Search results for: Vector Error Correction Model (VECM)
4101 Aerodynamic Study of an Open Window Moving Bus with Passengers
Authors: Pawan Kumar Pant, Bhanu Gupta, S. R. Kale, S. V. Veeravalli
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In many countries, buses are the principal means of transport, of which a majority are naturally ventilated with open windows. The design of this ventilation has little scientific basis and to address this problem a study has been undertaken involving both experiments and numerical simulations. The flow pattern inside and around of an open window bus with passengers has been investigated in detail. A full scale three-dimensional numerical simulation has been used for a) a bus with closed windows and b) with open windows. In either simulation, the bus had 58 seated passengers. The bus dimensions used were 2500 mm wide × 2500 mm high (exterior) × 10500 mm long and its speed was set at 40 km/h. In both cases, the flow separates at the top front edge forming a vortex and reattaches close to the mid-length. This attached flow separates once more as it leaves the bus. However, the strength and shape of the vortices at the top front and wake region is different for both cases. The streamline pattern around the bus is also different for the two cases. For the bus with open windows, the dominant airflow inside the bus is from the rear to the front of the bus and air velocity at the face level of the passengers was found to be 1/10th of the free stream velocity. These findings are in good agreement with flow visualization experiments performed in a water channel at 10 m/s, and with smoke/tuft visualizations in a wind tunnel with a free-stream velocity of approximately 40 km/h on a 1:25 scaled Perspex model.Keywords: air flow, moving bus, open windows, vortex, wind tunnel
Procedia PDF Downloads 2364100 Removal of Chromium (VI) from Aqueous Solution by Teff (Eragrostis Teff) Husk Activated Carbon: Optimization, Kinetics, Isotherm, and Practical Adaptation Study Using Response Surface Methodology
Authors: Tsegaye Adane Birhan
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Recently, rapid industrialization has led to the excessive release of heavy metals such as Cr (VI) into the environment. Exposure to chromium (VI) can cause kidney and liver damage, depressed immune systems, and a variety of cancers. Therefore, treatment of Cr (VI) containing wastewater is mandatory. This study aims to optimize the removal of Cr (VI) from an aqueous solution using locally available Teff husk-activated carbon adsorbent. The laboratory-based study was conducted on the optimization of Cr (VI) removal efficiency of Teff husk-activated carbon from aqueous solution. A central composite design was used to examine the effect of the interaction of process parameters and to optimize the process using Design Expert version 7.0 software. The optimized removal efficiency of Teff husk activated carbon (95.597%) was achieved at 1.92 pH, 87.83mg/L initial concentration, 20.22g/L adsorbent dose and 2.07Hrs contact time. The adsorption of Cr (VI) on Teff husk-activated carbon was found to be best fitted with pseudo-second-order kinetics and Langmuir isotherm model of the adsorption. Teff husk-activated carbon can be used as an efficient adsorbent for the removal of chromium (VI) from contaminated water. Column adsorption needs to be studied in the future.Keywords: batch adsorption, chromium (VI), teff husk activated carbon, response surface methodology, tannery wastewater
Procedia PDF Downloads 194099 Influence of P-Y Curves on Buckling Capacity of Pile Foundation
Authors: Praveen Huded, Suresh Dash
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Pile foundations are one of the most preferred deep foundation system for high rise or heavily loaded structures. In many instances, the failure of the pile founded structures in liquefiable soils had been observed even in many recent earthquakes. Recent centrifuge and shake table experiments on two layered soil system have credibly shown that failure of pile foundation can occur because of buckling, as the pile behaves as an unsupported slender structural element once the surrounding soil liquefies. However the buckling capacity depends on largely on the depth of soil liquefied and its residual strength. Hence it is essential to check the pile against the possible buckling failure. Beam on non-linear Winkler Foundation is one of the efficient method to model the pile-soil behavior in liquefiable soil. The pile-soil interaction is modelled through p-y springs, different author have proposed different types of p-y curves for the liquefiable soil. In the present paper the influence two such p-y curves on the buckling capacity of pile foundation is studied considering initial geometric and non-linear behavior of pile foundation. The proposed method is validated against experimental results. Significant difference in the buckling capacity is observed for the two p-y curves used in the analysis. A parametric study is conducted to understand the influence of pile diameter, pile flexural rigidity, different initial geometric imperfections, and different soil relative densities on buckling capacity of pile foundation.Keywords: Pile foundation , Liquefaction, Buckling load, non-linear py curve, Opensees
Procedia PDF Downloads 1664098 Effect of High Pressure Treatment on the Microbial Contamination and on Some Chemical and Physical Properties of Minced Chicken
Authors: Siddig H. Hamad, Salah M. Al-Eid, Fahad M. Al-Jassas
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Composite samples of minced chicken were vacuum-packaged and pressure treated at 300, 400, 450 and 500 MPa in a Stansted 'FOOD-LAB' model S-FL-850-9-W high hydrostatic pressure research apparatus (Stansted Fluid Power Ltd., Stansted, UK). Treated and untreated samples were then stored at 3°C, and microbial content as well as some chemical and physical properties monitored. The microbial load of the untreated samples reached the spoilage level of 107 cfu/g in about one week, resulting in bad smell and dark brown color. The pressure treatments reduced total bacterial counts by about 1.8 to 3.2 log10 cycles and reduced counts of Enterobacteriaceae and Salmonella to non-detectable levels. The color of meat was slightly affected, but pH, moisture content and the oxidation products of lipids were not substantially changed. The treatment killed mainly gram negative bacteria but also caused sub-lethal injury to part of the population resulting in prolonged lag phase. The population not killed by the 350 to 450 MPa treatments grew relatively slowly during storage, and its loads reached spoilage level in 4 to 6 weeks, while the load of the population treated at 500 MPa did not reach this level till the end of a storage period of 9 weeks.Keywords: chicken, cold storage, microbial spoilage, high hydrostatic pressure
