simulation. For this, a multi phenomenological analysis and characterization are necessary to understand the various aspects involved in plastic deformation, namely the stress-strain relations and also the variations of electrical conductivity and magnetic permeability associated with the metallurgical changes due to plastic deformation. Aiming a complete mechanical-microstructural characterization, uniaxial tensile tests involving successive cycles of loading and unloading were performed, as well as biaxial tests such as the Erichsen test. Also, nondestructive evaluation comprising eddy currents to verify microstructural changes due to plastic deformation and ultrasonic tests to evaluate the local variations of thickness were made. The material parameters for the stable yield function and the monotonic strain hardening were obtained using uniaxial tension tests in different material directions and balanced biaxial tests. Both the decrease of the modulus of elasticity and Bauschinger effect were determined through the load-unload tensile tests. By means of the eddy currents tests, it was possible to verify changes in the magnetic permeability of the material according to the different plastically deformed areas. The ultrasonic tests were an important aid to quantify the local plastic extension. With these data, it is possible to parameterize the different models of kinematic hardening to better approximate the results obtained by simulation with the experimental results, which are fundamental for the springback prediction of the stamped parts.Keywords: advanced high strength steel, Bauschinger effect, sheet metal forming, springback
Procedia PDF Downloads 2221048 Performance Based Design of Masonry Infilled Reinforced Concrete Frames for Near-Field Earthquakes Using Energy Methods
Authors: Alok Madan, Arshad K. Hashmi
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Performance based design (PBD) is an iterative exercise in which a preliminary trial design of the building structure is selected and if the selected trial design of the building structure does not conform to the desired performance objective, the trial design is revised. In this context, development of a fundamental approach for performance based seismic design of masonry infilled frames with minimum number of trials is an important objective. The paper presents a plastic design procedure based on the energy balance concept for PBD of multi-story multi-bay masonry infilled reinforced concrete (R/C) frames subjected to near-field earthquakes. The proposed energy based plastic design procedure was implemented for trial performance based seismic design of representative masonry infilled reinforced concrete frames with various practically relevant distributions of masonry infill panels over the frame elevation. Non-linear dynamic analyses of the trial PBD of masonry infilled R/C frames was performed under the action of near-field earthquake ground motions. The results of non-linear dynamic analyses demonstrate that the proposed energy method is effective for performance based design of masonry infilled R/C frames under near-field as well as far-field earthquakes.Keywords: masonry infilled frame, energy methods, near-fault ground motions, pushover analysis, nonlinear dynamic analysis, seismic demand
Procedia PDF Downloads 2851047 Parameters Affecting the Elasto-Plastic Behavior of Outrigger Braced Walls to Earthquakes
Authors: T. A. Sakr, Hanaa E. Abd-El-Mottaleb
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Outrigger-braced wall systems are commonly used to provide high rise buildings with the required lateral stiffness for wind and earthquake resistance. The existence of outriggers adds to the stiffness and strength of walls as reported by several studies. The effects of different parameters on the elasto-plastic dynamic behavior of outrigger-braced wall systems to earthquakes are investigated in this study. Parameters investigated include outrigger stiffness, concrete strength, and reinforcement arrangement as the main design parameters in wall design. In addition to being significant to the wall behavior, such parameters may lead to the change of failure mode and the delay of crack propagation and consequently failure as the wall is excited by earthquakes. Bi-linear stress-strain relation for concrete with limited tensile strength and truss members with bi-linear stress-strain relation for reinforcement were used in the finite element analysis of the problem. The famous earthquake record, El-Centro, 1940 is used in the study. Emphasis was given to the lateral drift, normal stresses and crack pattern as behavior controlling determinants. Results indicated significant effect of the studied parameters such that stiffer outrigger, higher grade concrete and concentrating the reinforcement at wall edges enhance the behavior of the system. Concrete stresses and cracking behavior are sigbificantly enhanced while lesser drift improvements are observed.Keywords: outrigger, shear wall, earthquake, nonlinear
Procedia PDF Downloads 2771046 Physical, Morphological, and Rheological Properties of Polypropylene Modified Bitumen
Authors: Nioushasadat Haji Seyed Javadi, Ailar Hajimohammadi, Nasser Khalili
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The common method to improve the performance of asphalt binders is through modification. The utilization of recycled plastics for asphalt modification has been the subject of research studies due to their environmental and economic benefits over using commercial polymers. Polypropylene (PP) is one of the most available recycled plastics in Australia. Unlike other plastics, its contamination with other plastics during the recycling process is negligible. Therefore, the quality of recycled plastic is high, which makes it a good candidate for road construction applications. To assess its effectiveness for bitumen modification, three different grades of PP were selected. The PP grades were compared for blendability with bitumen, and the best suitable grade was chosen for further studies. The PP-modified bitumen and the base bitumen were then compared through physical and rheological properties. The stability of the PP-modified bitumen at elevated temperatures was measured, and the morphology of the samples before and after the storage stability was characterized by fluorescent microscopy. The results showed that PP had a significant influence on reducing the penetration and increasing the viscosity and the rutting resistance of the virgin bitumen. Storage stability test results indicated that the difference between the softening point of the top and bottom section of the tube sample is below the defined limit, which means the PP-modified bitumen is storage stable. However, the fluorescence microscopy results showed that the distribution of the PP particles in the bitumen matrix in the top and bottom sections of the tube are significantly different, which is an indicator of poor storage stability.Keywords: polypropylene, waste plastic, bitumen, road pavements, storage stability, fluorescent microscopy, morphology
Procedia PDF Downloads 711045 Structural Performance Evaluation of Concrete Beams Reinforced with Recycled and Virgin Plastic Fibres
Authors: Vighnesh Daas, David B. Tann, Mahmood Datoo
