Search results for: finite difference modelling

Authors: Selma Bouasria, Mahi Abdelkader, Abbès Azzi, Herouz Keltoum

Abstract:

Ventilation in buildings is a key element to provide high indoor air quality. Its efficiency appears as one of the most important factors in maintaining thermal comfort for occupants of buildings. Personal displacement ventilation is a new ventilation concept that combines the positive features of displacement ventilation with those of task conditioning or personalized ventilation. This work aims to study numerically the supply air flow in a room to optimize a comfortable microclimate for an occupant. The room is heated, and a dummy is designed to simulate the occupant. Two types of configurations were studied. The first consist of a room without windows; and the second one is a local equipped with a window. The influence of the blowing speed and the solar radiation coming from the window on the thermal comfort of the occupant is studied. To conduct this study we used the turbulence models, namely the high Reynolds k-e, the RNG and the SST models. The numerical tool used is based on the finite volume method. The numerical simulation of the supply air flow in a room can predict and provide a significant information about indoor comfort.

Keywords: local, comfort, thermique, ventilation, internal environment

Procedia PDF Downloads 394

Authors: Ali Abd El-Aty, Ahmed Tauseef, Ahmad Farooq

Abstract:

This research aims at analyzing and optimizing the hydroforming process parameters to achieve a sound bulged tube without failure. Theoretical constitutive model is formulated to develop a working diagram including process window, which represents the optimize region to carry out the hydroforming process and predict the type of tube failure during the process accurately. The model is applied into different bulging ratios for low carbon steel (C1010). From this study, it is concluded that the tubes with bulging ratios up to 50% and 70% are successfully formed without defects. The tubes with bulging ratio of 90% are successfully formed by hydroforming with optimized the loading path (axial feed versus internal pressure) within the process window. The working diagram is modified due to different types of formation of wrinkling during the hydroforming process. The formation of wrinkles with increasing axial feed can be useful in terms of the achievement of higher bulging ratio and/or less thinning and this type of wrinkles can be overcome through the internal pressure in the later stage of the hydroforming process. On the other hand, the formation of wrinkles may be harmful, if it cannot be reversed.

Keywords: finite element, hydroforming, process window, wrinkling

Procedia PDF Downloads 268

Authors: Routsukol Sunalai

Abstract:

This research purpose is to study and compare the administration of Buddhist monks at northeastern Thailand. The samples used in the study are the priest in the Northeast by simple random sampling for 190 sampling. The tools used in this study is questioner were created in the 40 question items. The statistics used for data analysis were percentage, average, and standard deviation. The research found that the human resources management for the Buddhist monks as a whole is moderate. But it was found that the highest average is the policy followed by the management information. The Buddhist monks aged less than 25 years old with the overall difference was not significant. The priests who are less than 10 years in the monk experience and the priest has long held in the position for 10 years are not different in the significant level.

Keywords: employee job-related outcomes, ethical institutionalization, quality of work life, stock exchange of Thailand

Procedia PDF Downloads 198

Authors: Mona Yacoub, Ahmed Amin Mousa

Abstract:

The current work presents a program for children in Egypt. This program involved a collection of artistic activities that purposes to improve some language, artistic skills of kindergarten children. The researchers have prepared a questionnaire for the link between the target group and the content. The questionnaire has been presented to experts for adjudicating. The program was applied to a group of 30 children. Another questionnaire has been prepared by the researchers for measuring the activities’ effect on the children. The second questionnaire was considered as the pre-test and post-test. Finally, after applying the activities and the questionnaire, the researchers detected a significant difference in favor of the post-test results.

Keywords: Developing, concepts, kindergarten, children, graphic activities

Procedia PDF Downloads 141

Authors: Aliana Leong, T. C. Huan

Abstract:

The purpose of Nostalgic themed tourism product is becoming popular in many countries. This study intends to investigate the role of nostalgia in destination image, experiential value and their effect on subsequent behavioral intention. The survey used stratified sampling method to include respondents from all the nearby Asian regions. The sampling is based on the data of inbound tourists provided by the Statistics and Census Service (DSEC) of government of Macau. The questionnaire consisted of five sections of 5 point Likert scale questions: (1) nostalgia, (2) destination image both before and after experience, (3) expected value, (4) experiential value, and (5) future visit intention. Data was analysed with structural equation modelling. The result indicates that nostalgia plays an important part in forming destination image and experiential value before individual had a chance to experience the destination. The destination image and experiential value share a bidirectional causal relationship that eventually contributes to future visit intention. The study also discovered that while experiential value is more effective in generating destination image, the later contribute more to future visit intention. The research design measures destination image and experiential value before and after respondents had experience the destination. The distinction between destination image and expected/experiential value can be examined because the longitudinal design of research method. It also allows this study to observe how nostalgia translates to future visit intention.