Procedia PDF Downloads 2464097 Understanding Chances and Challenges of Family Planning: Qualitative Study in Indonesia's Banyumas District
Authors: Utsamani Cintyamena, Sandra Frans Olivia, Shita Lisyadewi, Ariane Utomo
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Family planning is one of fundamental aspects in preventing maternal morbidity and mortality. However, the prevalence rate of Indonesia’s married women in choosing contraception is low. This study purpose to assess opportunities and challenges in family planning. Methodology: We conducted a qualitative study in Banyumas District which has huge reduction of maternal mortality rate from 2013 to 2015. Four focus group discussions and four small group discussions were conducted to assess knowledge and attitude of women in using contraceptive and their method of choice, as well as in-depth interview to four health workers and two family planning field officers as triangulation. Thematic content analysis was done manually. Results: Key themes emerge across interviews including (1) first choice of contraception is the one that they previously had, provided that they did not encountered problems with it, (2) rumor and fear of side effect affected their method of choice, (3) selection of contraceptive method was influenced by approval of husband, believes, and role model in community. Conclusion: Collaboration of health worker, family planning field officers, community, as well as support from stakeholder, must be increased to socializing family planning.Keywords: attitude, challenge, chance, family planning, knowledge
Procedia PDF Downloads 1504096 Altered L-Type Calcium Channel Activity in Atrioventricular Nodal Myocytes from Rats with Streptozotocin-Induced Type I Diabetes Mellitus
Authors: Kathryn H. Yull, Lina T. Al Kury, Frank Christopher Howarth
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Cardiovascular diseases are frequently reported in patients with Type-1 Diabetes mellitus (DM). In addition to changes in cardiac muscle inotropy, electrical abnormalities are also commonly observed in these patients. In the present study, using streptozotocin (STZ) rat model of Type-1 DM, we have characterized the changes in L-type calcium channel activity in single atrioventricular nodal (AVN) myocytes. Ionic currents were recorded from AVN myocytes isolated from the hearts of control rats and from those with STZ-induced diabetes. Patch-clamp recordings were used to assess changes in cellular electrical activity in individual myocytes. Type-1 DM significantly altered the cellular characteristics of L-type calcium current (ICaL). A reduction in peak ICaL density was observed, with no corresponding changes in the activation parameters of the current. ICaL also exhibited faster time-dependent inactivation in AVN myocytes from diabetic rats. A negative shift in the voltage dependence of inactivation was also evident. These findings demonstrate that experimentally–induced type-1 DM significantly alters AVN L-type calcium channel cellular electrophysiology. The changes in ion channel activity may underlie the abnormalities in the cardiac electrical function that contribute to the high mortality levels in patients with DM.Keywords: cardiac, ion-channel, diabetes, atrioventricular node, calcium channel
Procedia PDF Downloads 3474095 Starch Valorization: Biorefinery Concept for the Circular Bioeconomy
Authors: Maider Gómez Palmero, Ana Carrasco Pérez, Paula de la Sen de la Cruz, Francisco Javier Royo Herrer, Sonia Ascaso Malo
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The production of bio-based products for different purposes is one of the strategies that has grown the most at European and even global levels, seeking to contribute to mitigating the impacts associated with climate change and to achieve the ambitious objectives set in this regard. However, the substitution of fossil-based products for bio-based products requires a challenging and deep transformation and adaptation of the secondary and primary sectors and, more specifically, in the latter, the agro-industries. The first step to developing a bio-based value chain focuses on the availability of a resource with the right characteristics for the substitution sought. This, in turn, requires a significant reshaping of the forestry/agricultural sector but also of the agro-industry, which has a relevant potential to be deployed as a supplier and develop a robust logistical supply chain and to market a biobased raw material at a competitive price. However, this transformation may involve a profound restructuring of its traditional business model to incorporate biorefinery concepts. In this sense, agro-industries that generate by-products in their processes that are currently not valorized, such as potato processing rejects or the starch found in washing water, constitute a potential raw material that can be used for different bio-applications. This article aims to explore this potential to evaluate the most suitable bio applications to target and identify opportunities and challenges.Keywords: starch valorisation, biorefinery, bio-based raw materials, bio-applications
Procedia PDF Downloads 554094 Estimating Bridge Deterioration for Small Data Sets Using Regression and Markov Models
Authors: Yina F. Muñoz, Alexander Paz, Hanns De La Fuente-Mella, Joaquin V. Fariña, Guilherme M. Sales
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The primary approach for estimating bridge deterioration uses Markov-chain models and regression analysis. Traditional Markov models have problems in estimating the required transition probabilities when a small sample size is used. Often, reliable bridge data have not been taken over large periods, thus large data sets may not be available. This study presents an important change to the traditional approach by using the Small Data Method to estimate transition probabilities. The results illustrate that the Small Data Method and traditional approach both provide similar estimates; however, the former method provides results that are more conservative. That is, Small Data Method provided slightly lower than expected bridge condition ratings compared with the traditional approach. Considering that bridges are critical infrastructures, the Small Data Method, which uses more information and provides more conservative estimates, may be more appropriate when the available sample size is small. In addition, regression analysis was used to calculate bridge deterioration. Condition ratings were determined for bridge groups, and the best regression model was selected for each group. The results obtained were very similar to those obtained when using Markov chains; however, it is desirable to use more data for better results.Keywords: concrete bridges, deterioration, Markov chains, probability matrix