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The incorporation of recycled plastic fibres in concrete as reinforcement is a potential sustainable alternative for replacement of ordinary steel bars. It provides a scope for waste reduction and re-use of plastics in the construction industry on a large scale. Structural use of fibre reinforced concrete is limited to short span members and low reliability classes. In this study, recycled carpet fibres made of 95% polypropylene with length of 45mm were used for experimental investigations. The performance of recycled polypropylene fibres under structural loading has been compared with commercially available virgin fibres at low volume fractions of less than 1%. A series of 100 mm cubes and 125x200x2000 mm beams were used to conduct strength tests in bending and compression to measure the influence of type and volume of fibres on the structural behaviour of fibre reinforced concrete beams. The workability of the concrete mix decreased as a function of fibre content and resulted in a modification of the mix design. The beams failed in a pseudo-ductile manner with an enhanced bending capacity. The specimens showed significant improvement in the post-cracking behaviour and load carrying ability as compared to conventional reinforced concrete members. This was associated to the binding properties of the fibres in the concrete matrix. With the inclusion of fibres at low volumes of 0-0.5%, there was reduction in crack sizes and deflection. This study indicates that the inclusion of recycled polypropylene fibres at low volumes augments the structural behaviour of concrete as compared to conventional reinforced concrete as well as virgin fibre reinforced concrete.Keywords: fibre reinforced concrete, polypropylene, recycled, strength
Procedia PDF Downloads 2391044 High Heating Value Bio-Chars from a Bio-Oil Upgrading Process
Authors: Julius K. Gane, Mohamad N. Nahil, Paul T. Williams
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In today’s world of rapid population growth and a changing climate, one way to mitigate various negative effects is via renewable energy solutions. Energy and power as basic requirements in almost all human endeavours are also the banes of the changing climate and the impacts thereof. Thus it is crucial to develop innovative and environmentally friendly energy options to ameliorate various negative repercussions. Upgrading of fast pyrolysis bio-oil via hydro-treatment offers such opportunities, as quality renewable liquid transportation fuels can be produced. The process, however, is typically accompanied by bio-char formation as a by-product. The goal of this work was to study the yield and some properties of bio-chars formed from a hydrotreatment process, with an overall aim to promote the valuable utilization of wastes or by-products from renewable energy technologies. It is assumed that bio-chars that have comparable energy contents with coals will be more desirable as solid energy materials due to renewability and environmental friendliness. Therefore, the analytical work in this study focused mainly on determining the higher heating value (HHV) of the chars. The method involved the reaction of bio-oil in an autoclave supplied by the Parr Instrument Company, IL, USA. Two main parameters (different temperatures and resident times) were investigated. The chars were characterized using a Thermo EA2000 CHNS analyser, then oxygen contents and HHVs computed based on the literature. From the results, these bio-chars can readily serve as feedstocks for the production of renewable solid fuels. Their HHVs ranged between 29.26-39.18 MJ/kg, affected by different temperatures and retention times. There was an inverse relationship between the oxygen content and the HHVs of the chars. It can, therefore, be concluded that it is possible to optimize the process efficiency of the hydrotreatment process used through the production of renewable energy materials from the 'waste’ char by-products. Future work should consider developing a suitable balance between the primary objective of bio-oil upgrading processes (which is to improve the quality of the liquid fuels) and the conversion of its solid wastes into value-added products such as smokeless briquettes.Keywords: bio-char, renewable solid biofuels, valorisation, waste-to-energy
Procedia PDF Downloads 1231043 Community Involvement and Willingness To Pay for Municipal Solid Waste Management Activities in Rapid Urbanized Region: A Case Study of Mnadani and Madukani Wards-Dodoma Urban
Authors: Isabela Thomas Mkude
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This research was done to assess how the community is involved in waste management activities and their willingness to pay for services. Mnadani and Madukani are among the old wards in Dodoma urban. These two areas are similar and face numerous environmental problems, poor solid waste management practices being among them. People realize problems because they live with them daily but the study advice that the only way to stay off problems is to find appropriate measures. The findings recognized some problems that led to poor community involvement solid waste management the study areas. Lack of community education on how to deal with solid wastes, poor responsibility of ward leaders in issues concerning the environment and in active participation of communities in environmental meeting are among other major problems found during the research. The research also revealed that there is low willingness to pay for waste collection among communities and financial problems that make environmental committee inactive; that leading to a poor disposal and unavailable collection facilities in urban area. Although the municipal improves disposal activities by increasing amount of waste to be disposed off by 11% in three years, the amount of waste that collected is also increasing by 41% each day. It is advised that some corrective measures need to be put in place so that the communities are well involved in managing solid wastes as the best way to attain achievement in keeping the urban free from solid waste. Environmental education dissemination to the communities is needed so that they become responsible and dedicated citizen on the environment. There should be some incentives from government to the wards local government and CBOs so that they can practically implement solid waste management programs and to attract formation of more groups and motivate the present groups. Capacity building programs to the ward leaders need to be given priority so that leaders are well organized and able to plan, coordinate and cooperate with various governmental institutions, and NGOs responsible for development and environmental management.Keywords: solid waste, waste management, public involvement, rapid urbanized region
Procedia PDF Downloads 3411042 Modern Methods of Construction (MMC): The Potentials and Challenges of Using Prefabrication Technology for Building Modern Houses in Afghanistan
Authors: Latif Karimi, Yasuhide Mochida