Keywords: nostalgia, destination image, experiential value, future visit intention

Procedia PDF Downloads 380

Authors: Jane N. O'Sullivan

Abstract:

Although it is widely believed that fertility decline has benefitted economic advancement, particularly in East and South-East Asian countries, the causal mechanisms for this stimulus are contested. Since the turn of this century, demographic dividend theory has been increasingly recognised, hypothesising that higher proportions of working-age people can contribute to economic expansion if conditions are met to employ them productively. Population growth rate, as a systemic condition distinct from age composition, has not been similar attention since the 1970s and has lacked methodology for quantitative assessment. This paper explores conceptual and empirical quantification of the burden of expanding physical capital to accommodate a growing population. In proof-of-concept analyses of Australia and the United Kingdom, actual expenditure on gross fixed capital formation was compiled over four decades and apportioned to maintenance/turnover or expansion to accommodate population growth, based on lifespan of capital assets and population growth rate. In both countries, capital expansion was estimated to cost 6.5-7.0% of GDP per 1% population growth rate. This opportunity cost impedes the improvement of per capita capacity needed to realise the potential of the working-age population. Economic modelling of demographic scenarios have to date omitted this channel of influence; the implications of its inclusion are discussed.

Keywords: age dependency, demographic dividend, infrastructure, population growth rate

Procedia PDF Downloads 121

Authors: Güler Duru Aşiret

Abstract:

Introduction: Poor sleep quality is a common problem among the older people living in nursing homes. Our study aimed at assessing the effect of individual reminiscence therapy on the sleep quality of the elderly living in nursing homes. Methods: The study had 22 people in the intervention group and 24 people in the control group. The intervention group had reminiscence therapy once a week for 12 weeks in the form of individual sessions of 25-30 minutes. In our study, we first determined the dates suitable for the intervention group and researcher and planned the date and time of individual reminiscence therapies, which would take 12 weeks. While preparing this schedule, we considered subjects’ time schedules for their regular visits to health facilities and the arrival of their visitors. At this stage, the researcher informed the participants that their regular attendance in sessions would affect the intervention outcome. One topic was discussed every week. Weekly topics included: introduction in the first week; childhood and family life, school days, starting work and work life (a day at home for housewives), a fun day out of home, marriage (friendship for the singles), plants and animals they loved, babies and children, food and cooking, holidays and travelling, special days and celebrations, assessment and closure, in the following weeks respectively. The control group had no intervention. Study data was collected by using an introductory information form and the Pittsburgh Sleep Quality Index (PSQI). Results: In our study, participants’ average age was 76.02 ± 7.31. 58.7% of them were male and 84.8% were single. All of them had at least one chronic disease. 76.1% did not need help for performing their daily life activities. The length of stay in the institution was 6.32 ± 3.85 years. According to the participants’ descriptive characteristics, there was no difference between groups. While there was no statistically significant difference between the pretest PSQI median scores (p > 0.05) of both groups, PSQI median score had a statistically significant decrease after 12 weeks of reminiscence therapy (p < 0.05). There was no statistically significant change in the median scores of the subcomponents of sleep latency, sleep duration, sleep efficiency, sleep disturbance and use of sleep medication before and after reminiscence therapy. After the 12-weeks reminiscence therapy, there was a statistically significant change in the median scores for the PSQI subcomponents of subjective sleep quality (p<0.05). Conclusion: Our study found that reminiscence therapy increased the sleep quality of the elderly living in nursing homes. Acknowledgment: This study (project no 2017-037) was supported by the Scientific Research Projects Coordination Unit of Aksaray University. We thank the elderly subjects for their kind participation.

Keywords: nursing, older people, reminiscence therapy, sleep

Procedia PDF Downloads 113

Authors: Nader H. Ghareeb, Mohamed S. Gaith, Sayed M. Soleimani

Abstract:

In modern engineering, weight optimization has a priority during the design of structures. However, optimizing the weight can result in lower stiffness and less internal damping, causing the structure to become excessively prone to vibration. To overcome this problem, active or smart materials are implemented. The coupled electromechanical properties of smart materials, used in the form of piezoelectric ceramics in this work, make these materials well-suited for being implemented as distributed sensors and actuators to control the structural response. The smart structure proposed in this paper is composed of a cantilevered steel beam, an adhesive or bonding layer, and a piezoelectric actuator. The static deflection of the structure is derived as function of the piezoelectric voltage, and the outcome is compared to theoretical and experimental results from literature. The relation between the voltage and the piezoelectric moment at both ends of the actuator is also investigated and a reduced finite element model of the smart structure is created and verified. Finally, a linear controller is implemented and its ability to attenuate the vibration due to the first natural frequency is demonstrated.