Procedia PDF Downloads 3384093 Amino Acid Derivatives as Green Corrosion Inhibitors for Mild Steel in 1M HCl: Electrochemical, Surface and Density Functional Theory Studies
Authors: Jiyaul Haque, Vandana Srivastava, M. A. Quraishi
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The amino acids based corrosion inhibitors 2-(3-(carboxymethyl)-1H-imidazol-3-ium-1-yl) acetate (Z-1),2-(3-(1-carboxyethyl)-1H-imidazol-3-ium-1-yl) propanoate (Z-2) and 2-(3-(1-carboxy-2-phenylethyl)-1H-imidazol-3-ium-1-yl)-3- phenylpropanoate (Z-3) were synthesized by the reaction of amino acids, glyoxal and formaldehyde, and characterized by the FTIR and NMR spectroscopy. The corrosion inhibition performance of synthesized inhibitors was studied by electrochemical (EIS and PDP), surface and DFT methods. The results show, the studied Z-1, Z-2 and Z-3 are effective inhibitors, showed the maximum inhibition efficiency of 88.52 %, 89.48 and 96.08% at concentration 200ppm, respectively. The results of potentiodynamic polarization (PDP) study showed that Z-1 act as a cathodic inhibitor, while Z-2 and Z-3 act as mixed type inhibitors. The results of electrochemical impedance spectroscopy (EIS) studies showed that zwitterions inhibit the corrosion through adsorption mechanism. The adsorption of synthesized zwitterions on the mild steel surface was followed the Langmuir adsorption isotherm. The formation of zwitterions film on mild steel surface was confirmed by the scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). The quantum chemical parameters were used to study the reactivity of inhibitors and supported the experimental results. An inhibitor adsorption model is proposed.Keywords: electrochemical impedance spectroscopy, green corrosion inhibitors, mild steel, SEM, quantum chemical calculation, zwitterions
Procedia PDF Downloads 1964092 Quantification of Size Segregated Particulate Matter Deposition in Human Respiratory Tract and Health Risk to Residents of Glass City
Authors: Kalpana Rajouriya, Ajay Taneja
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The objective of the present study is to investigate the regional and lobar deposition of size-segregated PM in respiratory tract of human body. PM in different fractions is monitored using the Grimm portable environmental dust monitor during winter season in Firozabad; a Glass city of India. PM10 concentration (200.817g/m³) was 4.46 and 2.0 times higher than the limits prescribed by WHO (45g/m⁻³) and NAAQS (100g/m⁻³) government agencies. PM2.5 concentration (83.538 g/m3) was 5.56 and 1.39 times higher from WHO (15g/m-3) and NAAQS (60g/m⁻³) limits. Results inferred that PM10 and PM2.5 was highest deposited in head region (0.3477-0.5622 & 0.366-0.4704) followed by pulmonary region, especially in the 9-21year old persons. The variation in deposition percentage in our study is mainly due to the airway geometry, PM size, and its deposition mechanisms. The coarse fraction, due to its large size, cannot follow the airway path and mostly gets deposited by inertial impaction in the head region and its bifurcations. The present study results inferred that Coarse and fine PM deposition was highly visualized in 9 (8.45610⁻⁴ g, 2.91110⁻⁴g) year and 3 (1.49610⁻⁴ g, 8.59310⁻⁵g) month age category. So, the 9year children and 3month infants category have high level of health risk.Keywords: particulate matter, MPPD model, regional deposition, lobar deposition, health risk
Procedia PDF Downloads 624091 Agile Methodology for Modeling and Design of Data Warehouses -AM4DW-
Authors: Nieto Bernal Wilson, Carmona Suarez Edgar
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The organizations have structured and unstructured information in different formats, sources, and systems. Part of these come from ERP under OLTP processing that support the information system, however these organizations in OLAP processing level, presented some deficiencies, part of this problematic lies in that does not exist interesting into extract knowledge from their data sources, as also the absence of operational capabilities to tackle with these kind of projects. Data Warehouse and its applications are considered as non-proprietary tools, which are of great interest to business intelligence, since they are repositories basis for creating models or patterns (behavior of customers, suppliers, products, social networks and genomics) and facilitate corporate decision making and research. The following paper present a structured methodology, simple, inspired from the agile development models as Scrum, XP and AUP. Also the models object relational, spatial data models, and the base line of data modeling under UML and Big data, from this way sought to deliver an agile methodology for the developing of data warehouses, simple and of easy application. The methodology naturally take into account the application of process for the respectively information analysis, visualization and data mining, particularly for patterns generation and derived models from the objects facts structured.Keywords: data warehouse, model data, big data, object fact, object relational fact, process developed data warehouse
Procedia PDF Downloads 4124090 Risk Management through Controlling in Industrial Enterprises Operating in Slovakia
Authors: Mária Hudáková, Mária Lusková
