Search results for: index structural equation model
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 22943

Search results for: index structural equation model

11183 Use of the SWEAT Analysis Approach to Determine the Effectiveness of a School's Implementation of Its Curriculum

Authors: Prakash Singh

Abstract:

The focus of this study is on the use of the SWEAT analysis approach to determine how effectively a school, as an organization, has implemented its curriculum. To gauge the feelings of the teaching staff, unstructured interviews were employed in this study, asking the participants for their ideas and opinions on each of the three identified aspects of the school: instructional materials, media and technology; teachers’ professional competencies; and the curriculum. This investigation was based on the five key components of the SWEAT model: strengths, weaknesses, expectations, abilities, and tensions. The findings of this exploratory study evoke the significance of the SWEAT achievement model as a tool for strategic analysis to be undertaken in any organization. The findings further affirm the usefulness of this analytical tool for human resource development. Employees have expectations, but competency gaps in their professional abilities may hinder them from fulfilling their tasks in terms of their job description. Also, tensions in the working environment can contribute to their experiences of tobephobia (fear of failure). The SWEAT analysis approach detects such shortcomings in any organization and can therefore culminate in the development of programmes to address such concerns. The strategic SWEAT analysis process can provide a clear distinction between success and failure, and between mediocrity and excellence in organizations. However, more research needs to be done on the effectiveness of the SWEAT analysis approach as a strategic analytical tool.

Keywords: SWEAT analysis, strategic analysis, tobephobia, competency gaps

Procedia PDF Downloads 491
11182 Modeling and Simulation of Organic Solar Cells Based on P3HT:PCBM using SCAPS 1-D (Influence of Defects and Temperature on the Performance of the Solar Cell)

Authors: Souhila Boukli Hacene, Djamila Kherbouche, Abdelhak Chikhaoui

Abstract:

In this work, we elucidate theoretically the effect of defects and temperature on the performance of the organic bulk heterojunction solar cell (BHJ) P3HT: PCBM. We have studied the influence of their parameters on cell characteristics. For this purpose, we used the effective medium model and the solar cell simulator (SCAPS) to model the characteristics of the solar cell. We also explore the transport of charge carriers in the device. It was assumed that the mixture is lightly p-type doped and that the band gap contains acceptor defects near the HOMO level with a Gaussian distribution of energy states at 100 and 50 meV. We varied defects density between 1012-1017 cm-3, from 1016 cm-3, a total decrease of the photovoltaic characteristics due to the increase of the non-radiative recombination can be noticed. Then we studied the effect of variation of the electron and the hole capture cross-section on the cell’s performance, we noticed that the cell obtains a better efficiency of about 3.6% for an electron capture cross section ≤ 10-15 cm2 and a hole capture cross section ≤ 10-19 cm2. On the other hand, we also varied the temperature between 120K and 400K. We observed that the temperature of the solar cell induces a noticeable effect on its voltage. While the effect of temperature on the solar cell current is negligible.

Keywords: organic solar cell, P3HT:PCBM, defects, temperature, SCAPS

Procedia PDF Downloads 70
11181 Monte Carlo Simulation of Thyroid Phantom Imaging Using Geant4-GATE

Authors: Parimalah Velo, Ahmad Zakaria

Abstract:

Introduction: Monte Carlo simulations of preclinical imaging systems allow opportunity to enable new research that could range from designing hardware up to discovery of new imaging application. The simulation system which could accurately model an imaging modality provides a platform for imaging developments that might be inconvenient in physical experiment systems due to the expense, unnecessary radiation exposures and technological difficulties. The aim of present study is to validate the Monte Carlo simulation of thyroid phantom imaging using Geant4-GATE for Siemen’s e-cam single head gamma camera. Upon the validation of the gamma camera simulation model by comparing physical characteristic such as energy resolution, spatial resolution, sensitivity, and dead time, the GATE simulation of thyroid phantom imaging is carried out. Methods: A thyroid phantom is defined geometrically which comprises of 2 lobes with 80mm in diameter, 1 hot spot, and 3 cold spots. This geometry accurately resembling the actual dimensions of thyroid phantom. A planar image of 500k counts with 128x128 matrix size was acquired using simulation model and in actual experimental setup. Upon image acquisition, quantitative image analysis was performed by investigating the total number of counts in image, the contrast of the image, radioactivity distributions on image and the dimension of hot spot. Algorithm for each quantification is described in detail. The difference in estimated and actual values for both simulation and experimental setup is analyzed for radioactivity distribution and dimension of hot spot. Results: The results show that the difference between contrast level of simulation image and experimental image is within 2%. The difference in the total count between simulation and actual study is 0.4%. The results of activity estimation show that the relative difference between estimated and actual activity for experimental and simulation is 4.62% and 3.03% respectively. The deviation in estimated diameter of hot spot for both simulation and experimental study are similar which is 0.5 pixel. In conclusion, the comparisons show good agreement between the simulation and experimental data.