Keywords: active linear control, lyapunov stability theorem, piezoelectricity, smart structure, static deflection

Procedia PDF Downloads 374

Authors: Danielle A. Walker, Kyle L. Johnson, Patrick J. Fox, Jacen S. Moore

Abstract:

The HIV Continuum of Care has become a universal model to provide context for the process of HIV testing, linkage to care, treatment, and viral suppression. HIV testing is the first step in moving toward community viral suppression. Countries with a lower socioeconomic status experience the lowest rates of testing and access to care. The Democratic Republic of the Congo is located in the heart of sub-Saharan Africa, where testing and access to care are low and women experience higher HIV prevalence compared to men. In the Democratic Republic of the Congo there is only a 21.6% HIV testing rate among women. Because a critical gap exists between a woman’s risk of contracting HIV and the decision to be tested, this study was conducted to obtain a better understanding of the relationship between factors that could influence HIV testing among women. The datasets analyzed were from the 2013-14 Democratic Republic of the Congo Demographic and Health Survey Program. The data was subset for women with an age range of 18-49 years. All missing cases were removed and one variable was recoded. The total sample size analyzed was 14,982 women. The results showed that there did not seem to be a difference in HIV testing by mean age. Out of 11 religious categories (Catholic, Protestant, Armee de salut, Kimbanguiste, Other Christians, Muslim, Bundu dia kongo, Vuvamu, Animist, no religion, and other), those who identified as Other Christians had the highest testing rate of 25.9% and those identified as Vuvamu had a 0% testing rate (p<0.001). There was a significant difference in testing by religion. Only 0.7% of women surveyed identified as having no religious affiliation. This suggests partnerships with key community and religious leaders could be a tool to increase testing. Over 60% of women who had never been tested for HIV did not know where to be tested. This highlights the need to educate communities on where testing facilities can be located. Almost 80% of women who believed HIV could be transmitted by supernatural means and/or witchcraft had never been tested before (p=0.08). Cultural beliefs could influence risk perception and testing decisions. Consequently, misconceptions need to be considered when implementing HIV testing and prevention programs. Location by province, years of education, and wealth index were also analyzed to control for socioeconomic status. Kinshasa had the highest testing rate of 54.2% of women living there, and both Equateur and Kasai-Occidental had less than a 10% testing rate (p<0.001). As the education level increased up to 12 years, testing increased (p<0.001). Women within the highest quintile of the wealth index had a 56.1% testing rate, and women within the lowest quintile had a 6.5% testing rate (p<0.001). This study concludes that further research is needed to identify culturally competent methods to increase HIV education programs, build partnerships with key community leaders, and improve knowledge on access to care.

Keywords: Democratic Republic of the Congo, cultural beliefs, education, HIV testing

Procedia PDF Downloads 274

Authors: Hernani Brinati, Mardel de Conti, Moyses Szajnbok, Valentina Domiciano

Abstract:

This study brings a mathematical model and examples for the numerical prediction of submersible maneuvers in the horizontal and in the vertical planes. The geometry of the submarine is here taken as a body of revolution plus a sail, two horizontal and two vertical rudders. The model includes the representation of the hull resistance and of the propeller thrust and torque, what enables to consider the variation of the longitudinal component of the velocity of the ship when maneuvering. The hydrodynamic forces are represented through power series expansions of the acceleration and velocity components. The hydrodynamic derivatives for the body of revolution are mostly estimated based on fundamental principles applicable to the flow around airplane fuselages in the subsonic regime. The hydrodynamic forces for the sail and rudders are estimated based on a finite aspect ratio wing theory. The objective of this study is to build an expedite model for submarine maneuvers prediction, based on fundamental principles, which may be convenient in the early stages of the ship design. This model is tested against available numerical and experimental data.

Keywords: submarine maneuvers, submarine, maneuvering, dynamics

Procedia PDF Downloads 618

Authors: Anton Golubkov, Gleb Ermachkov, Aleksandr Smerdin, Oleg Sidorov, Victor Philippov

Abstract:

Current collection quality is one of the limiting factors when increasing trains movement speed in the rail sector. With the movement speed growth, the impact forces on the current collector from the rolling stock and the aerodynamic influence increase, which leads to the spread in the contact pressure values, separation of the current collector head from the contact wire, contact arcing and excessive wear of the contact elements. The upcoming trend in resolving this issue is the use of the automatic control systems providing stabilization of the contact pressure value. The present paper considers the features of the contemporary automatic control systems of the current collector’s pressure; their major disadvantages have been stated. A scheme of current collector pressure automatic control has been proposed, distinguished by a proactive influence on undesirable effects. A mathematical model of contact strips wearing has been presented, obtained in accordance with the provisions of the central composition rotatable design program. The analysis of the obtained dependencies has been carried out. The procedures for determining the optimal current collector pressure on the contact wire and the pressure control principle in the pneumatic drive have been described.