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This report is focused on widening the theoretical knowledge as well as controlling practical application from the risk management point of view, regarding to dynamic business changes that have occurred in Slovakia which recently has been considered to be an environment full of risk and uncertainty. The idea of the report is the proposal of the controlling operation model in the course of risk management process in an enterprise operating in Slovakia, by which the controller is able to identify early risk factors in suggested major areas of the business management upon appropriate business information integration, consecutive control and prognoses and to prepare in time full-value documents in order to suggest measures for reduction thereof. Dealing with risk factors, that can quickly limit the growth potential of the enterprise, is an essential part of managerial activities on each level. This is the reason why mutual unofficial, ergo collegial cooperation of individual departments is necessary for controlling application from the business risk management point of view. An important part of the report is elaborated survey of the most important risk factors existing in major management areas of enterprises operating in Slovakia. The outcome of the performed survey is a catalogue of the most important enterprise risk factors. The catalogue serves for better understanding risk factors affecting the Slovak enterprises, their importance and evaluation.Keywords: controlling, information, risks, risk factor, crisis
Procedia PDF Downloads 3974089 Effect of Improved Potato Varieties Adoption on Farmers' Income in Ethiopia: An Endogenous Switching Approach
Authors: Tsion Tekalegn
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In Ethiopia, improved potato varieties are essential for food security, but smallholders' adoption of improved technologies limits their productivity. For this study, data was collected based on a structured questionnaire randomly collected from the 329 sample farmers (158 adopters and 171 non-adopters). We estimate the adoption of improved variety and causal impact using Endogenous Switching Regression (ESR), and a propensity Score Matching (PSM) was used to test the treatment effect. This helps us estimate the effect of improved potato variety on smallholder farmer income by controlling for the role of the selection bias problem stemming from both observed and unobserved heterogeneity. According to the result, key determinants influencing adoption include livestock ownership, access to extension services, and farming experience, which positively affect the likelihood of adopting improved varieties. In contrast, access to irrigation negatively correlates with adoption, suggesting that farmers with reliable water sources perceive less need for improved varieties. The ESR model result confirmed that improved potato variety adoption increases the smallholder farmer income with an estimated gain of 8.77%. Thus, to improve the potato variety of the farming households, the government should give due emphasis to potato production, and the extension services need to be strengthened.Keywords: adoption, improved potato varieties, endogenous switching regression, Ethiopia
Procedia PDF Downloads 384088 Effects of Climate Change and Livelihood Diversification on Gendered Productivity Gap of Farmers in Northern Regions of Ghana
Authors: William Adzawla
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In the midst of climate variability and change, the role of gender in ensuring food production remains vital. Therefore, this study analysed the gendered productivity among maize farmers, and the effects of climate change and variability as well as livelihood diversification on gendered productivity gap. This involved a total of 619 farmers selected through a multistage sampling procedure. The data was analysed using Oaxaca Blinder decomposition model. From the result, there is a significant productivity gap of 58.8% and 44.8% between male and female heads, and between male heads and female spouses, respectively. About 87.47% and 98.08% of the variations in gendered productivity were explained by resource endowment. While livelihood diversification significantly influenced gendered productivity through endowment and coefficient effect, climate variables significantly affect productivity gap through only coefficient effects. The study concluded that there is a substantial gendered productivity gap among farmers and this is particularly due to differences in endowment. Generally, there is a high potential of reducing gendered productivity gaps through the provision of equal diversification opportunities and reducing females’ vulnerability to climate change. Among the livelihood activities, off-farm activities such as agro-processing and shea butter processing should be promoted. Similarly, the adoption of on-farm adaptation strategies should be promoted among the farmers.Keywords: climate change and variability, gender, livelihood diversification, oaxaca-blinder decomposition, productivity gap
Procedia PDF Downloads 1734087 A Longitudinal Study of Psychological Capital, Parent-Child Relationships, and Subjective Well-Beings in Economically Disadvantaged Adolescents
Authors: Chang Li-Yu
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Purposes: The present research focuses on exploring the latent growth model of psychological capital in disadvantaged adolescents and assessing its relationship with subjective well-being. Methods: Longitudinal study design was utilized and the data was from Taiwan Database of Children and Youth in Poverty (TDCYP), using the student questionnaires from 2009, 2011, and 2013. Data analysis was conducted using both univariate and multivariate latent growth curve models. Results: This study finds that: (1) The initial state and growth rate of individual factors such as parent-child relationships, psychological capital, and subjective wellbeing in economically disadvantaged adolescents have a predictive impact; (2) There are positive interactive effects in the development among factors like parentchild relationships, psychological capital, and subjective well-being in economically disadvantaged adolescents; and (3) The initial state and growth rate of parent-child relationships and psychological capital in economically disadvantaged adolescents positively affect the initial state and growth rate of their subjective well-being. Recommendations: Based on these findings, this study concretely discusses the significance of psychological capital and family cohesion for the mental health of economically disadvantaged youth and offers suggestions for counseling, psychological therapy, and future research.Keywords: economically disadvantaged adolescents, psychological capital, parent-child relationships, subjective well-beings
Procedia PDF Downloads 624086 Integrating Eco-Hydraulics and Landscape Ecology to Unveiling the Degradation Mechanism of Chinese Sturgeon Spawning Habitats