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The purpose of this paper is to study Modern Methods of Construction (MMC); specifically, the prefabrication technology and check the applicability, suitability, and benefits of this construction technique over conventional methods for building new houses in Afghanistan. Construction industry and house building sector are a key contributor to Afghanistan’s economy. However, this sector is challenged with lack of innovation and severe impacts that it has on the environment due to huge amount of construction waste from building, demolition and or renovation activities. This paper studies the prefabrication technology, a popular MMC that is becoming more common, improving in quality and being available in a variety of budgets. Several feasibility studies worldwide have revealed that this method is the way forward in improving construction industry performance as it has been proven to reduce construction time, construction wastes and improve the environmental performance of the construction processes. In addition, this study emphasizes on 'sustainability' in-house building, since it is a common challenge in housing construction projects on a global scale. This challenge becomes more severe in the case of under-developed countries, like Afghanistan. Because, most of the houses are being built in the absence of a serious quality control mechanism and dismissive to basic requirements of sustainable houses; well-being, cost-effectiveness, minimization - prevention of wastes production during construction and use, and severe environmental impacts in view of a life cycle assessment. Methodology: A literature review and study of the conventional practices of building houses in urban areas of Afghanistan. A survey is also being completed to study the potentials and challenges of using prefabrication technology for building modern houses in the cities across the country. A residential housing project is selected for case study to determine the drawbacks of current construction methods vs. prefabrication technique for building a new house. Originality: There are little previous research available about MMC considering its specific impacts on sustainability related to house building practices. This study will be specifically of interest to a broad range of people, including planners, construction managers, builders, and house owners.Keywords: modern methods of construction (MMC), prefabrication, prefab houses, sustainable construction, modern houses
Procedia PDF Downloads 2391041 Biodegradable Drinking Straws Made From Naturally Dried and Fallen Coconut Leaves: Impact on Rural Circular Economy and Environmental Sustainability
Authors: Saji Varghese
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Naturally dried and fallen coconut leaves and found in abundance in India and other coconut growing regions of the world. These fallen coconut leaves are usually burnt by farmers in landfills and open kitchens, leading to CO2 and particulate emissions. The innovation of biodegradable drinking straws from naturally dried and fallen coconut leaves by this researcher and his team has opened up opportunities to create value out of this agri-waste leading to i. prevention of burning of these discarded leaves ii. income generating opportunities to women in rural areas of coconut growing regions iii. an alternative to single use plastic straws. The team has developed five special purpose machines, which are deployed in the three villages on a pilot basis where 36 women are employed. The women are trained in the use of these machines, and the straws which are in good demand are sold globally. The present paper analyses the prospective impact of this innovation on the incomes of women working at the straw production centres and the consequent impact on their standards of living, The paper also analyses the impact of this innovation in the reduction of CO2 and particulate emissions and makes a case for support from Govt and Non Govt organizations in coconut growing regions to set up straw production centres to boost rural circular economy and to reduce carbon footprint and eliminate plastic pollutionKeywords: drinking straws, coconut leaves, circular economy, sustainability
Procedia PDF Downloads 1281040 Modeling of Large Elasto-Plastic Deformations by the Coupled FE-EFGM
Authors: Azher Jameel, Ghulam Ashraf Harmain
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In the recent years, the enriched techniques like the extended finite element method, the element free Galerkin method, and the Coupled finite element-element free Galerkin method have found wide application in modeling different types of discontinuities produced by cracks, contact surfaces, and bi-material interfaces. The extended finite element method faces severe mesh distortion issues while modeling large deformation problems. The element free Galerkin method does not have mesh distortion issues, but it is computationally more demanding than the finite element method. The coupled FE-EFGM proves to be an efficient numerical tool for modeling large deformation problems as it exploits the advantages of both FEM and EFGM. The present paper employs the coupled FE-EFGM to model large elastoplastic deformations in bi-material engineering components. The large deformation occurring in the domain has been modeled by using the total Lagrangian approach. The non-linear elastoplastic behavior of the material has been represented by the Ramberg-Osgood model. The elastic predictor-plastic corrector algorithms are used for the evaluation stresses during large deformation. Finally, several numerical problems are solved by the coupled FE-EFGM to illustrate its applicability, efficiency and accuracy in modeling large elastoplastic deformations in bi-material samples. The results obtained by the proposed technique are compared with the results obtained by XFEM and EFGM. A remarkable agreement was observed between the results obtained by the three techniques.Keywords: XFEM, EFGM, coupled FE-EFGM, level sets, large deformation
Procedia PDF Downloads 4431039 Alpha-To-Omega Phase Transition in Bulk Nanostructured Ti and (α+β) Ti Alloys
Authors: Askar Kilmametov, Julia Ivanisenko, Boris Straumal, Horst Hahn
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The high-pressure α- to ω-phase transition was discovered in elemental Ti and Zr fifty years ago using static high pressure and then observed to appear between 2 and 12 GPa at room temperature, depending on the experimental technique, the pressure environment, and the sample purity. The fact that ω-phase is retained in a metastable state in ambient condition after the removal of the pressure has been used to check the changes in magnetic and superconductive behavior, electron band structure and mechanical properties. However, the fundamental knowledge on a combination of both mechanical treatment and high applied pressure treatments for ω-phase formation in Ti alloys is currently lacking and has to be studied in relation to improved mechanical properties of bulk nanostructured states. In the present study, nanostructured (α+β) Ti alloys containing β-stabilizing elements such as Co, Fe, Cr, Nb were performed by severe plastic deformation, namely high pressure torsion (HPT) technique. HPT-induced α- to ω-phase transformation was revealed in dependence on applied pressure and shear strains by means of X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The transformation kinetics was compared with the kinetics of pressure-induced transition. Orientation relationship between α-, β- and ω-phases was taken into consideration and analyzed according to theoretical calculation proposed earlier. The influence of initial state before HPT appeared to be considerable for subsequent α- to ω-phase transition. Thermal stability of the HPT-induced ω-phase was discussed as well in the frame of mechanical behavior of Ti and Ti-based alloys produced by shear deformation under high applied pressure.Keywords: bulk nanostructured materials, high pressure phase transitions, severe plastic deformation, titanium alloys