Keywords: contact strip, current collector, high-speed running, program control, wear

Procedia PDF Downloads 131

Authors: H. Ben Salah, A. Gannoun, C. de Peretti, A. Trabelsi

Abstract:

The Downside Risk (DSR) model for portfolio optimisation allows to overcome the drawbacks of the classical mean-variance model concerning the asymetry of returns and the risk perception of investors. This model optimization deals with a positive definite matrix that is endogenous with respect to portfolio weights. This aspect makes the problem far more difficult to handle. For this purpose, Athayde (2001) developped a new recurcive minimization procedure that ensures the convergence to the solution. However, when a finite number of observations is available, the portfolio frontier presents an appearance which is not very smooth. In order to overcome that, Athayde (2003) proposed a mean kernel estimation of the returns, so as to create a smoother portfolio frontier. This technique provides an effect similar to the case in which we had continuous observations. In this paper, taking advantage on the the robustness of the median, we replace the mean estimator in Athayde's model by a nonparametric median estimator of the returns. Then, we give a new version of the former algorithm (of Athayde (2001, 2003)). We eventually analyse the properties of this improved portfolio frontier and apply this new method on real examples.

Keywords: Downside Risk, Kernel Method, Median, Nonparametric Estimation, Semivariance

Procedia PDF Downloads 473

Authors: Diom Loreen Ndum, Omarine Njimanted

Abstract:

With increasing automation in clinical laboratories, the requirements for quality control materials have greatly increased in order to monitor daily performance. The constant use of commercial control material is not economically feasible for many developing countries because of non-availability or the high-cost of the materials. Therefore, preparation and use of in-house quality control serum will be a very cost-effective measure with respect to laboratory needs.The objective of this study was to determine the efficacy of in-house prepared pooled sera with respect to commercially acquired control sample for routine internal quality control at the Nkwen District Hospital Laboratory. This was an analytical study, serum was taken from leftover serum samples of 5 healthy adult blood donors at the blood bank of Nkwen District Hospital, which had been screened negative for human immunodeficiency virus (HIV), hepatitis C virus (HCV) and Hepatitis B antigens (HBsAg), and were pooled together in a sterile container. From the pooled sera, sixty aliquots of 150µL each were prepared. Forty aliquots of 150µL each of commercially acquired samples were prepared after reconstitution and stored in a deep freezer at − 20°C until it was required for analysis. This study started from the 9th June to 12th August 2022. Every day, alongside with commercial control sample, one aliquot of pooled sera was removed from the deep freezer and allowed to thaw before analyzed for the following parameters: blood urea, serum creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), potassium and sodium. After getting the first 20 values for each parameter of pooled sera, the mean, standard deviation and coefficient of variation were calculated, and a Levey-Jennings (L-J) chart established. The mean and standard deviation for commercially acquired control sample was provided by the manufacturer. The following results were observed; pooled sera had lesser standard deviation for creatinine, urea and AST than commercially acquired control samples. There was statistically significant difference (p<0.05) between the mean values of creatinine, urea and AST for in-house quality control when compared with commercial control. The coefficient of variation for the parameters for both commercial control and in-house control samples were less than 30%, which is an acceptable difference. The L-J charts revealed shifts and trends (warning signs), so troubleshooting and corrective measures were taken. In conclusion, in-house quality control sample prepared from pooled serum can be a good control sample for routine internal quality control.

Keywords: internal quality control, levey-jennings chart, pooled sera, shifts, trends, westgard rules

Procedia PDF Downloads 61

Authors: Ali Fazeli Moslehabadi

Abstract:

One of the topics discussed in civil projects, during the execution of the project, which the continuous change of work volumes is usually the characteristics of these types of projects, is how to calculate the volume of done work. The difference in volumes announced by the execution unit with the estimated volume by the technical office unit, has direct effect on the announced progress of the project. This issue can show the progress of the project more or less than actual value and as a result making mistakes for stakeholders and project managers and misleading them. This article intends to introduce some practical methods for calculating the volume of done work in civil projects. It then reviews the strengths and weaknesses of each of them, in order to resolve these contradictions and conflicts.

Keywords: technical skills, systemic skills, communication skills, done work volume calculation techniques

Procedia PDF Downloads 141

Authors: Rabia Genc, Aysun Eksioglu, Emine Serap Sarican, Sibel Icke

Abstract:

Today the habit of cigarette smoking is among one of the most important public health concerns because of the health problems it leads to. The most important and hazardous group to use tobacco and tobacco products is adolescents and teenagers. And one of the most effective ways to prevent them from starting to smoke is education. This research is a kind of educational intervention study which was carried out in order to evaluate the effect of peer education on the teenagers' knowledge about smoking. The research was carried out between October 15, 2013 and September 9, 2015 at Ege University Ataturk Vocational Health School. The population of the research comprised of the students that have been studying at Ege University Atatürk Vocational Health School, Midwifery Department (N=390). The peer educator group that would give training on smoking consisted of 10 people, and the peer groups that would be trained were divided into two groups via simple randomization as experimental group (n=185) and control group (n=185). Questionnaire, information evaluation form, and informed consent forms were used as date collection tools. The analysis of the data which were collected in the study was carried out on Statistical Package for Social Science (SPSS 15.0). It was found out that 62.5 % of the students who were in peer educator group had smoked in some period of their lives; however, none of them continued to smoke. When they were asked about their reasons to start smoking, 25% said they just wanted to try it, and 25% of them answered that it was because of their friend groups. When the pre-peer education and post-peer education point averages of peer educator group were evaluated, the results showed that there was a significant difference between the point averages (p < 0.05). When the cigarette use of experimental group and the control group were evaluated, it was clear that 18.2% of the experimental group and 24.2%of the control group still smokes. 9.1% of the experimental group and 14.8% of control group stated that they started smoking because of their friend groups. Among the students who smoke 15.9% of the ones who belongs to the experimental group and 21.9% of the ones who belong to the control group stated they are thinking of quitting smoking. It was clear that there is a significant difference between the pre-education and post-education point averages of experimental group statistically (p ≤ 0.05); however, in terms of control group, there were no significant differences between the pre-test post-test averages statistically. Between the pre-test post-test averages of experimental and control groups there were not any statistically significant differences (p > 0.05). It was found out in the study that the peer education programme is not effective on the smoking habit of Vocational Health School students. When the future studies are being planned in order to evaluate the peer education activity, it can be taken into consideration that the peer education takes a long term and the students in the educator group will be more enthusiastic and a kind of leader in their environment.

Keywords: midwifery, peer, peer education, smoking

Procedia PDF Downloads 204

Authors: Mariam Jaber, Abdullah Yahya, Mohammad Alkhedher

Abstract:

The shift toward sustainable energy solutions increasingly focuses on hydrogen, recognized for its potential as a clean energy carrier. Despite its benefits, hydrogen storage poses significant challenges, primarily due to its low energy density and high volatility. Among the various solutions, pressure vessels designed for hydrogen storage range from Type I to Type V, each tailored for specific needs and benefits. Notably, Type V vessels, with their all-composite, liner-less design, significantly reduce weight and costs while optimizing space and decreasing maintenance demands. This study focuses on optimizing Type V hydrogen storage tanks by examining how different shapes affect performance in drop tests—a crucial aspect of achieving ISO 15869 certification. This certification ensures that if a tank is dropped, it will fail in a controlled manner, ideally by leaking before bursting. While cylindrical vessels are predominant in mobile applications due to their manufacturability and efficient use of space, spherical vessels offer superior stress distribution and require significantly less material thickness for the same pressure tolerance, making them advantageous for high-pressure scenarios. However, spherical tanks are less efficient in terms of packing and more complex to manufacture. Additionally, this study introduces toroidal vessels to assess their performance relative to the more traditional shapes, noting that the toroidal shape offers a more space-efficient option. The research evaluates how different shapes—spherical, cylindrical, and toroidal—affect drop test outcomes when combined with various composite materials and layup configurations. The ultimate goal is to identify optimal vessel geometries that enhance the safety and efficiency of hydrogen storage systems. For our materials, we selected high-performance composites such as Carbon T-700/Epoxy, Kevlar/Epoxy, E-Glass Fiber/Epoxy, and Basalt/Epoxy, configured in various orientations like [0,90]s, [45,-45]s, and [54,-54]. Our tests involved dropping tanks from different angles—horizontal, vertical, and 45 degrees—with an internal pressure of 35 MPa to replicate real-world scenarios as closely as possible. We used finite element analysis and first-order shear deformation theory, conducting tests with the Abaqus Explicit Dynamics software, which is ideal for handling the quick, intense stresses of an impact. The results from these simulations will provide valuable insights into how different designs and materials can enhance the durability and safety of hydrogen storage tanks. Our findings aim to guide future designs, making them more effective at withstanding impacts and safer overall. Ultimately, this research will contribute to the broader field of lightweight composite materials and polymers, advancing more innovative and practical approaches to hydrogen storage. By refining how we design these tanks, we are moving toward more reliable and economically feasible hydrogen storage solutions, further emphasizing hydrogen's role in the landscape of sustainable energy carriers.