Keywords: gamma camera, Geant4 application of tomographic emission (GATE), Monte Carlo, thyroid imaging

Procedia PDF Downloads 261
11180 Three Dimensional Model of Full Scale Plate Load Test on Stone Column in Sabkha Deposit: Case Study from Jubail Industrial City - Saudi Arabia

Authors: Hassan. A. Abas, Saad A. Aiban

Abstract:

Soil improvement by means of stone column method is used to improve sabkha soils in order to limit total and differential settlement and to achieve the required bearing capacity. Full-scale plate test was performed on site to confirm the achievement of required bearing capacity at the specified settlement. Despite the fact that this technique is widely used to improve sabkha soils, there are no studies focusing on the behavior of stone columns in such problematic soils. Sabkha soils are known for its high compressibility, low strength and water sensitivity due to loss of salt cementation upon flooding during installation of stone columns. Numerical modeling of plate load test assist to understand complicated behavior of sabkha – stone column interaction. This paper presents a three-dimensional Finite element model, using PLAXIS 3D software, to simulate vertical plate load tests on a stone column installed in sabkha. The predicted settlement values are in reasonable agreement with the field measure values and the field load - settlement curve can be predicted with good accuracy.

Keywords: soil improvement, stone column, sabkha, PLAXIS 3D

Procedia PDF Downloads 371
11179 Modeling of Microelectromechanical Systems Diaphragm Based Acoustic Sensor

Authors: Vasudha Hegde, Narendra Chaulagain, H. M. Ravikumar, Sonu Mishra, Siva Yellampalli

Abstract:

Acoustic sensors are extensively used in recent days not only for sensing and condition monitoring applications but also for small scale energy harvesting applications to power wireless sensor networks (WSN) due to their inherent advantages. The natural frequency of the structure plays a major role in energy harvesting applications since the sensor key element has to operate at resonant frequency. In this paper, circular diaphragm based MEMS acoustic sensor is modelled by Lumped Element Model (LEM) and the natural frequency is compared with the simulated model using Finite Element Method (FEM) tool COMSOL Multiphysics. The sensor has the circular diaphragm of 3000 µm radius and thickness of 30 µm to withstand the high SPL (Sound Pressure Level) and also to withstand the various fabrication steps. A Piezoelectric ZnO layer of thickness of 1 µm sandwiched between two aluminium electrodes of thickness 0.5 µm and is coated on the diaphragm. Further, a channel with radius 3000 µm radius and length 270 µm is connected at the bottom of the diaphragm. The natural frequency of the structure by LEM method is approximately 16.6 kHz which is closely matching with that of simulated structure with suitable approximations.

Keywords: acoustic sensor, diaphragm based, lumped element modeling (LEM), natural frequency, piezoelectric

Procedia PDF Downloads 416
11178 Investigations on the Seismic Performance of Hot-Finished Hollow Steel Sections

Authors: Paola Pannuzzo, Tak-Ming Chan

Abstract:

In seismic applications, hollow steel sections show, beyond undeniable esthetical appeal, promising structural advantages since, unlike open section counterparts, they are not susceptible to weak-axis and lateral-torsional buckling. In particular, hot-finished hollow steel sections have homogeneous material properties and favorable ductility but have been underutilized for cyclic bending. The main reason is that the parameters affecting their hysteretic behaviors are not yet well understood and, consequently, are not well exploited in existing codes of practice. Therefore, experimental investigations have been conducted on a wide range of hot-finished rectangular hollow section beams with the aim to providing basic knowledge for evaluating their seismic performance. The section geometry (width-to-thickness and depth-to-thickness ratios) and the type of loading (monotonic and cyclic) have been chosen as the key parameters to investigate the cyclic effect on the rotational capacity and to highlight the differences between monotonic and cyclic load conditions. The test results provide information on the parameters that affect the cyclic performance of hot-finished hollow steel beams and can be used to assess the design provisions stipulated in the current seismic codes of practice.