Authors: Xuan Ban, Li Pengsheng, Pengcheng Li, Ming Zhang, ChuYang Zheng, Qingjing Wu, Hao Du
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Assessing habitat quality is essential for habitat restoration and conservation, especially for critically endangered species such as the Chinese sturgeon, a 1.4-million-year-old anadromous fish known as a ‘living fossil’. This species faces significant threats to its habitat in the Yangtze River, where it has ceased to reproduce naturally and the wild population is close to extinction. Our study provides a nuanced understanding of habitat degradation by integrating ecohydraulics and landscape ecology, focusing on the mechanisms behind the degradation of the sturgeon's spawning grounds. Using the Geographic Detector Model and physical habitat simulation, we analyze how ecohydraulic parameters, in particular those related to turbulent kinetic energy, affect sturgeon spawning. We also assess habitat fragmentation and patch size, which are key determinants of habitat quality and connectivity. Our results link the decline in habitat quality to the loss of spawning habitat due to dam construction and changes in water flow. To address this, we propose interventions such as flow optimization during the spawning season and topography rehabilitation to improve spawning conditions and support sturgeon recovery. This work contributes to the development of a comprehensive approach to assessing habitat quality and provides a scientific basis for conservation strategies for threatened fish species.Keywords: Chinese sturgeon, spawning ground, eco-hydraulics, landscape index, habitat suitability, habitat quality
Procedia PDF Downloads 104085 Utilisation of Sports and Games for Psychosocial Rehabilitation of Internally Displaced Persons in Maiduguri, Nigeria
Authors: Stephen Hamafyelto, Hussaini Garba, Mary Pindar Ndahi
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The study was carried out with the intent to mitigate the trauma experienced by victims of insurgent attacks by the so-called Boko Haram militants in Borno state of Nigeria. The area was ridden by the crisis over the past 9 years. As a result, many people were killed, maimed and raped. Some others suffered all manner of inhuman treatment at the hands of their captors. The extent to which this dehumanized treatment has gone and impacted on the people in this area has left most of them traumatised. Victims who survived the attacks have been resettled in camps provided by government where their needs have been cared for. This can never be the same with their natural habitats. Many interventions have also been done by government, non-governmental organisations and corporate and individual bodies. In this regard, social needs of the victims have been the immediate concerns of most organisations, where food, shelter, and clothing were provided. However, there is little that has been done to rehabilitate these victims psychosocially. In this regard, sports and games including the victims’ local games were used to provide psychosocial rehabilitation of victims. The intent was to bring them back to social reality, social inclusion, and stable emotions and peer integration. Descriptive statistics and Multivariate analysis were done. No statistically significant difference was found among male and female children and adults in terms of psychosocial rehabilitation using sports and games.Keywords: social reality, social inclusion, emotional intellegence, peer model
Procedia PDF Downloads 2084084 The Behaviour of Laterally Loaded Piles Installed in the Sand with Enlarged Bases
Authors: J. Omer, H. Haroglu
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Base enlargement in piles was invented to enhance pile resistance in downward loading, but the contribution of an enlarged base to the lateral load resistance of a pile has not been fully exploited or understood. This paper presents a laboratory investigation of the lateral capacity and deformation response of small-scale steel piles with enlarged bases installed in dry sand. Static loading tests were performed on 24 model piles having different base-to-shaft diameter ratios. The piles were installed in a box filled with dry sand, and lateral loads were applied to the pile tops using a pulley system. The test piles had shaft diameters of 20 mm, 16 mm, and 10 mm; base diameters of 900 mm, 700 mm, and 500 mm. As a control, a pile without base enlargement was tested to allow comparisons with the enlarged base piles. Incremental maintained loads were applied until pile failure approached while recording pile head deflections with high-precision dial gauges. The results showed that the lateral capacity increased with an increase in base diameter, albeit by different percentages depending on the shaft diameters and embedment length in the sand. There was always an increase in lateral capacity with increasing embedment length. Also, it was observed that an enlarged pile base had deflected less at a given load when compared to the control pile. Therefore, the research demonstrated the benefits of lateral capacity and stability of enlarging a pile base.Keywords: pile foundations, enlarged base, lateral loading
Procedia PDF Downloads 1594083 Metropolis-Hastings Sampling Approach for High Dimensional Testing Methods of Autonomous Vehicles
Authors: Nacer Eddine Chelbi, Ayet Bagane, Annie Saleh, Claude Sauvageau, Denis Gingras
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As recently stated by National Highway Traffic Safety Administration (NHTSA), to demonstrate the expected performance of a highly automated vehicles system, test approaches should include a combination of simulation, test track, and on-road testing. In this paper, we propose a new validation method for autonomous vehicles involving on-road tests (Field Operational Tests), test track (Test Matrix) and simulation (Worst Case Scenarios). We concentrate our discussion on the simulation aspects, in particular, we extend recent work based on Importance Sampling by using a Metropolis-Hasting algorithm (MHS) to sample collected data from the Safety Pilot Model Deployment (SPMD) in lane-change scenarios. Our proposed MH sampling method will be compared to the Importance Sampling method, which does not perform well in high-dimensional problems. The importance of this study is to obtain a sampler that could be applied to high dimensional simulation problems in order to reduce and optimize the number of test scenarios that are necessary for validation and certification of autonomous vehicles.Keywords: automated driving, autonomous emergency braking (AEB), autonomous vehicles, certification, evaluation, importance sampling, metropolis-hastings sampling, tests