Keywords: hydrogen storage, drop test, composite materials, type V tanks, finite element analysis

Procedia PDF Downloads 25

Authors: Arya Prakash Padhi, Anupam Chakrabarti, Rajib Chowdhury

Abstract:

Topology or layout optimization often gives better performing economic structures and is very helpful in the conceptual design phase. But traditionally it is being done in finite element-based optimization schemes which, although gives a good result, is very time-consuming especially in 3D structures. Among other alternatives machine learning, especially deep learning-based methods, have a very good potential in resolving this computational issue. Here convolutional neural network (3D-CNN) based variational auto encoder (VAE) is trained using a dataset generated from commercially available topology optimization code ABAQUS Tosca using solid isotropic material with penalization (SIMP) method for compliance minimization. The encoded data in latent space is then fed to a 3D generative adversarial network (3D-GAN) to generate the outcome in 64x64x64 size. Here the network consists of 3D volumetric CNN with rectified linear unit (ReLU) activation in between and sigmoid activation in the end. The proposed network is seen to provide almost optimal results with significantly reduced computational time, as there is no iteration involved.

Keywords: 3D generative adversarial network, deep learning, structural topology optimization, variational auto encoder

Procedia PDF Downloads 157

Authors: Hamdy M. Youssef, Eman A. Al-Lehaibi

Abstract:

Due to many applications and problems in the fields of plasma physics, geophysics, and other many topics, the interaction between the strain field and the magnetic field has to be considered. Adomian introduced the decomposition method for solving linear and nonlinear functional equations. This method leads to accurate, computable, approximately convergent solutions of linear and nonlinear partial and ordinary differential equations even the equations with variable coefficients. This paper is dealing with a mathematical model of generalized thermoelasticity of a half-space conducting medium. A magnetic field with constant intensity acts normal to the bounding plane has been assumed. Adomian’s decomposition method has been used to solve the model when the bounding plane is taken to be traction free and thermally loaded by harmonic heating. The numerical results for the temperature increment, the stress, the strain, the displacement, the induced magnetic, and the electric fields have been represented in figures. The magnetic field, the relaxation time, and the angular thermal load have significant effects on all the studied fields.

Keywords: Adomian’s decomposition method, magneto-thermoelasticity, finite conductivity, iteration method, thermal load

Procedia PDF Downloads 136

Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi

Abstract:

Time dependent settlement due to loading on soft saturated soils produces many problems such as high consolidation settlements and low consolidation rates. Also, long term consolidation settlement of soft soil underlying the embankment leads to unpredicted settlements and cracks on soil surface. Preloading method is an effective improvement method to solve this problem. Using vertical drains in preloading method is an effective method for improving soft soils. Applying deep soil mixing method on soft soils is another effective method for improving soft soils. There are little studies on using two methods of preloading and deep soil mixing simultaneously. In this paper, the concurrent effect of preloading with deep soil mixing by vertical drains is investigated through a finite element code, Plaxis2D. The influence of parameters such as deep soil mixing columns spacing, existence of vertical drains and distance between them, on settlement and stability factor of safety of embankment embedded on soft soil is investigated in this research.

Keywords: preloading, soft soil, vertical drains, deep soil mixing, consolidation settlement

Procedia PDF Downloads 201

Authors: Petra Balla, Gabor Manhertz, Akos Antal

Abstract:

Nowadays spinal deformities are very frequent problems among teenagers. Scheuermann disease is a one dimensional deformity of the spine, but it has prevalence over 11% of the children. A traditional technology, the moiré method was used by us for screening and diagnosing this type of spinal deformity. A LabVIEW program has been developed to evaluate the moiré pictures of patients with Scheuermann disease. Two different solutions were tested in this computer program, the extreme and the inflexion point calculation methods. Effects using these methods were compared and according to the results both solutions seemed to be appropriate. Statistical results showed better efficiency in case of the extreme search method where the average difference was only 6,09⁰.

Keywords: spinal deformity, picture evaluation, Moiré method, Scheuermann disease, curve detection, Moiré topography

Procedia PDF Downloads 340

Authors: M. Chelemal Dezfoul Nejad, M. Moradi, M. Mesbah, M. Javaheri

Abstract:

This study was conducted in order to characterize the different levels of dietary vitamin C on some of biochemical parameters of Barbus grypus. For this purpose 300 Barbus grypus were divided into 15 groups. Five levels of vitamin C (0, 200, 400, 800, 1600 mg kg-1 diet) and their combination were used to prepare five experimental diets. The fish were fed 3% of their wet b.wt. per day for a 60 days period. Blood samples were obtained from six fish of each tank at the end of experiment. The results reveal that fish fed diets containing 1600 mg kg-1 vitamin C had a significant decrease in the mean amount of cholesterol, glucose and triglyceride (p<0.05). Also, there was no significant difference in the mean amount of total protein, albumin, BuN, phosphorus, sodium and potassium between the fish fed with the different diets designed for this experiment (p>0.05).