Keywords: bending, cyclic test, finite element modeling, hollow sections, hot-finished sections

Procedia PDF Downloads 139
11177 Immediate and Long-Term Effect of the Sawdust Usage on Shear Strength of the Clayey Silt Soil

Authors: Dogan Cetin, Omar Hamdi Jasim

Abstract:

Using some additives is very common method to improve the soil properties such as shear strength, bearing capacity; and to reduce the settlement and lateral deformation. Soil reinforcement with natural materials is an attractive method to improve the soil properties because of their low cost. However, the studies conducted by using natural additive are very limited. This paper presents the results of an investigation on the immediate and long-term effects of the sawdust on the shear strength behavior of a clayey silt soil obtained in Arnavutkoy in Istanbul with sawdust. Firstly, compaction tests were conducted to be able to optimum moisture content for every percentage of sawdust. The samples were obtained from compacted soil at optimum moisture content. UU Triaxial Tests were conducted to evaluate the response of randomly distributed sawdust on the strength of low plasticity clayey silt soil. The specimens were tested with 1%, 2% and 3% content of sawdust. It was found that the undrained shear strength of clay soil with 1%, 2% and 3% sawdust were increased respectively 4.65%, 27.9% and 39.5% higher than the soil without additive. At 5%, shear strength of clay soil decreased by 3.8%. After 90 days cure period, the shear strength of the soil with 1%, 2%, 3% and %5 increased respectively 251%, 302%, 260% and 153%. It can be said that the effect of the sawdust usage has a remarkable effect on the undrained shear strength of the soil. Besides the increasing undrained shear strength, it was also found that the sawdust decreases the liquid limit, plastic limit and plasticity index by 5.5%, 2.9 and 10.9% respectively.

Keywords: compaction test, sawdust, shear strength, UU Triaxial Test

Procedia PDF Downloads 335
11176 Investigating University Language Teacher’s Perception of Their Identities in the Algerian Multilingual Context

Authors: Yousra Drissi

Abstract:

This research explores language teacher identity in a multilingual context where both teachers and students come from different linguistic backgrounds. It seeks to understand how teachers perceive themselves as language teachers in this context in relation to different influencing factors, both internal and external. This study is being conducted due to the importance of language teacher identity (LTI) in the university context, which is being neglected in the present literature (in an attempt to address the gap in the present literature). The broader aim of this study is to bring attention to language teacher identity along with the different influencing elements which can either promote or hinder its development. In this research, we are using the sociocultural theory and post-structural theory. This research uses the mixed methods approach to collect and analyse relevant data. A structured survey was distributed to language teachers from different universities around Algeria, followed by in-depth interviews. Results are supposed to show the different points in self-perception that these teachers share or differ in. they will also help us identify the different internal and external factors that can be of influence. However, the results of this research can be used by institutions as well as decision-makers to better understand university teachers and help them improve their teaching practices by empowering their language teacher identity, starting from teacher education programs to continuous teacher development programs.

Keywords: identity, language teacher identity, multilingualism, university teacher

Procedia PDF Downloads 62
11175 The 5S Responses of Obese Teenagers in Verbal Bullying

Authors: Alpha Bolinao, Francine Rose De Castro, Jessie Kate Lumba, Raztine Mae Paeste, Hannah Grace Tosio

Abstract:

The present study aimed to know the role of verbal bullying in the lives of obese teenagers exposed to it. The study employed a qualitative design specifically the phenomenological approach that focuses on the obese teenagers’ verbal bullying experiences. The study also used the social constructivism approach wherein it described the obese teenagers’ verbal bullying experiences as they interact with the social world. Through purposive and referral sampling technique, the researchers were able to choose twelve (12) respondents from different schools around the City of Manila, enrolled in the School Year 2015-2016, ages 16-21 years old, has experienced verbal bullying for the last ten (10) years and with the Body Mass Index (BMI) of equal to or greater than 30. Upon the consent of the respondents, ethical considerations were ensured. In-depth one (1) hour interviews were guided by the researchers’ aide memoir. The recorded interviews were transcribed into a field text and the responses were thoroughly analyzed through Thematic Analysis and Kelly’s Repertory Grid. It was found that the role of verbal bullying in the lives of obese teenagers exposed to it is a process and is best described through a syringe, or the 5S Responses of Obese Teenagers in Bullying, with five conceptual themes which also signify the experiences and the process that obese teenagers have gone through after experiencing verbal bullying. The themes conceptualized were: Suffering, self-doubt, suppression, self-acceptance and sanguineness. This paper may serve as a basis for a counseling program to help the obese teenagers cope with their bullying experiences.