Procedia PDF Downloads 4101038 The Effect of Zeolite on Sandy-Silt Soil Mechanical Properties
Authors: Shahryar Aftabi, Saeed Fathi, Mohammad H. Aminfar
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It is well known that cemented sand is one of the best approaches for soil stabilization. In some cases, a blend of sand, cement and other pozzolan materials such as zeolite, nano-particles and fiber can be widely (commercially) available and be effectively used in soil stabilization, especially in road construction. In this research, we investigate the effects of CaO which is based on the geotechnical characteristics of zeolite composition with sandy silt soil. Zeolites have low amount of CaO in their structures, that is, varying from 3% to 10%, and by removing the cement paste, we want to investigate the effect of zeolite pozzolan without any activator on soil samples strength. In this research, experiments are concentrated on various weight percentages of zeolite in the soil to examine the effect of the zeolite on drainage shear strength and California Bearing Ratio (CBR) both with and without curing. The study also investigates their liquid limit and plastic limit behavior and makes a comparative result by using Feng's and Wroth-Wood's methods in fall cone (cone penetrometer) device; in the final the SEM images have been presented. The results show that by increasing the percentage of zeolite in without-curing samples, the fine zeolite particles increase some soil's strength, but in the curing-state we can see a relatively higher strength toward without-curing state, since the zeolites have no plastic behavior, the pozzolanic property of zeolites plays a much higher role than cementing properties. Indeed, it is better to combine zeolite particle with activator material such as cement or lime to gain better results.Keywords: California bearing ratio, CBR, direct shear, fall-cone, sandy silt, SEM, zeolite
Procedia PDF Downloads 1251037 Ecological Investigations for the Control of Aedes aegypti (Diptera: Culicidae) in the Selected Study Districts of Punjab, Pakistan
Authors: Muhammad Sohail Sajid, Muhammad Abdullah Malik, Muhammad Saqib, Faiz Ahmad Raza, Waseem Akram
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Aedes (Ae.) aegypti, the vector of pathogens of one health significance, has gained currency over the last decade. The present study reports the prevalence of A. aegypti larvae in indoor and outdoor niches from the three districts of different agro-geo-climatic zones of Punjab, including Chakwal (north), Faisalabad (central), and Dera Ghazi Khan (south). Mosquito larvae were collected, preserved, and transferred for identification. The relevant data were collected on a predesigned questionnaire. Stegomyia indices, including House Index (HI), Breteau Index (BI), and Container Index (CI), were calculated. The association of different breeding containers with the prevalence of Ae. aegypti larvae were estimated through Chi-square analysis. The highest Stegomyia indices were calculated in Chakwal (HI = 46.61%, BI = 91.67%, and CI = 15.28%) as compared to Faisalabad (HI = 34.11%, BI = 68.75% and, CI = 13.04%) and DG Khan (HI = 28.39%, BI = 68.23% and, CI = 11.29%), respectively. Irrespective of the geographical area, earthen jars, water tanks, and tree holes were found to be significantly associated (p < 0.05) with the abundance of Ae. aegypti larvae. However, tires and plastic bottles in Faisalabad and DG Khan while flower tubs and plastic buckets in Faisalabad and Chakwal were found to be significantly associated (p < 0.05) with the larval abundance. The results are a maiden attempt to correlate the magnitude of Ae. aegypti larvae in various microclimatic niches of Punjab, Pakistan, which might help in policy-making for preventive management of the menace.Keywords: Aedes aegypti, ecology, breeding habitats, Stegomyia indices, breeding containers
Procedia PDF Downloads 1131036 Finite Element Analysis of Hollow Structural Shape (HSS) Steel Brace with Infill Reinforcement under Cyclic Loading
Authors: Chui-Hsin Chen, Yu-Ting Chen
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Special concentrically braced frames is one of the seismic load resisting systems, which dissipates seismic energy when bracing members within the frames undergo yielding and buckling while sustaining their axial tension and compression load capacities. Most of the inelastic deformation of a buckling bracing member concentrates in the mid-length region. While experiencing cyclic loading, the region dissipates most of the seismic energy being input into the frame. Such a concentration makes the braces vulnerable to failure modes associated with low-cycle fatigue. In this research, a strategy to improve the cyclic behavior of the conventional steel bracing member is proposed by filling the Hollow Structural Shape (HSS) member with reinforcement. It prevents the local section from concentrating large plastic deformation caused by cyclic loading. The infill helps spread over the plastic hinge region into a wider area hence postpone the initiation of local buckling or even the rupture of the braces. The finite element method is introduced to simulate the complicated bracing member behavior and member-versus-infill interaction under cyclic loading. Fifteen 3-D-element-based models are built by ABAQUS software. The verification of the FEM model is done with unreinforced (UR) HSS bracing members’ cyclic test data and aluminum honeycomb plates’ bending test data. Numerical models include UR and filled HSS bracing members with various compactness ratios based on the specification of AISC-2016 and AISC-1989. The primary variables to be investigated include the relative bending stiffness and the material of the filling reinforcement. The distributions of von Mises stress and equivalent plastic strain (PEEQ) are used as indices to tell the strengths and shortcomings of each model. The result indicates that the change of relative bending stiffness of the infill is much more influential than the change of material in use to increase the energy dissipation capacity. Strengthen the relative bending stiffness of the reinforcement results in additional energy dissipation capacity to the extent of 24% and 46% in model based on AISC-2016 (16-series) and AISC-1989 (89-series), respectively. HSS members with infill show growth in 𝜂Local Buckling, normalized energy cumulated until the happening of local buckling, comparing to UR bracing members. The 89-series infill-reinforced members have more energy dissipation capacity than unreinforced 16-series members by 117% to 166%. The flexural rigidity of infills should be less than 29% and 13% of the member section itself for 16-series and 89-series bracing members accordingly, thereby guaranteeing the spread over of the plastic hinge and the happening of it within the reinforced section. If the parameters are properly configured, the ductility, energy dissipation capacity, and fatigue-life of HSS SCBF bracing members can be improved prominently by the infill-reinforced method.Keywords: special concentrically braced frames, HSS, cyclic loading, infill reinforcement, finite element analysis, PEEQ