Keywords: Barbus grypus, vitamin C, biochemical parameters, diet

Procedia PDF Downloads 440

Authors: J. Sharon Mano Pappu, Sathyanarayana N. Gummadi

Abstract:

Growth of Debaryomyces nepalensis on mixed substrates in batch culture follows diauxic pattern of completely utilizing glucose during the first exponential growth phase, followed by an intermediate lag phase and a second exponential growth phase consuming xylose. The present study deals with the development of cybernetic mathematical model for prediction of xylitol production and yield. Production of xylitol from xylose in batch fermentation is investigated in the presence of glucose as the co-substrate. Different ratios of glucose and xylose concentrations are assessed to study the impact of multi substrate on production of xylitol in batch reactors. The parameters in the model equations were estimated from experimental observations using integral method. The model equations were solved simultaneously by numerical technique using MATLAB. The developed cybernetic model of xylose fermentation in the presence of a co-substrate can provide answers about how the ratio of glucose to xylose influences the yield and rate of production of xylitol. This model is expected to accurately predict the growth of microorganism on mixed substrate, duration of intermediate lag phase, consumption of substrate, production of xylitol. The model developed based on cybernetic modelling framework can be helpful to simulate the dynamic competition between the metabolic pathways.

Keywords: co-substrate, cybernetic model, diauxic growth, xylose, xylitol

Procedia PDF Downloads 313

Authors: Chun-Qing Li, Hassan Baji, Wei Yang

Abstract:

Corrosion of steel in reinforced concrete structures is a major problem worldwide. The volume expansion of corrosion products causes concrete cover cracking, which could lead to delamination of concrete cover. The time to cover cracking plays a key role to the assessment of serviceability of reinforced concrete structures subjected to corrosion. Many analytical, numerical, and empirical models have been developed to predict the time to cracking initiation due to corrosion. In this study, a numerical model based on finite element modeling of corrosion-induced cracking process is used. In order to predict the service life based on time to cover initiation, the numerical approach is coupled with a probabilistic procedure. In this procedure, all the influential factors affecting time to cover cracking are modeled as random variables. The results show that the time to cover cracking is highly variables. It is also shown that rust product expansion ratio and the size of more porous concrete zone around the rebar are the most influential factors in predicting service life of corrosion-affected structures.

Keywords: corrosion, crack width, probabilistic, service life

Procedia PDF Downloads 197

Authors: Ruixia Liu

Abstract:

Qinghai-Tibet Plateau has an important influence on the precipitation of its lower reaches. Data from remote sensing has itself advantage and numerical prediction model which assimilates RS data will be better than other. We got the assimilation data of MHS and terrestrial and sounding from GSI, and introduced the result into WRF, then got the result of RH and precipitation forecast. We found that assimilating MHS and terrestrial and sounding made the forecast on precipitation, area and the center of the precipitation more accurate by comparing the result of 1h,6h,12h, and 24h. Analyzing the difference of the initial field, we knew that the data assimilating about Qinghai-Tibet Plateau influence its lower reaches forecast by affecting on initial temperature and RH.

Keywords: Qinghai-Tibet Plateau, precipitation, data assimilation, GSI

Procedia PDF Downloads 221

Authors: Justyna Rybicka, Ashutosh Tiwari, Shane Enticott

Abstract:

In the age of automation and computation aiding manufacturing, it is clear that manufacturing systems have become more complex than ever before. Although technological advances provide the capability to gain more value with fewer resources, sometimes utilisation of the manufacturing capabilities available to organisations is difficult to achieve. Flexible manufacturing systems (FMS) provide a unique capability to manufacturing organisations where there is a need for product range diversification by providing line efficiency through production flexibility. This is very valuable in trend driven production set-ups or niche volume production requirements. Although FMS provides flexible and efficient facilities, its optimal set-up is key in achieving production performance. As many variables are interlinked due to the flexibility provided by the FMS, analytical calculations are not always sufficient to predict the FMS’ performance. Simulation modelling is capable of capturing the complexity and constraints associated with FMS. This paper demonstrates how discrete event simulation (DES) can address complexity in an FMS to optimise the production line performance. A case study of an automotive FMS is presented. The DES model demonstrates different configuration options depending on prioritising objectives: utilisation and throughput. Additionally, this paper provides insight into understanding the impact of system set-up constraints on the FMS performance and demonstrates the exploration into the optimal production set-up.

Keywords: discrete event simulation, flexible manufacturing system, capacity performance, automotive

Procedia PDF Downloads 312

Authors: Lee Chiau Yeng, Norhayani Othman

Abstract:

Regenerated cellulose fiber is fabricated in the NaOH/urea aqueous solution. In this work, cellulose is dissolved in 7 .wt% NaOH/12 .wt% urea in the temperature of -12 °C to prepare regenerated cellulose. Thermal and structure properties of cellulose and regenerated cellulose was compared and investigated by Field Emission Scanning Electron Microscopy (FeSEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric analysis (TGA), and Differential Scanning Calorimetry. Results of FeSEM revealed that the regenerated cellulose fibers showed a more circular shape with irregular size due to fiber agglomeration. FTIR showed the difference in between the structure of cellulose and the regenerated cellulose fibers. In this case, regenerated cellulose fibers have a cellulose II crystalline structure with lower degree of crystallinity. Regenerated cellulose exhibited better thermal stability than the cellulose.

