Search results for: incremental plastic displacement

Authors: Mohammad Aminnia, Mahmood Hosseini

Abstract:

Environmental and functional conditions sometimes necessitate the architectural plan of the building to be asymmetric, and this result in an asymmetric structure. In such cases, finding an optimal pattern for locating the components of the lateral load bearing system, including shear walls, in the building’s plan is desired. In case of shear walls, in addition to the location, the shape of the wall cross-section is also an effective factor. Various types of shear wall and their proper layout might come effective in better stiffness distribution and more appropriate seismic response of the building. Several studies have been conducted in the context of analysis and design of shear walls; however, few studies have been performed on making decisions for the location and form of shear walls in multi-story buildings, especially those with irregular plan. In this study, an attempt has been made to obtain the most reliable seismic behavior of multi-story reinforced concrete vertically chamfered buildings by using more appropriate shear walls form and arrangement in 7-, 10-, 12-, and 15-story buildings. The considered forms and arrangements include common rectangular walls and L-, T-, U- and Z-shaped plan, located as the core or in the outer frames of the building structure. Comparison of seismic behaviors of the buildings, including maximum roof displacement, and particularly the formation of plastic hinges and their distribution in the buildings’ structures, have been done based on the results of a series of nonlinear time history analyses by using a set of selected earthquake records. Results show that shear walls with U-shaped cross-section, placed as the building central core, and also walls with Z-shaped cross-section, placed at the corners give the building more reliable seismic behavior.

Keywords: vertically chamfered buildings, non-linear time history analyses, l-, t-, u- and z-shaped plan walls

Procedia PDF Downloads 240

Authors: Sao-Jeng Chao, Wen-Cheng Chen, Wei-Humg Lu

Abstract:

In order to prevent encountering unpredictable factors, geotechnical engineers always conduct numerical analysis for braced excavation design. Simulation work in advance can predict the response of subsequent excavation and thus will be designed to increase the security coefficient of construction. The parameters that are considered include geological conditions, soil properties, soil distributions, loading types, and the analysis and design methods. National Ilan University is located on the LanYang plain, mainly deposited by clayey soil and loose sand, and thus is vulnerable to external influence displacement. National Ilan University experienced a construction of braced excavation with a complete program of monitoring excavation. This study takes advantage of a one-dimensional finite element method RIDO to simulate the excavation process. The predicted results from numerical simulation analysis are compared with the monitored results of construction to explore the differences between them. Numerical simulation analysis of the excavation process can be used to analyze retaining structures for the purpose of understanding the relationship between the displacement and supporting system. The resulting deformation and stress distribution from the braced excavation cab then be understand in advance. The problems can be prevented prior to the construction process, and thus acquire all the affected important factors during design and construction.

Keywords: excavation, numerical simulation, RIDO, retaining structure

Procedia PDF Downloads 238

Authors: Anwar U. Haque, Waqar Asrar, Ashraf Ali Omar, Erwin Sulaeman, Jaffer Sayed Mohamed Ali

Abstract:

Due to the interference effects, the intrinsic aerodynamic parameters obtained from the individual component testing are always fundamentally different than those obtained for complete model testing. Consideration and limitation for such testing need to be taken into account in any design work related to the component buildup method. In this paper, the scaled model of a straight rectangular canard of a hybrid buoyant aircraft is tested at 50 m/s in IIUM-LSWT (Low-Speed Wind Tunnel). Model and its attachment with the balance are kept rigid to have results free from the aeroelastic distortion. Based on the velocity profile of the test section’s floor; the height of the model is kept equal to the corresponding boundary layer displacement. Balance measurements provide valuable but limited information of the overall aerodynamic behavior of the model. Zero lift coefficient is obtained at -2.2o and the corresponding drag coefficient was found to be less than that at zero angles of attack. As a part of the validation of low fidelity tool, the plot of lift coefficient plot was verified by the experimental data and except the value of zero lift coefficient, the overall trend has under-predicted the lift coefficient. Based on this comparative study, a correction factor of 1.36 is proposed for lift curve slope obtained from the panel method.

Keywords: wind tunnel testing, boundary layer displacement, lift curve slope, canard, aerodynamics

Procedia PDF Downloads 450

Authors: Petri Kouvo, Aino Kainulainen, Kimmo Koivunen

Abstract:

Separate collection system for recyclable wastes in the Helsinki region was ranked second best of European capitals. The collection system includes paper, cardboard, glass, metals and biowaste. Residual waste is collected and used in energy production. The collection system excluding paper is managed by the Helsinki Region Environmental Services HSY, a public organization owned by four municipalities (Helsinki, Espoo, Kauniainen and Vantaa). Paper collection is handled by the producer responsibility scheme. The efficiency of the collection system in the Helsinki region relies on a good coverage of door-to-door-collection. All properties with 10 or more dwelling units are required to source separate biowaste and cardboard. This covers about 75% of the population of the area. The obligation is extended to glass and metal in properties with 20 or more dwelling units. Other success factors include public awareness campaigns and a fee system that encourages recycling. As a result of waste management regulations for source separation of recyclables and biowaste, nearly 50 percent of recycling rate of household waste has been reached. For households and small and medium size enterprises, there is a sorting station fleet of five stations available. More than 50 percent of wastes received at sorting stations is utilized as material. The separate collection of plastic packaging in Finland will begin in 2016 within the producer responsibility scheme. HSY started supplementing the national bring point system with door-to-door-collection and pilot operations will begin in spring 2016. The result of plastic packages pilot project has been encouraging. Until the end of 2016, over 3500 apartment buildings have been joined the piloting, and more than 1800 tons of plastic packages have been collected separately. In the summer 2015 a novel partial flow digestion process combining digestion and tunnel composting was adopted for source separated household and commercial biowaste management. The product gas form digestion process is converted in to heat and electricity in piston engine and organic Rankine cycle process with very high overall efficiency. This paper describes the efficient collection system and discusses key success factors as well as main obstacles and lessons learned as well as the partial flow process for biowaste management.