Procedia PDF Downloads 2904082 Accelerated Structural Reliability Analysis under Earthquake-Induced Tsunamis by Advanced Stochastic Simulation
Authors: Sai Hung Cheung, Zhe Shao
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Recent earthquake-induced tsunamis in Padang, 2004 and Tohoku, 2011 brought huge losses of lives and properties. Maintaining vertical evacuation systems is the most crucial strategy to effectively reduce casualty during the tsunami event. Thus, it is of our great interest to quantify the risk to structural dynamic systems due to earthquake-induced tsunamis. Despite continuous advancement in computational simulation of the tsunami and wave-structure interaction modeling, it still remains computationally challenging to evaluate the reliability (or its complement failure probability) of a structural dynamic system when uncertainties related to the system and its modeling are taken into account. The failure of the structure in a tsunami-wave-structural system is defined as any response quantities of the system exceeding specified thresholds during the time when the structure is subjected to dynamic wave impact due to earthquake-induced tsunamis. In this paper, an approach based on a novel integration of the Subset Simulation algorithm and a recently proposed moving least squares response surface approach for stochastic sampling is proposed. The effectiveness of the proposed approach is discussed by comparing its results with those obtained from the Subset Simulation algorithm without using the response surface approach.Keywords: response surface model, subset simulation, structural reliability, Tsunami risk
Procedia PDF Downloads 3874081 Roller Pump-Induced Tubing Rupture during Cardiopulmonary Bypass
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We analyzed the effects of variations in the diameter of silicone rubber and polyvinyl chloride (PVC) tubings on the likelihood of tubing rupture during modeling of accidental arterial line clamping in cardiopulmonary bypass with a roller pump. A closed CPB circuit constructed with a roller pump was tested with both PVC and silicone rubber tubings of 1/2, 3/8, and 1/4 inch internal diameter. Arterial line pressure was monitored, and an occlusive clamp was placed across the tubing distal to the pressure monitor site to model an accidental arterial line occlusion. A CCD camera with 512(H) x 492(V) pixels was installed above the roller pump to measure tubing diameters at pump outlet, where the maximum deformations (distension) of the tubings occurred. Quantitative measurement of the changes of tubing diameters with the change of arterial line pressure was performed using computerized image processing techniques. A visible change of tubing diameter was generally noticeable by around 250 psi of arterial line pressure, which was already very high. By 1500 psi, the PVC tubings showed an increase of diameter of between 5-10 %, while the silicone rubber tubings showed an increase between 20-25 %. Silicone rubber tubings of all sizes showed greater distensibility than PVC tubings of equivalent size. In conclusion, although roller-pump induced tubing rupture remains a theoretical problem during cardiopulmonary bypass in terms of the inherent mechanism of the pump, in reality such an occurrence is impossible in real clinical conditions.Keywords: roller pump, tubing rupture, cardiopulmonary bypass, arterial line
Procedia PDF Downloads 2954080 Optimal Design of Submersible Permanent Magnet Linear Synchronous Motor Based Design of Experiment and Genetic Algorithm
Authors: Xiao Zhang, Wensheng Xiao, Junguo Cui, Hongmin Wang
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Submersible permanent magnet linear synchronous motors (SPMLSMs) are electromagnetic devices, which can directly drive plunger pump to obtain the crude oil. Those motors have been gradually applied in oil fields due to high thrust force density and high efficiency. Since the force performance closely depends on the concrete structural parameters, the seven different structural parameters are investigated in detail. This paper presents an optimum design of an SPMLSM to minimize the detent force and maximize the thrust by using design of experiment (DOE) and genetic algorithm (GA). The three significant structural parameters (air-gap length, slot width, pole-arc coefficient) are separately screened using 27 1/16 fractional factorial design (FFD) to investigate the significant effect of seven parameters used in this research on the force performance. Response surface methodology (RSM) is well adapted to make analytical model of thrust and detent force with constraints of corresponding significant parameters and enable objective function to be easily created, respectively. GA is performed as a searching tool to search for the Pareto-optimal solutions. By finite element analysis, the proposed PMLSM shows merits in improving thrust and reducing the detent force dramatically.Keywords: optimization, force performance, design of experiment (DOE), genetic algorithm (GA)
Procedia PDF Downloads 2914079 Topics of Blockchain Technology to Teach at Community College
Authors: Penn P. Wu, Jeannie Jo
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Blockchain technology has rapidly gained popularity in industry. This paper attempts to assist academia to answer four questions. First, should community colleges begin offering education to nurture blockchain-literate students for the job market? Second, what are the appropriate topical areas to cover? Third, should it be an individual course? And forth, should it be a technical or management course? This paper starts with identifying the knowledge domains of blockchain technology and the topical areas each domain has, and continues with placing them in appropriate academic territories (Computer Sciences vs. Business) and subjects (programming, management, marketing, and laws), and then develops an evaluation model to determine the appropriate topical area for community colleges to teach. The evaluation is based on seven factors: maturity of technology, impacts on management, real-world applications, subject classification, knowledge prerequisites, textbook readiness, and recommended pedagogies. The evaluation results point to an interesting direction that offering an introductory course is an ideal option to guide students through the learning journey of what blockchain is and how it applies to business. Such an introductory course does not need to engage students in the discussions of mathematics and sciences that make blockchain technologies possible. While it is inevitable to brief technical topics to help students build a solid knowledge foundation of blockchain technologies, community colleges should avoid offering students a course centered on the discussion of developing blockchain applications.Keywords: blockchain, pedagogies, blockchain technologies, blockchain course, blockchain pedagogies