Keywords: regenerated cellulose, cellulose, NaOH, urea

Procedia PDF Downloads 411

Authors: A. T. Kassem

Abstract:

Fires areconsidered a common hazardous action that any building may face. Most buildings’ structural elements are designed, taking into consideration precautions for fire safety, using deterministic design approaches. Public and highly important buildings are commonly designed considering standard fire rating and, in many cases, contain large compartments with central domes. Real fire scenarios are not commonly brought into action in structural design of buildings because of complexities in both scenarios and analysis tools. This paper presents a modern approach towards analysis of spherical domes in real fire condition via implementation of building information modelling, and adopting a probabilistic approach. BIMhas been implemented to bridge the gap between various software packages enabling them to function interactively to model both real fire and corresponding structural response. Ventilation controlled fires scenarios have been modeled using both “Revit” and “Pyrosim”. Monte Carlo simulation has been adopted to engage the probabilistic analysis approach in dealing with various parameters. Conclusions regarding failure probability and fire endurance, in addition to the effects of various parameters, have been extracted.

Keywords: concrete, spherical domes, ventilation controlled fires, BIM, monte carlo simulation, pyrosim, revit

Procedia PDF Downloads 83

Authors: Rasha Aljaryian, Lalit Kumar

Abstract:

Climate is undergoing continuous change and this trend will affect the cultivation areas ofmost crops, including wheat (Triticum aestivum L.), in the future. The current suitable cultivation areas may become unsuitable climatically. Countries that depend on wheat cultivation and export may suffer an economic loss because of production decline. On the other hand, some regions of the world could gain economically by increasing cultivation areas. This study models the potential future climatic suitability of wheat by using CLIMEX software. Two different global climate models (GCMs) were used, CSIRO-Mk3.0 (CS) and MIROC-H (MR), with two emission scenarios (A2, A1B). The results of this research indicate that the suitable climatic areas for wheat in the southern hemisphere, such as Australia, are expected to contract by the end of this century. However, some unsuitable or marginal areas will become climatically suitable under future climate scenarios. In North America and Europe further expansion inland could occur. Also, the results illustrate that heat and dry stresses as abiotic climatic factors will play an important role in wheat distribution in the future. Providing sufficient information about future wheat distribution will be useful for agricultural ministries and organizations to manage the shift in production areas in the future. They can minimize the expected harmful economic consequences by preparing strategic plans and identifying new areas for wheat cultivation.

Keywords: Climate change, Climate modelling, CLIMEX, Triticum aestivum, Wheat

Procedia PDF Downloads 237

Authors: Omar Moafaq Saleh Aljanabi, Noradiva Hamzah, Ruhanita Maelah

Abstract:

In today’s challenging global economy, which is driven by information and knowledge, risk management is undergoing a great change, as organizations shift from traditional and compartmental risk management to an enterprise-wide approach. Enterprise risk management (ERM), which aims at increasing the sustainability of an organization and achieving competitive advantage, is gaining global attention and fast becoming an essential concern in all industries. Furthermore, in order to be effective, ERM should be managed by managers with high-level skills and knowledge. Despite the importance of the knowledge embedded in, there remains a paucity of evidence concerning how human capital could influence the organization’s ERM. Responses from 116 public listed companies (PLCs) on the main market of Bursa Malaysia were analyzed using Structural Equation Modelling (SEM). This study found that there is a significant association between ERM and organizational performance. The results also indicate that human capital has a positive moderating effect on the relationship between ERM and performance. The study contributes to the ERM literature by providing empirical evidence on the relationship between ERM, human capital, and organizational performance. Findings from this study also provide guidelines for managers, policy makers, and the regulatory bodies, to evaluate the ERM practices in PLCs.

Keywords: enterprise risk management, human capital, organizational performance, Malaysian public listed companies

Procedia PDF Downloads 176

Authors: Haider Aamir, Muhammad Ali Khalid

Abstract:

Electricity harvesting speed bump (EHSB) is speed breaker of conventional shape, but the difference is that it is not fixed, rather it moves up and down, and electricity can be generated from its vibrating motion. This speed bump consists of an upper cover which will move up and down, a shaft mechanism which will be used to drive the generator and a rack and pinion mechanism which will connect the cover and shaft. There is a spring mechanism to return the cover to its initial state when a vehicle has passed over the bump. Produced energy in the past was up to 80 Watts. For this purpose, a clutch mechanism is used so that both the up-down movements of the cover can be used to drive the generator. Mechanical Motion Rectifier (MMR) mechanism ensures the conversion of both the linear motions into rotational motion which is used to drive the generator.

Keywords: electricity harvesting, generator, rack and pinion, stainless steel shaft

Procedia PDF Downloads 256