Keywords: biowaste, HSY, MSW, plastic packages, recycling, separate collection

Procedia PDF Downloads 195

Authors: Carmen Nechita

Abstract:

This research explores the world of Syrian refugee women living in Dresden and their efforts to reconstruct their lives in the state of Saxony in Germany. The focus is on the initial period of adjustment and understanding how refugee women use culture, family ties, and tradition to contest and rebuild new relationships with the host country. Faced with a new status as “the refugee”, women have to re-imagine their ethno-cultural identity in order to cope with life in Diaspora. In order to understand the coping mechanism and the displacement effects on Syrian women, interviews with twelve refugee women were conducted. Traumatic experiences of loss and oppression are at the core of their confessions. While gender violence, abuse and patriarchal framework shape their narratives, this research argues that there is a need to look at this from a cultural perspective and try to distance ourselves from the western paradigm. The way Syrian women refute and rebuild their national and ethno-cultural identity in order to negotiate for themselves new space within German borders is explored. Two discourses are bridged: one of multiculturalism and one of tradition in order to explain how Syrian women experience western notions of family, womanhood and spousal dynamics. The process is painful, traumatic and marked by feelings of low self-worth, but in the end, new codes emerge and these women come out more empowered. The paper includes the migration experience and explores the ways in which Syrian refugee women tend to tell their complex stories, and how they reconstruct their identity in a new territory while faced with a different culture that discriminates against them. During the research, four distinct phases in the acculturation period were identified: “the survival”, “the honeymoon period”, “the isolation period” and “the anger period”. Each phase is analyzed in order to understand what triggers them, how women migrate from one phase to another and what can be done to make the process easier. This paper contributes to the field of refugee studies by offering a thorough understanding of the initial phases of the acculturation process in the case of Syrian refugee women. The study examines the fleeing and settlement experience in order to understand the complex ways that refugee women cope with the traumatic experience of settlement in another country and in a different culture. *Almanya: The Arabic word for Germany.

Keywords: displacement, migration, refugee women, Syria

Procedia PDF Downloads 238

Authors: Arturs Macanovskis, Vitalijs Lusis, Andrejs Krasnikovs

Abstract:

Work has three stages. In the first stage was examined pull-out process for steel fiber was embedded into a concrete by one end and was pulled out of concrete under the angle to pulling out force direction. Angle was varied. Length of steel fiber was 26 mm, diameter 0.5 mm. On the obtained force- displacement diagrams were observed jumps. For such mechanical behavior explanation, fiber channel in concrete surface microscopical experimental investigation, using microscope KEYENCE VHX2000, was performed. Surface of fiber channel in concrete matrix after pull-out test (fiber angle to pulling out force direction 70°). At the second stage were obtained diagrams for load- crack opening displacement for breaking homogeneously reinforced and layered fiber concrete prisms (with dimensions 10x10x40 cm) subjected to 4-point bending. After testing was analyzed main crack. On the main crack’s both surfaces were recognized all pulled out fibers their locations, angles to crack surface and lengths of pull-out fibers parts. At the third stage elaborated prediction model for the fiber-concrete beam, failure under bending, using the following data: a) diagrams for fibers pulling out at different angles; b) experimental data about steel-straight fibers locations in the main crack.

Keywords: fiberconcrete, pull-out, fiber channel, layered fiberconcrete

Procedia PDF Downloads 425

Authors: Manjari Rai

Abstract:

Urbanization is an inevitable process of development of human society and an outcome of economic development and scientific and technological progress. While urbanization process in promoting the development of human civilization, also no doubt, urban landscape has been a corresponding impact. Urban environment has suffered unprecedented damage majorly due to the increase in urban population density and heavy migration rate, traffic congestion, and environmental pollution. All this have however led to a major ecological degradation and imbalance. As lands are used for the rapid and unplanned urbanization, the green lands are diminished, and severe pollution is created by waste products. Plastic, the most alarming waste at landfill sites, is yet uncontrolled. Therefore, initiatives must be taken to reduce plastic mediated pollution and increase green application. However, increasing green land is not possible due to the landfill by urban structures. In order to create a harmonious environment, sustainable development in the urban landscape becomes a matter of prime focus. This paper thus discusses the concept of ecological design combined with the urban landscape design, green landscape design on urban structures and sustainable development through the use of recyclable waste materials which is also a low costing approach of urban landscape design.

Keywords: ecological, degradation sustainable, landscape, urban

Procedia PDF Downloads 394

Authors: Bambang Piscesa, Mario M. Attard, Dwi Presetya, Ali K. Samani

Abstract:

A numerical strategy formulated using a plasticity approach is presented to model spalling of the concrete cover in reinforced concrete columns. The stage at which the concrete cover within reinforced concrete column spalls has a direct bearing on the load capacity. The concrete cover can prematurely spall before the full cross-section can be utilized if the concrete is very brittle under compression such as for very high strength concretes. If the confinement to the core is high enough, the column can achieve a higher peak load by utilizing the core. A numerical strategy is presented to model spalling of the concrete cover. Various numerical strategies are employed to model the behavior of reinforced concrete columns which include: (1) adjusting the material properties to incorporate restrained shrinkage; (2) modifying the plastic dilation rate in the presence of the tensile pressure; (3) adding a tension cut-off failure surface and (4) giving the concrete cover region and the column core different material properties. Numerical comparisons against experimental results are carried out that shown excellent agreement with the experimental results and justify the use of the proposed strategies to predict the axial load capacity of reinforce concrete columns.