Procedia PDF Downloads 1354078 Operational Software Maturity: An Aerospace Industry Analysis
Authors: Raúl González Muñoz, Essam Shehab, Martin Weinitzke, Chris Fowler, Paul Baguley
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Software applications have become crucial to the aerospace industry, providing a wide range of functionalities and capabilities used during the design, manufacturing and support of aircraft. However, as this criticality increases, so too does the risk for business operations when facing a software failure. Hence, there is a need for new methodologies to be developed to support aerospace companies in effectively managing their software portfolios, avoiding the hazards of business disruption and additional costs. This paper aims to provide a definition of operational software maturity, and how this can be used to assess software operational behaviour, as well as a view on the different aspects that drive software maturity within the aerospace industry. The key research question addressed is, how can operational software maturity monitoring assist the aerospace industry in effectively managing large software portfolios? This question has been addressed by conducting an in depth review of current literature, by working closely with aerospace professionals and by running an industry case study within a major aircraft manufacturer. The results are a software maturity model composed of a set of drivers and a prototype tool used for the testing and validation of the research findings. By utilising these methodologies to assess the operational maturity of software applications in aerospace, benefits in maintenance activities and operations disruption avoidance have been observed, supporting business cases for system improvement.Keywords: aerospace, software lifecycle, software maintenance, software maturity
Procedia PDF Downloads 3274077 Rapid Evidence Remote Acquisition in High-Availability Server and Storage System for Digital Forensic to Unravel Academic Crime
Authors: Bagus Hanindhito, Fariz Azmi Pratama, Ulfah Nadiya
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Nowadays, digital system including, but not limited to, computer and internet have penetrated the education system widely. Critical information such as students’ academic records is stored in a server off- or on-campus. Although several countermeasures have been taken to protect the vital resources from outsider attack, the defense from insiders threat is not getting serious attention. At the end of 2017, a security incident that involved academic information system in one of the most respected universities in Indonesia affected not only the reputation of the institution and its academia but also academic integrity in Indonesia. In this paper, we will explain our efforts in investigating this security incident where we have implemented a novel rapid evidence remote acquisition method in high-availability server and storage system thus our data collection efforts do not disrupt the academic information system and can be conducted remotely minutes after incident report has been received. The acquired evidence is analyzed during digital forensic by constructing the model of the system in an isolated environment which allows multiple investigators to work together. In the end, the suspect is identified as a student (insider), and the investigation result is used by prosecutors to charge the suspect as an academic crime.Keywords: academic information system, academic crime, digital forensic, high-availability server and storage, rapid evidence remote acquisition, security incident
Procedia PDF Downloads 1544076 Application of Nitric Acid Modified Cocos nucifera, Pennisetum glaucum and Sorghum bicolor Activated Carbon for Adsorption of H₂S Gas
Authors: Z. N. Ali, O. A. Babatunde, S. Garba, H. M. S. Haruna
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The potency of modified and unmodified activated carbons prepared from shells of Cocos nucifera (coconut shell), straws of Pennisetum glaucum (millet) and Sorghum bicolor (sorghum) for adsorption of hydrogen sulphide gas were investigated using an adsorption apparatus (stainless steel cylinder) at constant temperature (ambient temperature). The adsorption equilibria states were obtained when the pressure indicated on the pressure gauge remained constant. After modification with nitric acid, results of the scanning electron microscopy of the unmodified and modified activated carbons showed that HNO3 greatly improved the formation of micropores and mesopores on the activated carbon surface. The adsorption of H2S gas was found to be highest in modified Cocos nucifera activated carbon with maximum monolayer coverage of 28.17 mg/g, and the adsorption processes were both physical and chemical with the physical process being predominant. The adsorption data were well fitted into the Langmuir isotherm model with the adsorption capacities of the activated carbons in the order modified Cocos nucifera > modified Pennisetum glaucum > modified Sorghum bicolor > unmodified Cocos nucifera > unmodified Pennisetum glaucum > unmodified Sorghum bicolour.Keywords: activated carbon adsorption, hydrogen sulphide, nitric acid, modification, stainless steel cylinder
Procedia PDF Downloads 1414075 CFD Investigation on Heat Transfer and Friction Characteristics of Rib Roughened Evacuated Tube Collector Solar Air Heater
Authors: Mohit Singla, Vishavjeet Singh Hans, Sukhmeet Singh