Procedia PDF Downloads 901035 Corrosion Response of Friction Stir Processed Mg-Zn-Zr-RE Alloy
Authors: Vasanth C. Shunmugasamy, Bilal Mansoor
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Magnesium alloys are increasingly being considered for structural systems across different industrial sectors, including precision components of biomedical devices, owing to their high specific strength, stiffness and biodegradability. However, Mg alloys exhibit a high corrosion rate that restricts their application as a biomaterial. For safe use as biomaterial, it is essential to control their corrosion rates. Mg alloy corrosion is influenced by several factors, such as grain size, precipitates and texture. In Mg alloys, microgalvanic coupling between the α-Mg matrix and secondary precipitates can exist, which results in an increased corrosion rate. The present research addresses this challenge by engineering the microstructure of a biodegradable Mg–Zn–RE–Zr alloy by friction stir processing (FSP), a severe plastic deformation process. The FSP-processed Mg alloys showed improved corrosion resistance and mechanical properties. FSPed Mg alloy showed refined grains, a strong basal texture and broken and uniformly distributed secondary precipitates in the stir zone. Mg, alloy base material, exposed to In vitro corrosion medium showed micro galvanic coupling between precipitate and matrix, resulting in the unstable passive layer. However, FS processed alloy showed uniform corrosion owing to stable surface film formation. The stable surface film is attributed to refined grains, preferred texture and distribution of precipitates. The research results show promising potential for Mg alloy to be developed as a biomaterial.Keywords: biomaterials, severe plastic deformation, magnesium alloys, corrosion
Procedia PDF Downloads 281034 Development of Methods for Plastic Injection Mold Weight Reduction
Authors: Bita Mohajernia, R. J. Urbanic
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Mold making techniques have focused on meeting the customers’ functional and process requirements; however, today, molds are increasing in size and sophistication, and are difficult to manufacture, transport, and set up due to their size and mass. Presently, mold weight saving techniques focus on pockets to reduce the mass of the mold, but the overall size is still large, which introduces costs related to the stock material purchase, processing time for process planning, machining and validation, and excess waste materials. Reducing the overall size of the mold is desirable for many reasons, but the functional requirements, tool life, and durability cannot be compromised in the process. It is proposed to use Finite Element Analysis simulation tools to model the forces, and pressures to determine where the material can be removed. The potential results of this project will reduce manufacturing costs. In this study, a light weight structure is defined by an optimal distribution of material to carry external loads. The optimization objective of this research is to determine methods to provide the optimum layout for the mold structure. The topology optimization method is utilized to improve structural stiffness while decreasing the weight using the OptiStruct software. The optimized CAD model is compared with the primary geometry of the mold from the NX software. Results of optimization show an 8% weight reduction while the actual performance of the optimized structure, validated by physical testing, is similar to the original structure.Keywords: finite element analysis, plastic injection molding, topology optimization, weight reduction
Procedia PDF Downloads 2841033 NHS Tayside Plastic Surgery Induction Cheat Sheet and Video
Authors: Paul Holmes, Mike N. G.
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Foundation-year doctors face increased stress, pressure and uncertainty when starting new rotations throughout their first years of work. This research questionnaire resulted in an induction cheat sheet and induction video that enhanced the Junior doctor's understanding of how to work effectively within the plastic surgery department at NHS Tayside. The objectives and goals were to improve the transition between cohorts of junior doctors in ward 26 at Ninewells Hospital. Before this quality improvement project, the induction pack was 74 pages long and over eight years old. With the support of consultant Mike Ng a new up-to-date induction was created. This involved a questionnaire and cheat sheet being developed. The questionnaire covered clerking, venipuncture, ward pharmacy, theatres, admissions, specialties on the ward, the cardiac arrest trolley, clinical emergencies, discharges and escalation. This audit has three completed cycles between August 2022 and August 2023. The cheat sheet developed a concise two-page A4 document designed for doctors to be able to reference easily and understand the essentials. The document format is a table containing ward layout; specialty; location; physician associate, shift patterns; ward rounds; handover location and time; hours coverage; senior escalation; nights; daytime duties, meetings/MDTs/board meetings, important bleeps and codes; department guidelines; boarders; referrals and patient stream; pharmacy; absences; rota coordinator; annual leave; top tips. The induction video is a 10-minute in-depth explanation of all aspects of the ward. The video explores in more depth the contents of the cheat sheet. This alternative visual format familiarizes the junior doctor with all aspects of the ward. These were provided to all foundation year 1 and 2 doctors on ward 26 at Ninewells Hospital at NHS Tayside Scotland. This work has since been adopted by the General Surgery Department, which extends to six further wards and has improved the effective handing over of the junior doctor’s role between cohorts. There is potential to further expand the cheat sheet to other departments as the concise document takes around 30 minutes to complete by a doctor who is currently on that ward. The time spent filling out the form provides vital information to the incoming junior doctors, which has a significant possibility to improve patient care.Keywords: induction, junior doctor, handover, plastic surgery
Procedia PDF Downloads 761032 Elastoplastic Collapse Analysis of Pipe Bends Using Finite Element Analysis
Authors: Tawanda Mushiri, Charles Mbohwa