Keywords: spalling, concrete, plastic dilation, reinforced concrete columns

Procedia PDF Downloads 135

Authors: I. A Tijani, Y. F Wu, C.W. Lim

Abstract:

Concrete Damaged Plasticity Model (CDPM) is capable of modeling the stress-strain behavior of confined concrete. Nevertheless, the accuracy of the model largely depends on its parameters. To date, most research works mainly focus on the identification and modification of the parameters for fiber reinforced polymer (FRP) confined concrete prior to damage. And, it has been established that the FRP-strengthened concrete behaves differently to FRP-repaired concrete. This paper presents a modified plastic damage model within the context of the CDPM in ABAQUS for modelling of a uniformly FRP-confined repaired concrete under monotonic loading. The proposed model includes infliction damage, elastic stiffness, yield criterion and strain hardening rule. The distinct feature of damaged concrete is elastic stiffness reduction; this is included in the model. Meanwhile, the test results were obtained from a physical testing of repaired concrete. The dilation model is expressed as a function of the lateral stiffness of the FRP-jacket. The finite element predictions are shown to be in close agreement with the obtained test results of the repaired concrete. It was observed from the study that with necessary modifications, finite element method is capable of modeling FRP-repaired concrete structures.

Keywords: Concrete, FRP, Damage, Repairing, Plasticity, and Finite element method

Procedia PDF Downloads 118

Authors: Adil Hassabo

Abstract:

In this paper, a horizontal circular curve computations calculator is developed in Microsoft Windows. The developed calculator can be used for determining the necessary information required for setting out horizontal curves. Three methods are applied in the developed program namely: incremental chord method, total chord method, and the coordinates method. Computations of horizontal curves by the developed calculator is faster, easier, accurate, and less subject to errors comparable to the traditional method of calculations. Finally, the results obtained by the traditional method and by the developed calculator are presented for checking the behavior of the developed calculator.

Keywords: calculator, circular, computations, curve

Procedia PDF Downloads 137

Authors: Dhruv Sharma, Lynne Blair, Stephen Clune

Abstract:

Later life loneliness is a social issue that is increasing alongside an upward global population trend. As a society, one way that we have responded to this social challenge is through developing non-pharmacological interventions such as befriending services, activity clubs, meet-ups, etc. Through a systematic literature review, this paper suggests that currently there is an underrepresentation of radical innovation, and underutilization of digital technologies in developing loneliness interventions for older adults. This paper examines intervention studies that were published in English language, within peer reviewed journals between January 2005 and December 2014 across 4 electronic databases. In addition to academic databases, interventions found in grey literature in the form of websites, blogs, and Twitter were also included in the overall review. This approach yielded 129 interventions that were included in the study. A systematic approach allowed the minimization of any bias dictating the selection of interventions to study. A coding strategy based on a pattern analysis approach was devised to be able to compare and contrast the loneliness interventions. Firstly, interventions were categorized on the basis of their objective to identify whether they were preventative, supportive, or remedial in nature. Secondly, depending on their scope, they were categorized as one-to-one, community-based, or group based. It was also ascertained whether interventions represented an improvement, an incremental innovation, a major advance or a radical departure, in comparison to the most basic form of a loneliness intervention. Finally, interventions were also assessed on the basis of the extent to which they utilized digital technologies. Individual visualizations representing the four levels of coding were created for each intervention, followed by an aggregated visual to facilitate analysis. To keep the inquiry within scope and to present a coherent view of the findings, the analysis was primarily concerned the level of innovation, and the use of digital technologies. This analysis highlights a weak but positive correlation between the level of innovation and the use of digital technologies in designing and deploying loneliness interventions, and also emphasizes how certain existing interventions could be tweaked to enable their migration from representing incremental innovation to radical innovation for example. This analysis also points out the value of including grey literature, especially from Twitter, in systematic literature reviews to get a contemporary view of latest work in the area under investigation.

Keywords: ageing, loneliness, innovation, digital

Procedia PDF Downloads 98

Authors: Wenxin Mei, Jinhua Sun, Qingsong Wang

Abstract:

The volume expansion of lithium-ion batteries is mainly induced by intercalation induced stress within the negative electrode, resulting in capacity degradation and even battery failure. Stress generation due to lithium intercalation into graphite particles is investigated based on an electrochemical-mechanical model in this work. The two-dimensional model presented is fully coupled, inclusive of the impacts of intercalation-induced stress, stress-induced intercalation, to evaluate the lithium concentration, stress generation, and displacement intra and inter-particle. The results show that the distribution of lithium concentration and stress exhibits an analogous pattern, which reflects the relation between lithium diffusion and stress. The results of inter-particle stress indicate that larger Von-Mises stress is displayed where the two particles are in contact with each other, and deformation at the edge of particles is also observed, predicting fracture. Additionally, the maximum inter-particle stress at the end of lithium intercalation is nearly ten times the intraparticle stress. And the maximum inter-particle displacement is increased by 24% compared to the single-particle. Finally, the effect of graphite particle arrangement on inter-particle stress is studied. It is found that inter-particle stress with tighter arrangement exhibits lower stress. This work can provide guidance for predicting the intra and inter-particle stress to take measures to avoid cracking of electrode material.

Keywords: electrochemical-mechanical model, graphite particle, lithium concentration, lithium ion battery, stress

Procedia PDF Downloads 168

Authors: Arvan Prakash Ankitha, Madasamy Arockiasamy

Abstract:

The increasing demand for adopting pile foundations in bridgeshas pointed towardsthe need to constantly improve the existing analytical techniques for better understanding of the behavior of such foundation systems. This study presents a simplistic approach using the energy-based method to assess the displacement responses of piles subjected to general loading conditions: Axial Load, Lateral Load, and a Bending Moment. The governing differential equations and the boundary conditions for a bridge pile embedded in multi-layered soil strata subjected to the general loading conditions are obtained using the Hamilton’s principle employing variational principles and minimization of energies. The soil non-linearity has been incorporated through simple constitutive relationships that account for degradation of soil moduli with increasing strain values.A simple power law based on published literature is used where the soil is assumed to be nonlinear-elastic and perfectly plastic. A Tresca yield surface is assumed to develop the soil stiffness variation with different strain levels that defines the non-linearity of the soil strata. This numerical technique has been applied to a pile foundation in a two - layered soil strata for a pier supporting the bridge and solved using the software MATLAB R2019a. The analysis yields the bridge pile displacements at any depth along the length of the pile. The results of the analysis are in good agreement with the published field data and the three-dimensional finite element analysis results performed using the software ANSYS 2019R3. The methodology can be extended to study the response of the multi-strata soil supporting group piles underneath the bridge piers.