Keywords: obesity, obese teenagers, bullying, experiences

Procedia PDF Downloads 346
11174 Political Implications of Shared Authority: Efforts to Retain Indigenous Sovereignty Within the Modern Global Power Structures

Authors: David E. Wilkins

Abstract:

While colonialism in its many guises remains the dominant theoretical framework within which to analyze Indigenous relations with state powers, this paper takes a deep look at the treaty, policy, and statutory efforts initiated by both Indigenous peoples and colonial, and later federal representatives within what is now the United States that were intended to create a Native constituent state of the union. While these plans ultimately failed, they are indicative of the reality that, throughout much of the shared Indigenous and American history, there were both Native and non-Native political elites who were keen on the idea of incorporating Indigenous peoples into the burgeoning body politic. This paper explores why these plans arose, who the architects were that devised them, which Native peoples were involved in, and why they ultimately failed to be enacted. Although governmental relations within the US remain fraught and unpredictable, Native nations continue to wield a form of sovereignty that, while truncated, has maintained their distinctive political statuses. There is much to be learned from the exploration of these mixed successes and failures. There are other examples across the globe whereby Indigenous peoples like the Saami and the Māori have secured greater clarity of their retained autonomy through structural political arrangements with the states that have laid claim to their territories while the Ainu struggle to regain their status.

Keywords: indigenous, sovereignty, diplomacy, intergovernmental

Procedia PDF Downloads 54
11173 Discovering Groundbreaking Geopolymer-Based Materials with Versatile Designs, Ideal for the Construction and Infrastructure Industry

Authors: Maryam Kiani

Abstract:

Geopolymer has gained significant prominence worldwide and is now widely regarded as a potential alternative to conventional Portland cement. Nevertheless, for it to be widely accepted and incorporated into national and international standards, it is crucial to establish precise definitions and dependable mix design methodologies for geopolymer materials. The lack of a common definition and methodology has led to inconsistencies and perplexity across various areas of research. Addressing this concern is imperative for several reasons. To overcome the existing inconsistencies and confusion, concerted efforts should be made to establish clear definitions and robust mix design methodologies for geopolymer materials. This can be achieved through collaborative research, knowledge sharing, and engagement with industry experts. By doing so, we can pave the way for the widespread acceptance and utilization of geopolymer materials, revolutionizing the construction and infrastructure industry in a sustainable and environmentally friendly manner. The primary goal of this article is to offer clear explanations regarding the different meanings of geopolymer and the various methodologies used in geopolymer processes. Its main aim is to improve comprehension of both unary and binary geopolymer systems. By thoroughly exploring existing research, this article strives to illuminate the diverse methods and techniques utilized in the exciting field of geopolymer science.

Keywords: geopolymer, nanomaterials, structural materials, mechanical properties

Procedia PDF Downloads 96
11172 The Developmental Model of Self-Efficacy Emotional Intelligence and Social Maturity among High School Boys and Girls

Authors: Shrikant Chavan, Vikas Minchekar

Abstract:

The present study examined the self-efficacy, emotional intelligence and social maturity of High school boys and girls. Furthermore, study aimed at to foster the self-efficacy, emotional intelligence and social maturity of high school students. The study was conducted on 100 high school students, out of which 50 boys and 50 girls were selected through simple random sampling method from the Sangli city of Maharashtra state, India. The age range of the sample is 14 to 16 years. Self-efficacy scale developed by Jesusalem Schwarzer, Emotional intelligence scale developed by Hyde, Pethe and Dhar and social maturity scale developed by Rao were administered to the sample. Data was analyzed using mean, SD and ‘t’ test further Karl Pearson’s product moment, correlation of coefficient was used to know the correlation between emotional intelligence, self-efficacy, and social maturity. Results revealed that boys and girls did not differ significantly in their self-efficacy and social maturity. Further, the analysis revealed that girls are having high emotional intelligence compared to boys, which is significant at 0.01 level. It is also found that there is a significant and positive correlation between self-efficacy and emotional intelligence, self-efficacy and social maturity and emotional intelligence and social maturity. Some developmental strategies to strengthen the self-efficacy, emotional intelligence and social maturity of high school students are suggested in the study.