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When an external load is applied to one of its ends, a pipe’s bends cross section tends to deform significantly both in and out of its end plane. This shell type behaviour characteristic of pipe bends and mainly due to their curves geometry accounts for their greater flexibility. This added flexibility is also accompanied by stressed and strains that are much higher than those present in a straight pipe. The primary goal of this research is to study the elastic-plastic behaviour of pipe bends under out of plane moment loading. It is also required to study the effects of changing the value of the pipe bend factor and the value of the internal pressure on that behaviour and to determine the value of the limit moments in each case. The results of these analyses are presented in the form of load deflection plots for each load case belonging to each model. From the load deflection curves, the limit moments of each case are obtained. The limit loads are then compared to those computed using some of the analytical and empirical equation available in the literature. The effects of modelling parameters are also studied. The results obtained from small displacement and large displacement analyses are compared and the effects of using a strain hardened material model are also investigated. To better understand the behaviour of pipe elbows under out of plane bending and internal pressure, it was deemed important to know how the cross section deforms and to study the distribution of stresses that cause it to deform in a particular manner. An elbow with pipe bend factor h=0.1 to h=1 is considered and the results of the detailed analysis are thereof examined.Keywords: elasto-plastic, finite element analysis, pipe bends, simulation
Procedia PDF Downloads 3231031 A Case Study on the Seismic Performance Assessment of the High-Rise Setback Tower Under Multiple Support Excitations on the Basis of TBI Guidelines
Authors: Kamyar Kildashti, Rasoul Mirghaderi
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This paper describes the three-dimensional seismic performance assessment of a high-rise steel moment-frame setback tower, designed and detailed per the 2010 ASCE7, under multiple support excitations. The vulnerability analyses are conducted based on nonlinear history analyses under a set of multi-directional strong ground motion records which are scaled to design-based site-specific spectrum in accordance with ASCE41-13. Spatial variation of input motions between far distant supports of each part of the tower is considered by defining time lag. Plastic hinge monotonic and cyclic behavior for prequalified steel connections, panel zones, as well as steel columns is obtained from predefined values presented in TBI Guidelines, PEER/ATC72 and FEMA P440A to include stiffness and strength degradation. Inter-story drift ratios, residual drift ratios, as well as plastic hinge rotation demands under multiple support excitations, are compared to those obtained from uniform support excitations. Performance objectives based on acceptance criteria declared by TBI Guidelines are compared between uniform and multiple support excitations. The results demonstrate that input motion discrepancy results in detrimental effects on the local and global response of the tower.Keywords: high-rise building, nonlinear time history analysis, multiple support excitation, performance-based design
Procedia PDF Downloads 2811030 Theoretical Analysis of the Existing Sheet Thickness in the Calendering of Pseudoplastic Material
Authors: Muhammad Zahid
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The mechanical process of smoothing and compressing a molten material by passing it through a number of pairs of heated rolls in order to produce a sheet of desired thickness is called calendering. The rolls that are in combination are called calenders, a term derived from kylindros the Greek word for the cylinder. It infects the finishing process used on cloth, paper, textiles, leather cloth, or plastic film and so on. It is a mechanism which is used to strengthen surface properties, minimize sheet thickness, and yield special effects such as a glaze or polish. It has a wide variety of applications in industries in the manufacturing of textile fabrics, coated fabrics, and plastic sheeting to provide the desired surface finish and texture. An analysis has been presented for the calendering of Pseudoplastic material. The lubrication approximation theory (LAT) has been used to simplify the equations of motion. For the investigation of the nature of the steady solutions that exist, we make use of the combination of exact solution and numerical methods. The expressions for the velocity profile, rate of volumetric flow and pressure gradient are found in the form of exact solutions. Furthermore, the quantities of interest by engineering point of view, such as pressure distribution, roll-separating force, and power transmitted to the fluid by the rolls are also computed. Some results are shown graphically while others are given in the tabulated form. It is found that the non-Newtonian parameter and Reynolds number serve as the controlling parameters for the calendering process.Keywords: calendering, exact solutions, lubrication approximation theory, numerical solutions, pseudoplastic material
Procedia PDF Downloads 1381029 A Refrigerated Condition for the Storage of Glucose Test Strips at Health Promoting Hospitals: An Implication for Hospitals with Limited Air Conditioners
Authors: Wanutchaya Duanginta, Napaporn Apiratmateekul, Tippawan Sangkaew, Sunaree Wekinhirun, Kunchit Kongros, Wanvisa Treebuphachatsakul
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Thailand has a tropical climate with an average outdoor ambient air temperature of over 30°C, which can exceed manufacturer recommendations for the storage of glucose test strips. This study monitored temperature and humidity at actual sites of five sub-district health promoting hospitals (HPH) in Phitsanulok Province for the storage of glucose test strips in refrigerated conditions. Five calibrated data loggers were placed at the actual sites for glucose test strip storage at five HPHs for 8 weeks between April and June. For the stress test, two lot numbers of glucose test strips, each with two glucose meters, were kept in a plastic box with desiccants and placed in a refrigerator with the temperature calibrated to 4°C and at room temperature (RT). Temperature and humidity in the refrigerator and at RT were measured every hour for 30 days. The mean temperature for storing test strips at the five HPHs ranged from 29°C to 33°C, and three of the five HPHs (60%) had a mean temperature above 30°C. The refrigerator temperatures were 3.8 ± 2.0°C (2.0°C to 6.5°C), and relative humidity was 51 ± 2% (42 to 54%). The maximum of blood glucose testing by glucose meters when the test strips were stored in a refrigerator were not significantly different (p > 0.05) from unstressed test strips for both glucose meters using amperometry-GDH-PQQ and amperometry-GDH-FAD principles. Opening the test strip vial daily resulted in higher variation than when refrigerated after a single-use. However, the variations were still within an acceptable range. This study concludes that glucose tested strips can be stored in plastic boxes in a refrigerator if it is well-controlled for temperature and humidity. Storage of glucose-tested strips in the refrigerator during hot and humid weather may be useful for HPHs with limited air conditioners.Keywords: environmental stressed test, thermal stressed test, quality control, point-of-care testing
Procedia PDF Downloads 1851028 The Lessons Learned from Managing Malignant Melanoma During COVID-19 in a Plastic Surgery Unit in Ireland
Authors: Amenah Dhannoon, Ciaran Martin Hurley, Laura Wrafter, Podraic J. Regan