Keywords: pile foundations, deep foundations, multilayer soil strata, energy based method

Procedia PDF Downloads 111

Authors: Mostafa Jafarian Abyaneh, Khashayar Jafari, Vahab Toufigh

Abstract:

The cost of experiments on different types of concrete has raised the demand for prediction of their behavior with numerical analysis. In this research, an advanced numerical model has been presented to predict the complete elastic-plastic behavior of polymer concrete (PC), high-strength concrete (HSC), high performance concrete (HPC) along with different steel fiber contents under uniaxial compression. The accuracy of the numerical response was satisfactory as compared to other conventional simple models such as Mohr-Coulomb and Drucker-Prager. In order to predict the complete elastic-plastic behavior of specimens including softening behavior, disturbed state concept (DSC) was implemented by nonlinear finite element analysis (NFEA) and hierarchical single surface (HISS) failure criterion, which is a failure surface without any singularity.

Keywords: disturbed state concept (DSC), hierarchical single surface (HISS) failure criterion, high performance concrete (HPC), high-strength concrete (HSC), nonlinear finite element analysis (NFEA), polymer concrete (PC), steel fibers, uniaxial compression test

Procedia PDF Downloads 292

Authors: Sonia Butalia, Huong Luu, Alexis Guigue, Karen J. B. Martins, Khanh Vu, Scott W. Klarenbach

Abstract:

Obesity is associated with significant personal impacts on health and has a substantial economic burden on payers due to increased healthcare use. A contemporary estimate of the healthcare costs associated with obesity at the population level are lacking. This evidence may provide further rationale for weight management strategies. Methods: Adults who underwent a medical procedure between 2012 and 2019 in Alberta, Canada were categorized into the investigational cohort (had body mass index [BMI]-defined class 2 or 3 obesity based on a procedure-associated code) and the control cohort (did not have the BMI procedure-associated code); those who had bariatric surgery were excluded. Characteristics were presented and healthcare costs ($CDN) determined over a 1-year observation period (2019/2020). Logistic regression and a generalized linear model with log link and gamma distribution were used to assess total healthcare costs (comprised of hospitalizations, emergency department visits, ambulatory care visits, physician visits, and outpatient prescription drugs); potential confounders included age, sex, region of residence, and whether the medical procedure was performed within 6-months before the observation period in the partial adjustment, and also the type of procedure performed, socioeconomic status, Charlson Comorbidity Index (CCI), and seven obesity-related health conditions in the full adjustment. Cost ratios and estimated cost differences with 95% confidence intervals (CI) were reported; incremental cost differences within the adjusted models represent referent cases. Results: The investigational cohort (n=220,190) was older (mean age: 53 standard deviation [SD]±17 vs 50 SD±17 years), had more females (71% vs 57%), lived in rural areas to a greater extent (20% vs 14%), experienced a higher overall burden of disease (CCI: 0.6 SD±1.3 vs 0.3 SD±0.9), and were less socioeconomically well-off (material/social deprivation was lower [14%/14%] in the most well-off quintile vs 20%/19%) compared with controls (n=1,955,548). Unadjusted total healthcare costs were estimated to be 1.77-times (95% CI: 1.76, 1.78) higher in the investigational versus control cohort; each healthcare resource contributed to the higher cost ratio. After adjusting for potential confounders, the total healthcare cost ratio decreased, but remained higher in the investigational versus control cohort (partial adjustment: 1.57 [95% CI: 1.57, 1.58]; full adjustment: 1.21 [95% CI: 1.20, 1.21]); each healthcare resource contributed to the higher cost ratio. Among urban-dwelling 50-year old females who previously had non-operative procedures, no procedures performed within 6-months before the observation period, a social deprivation index score of 3, a CCI score of 0.32, and no history of select obesity-related health conditions, the predicted cost difference between those living with and without obesity was $386 (95% CI: $376, $397). Conclusions: If these findings hold for the Canadian population, one would expect an estimated additional $3.0 billion per year in healthcare costs nationally related to BMI-defined obesity (based on an adult obesity rate of 26% and an estimated annual incremental cost of $386 [21%]); incremental costs are higher when obesity-related health conditions are not adjusted for. Results of this study provide additional rationale for investment in interventions that are effective in preventing and treating obesity and its complications.

Keywords: administrative data, body mass index-defined obesity, healthcare cost, real world evidence

Procedia PDF Downloads 91

Authors: Johns Paul, Santhosh J. Nalluveettil, P. Purushothaman, M. Premdas

Abstract:

Lunar landing is one of the most critical phases of lunar mission. The lander is provided with a soft landing system to prevent structural damage of lunar module by absorbing the landing shock and also assure stability during landing. Presently available software are not capable to simulate the rigid body dynamics coupled with contact simulation and elastic/plastic deformation analysis. Hence a separate mathematical model has been generated for studying the dynamics of a typical lunar soft lander. Parameters used in the analysis includes lunar surface slope, coefficient of friction, initial touchdown velocity (vertical and horizontal), mass and moment of inertia of lander, crushing force due to energy absorbing material in the legs, number of legs and geometry of lander. The mathematical model is capable to simulate plastic and elastic deformation of honey comb, frictional force between landing leg and lunar soil, surface contact simulation, lunar gravitational force, rigid body dynamics and linkage dynamics of inverted tripod landing gear. The non linear differential equations generated for studying the dynamics of lunar lander is solved by numerical method. Matlab programme has been used as a computer tool for solving the numerical equations. The position of each kinematic joint is defined by mathematical equations for the generation of equation of motion. All hinged locations are defined by position vectors with respect to body fixed coordinate. The vehicle rigid body rotations and motions about body coordinate are only due to the external forces and moments arise from footpad reaction force due to impact, footpad frictional force and weight of vehicle. All these force are mathematically simulated for the generation of equation of motion. The validation of mathematical model is done by two different phases. First phase is the validation of plastic deformation of crushable elements by employing conservation of energy principle. The second phase is the validation of rigid body dynamics of model by simulating a lander model in ADAMS software after replacing the crushable elements to elastic spring element. Simulation of plastic deformation along with rigid body dynamics and contact force cannot be modeled in ADAMS. Hence plastic element of primary strut is replaced with a spring element and analysis is carried out in ADAMS software. The same analysis is also carried out using the mathematical model where the simulation of honeycomb crushing is replaced by elastic spring deformation and compared the results with ADAMS analysis. The rotational motion of linkages and 6 degree of freedom motion of lunar Lander about its CG can be validated by ADAMS software by replacing crushing element to spring element. The model is also validated by the drop test results of 4 leg lunar lander. This paper presents the details of mathematical model generated and its validation.