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Heat transfer and friction characteristics of evacuated tube collector solar air heater artificially roughened with periodic circular rib of uniform cross-section were investigated. The present investigation was carried out in ANSYS Fluent 15.0 to study the impact of roughness geometry parameters, i.e. relative roughness pitch (P/e) of 8 and relative roughness height (e/Dh) of 0.064 and flow parameters, i.e. Reynolds number range of 2500-8000 on Nusselt number and friction factor. RNG k-ε with enhanced wall treatment turbulence model was selected for analysis. The results obtained for roughened evacuated tube collector has been compared with smooth evacuated tube collector for the similar flow conditions. With the increment in Reynolds number from 2500 to 8000, Nusselt number augments while friction factor decreases. Maximum enhancement ratio of Nusselt number and friction factor was 1.71 and 2.7 respectively, obtained at Reynolds number value of 8000. The value of thermo-hydraulic performance parameter was varied between 1.18 - 1.23 for the entire range of Reynolds number, indicates the advantage to use the roughened evacuated tube collector over smooth evacuated tube collector in solar air heater.Keywords: artificial roughness, evacuated tube collector, friction factor, Nusselt number
Procedia PDF Downloads 1624074 Thyroid Stimulating Hormone Is a Biomarker for Stress: A Prospective Longitudinal Study
Authors: Jeonghun Lee
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Thyroid-stimulating hormone (TSH) is regulated by the negative feedback of T3 and T4 but is affected by cortisol and cytokines during allostasis. Hence, TSH levels can be influenced by stress through cortisol. In the present study, changes in TSH levels under stress and the potential of TSH as a stress marker were examined in patients lacking T3 or T4 feedback after thyroid surgery. The three stress questionnaires (Korean version of the Daily Stress Inventory, Social Readjustment Rating Scale, and Stress Overload Scale-Short [SOSS]), open-ended question (OQ), and thyroid function tests were performed twice in 106 patients enrolled from January 2019 to October 2020. Statistical analysis was performed using the generalized linear mixed effect model (GLMM) in R software version 4.1.0. In a multiple LMM involving 106 patients, T3, T4, SOSS (category), open-ended questions, the extent of thyroidectomy, and preoperative TSH were significantly correlated with lnTSH. T3 and T4 increased by 1 and lnTSH decreased by 0.03, 3.52, respectively. In case of a stressful event on OQ, lnTSH increased by 1.55. In the high-risk group, lnTSH increased by 0.79, compared with the low group (p<0.05). TSH had a significant relationship with stress, together with T3, T4, and the extent of thyroidectomy. As such, it has the potential to be used as a stress marker, though it showed a low correlation with other stress questionnaires. To address this limitation, questionnaires on various social environments and research on copy strategies are necessary for future studies.Keywords: stress, surgery, thyroid stimulating hormone, thyroidectomy
Procedia PDF Downloads 934073 Critical Factors in the Formation, Development and Survival of an Eco-Industrial Park: A Systemic Understanding of Industrial Symbiosis
Authors: Iván González, Pablo Andrés Maya, Sebastián Jaén
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Eco-industrial parks (EIPs) work as networks for the exchange of by-products, such as materials, water, or energy. This research identifies the relevant factors in the formation of EIPs in different industrial environments around the world. Then an aggregation of these factors is carried out to reduce them from 50 to 17 and classify them according to 5 fundamental axes. Subsequently, the Vester Sensitivity Model (VSM) systemic methodology is used to determine the influence of the 17 factors on an EIP system and the interrelationship between them. The results show that the sequence of effects between factors: Trust and Cooperation → Business Association → Flows → Additional Income represents the “backbone” of the system, being the most significant chain of influences. In addition, the Organizational Culture represents the turning point of the Industrial Symbiosis on which it must act correctly to avoid falling into unsustainable economic development. Finally, the flow of Information should not be lost since it is what feeds trust between the parties, and the latter strengthens the system in the face of individual or global imbalances. This systemic understanding will enable the formulation of pertinent policies by the actors that interact in the formation and permanence of the EIP. In this way, it seeks to promote large-scale sustainable industrial development, integrating various community actors, which in turn will give greater awareness and appropriation of the current importance of sustainability in industrial production.Keywords: critical factors, eco-industrial park, industrial symbiosis, system methodology
Procedia PDF Downloads 1264072 Illegitimate Pain and Ideology: Building a Theoretical Model for Future Analyses
Authors: J. Scott Kenney
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Not all pain is created equal. In recent decades, the concept of Illegitimate pain has begun to shed light on the phenomena of emotional and physical pain that is misunderstood, neglected, or stigmatized, broadly conceptualized along dimensions of relative legitimation and physicality. Yet, beyond a pioneering study of the suffering of closeted LGBTQ + individuals, along with an analysis of the pains experienced by students at a religious boarding school, there has been insufficient attention to what lies behind such marginalized suffering beyond the original claim that it relates to broad interpretive standards and structured power relations, mediated through interaction in various groups/settings. This paper seeks to delve theoretically into this underdeveloped terrain. Building on earlier work, it takes direct aim at the definitional aspect that lies analytically prior to such matters, theoretically unpacking the role of ideology. Following a general introduction focused on theoretical relationships between social structure, power, and ideas, the paper reviews a range of sociological literature on relevant matters. After condensing the insights from these various literatures into a series of theoretical statements, the paper analytically engages with these to articulate a series of theoretical and methodological elaborations intended to practically assist researchers in empirically examining such matters in today's complex social environment.Keywords: deviance, ideology, illegitimate pain, social theory, victimization
Procedia PDF Downloads 52