Keywords: self-efficacy, emotional intelligence, social maturity, developmental model and high school students

Procedia PDF Downloads 455
11171 Instructional Coaches' Perceptions of Professional Development: An Exploration of the School-Based Support Program

Authors: Youmen Chaaban, Abdallah Abu-Tineh

Abstract:

This article examines the development of a professional development (PD) model for educator growth and learning that is embedded into the school context. The School based Support Program (SBSP), designed for the Qatari context, targets the practices, knowledge, and skills of both school leadership and teachers in an attempt to improve students’ learning outcomes. Key aspects of the model include the development of learning communities among teachers, strong leadership that supports school improvement activities, and the use of research-based PD to improve teacher practices and student achievement. This paper further presents the results of a qualitative study examining the perceptions of nineteen instructional coaches about the strengths of the PD program, the challenges they face in their day-to-day implementation of the program, and their suggestions for the betterment of the program’s implementation and outcomes. Data were collected from the instructional coaches through open-ended surveys followed by focus group interviews. The instructional coaches reported several strengths, which were compatible with the literature on effective PD. However, the challenges they faced were deeply rooted within the structure of the program, in addition to external factors operating at the school and Ministry of Education levels. Thus, a general consensus on the way the program should ultimately develop was reached.

Keywords: situated professional development, school reform, instructional coach, school based support program

Procedia PDF Downloads 338
11170 Response of Insulin Resistance Indicators to Aerobic Exercise at Different Intensities in Obese College Students

Authors: Long-Shan Wu, Ming-Chen Ko, Chien-Chang Ho, Po-Fu Lee, Li-Yun Chen, Ching-Yu Tseng

Abstract:

The purpose of this study was to determine whether progressive aerobic exercise intensity effects the changes in insulin resistance indicators among obese college students in Taiwan. Forty-eight obese subjects [body mass index (BMI) ≧ 27 kg/m2, aged 18-26 years old] were randomized into four equal groups (n = 12): light-intensity training group (LITG): 40-50% of their heart rate reserve (HRR); middle-intensity training group (MITG): 50-70% of their HRR; high-intensity training group (HITG): 70-80% of their HRR, and control group (CG). The aerobic exercise training program was performed 60 minutes per day on a treadmill three days/week in a training period of 12 weeks. All subjects’ anthropometric data, blood biochemical parameters, and health-related physical fitness components were measured at baseline and after 12 weeks. At baseline, all insulin resistance indicators did not differ significantly among the four groups (p > 0.05). After 12-week exercise intervention, the HITG had significantly more changes in insulin level than the MITG, LITG, and CG. Our findings suggested that a short-term aerobic exercise program can play an important role in improving insulin resistance indicators; either middle-intensity training significantly increases the insulin level, but the high-intensity exercise training program effectively improves obese college students’ insulin resistance.

Keywords: aerobic training, exercise intensity, insulin resistance, obesity

Procedia PDF Downloads 284
11169 How Group Education Impacts Female Factory Workers’ Behavior and Readiness to Receive Mammography and Pap Smears

Authors: Memnun Seven, Mine Bahar, Aygül Akyüz, Hatice Erdoğan

Abstract:

Background: The workplace has been deemed a suitable location for educating many women at once about cancer screening. Objective: To determine how group education about early diagnostic methods for breast and cervical cancer affects women’s behavior and readiness to receive mammography and Pap smears. Methods: This semi-interventional study was conducted at a textile factory in Istanbul, Turkey. Female workers (n = 125) were included in the study. A participant identification form and knowledge evaluation form developed for this study, along with the trans-theoretical model, were used to collect data. A 45-min interactive group education was given to the participants. Results: Upon contacting participants 3 months after group education, 15.4% (n = 11) stated that they had since received a mammogram and 9.8% (n = 7) a Pap smear. As suggested by the trans-theoretical model, group education increased participants’ readiness to receive cancer screening, along with their knowledge of breast and cervical cancer. Conclusions: Group education positively impacted women’s knowledge of cancer and their readiness to receive mammography and Pap smears. Group education can therefore potentially create awareness of cancer screening tests among women and improve their readiness to receive such tests.