Keywords: honeycomb, landing leg tripod, lunar lander, primary link, secondary link

Procedia PDF Downloads 325

Authors: Mahmoud F. Awad-Allah, Mohammed Rabeih, Eman Abdel Baseer

Abstract:

Soft to very soft soil deposits are widely speared in some areas of Egypt such as East Port Said, Damietta, Kafr El-Sheik, Alexandria, etc. The construction projects in these areas have faced the challenge of the presence of extended deep layers of soft and very soft clays which reach to depths of 40 to 60 m from the ground level. Stone columns are commonly used to support structures overlying soft ground soils and surcharged by embankment type loading. Therefore, this paper introduces a wide comparison numerical study between the ordinary stone columns (OSC) versus the geosynthetic encased stone columns (ESC) installed in soft clay soil deposit using finite element method (FEM). Parametric study of an embankment on soft soils reinforced with stone columns is performed using commercial computer program based on the finite element technique (PLAXIS 2D). The investigation will present the influence of the following parameters: diameter of stone columns, stiffness of geosynthetic encasement, embedded depth of stone column from ground level, and the length encasement of the stone column on the consolidation time, vertical settlement, and lateral displacement of soft clay soil formations.

Keywords: finite element method, geosynthetic, lateral displacement, settlement, soft clay

Procedia PDF Downloads 183

Authors: Jesús David Argueta Moreno, Taria Ruiz, Cesar Ortega

Abstract:

This qualitative investigation represents the first stage of the human capital engineering analysis, along the small and medium textile manufacturing companies, located on the city of Tegucigalpa, Honduras where the symptoms of the local manufacturing industry´s describe a severe gender displacement phenomenon. The evaluation of this phenomena, intends to trigger the Honduran small and medium technology manufactures into a collective performance, analysis through the development of a sectorial diagnose and the creation of a manufacturers guide, personalized. In accordance to the Honduran textile manufacturing needs, in order to strengthen their personnel capacities and thereby smoothen the gender equilibrium on this particular sector. It is worth mentioning, that on the last decade, the female gender has gathered positive statistics upon Central American job market´s, were the local business landscape describes a significant displacement of the Honduran female operators over the male gender workers that has significantly diminished their employment predominance. On the other hand, this study aims to evaluate the main features that impact on the job market local gender supplanting. On the other hand, this document aims to holistically describe the Honduran manufacturing context, as well as the current textile operator qualifications, in order to infer over the most proper human resources enforcement approaches/techniques on the industry.

Keywords: gender predominance, manufacturing, higher education institutions, emerging trends

Procedia PDF Downloads 410

Authors: Daniel Y. Abebe, Jaehyouk Choi

Abstract:

Link-to-column connection in eccentrically braced frames (EBF) has been a critical problem since the link flange connected to the column fractured prior to the required link rotation. Even though the problem in link-to-column connection still exist, the use of an eccentrically braced frame (EBF) is increasing day by day as EBF have high elastic stiffness, stable inelastic response under repeated lateral loading, and excellent ductility and energy dissipation capacity. In order to address this problem, a reduced web and flange link section is proposed and evaluated in this study. Reducing the web with holes makes the link to control the failure at the edge of holes introduced. Reducing the flange allows the link to control the location at which the plastic hinge is formed. Thus, the failure supposed to occur in the link flange connected at the connection move to the web and to the reduced link flange. Nonlinear FE analysis and experimental investigations have been done on the developed links, and the result shows that the link satisfies the plastic rotation limit recommended in AICS-360-10. Design equations that define the behavior of the proposed link have been recommended, and the equations were verified through the experimental and FE analysis results.

Keywords: EBFs, earthquake disaster, link-to-column connection, reduced link section

Procedia PDF Downloads 353

Authors: N. Singh, G. K. Darbha

Abstract:

Since the last decade, a wave of research has begun to study the prevalence and impact of ever-increasing plastic pollution in the environment. The wide application and ubiquitous distribution of plastic have become a global concern due to its persistent nature. The disposal of plastics has emerged as one of the major challenges for waste management landfills. Microplastics (MPs) have found its existence in almost every environment, from the high altitude mountain lake to the deep sea sediments, polar icebergs, coral reefs, estuaries, beaches, and river, etc. Microplastics are fragments of plastics with size less than 5 mm. Microplastics can be classified as primary microplastics and secondary microplastics. Primary microplastics includes purposefully introduced microplastics into the end products for consumers (microbeads used in facial cleansers, personal care product, etc.), pellets (used in manufacturing industries) or fibres (from textile industries) which finally enters into the environment. Secondary microplastics are formed by disintegration of larger fragments under the exposure of sunlight, mechanical abrasive forces by rain, waves, wind and/or water. A number of factors affect the quantity of microplastic present in freshwater environments. In addition to physical forces, human population density proximal to the water body, proximity to urban centres, water residence time, and size of the water body also affects plastic properties. With time, other complex processes in nature such as physical, chemical and biological break down plastics by interfering with its structural integrity. Several studies demonstrate that microplastics found in wastewater sludge being used as manure for agricultural fields, thus having the tendency to alter the soil environment condition influencing the microbial population as well. Inadequate data are available on the fate and transport of microplastics under varying environmental conditions that are required to supplement important information for further research. In addition, microplastics have the tendency to absorb heavy metals and hydrophobic organic contaminants such as PAHs and PCBs from its surroundings and thus acting as carriers for these contaminants in the environment system. In this study, three kinds of microplastics (polyethylene, polypropylene and expanded polystyrene) of different densities were chosen. Plastic samples were placed in sand with different aqueous media (distilled water, surface water, groundwater and marine water). It was incubated at varying temperatures (25, 35 and 40 °C) and agitation levels (rpm). The results show that the number of plastic fragments enhanced with increase in temperature and agitation speed. Moreover, the rate of disintegration of expanded polystyrene is high compared to other plastics. These results demonstrate that temperature, salinity, and mechanical abrasion plays a major role in degradation of plastics. Since weathered microplastics are more harmful as compared to the virgin microplastics, long-term studies involving other environmental factors are needed to have a better understanding of degradation of plastics.