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Introduction: The COVID-19 pandemic continues to present unprecedented challenges for healthcare systems. This has resulted in the pragmatic shift in the practice of plastic surgery units worldwide. During this period, many units reported a significant fall in urgent melanoma referrals, leading to patients presenting with advanced disease requiring more extensive surgery and inferior outcomes. Our objective was to evaluate our unit's experience with both non-invasive and invasive melanoma during the COVID-19 pandemic and characterize our experience and contrast it to that experienced by our neighbors in the UK, mainland Europe and North America. Methods: a retrospective chart review was performed on all patients diagnosed with invasive and non-invasive cutaneous melanoma between March to December of 2019 (control) compared to 2020 (COVID-19 pandemic) in a single plastic surgery unit in Ireland. Patient demographics, referral source, surgical procedures, tumour characteristics, radiological findings, oncological therapies and follow-up were recorded. All data were anonymized and stored in Microsoft Excel. Results: A total of 589 patients were included in the study. Of these, 314 (53%) with invasive melanoma, compared to 275 (47%) with the non-invasive disease. Overall, more patients were diagnosed with both invasive and non-invasive melanoma in 2020 than in 2019 (p<0.05). However, significantly longer waiting times in 2020 (64 days) compared to 2019 (28 days) (p<0.05), with the majority of the referral being from GP in 2019 (83%) compared to 61% in 2020. Positive sentinel lymph node were higher in 2019 at 56% (n=28) compared to 24% (n=22) in 2020. There was no statistically significant difference in the tutor characteristics or metastasis status. Discussion: While other countries have noticed a fall in the melanoma diagnosis. Our units experienced a higher number of disease diagnoses. This can be due to multiple reasons. In Ireland, the government reached an early agreement with the private sector to continue elective surgery on an urgent basis in private hospitals. This allowed access to local anesthetic procedures and local skin cancer cases were triaged to non-COVID-19 provider centers. Our unit also adapted a fast, effective and minimal patient contact strategy for triaging skin cancer based on telemedicine. Thirdly, a skin cancer nurse specialist maintained patient follow-ups and triaging a dedicated email service. Finally, our plastic surgery service continued to maintain a virtual complex skin cancer multidisciplinary team meeting during the pandemic, ensuring local clinical governance has adhered to each clinical case. Conclusion: Our study highlights that with the prompt efficient restructuring of services, we could reserve successful management of skin cancer even in the most devastating times. It is important to reflect on the success during the pandemic and emphasize the importance of preparation for a potentially difficult futureKeywords: malignant melanoma, skin cancer, COVID-19, triage
Procedia PDF Downloads 1641027 Composition and Distribution of Seabed Marine Litter Along Algerian Coast (Western Mediterranean)
Authors: Ahmed Inal, Samir Rouidi, Samir Bachouche
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The present study is focused on the distribution and composition of seafloor marine litter associated to trawlable fishing areas along Algerian coast. The sampling was done with a GOC73 bottom trawl during four (04) demersal resource assessment cruises, respectively, in 2016, 2019, 2021 and 2022, carried out on board BELKACEM GRINE R/V. A total of 254 fishing hauls were sampled for the assessment of marine litter. Hauls were performed between 22 and 600 m of depth, the duration was between 30 and 60 min. All sampling was conducted during daylight. After the haul, marine litter was sorted and split from the catch. Then, according to the basis of the MEDITS protocol, litters were sorted into six different categories (plastic, rubber, metal, wood, glass and natural fiber). Thereafter, all marine litter were counted and weighed separately to the nearest 0.5 g. The results shows that the maximums of marine litter densities in the seafloor of the trawling fishing areas along Algerian coast are, respectively, 1996 item/km2 in 2016, 5164 item/km2 in 2019, 2173 item/km2 in 2021 and 7319 item/km2 in 2022. Thus, the plastic is the most abundant litter, it represent, respectively, 46% of marine litter in 2016, 67% in 2019, 69% in 2021 and 74% in 2022. Regarding the weight of the marine litter, it varies between 0.00 and 103 kg in 2016, between 0.04 and 81 kg in 2019, between 0.00 and 68 Kg in 2021 and between 0.00 and 318 kg in 2022. Thus, the maximum rate of marine litter compared to the total catch approximate, respectively, 66% in 2016, 90% in 2019, 65% in 2021 and 91% in 2022. In fact, the average loss in catch is estimated, respectively, at 7.4% in 2016, 8.4% in 2019, 5.7% in 2021 and 6.4% in 2022. However, the bathymetric and geographical variability had a significant impact on both density and weight of marine litter. Marine litter monitoring program is necessary for offering more solution proposals.Keywords: composition, distribution, seabed, marine litter, algerian coast
Procedia PDF Downloads 601026 A Comparative Study of the Effects of Vibratory Stress Relief and Thermal Aging on the Residual Stress of Explosives Materials
Authors: Xuemei Yang, Xin Sun, Cheng Fu, Qiong Lan, Chao Han
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Residual stresses, which can be produced during the manufacturing process of plastic bonded explosive (PBX), play an important role in weapon system security and reliability. Residual stresses can and do change in service. This paper mainly studies the influence of vibratory stress relief (VSR) and thermal aging on residual stress of explosives. Firstly, the residual stress relaxation of PBX via different physical condition of VSR, such as vibration time, amplitude and dynamic strain, were studied by drill-hole technique. The result indicated that the vibratory amplitude, time and dynamic strain had a significant influence on the residual stress relief of PBX. The rate of residual stress relief of PBX increases first and then decreases with the increase of dynamic strain, amplitude and time, because the activation energy is too small to make the PBX yield plastic deformation at first. Then the dynamic strain, time and amplitude exceed a certain threshold, the residual stress changes show the same rule and decrease sharply, this sharply drop of residual stress relief rate may have been caused by over vibration. Meanwhile, the comparison between VSR and thermal aging was also studied. The conclusion is that the reduction ratio of residual stress after VSR process with applicable vibratory parameters could be equivalent to 73% of thermal aging with 7 days. In addition, the density attenuation rate, mechanical property, and dimensional stability with 3 months after VSR process was almost the same compared with thermal aging. However, compared with traditional thermal aging, VSR only takes a very short time, which greatly improves the efficiency of aging treatment for explosive materials. Therefore, the VSR could be a potential alternative technique in the industry of residual stress relaxation of PBX explosives.Keywords: explosives, residual stresses, thermal aging, vibratory stress relief, VSR