Keywords: environmental contamination, fragmentation, microplastics, temperature, weathering

Procedia PDF Downloads 138

Authors: Sangram Shamrao Patil, Hara Mohan Jena

Abstract:

Phthalates are among the most common organic pollutant since they have become widespread in the environment and found in sediments, natural waters, soils, plants, landfill leachates, biota including human tissue and aquatic organisms. Diethyl phthalate (DEP) is a low molecular weight phthalate which has wide applications as plasticizer and become a major cause of environmental pollution. Environmental protection agency (EPA) listed DEP as priority pollutant because of its toxicity and they recommended human health ambient water quality criterion for diethyl phthalate (DEP) as 4 mg/l. Therefore, wastes containing phthalates require proper treatment before being discharged into the environment. Biodegradation is attractive and efficient treatment method as it is cost effective and produces non-toxic end products. In the present study, a DEP degrading aerobic bacterium was isolated from soil contaminated with plastic industry wastewater. Morphological and biochemical characteristics of isolate were performed. 16S rRNA sequencing and phylogenetic analysis of isolate was carried out and it was identified as Empedobacter brevis. Isolate has been found to tolerate up to 1650 mg/l of DEP. This study will be significant for exploring an application of microbes for remediation of phthalates and development of a suitable bioreactor.

Keywords: diethyl phthalate, plasticizer, pollutant, biodegradation

Procedia PDF Downloads 251

Authors: Juan Eduardo Rolon Rios, Fredy Alejandro Orjuela, Alexander Garcia Mariaca

Abstract:

For banana and potato wastes, their peels are processed in order to make animal food with the condition that those wastes must not have started the decomposition process. One alternative to taking advantage of those wastes is to obtain a bioplastic based on starch from banana and potato shells. These products are 100% biodegradables, and researchers have been studying them for different applications, helping in the reduction of organic wastes and ordinary plastic wastes. Without petroleum affecting the prices of bioplastics, bioplastics market has a growing tendency and it is seen that it can keep this tendency in the medium term up to 350%. In this work, it will be shown the results for elasticity module and percent elongation for bioplastics obtained from a mixture of starch of bananas and potatoes peels, with glycerol as plasticizer. The experimental variables were the plasticizer percentage and the mixture between banana starch and potato starch. The results show that the bioplastics obtained can be used in different applications such as plastic bags or sorbets, verifying their admissible degradation percentages for each one of these applications. The results also show that they agree with the data found in the literature due to the fact that mixtures with a major amount of potato starch had the best mechanical properties because of the potato starch characteristics.

Keywords: bioplastics, fruit waste, mechanical testing, mechanical properties

Procedia PDF Downloads 269

Authors: Alireza Mirzaee, Soosan Abdollahi, Mohammad Abdollahi

Abstract:

Unreinforced Masonry (URM) wall is vulnerable in resisting horizontal load such as wind and seismic loading. It is due to the low tensile strength of masonry, the mortar connection between the brick units. URM structures are still widely used in the world as an infill wall and commonly constructed with door and window openings. This research aimed to investigate the behavior of URM wall with openings when horizontal load acting on it and developed load-drift relationship of the wall. The finite element (FE) method was chosen to numerically simulate the behavior of URM with openings. In this research, ABAQUS, commercially available FE software with explicit solver was employed. In order to ensure the numerical model can accurately represent the behavior of an URM wall, the model was validated for URM wall without openings using available experimental results. Load-displacement relationship of numerical model is well agreed with experimental results. Evidence shows the same load displacement curve shape obtained from the FE model. After validating the model, parametric study conducted on URM wall with openings to investigate the influence of area of openings and pre-compressive load on the horizontal load capacity of the wall. The result showed that the increasing of area of openings decreases the capacity of the wall in resisting horizontal loading. It is also well observed from the result that capacity of the wall increased with the increasing of pre-compressive load applied on the top of the walls.

Keywords: masonry constructions, performance at earthquake, MSJC-08 (ASD), bearing wall, tie-column

Procedia PDF Downloads 231

Authors: Johanna Perdomo, Riki Lamont, Edmund Pickering, Naomi C. Paxton, Maria A. Woodruff

Abstract:

Background: Tissue Engineering (TE) has combined advanced materials, such as biomaterials, to create affordable scaffolds and dynamic systems to generate stimulation of seeded cells on these scaffolds, improving and maintaining the cellular growth process in a cell culture. However, Few TE skin products have been clinically translated, and more research is required to produce highly biomimetic skin substitutes that mimic the native elasticity of skin in a controlled manner. Therefore, this work will be focused on the fabrication of a novel mechanical system to enhance the TE treatment approaches for the reparation of damaged tissue skin. Aims: To archive this, a soft robotic device will be created to emulate different deformation of skin stress. The design of this soft robot will allow the attachment of scaffolds, which will then be mechanically actuated. This will provide a novel and highly adaptable platform for dynamic cell culture. Methods: Novel, low-cost soft robot is fabricated via 3D printed moulds and silicone. A low cost, electro-mechanical device was constructed to actuate the soft robot through the controlled combination of positive and negative air pressure to control the different state of movements. Mechanical tests were conducted to assess the performance and calibration of each electronic component. Similarly, pressure-displacement test was performed on scaffolds, which were attached to the soft robot, applying various mechanical loading regimes. Lastly, digital image correlation test was performed to obtain strain distributions over the soft robot’s surface. Results: The control system can control and stabilise positive pressure changes for long hours. Similarly, pressure-displacement test demonstrated that scaffolds with 5µm of diameter and wavy geometry can displace at 100%, applying a maximum pressure of 1.5 PSI. Lastly, during the inflation state, the displacement of silicone was measured using DIC method, and this showed a parameter of 4.78 mm and strain of 0.0652. Discussion And Conclusion: The developed soft robot system provides a novel and low-cost platform for the dynamic actuation of tissue scaffolds with a target towards dynamic cell culture.

Keywords: soft robot, tissue engineering, mechanical stimulation, dynamic cell culture, bioreactor

Procedia PDF Downloads 77

Authors: Baba John, Abdullahi Mohammed

Abstract:

The aim of this research is to compare the analysis of biodegradation on polythene and plastics buried in fadama soil amended with Organic and Inorganic fertilizer. Physico- chemical properties of the samples were determined. Bacteria and Fungi implicated in the biodegradation were identified and enumerated. Physico- chemical properties before the analysis indicated pH range of the samples from 4.28 – 5.80 , While the percentage Organic carbon and Organic matter was highest in cow dung samples with 3.89% and 6.69% respectively. The total Nitrogen percentage was recorded to be highest in Chicken dropping (0.68), while the availability of Phosphorus (P), Sodium (Na), Pottasium (K), and Magnessium (mg) was recorded to be highest in F – soil (Control), with values to be 37ppm, 1.63 Cmolkg-1, 0.35 Cmolkg-1 and 1.18 Cmolkg-1 respectively, except for calcium which was recorded to be highest in Cow dung (5.80 Cmolkg-1). However, physico – chemical properties of the samples after analysis indicated pH range of 4.6 – 5.80, Percentage Organic carbon and Organic matter was highest in Fadama soil mixed with fertilizer, having 0.7% and 1.2% respectively. Total Percentage Nitrogen content was found to be highest (0.56) in Fadama soil mixed with poultry dropping. Availability of Sodium (Na), Pottasium (K), and Calcium (Ca) was recorded to be highest in Fadama Soil mixed with Cow dung with values to be 0.64 Cmolkg-1, 2.07 Cmolkg-1 and 3.36 Cmolkg-1 respectively. The percentage weight loss of polythene and plastic bags after nine months in fadama soil mixed with poultry dropping was 11.9% for polythene and 6.0% for plastics. Weight loss in fadama soil mixed with cow dung was 18.1% for polythene and 4.7% for plastics. Weight loss of polythene and plastic in fadama soil mixed with fertilizer (NPK) was 7.4% for polythene and 3.3% for plastics. While, the percentage weight loss of polythene and plastics after nine months of burial in fadama soil (control) was 3.5% and 0.0% respectively. The bacteria species isolated from Fadama soil, organic and inorganic fertilizers before amendments include: S. aureus, Micrococcus sp, Streptococcus. pyogenes, Psuedomonas aeruginosa Bacillus subtilis and Bacillus cereus. The fungi species include: Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Fusarium sp, Mucor sp Penicillium sp and Candida sp. The bacteria species isolated and characterized after nine months of seeding include: S. aureus, Micrococcus sp, S. pyogenes, P. aeruginosa and B. subtilis. The fungi species are: A. niger A. flavus, A. fumigatus, Mucor sp, Penicillium sp and Fusarium sp. The result of this study indicated that plastic materials can be degraded in the fadama soil irrespective of whether the soil is amended or not. The Period of composting also has a significant impact on the rate at which polythene and plastics are degraded.

Keywords: Fadama, fertilizer, plastic and polythene, biodegradation

Procedia PDF Downloads 507

Authors: Xianghe Dai, Dennis Lam, Therese Sheehan, Naveed Rehman, Jie Yang

Abstract:

Concrete is one of the most used construction materials that may be made onsite as fresh concrete and then placed in formwork to produce the desired shapes of structures. It has been recognized that the raw materials and mix proportion of concrete dominate the mechanical characteristics of hardened concrete, and the curing method and environment applied to the concrete in early stages of hardening will significantly influence the concrete properties, such as compressive strength, durability, permeability etc. In construction practice, there are various curing methods to maintain the presence of mixing water throughout the early stages of concrete hardening. They are also beneficial to concrete in hot weather conditions as they provide cooling and prevent the evaporation of water. Such methods include ponding or immersion, spraying or fogging, saturated wet covering etc. Also there are various curing methods that may be implemented to decrease the level of water lost which belongs to the concrete surface, such as putting a layer of impervious paper, plastic sheeting or membrane on the concrete to cover it. In the concrete material laboratory, accelerated strength gain methods supply the concrete with heat and additional moisture by applying live steam, coils that are subject to heating or pads that have been warmed electrically. Currently when determining the mechanical parameters of a concrete, the concrete is usually sampled from fresh concrete on site and then cured and tested in laboratories where standardized curing procedures are adopted. However, in engineering practice, curing procedures in the construction sites after the placing of concrete might be very different from the laboratory criteria, and this includes some standard curing procedures adopted in the laboratory that can’t be applied on site. Sometimes the contractor compromises the curing methods in order to reduce construction costs etc. Obviously the difference between curing procedures adopted in the laboratory and those used on construction sites might over- or under-estimate the real concrete quality. This paper presents the effect of three typical curing methods (air curing, water immersion curing, plastic film curing) and of maintaining concrete in steel moulds on the compressive strength development of normal concrete. In this study, Portland cement with 30% fly ash was used and different curing periods, 7 days, 28 days and 60 days were applied. It was found that the highest compressive strength was observed from concrete samples to which 7-day water immersion curing was applied and from samples maintained in steel moulds up to the testing date. The research results implied that concrete used as infill in steel tubular members might develop a higher strength than predicted by design assumptions based on air curing methods. Wrapping concrete with plastic film as a curing method might delay the concrete strength development in the early stages. Water immersion curing for 7 days might significantly increase the concrete compressive strength.