Procedia PDF Downloads 1491025 Micro-Meso 3D FE Damage Modelling of Woven Carbon Fibre Reinforced Plastic Composite under Quasi-Static Bending
Authors: Aamir Mubashar, Ibrahim Fiaz
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This research presents a three-dimensional finite element modelling strategy to simulate damage in a quasi-static three-point bending analysis of woven twill 2/2 type carbon fibre reinforced plastic (CFRP) composite on a micro-meso level using cohesive zone modelling technique. A meso scale finite element model comprised of a number of plies was developed in the commercial finite element code Abaqus/explicit. The interfaces between the plies were explicitly modelled using cohesive zone elements to allow for debonding by crack initiation and propagation. Load-deflection response of the CRFP within the quasi-static range was obtained and compared with the data existing in the literature. This provided validation of the model at the global scale. The outputs resulting from the global model were then used to develop a simulation model capturing the micro-meso scale material features. The sub-model consisted of a refined mesh representative volume element (RVE) modelled in texgen software, which was later embedded with cohesive elements in the finite element software environment. The results obtained from the developed strategy were successful in predicting the overall load-deflection response and the damage in global and sub-model at the flexure limit of the specimen. Detailed analysis of the effects of the micro-scale features was carried out.Keywords: woven composites, multi-scale modelling, cohesive zone, finite element model
Procedia PDF Downloads 1331024 Waste Management in a Hot Laboratory of Japan Atomic Energy Agency – 1: Overview and Activities in Chemical Processing Facility
Authors: Kazunori Nomura, Hiromichi Ogi, Masaumi Nakahara, Sou Watanabe, Atsuhiro Shibata
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Chemical Processing Facility of Japan Atomic Energy Agency is a basic research field for advanced back-end technology developments with using actual high-level radioactive materials such as irradiated fuels from the fast reactor, high-level liquid waste from reprocessing plant. In the nature of a research facility, various kinds of chemical reagents have been offered for fundamental tests. Most of them were treated properly and stored in the liquid waste vessel equipped in the facility, but some were not treated and remained at the experimental space as a kind of legacy waste. It is required to treat the waste in safety. On the other hand, we formulated the Medium- and Long-Term Management Plan of Japan Atomic Energy Agency Facilities. This comprehensive plan considers Chemical Processing Facility as one of the facilities to be decommissioned. Even if the plan is executed, treatment of the “legacy” waste beforehand must be a necessary step for decommissioning operation. Under this circumstance, we launched a collaborative research project called the STRAD project, which stands for Systematic Treatment of Radioactive liquid waste for Decommissioning, in order to develop the treatment processes for wastes of the nuclear research facility. In this project, decomposition methods of chemicals causing a troublesome phenomenon such as corrosion and explosion have been developed and there is a prospect of their decomposition in the facility by simple method. And solidification of aqueous or organic liquid wastes after the decomposition has been studied by adding cement or coagulants. Furthermore, we treated experimental tools of various materials with making an effort to stabilize and to compact them before the package into the waste container. It is expected to decrease the number of transportation of the solid waste and widen the operation space. Some achievements of these studies will be shown in this paper. The project is expected to contribute beneficial waste management outcome that can be shared world widely.Keywords: chemical processing facility, medium- and long-term management plan of JAEA facilities, STRAD project, treatment of radioactive waste
Procedia PDF Downloads 1411023 Effect of Starch and Plasticizer Types and Fiber Content on Properties of Polylactic Acid/Thermoplastic Starch Blend
Authors: Rangrong Yoksan, Amporn Sane, Nattaporn Khanoonkon, Chanakorn Yokesahachart, Narumol Noivoil, Khanh Minh Dang
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Polylactic acid (PLA) is the most commercially available bio-based and biodegradable plastic at present. PLA has been used in plastic related industries including single-used containers, disposable and environmentally friendly packaging owing to its renewability, compostability, biodegradability, and safety. Although PLA demonstrates reasonably good optical, physical, mechanical, and barrier properties comparable to the existing petroleum-based plastics, its brittleness and mold shrinkage as well as its price are the points to be concerned for the production of rigid and semi-rigid packaging. Blending PLA with other bio-based polymers including thermoplastic starch (TPS) is an alternative not only to achieve a complete bio-based plastic, but also to reduce the brittleness, shrinkage during molding and production cost of the PLA-based products. TPS is a material produced mainly from starch which is cheap, renewable, biodegradable, compostable, and non-toxic. It is commonly prepared by a plasticization of starch under applying heat and shear force. Although glycerol has been reported as one of the most plasticizers used for preparing TPS, its migration caused the surface stickiness of the TPS products. In some cases, mixed plasticizers or natural fibers have been applied to impede the retrogradation of starch or reduce the migration of glycerol. The introduction of fibers into TPS-based materials could reinforce the polymer matrix as well. Therefore, the objective of the present research is to study the effect of starch type (i.e. native starch and phosphate starch), plasticizer type (i.e. glycerol and xylitol with a weight ratio of glycerol to xylitol of 100:0, 75:25, 50:50, 25:75, and 0:100), and fiber content (i.e. in the range of 1-25 % wt) on properties of PLA/TPS blend and composite. PLA/TPS blends and composites were prepared using a twin-screw extruder and then converted into dumbbell-shaped specimens using an injection molding machine. The PLA/TPS blends prepared by using phosphate starch showed higher tensile strength and stiffness than the blends prepared by using the native one. In contrast, the blends from native starch exhibited higher extensibility and heat distortion temperature (HDT) than those from the modified starch. Increasing xylitol content resulted in enhanced tensile strength, stiffness, and water resistance, but decreased extensibility and HDT of the PLA/TPS blend. Tensile properties and hydrophobicity of the blend could be improved by incorporating silane treated-jute fibers.Keywords: polylactic acid, thermoplastic starch, Jute fiber, composite, blend
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