Keywords: compressive strength, air curing, water immersion curing, plastic film curing, maintaining in steel mould, comparison

Procedia PDF Downloads 276

Authors: Toake Endoh

Abstract:

Cross-border migration of people is a critical driver for sustainable economic development in the Asia-Pacific region. Meanwhile, the region is susceptible to mega-scale natural disasters, such as tsunami, earthquakes, and typhoons. When migrants are stranded in a foreign country by a disaster, who should be responsible for their safety and security? What legal or moral foundation is there to advocate for the protection and assistance of “migrants at risk (M@R)”? How can the states practice “good governance” in their response to displacement of the foreign migrants? This paper inquires how to protect foreign migrants displaced by a natural disaster under international law and proposes protective actions to be taken by of migrant-receiver governments. First, the paper discusses the theoretical foundation for protection of M@R and argues that the nation-states are charged of responsibility to protect at-risk foreigners as “internally displaced persons” in the light of the United Nations’ Guiding Principles of Internal Displacement (1998). Second, through the case study of the Kobe Earthquake in Japan (1995), the Tsunami in Thailand (2004), and the Hurricane Katrina in the U.S. (2005), the paper evaluates how effectively (or poorly) institutions and state actors addressed the specific vulnerability felt by M@R in these crises.

Keywords: internal displaced persons, natural disaster, international migration, responsibility to protect

Procedia PDF Downloads 292

Authors: Muhammad Aji Fajari, Ririt Aprilin Sumarsono

Abstract:

Particular instability of structural building under lateral load (e.g earthquake) will rise due to irregularity in vertical and horizontal direction as stated in SNI 03-1762-2012. The conventional slab has been considered for its less contribution in increasing the stability of the structure, except special slab system such as flat slab turned into account. In this paper, the analysis of flat slab system at Sequis Tower located in South Jakarta will be assessed its performance under earthquake. It consists of 6 floors of the basement where the flat slab system is applied. The flat slab system will be the main focus in this paper to be compared for its performance with conventional slab system under earthquake. Regarding the floor plan of Sequis Tower basement, re-entrant corner signed for this building is 43.21% which exceeded the allowable re-entrant corner is 15% as stated in ASCE 7-05 Based on that, the horizontal irregularity will be another concern for analysis, otherwise vertical irregularity does not exist for this building. Flat slab system is a system where the slabs use drop panel with shear head as their support instead of using beams. Major advantages of flat slab application are decreasing dead load of structure, removing beams so that the clear height can be maximized, and providing lateral resistance due to lateral load. Whilst, deflection at middle strip and punching shear are problems to be detail considered. Torsion usually appears when the structural member under flexure such as beam or column dimension is improper in ratio. Considering flat slab as alternative slab system will keep the collapse due to torsion down. Common seismic load resisting system applied in the building is a shear wall. Installation of shear wall will keep the structural system stronger and stiffer affecting in reduced displacement under earthquake. Eccentricity of shear wall location of this building resolved the instability due to horizontal irregularity so that the earthquake load can be absorbed. Performing linear dynamic analysis such as response spectrum and time history analysis due to earthquake load is suitable as the irregularity arise so that the performance of structure can be significantly observed. Utilization of response spectrum data for South Jakarta which PGA 0.389g is basic for the earthquake load idealization to be involved in several load combinations stated on SNI 03-1726-2012. The analysis will result in some basic seismic parameters such as period, displacement, and base shear of the system; besides the internal forces of the critical member will be presented. Predicted period of a structure under earthquake load is 0.45 second, but as different slab system applied in the analysis then the period will show a different value. Flat slab system will probably result in better performance for the displacement parameter compare to conventional slab system due to higher contribution of stiffness to the whole system of the building. In line with displacement, the deflection of the slab will result smaller for flat slab than a conventional slab. Henceforth, shear wall will be effective to strengthen the conventional slab system than flat slab system.

Keywords: conventional slab, flat slab, horizontal irregularity, response spectrum, shear wall

Procedia PDF Downloads 170

Authors: F. A. Abdel-Mohdy, M. K. El-Bisi, A. Abou-Okeil, A. A. Sleem, S. El-Sabbagh, Kawther El-Shafei, Hoda S. El-Sayed, S. M. ElSawy

Abstract:

Chitosan/ polyacrylic acid membranes containing different amounts of Al2(SO4) and/or TiO2 were prepared. The prepared membranes were characterized by measuring mechanical properties, such as tensile strength and elongation at break, swelling properties, antimicrobial properties against gram-positive and gram-negative bacteria and blood clotting. The results obtained indicate that the presence of Al2(SO4) and TiO2 in the membrane formulations have an incremental effect on the antimicrobial properties and blood clotting in albino rate.

Keywords: Chitosan, acrylic acid, antibacterial, blood clotting, membrane

Procedia PDF Downloads 470

Authors: Ronbanchob Apiratikul

Abstract:

This research studied recycled waste by the Recyclable Material Bank Project of 4 universities in the central region of Thailand for the evaluation of reducing greenhouse gas emissions compared with landfilling activity during July 2012 to June 2013. The results showed that the projects collected total amount of recyclable wastes of about 911,984.80 kilograms. Office paper had the largest amount among these recycled wastes (50.68% of total recycled waste). Groups of recycled waste can be prioritized from high to low according to their amount as paper, plastic, glass, mixed recyclables, and metal, respectively. The project reduced greenhouse gas emissions equivalent to about 2814.969 metric tons of carbon dioxide. The most significant recycled waste that affects the reduction of greenhouse gas emissions is office paper which is 70.16% of total reduced greenhouse gasses emission. According to amount of reduced greenhouse gasses emission, groups of recycled waste can be prioritized from high to low significances as paper, plastic, metals, mixed recyclables, and glass, respectively.

Keywords: recycling, garbage bank, waste management, recyclable wastes, greenhouse gases

Procedia PDF Downloads 405