Keywords: cancer screening, educational intervention, participation, women

Procedia PDF Downloads 317
11168 Gender Diversity in Early Years Education: An Exploratory Study Applied to Preschool Curriculum System in Romania

Authors: Emilia-Gheorghina Negru

Abstract:

As an EU goal, gender diversity in early year’s education aims and promotes equality of chances and respect for gender peculiarities of the pupils which are involved in formal educational activities. Early year’s education, as the first step to the Curriculum, prints to teachers the need to identify the role of the gender dimension on this stage, depending on the age level of preschool children through effective, complex, innovative and analytical awareness of gender diversity teaching and management strategies. Through gender educational work we, as teachers, will examine the effectiveness of the PATHS (Promoting Alternative Thinking Strategies) curriculum the gender development of school-aged children. PATHS and a school-based preventive intervention model are necessary to be designed to improve children's ability to discuss and understand equality and gender concepts. Our teachers must create an intervention model and provide PATHS lessons during the school year. Results of the intervention will be effective for both low- and high-risk children in improving their range of math’s skills for girls and vocabulary, fluency and emotional part for boys in discussing gender experiences, their efficacy beliefs regarding the management of equality in gender area, and their developmental understanding of some aspects of gender.

Keywords: gender, gender differences, gender equality, gender role, gender stereotypes

Procedia PDF Downloads 357
11167 Federalism and Foreign Affairs: The International Relations of Mexican Sub-State Governments

Authors: Jorge A. Schiavon

Abstract:

This article analyzes the international relations of sub-State governments (IRSSG) in Mexico. It aims to answer five questions: 1) What explains the recent and dramatic increase in their international activities? 2) What is the impact of federalism on the foreign affairs of the federal units? 3) What are the levels or degrees of IRSSG and how have they changed over the last years? 4) How do Mexican federal units institutionalize their international activities? 5) What are the perceptions and capacities of the federal units in their internationalization process? The first section argues that the growth in the IRSSG is generated by growing interdependence and globalization in the international system, and democratization, decentralization and structural reform in the national arena. The second section sustains that the renewed Mexican federalism has generated the incentives for SSG to participate more intensively in international affairs. The third section defends that there is a wide variation in their degree of international participation, which is measured in three moments in time (2004 2009 and 2014), and explains how this activity has changed in the last decade. The fourth section studies the institutionalization of the IRSSG in Mexico through the analysis of Inter-Institutional Agreements (IIA). Finally, the last section concentrates in explaining the perceptions and capacities of Mexican sub-State governments to conduct international relations.

Keywords: federalism, foreign policy, international relations of sub-state governments, paradiplomacy, Mexico

Procedia PDF Downloads 134
11166 Field Tests and Numerical Simulation of Tunis Soft Soil Improvement Using Prefabricated Vertical Drains

Authors: Marwa Ben Khalifa, Zeineb Ben Salem, Wissem Frikha

Abstract:

This paper presents a case study of “Radès la Goulette” bridge project using the technique of prefabricated vertical drains (PVD) associated with step by step construction of preloading embankments with averaged height of about 6 m. These embankments are founded on a highly compressible layer of Tunis soft soil. The construction steps included extensive soil instrumentation such as piezometers and settlement plates for monitoring the dissipation of excess pore water pressures and settlement during the consolidation of Tunis soft soil. An axisymmetric numerical model using the 2D finite difference code FLAC was developed and calibrated using laboratory tests to predict the soil behavior and consolidation settlements. The constitutive model impact for simulating the soft soil behavior is investigated. The results of analyses show that numerical analysis provided satisfactory predictions for the field performance during the construction of Radès la Goulette embankment. The obtained results show the effectiveness of PVD in the acceleration of the consolidation time. A comparison of numerical results with theoretical analysis was presented.

Keywords: tunis soft soil, radès bridge project, prefabricated vertical drains, FLAC, acceleration of consolidation

Procedia PDF Downloads 114
11165 Quantification of the Erosion Effect on Small Caliber Guns: Experimental and Numerical Analysis

Authors: Dhouibi Mohamed, Stirbu Bogdan, Chabotier André, Pirlot Marc

Abstract:

Effects of erosion and wear on the performance of small caliber guns have been analyzed throughout numerical and experimental studies. Mainly, qualitative observations were performed. Correlations between the volume change of the chamber and the maximum pressure are limited. This paper focuses on the development of a numerical model to predict the maximum pressure evolution when the interior shape of the chamber changes in the different weapon’s life phases. To fulfill this goal, an experimental campaign, followed by a numerical simulation study, is carried out. Two test barrels, « 5.56x45mm NATO » and « 7.62x51mm NATO,» are considered. First, a Coordinate Measuring Machine (CMM) with a contact scanning probe is used to measure the interior profile of the barrels after each 300-shots cycle until their worn out. Simultaneously, the EPVAT (Electronic Pressure Velocity and Action Time) method with a special WEIBEL radar are used to measure: (i) the chamber pressure, (ii) the action time, (iii) and the bullet velocity in each barrel. Second, a numerical simulation study is carried out. Thus, a coupled interior ballistic model is developed using the dynamic finite element program LS-DYNA. In this work, two different models are elaborated: (i) coupled Eularien Lagrangian method using fluid-structure interaction (FSI) techniques and a coupled thermo-mechanical finite element using a lumped parameter model (LPM) as a subroutine. Those numerical models are validated and checked through three experimental results, such as (i) the muzzle velocity, (ii) the chamber pressure, and (iii) the surface morphology of fired projectiles. Results show a good agreement between experiments and numerical simulations. Next, a comparison between the two models is conducted. The projectile motions, the dynamic engraving resistances and the maximum pressures are compared and analyzed. Finally, using this obtained database, a statistical correlation between the muzzle velocity, the maximum pressure and the chamber volume is established.

Keywords: engraving process, finite element analysis, gun barrel erosion, interior ballistics, statistical correlation

Procedia PDF Downloads 195
11164 Supporting Students with Autism Spectrum Disorder: A Model of Partnership and Capacity Building in Hong Kong

Authors: Irene T. Ho

Abstract:

Students with Autism Spectrum Disorder (ASD) studying in mainstream schools often face difficulties adjusting to school life and teachers often find it challenging to meet the needs of these students. The Hong Kong Jockey Club Autism Support Network (JC A-Connect) is an initiative launched in 2015 to enhance support for students with ASD as well as their families and schools. The School Support Programme of the Project aims at building the capacity of schools to provide quality education for these students. The present report provides a summary of the main features of the support model and the related evaluation results. The school support model was conceptualized in response to four observed needs: (1) inadequate teacher expertise in dealing with the related challenges, (2) the need to promote evidence-based practices in schools, (3) less than satisfactory home-school collaboration and whole-school participation, and (4) lack of concerted effort by different parties involved in providing support to schools. The resulting model had partnership and capacity building as two guiding tenets for the School Support Programme. There were two levels of partnership promoted in the project. At the programme support level, a platform that enables effective collaboration among major stakeholders was established, including the funding body that provides the necessary resources, the Education Bureau that helps to engage schools, university experts who provide professional leadership and research support, as well as non-governmental organization (NGO) professionals who provide services to the schools. At the programme implementation level, tripartite collaboration among teachers, parents and professionals was emphasized. This notion of partnership permeated efforts at capacity building targeting students with ASD, school personnel, parents and peers. During 2015 to 2018, school-based programmes were implemented in over 400 primary and secondary schools with the following features: (1) spiral Tier 2 (group) training for students with ASD to enhance their adaptive skills, led by professionals but with strong teacher involvement to promote transfer of knowledge and skills; (2) supplementary programmes for teachers, parents and peers to enhance their capability to support students with ASD; and (3) efforts at promoting continuing or transfer of learning, on the part of both students and teachers, to Tier 1 (classroom practice) and Tier 3 (individual training) contexts. Over 5,000 students participated in the Programme, representing about 50% of students diagnosed with ASD in mainstream public sector schools in Hong Kong. Results showed that the Programme was effective in helping students improve to various extents at three levels: achievement of specific training goals, improvement in adaptive skills in school, and change in ASD symptoms. The sense of competence of teachers and parents in dealing with ASD-related issues, measured by self-report rating scales, was also significantly enhanced. Moreover, effects on enhancing the school system to provide support for students with ASD, assessed according to indicators of inclusive education, were seen. The process and results of this Programme illustrate how obstacles to inclusive education for students with ASD could be overcome by strengthening the necessary partnerships and building the required capabilities of all parties concerned.

Keywords: autism, school support, skills training, teacher development, three-tier model

Procedia PDF Downloads 83
11163 Exploring Equity and Inclusion in the Context of Distance Education Using a Social Location Perspective

Authors: Boadi Agyekum

Abstract:

In this study, a social location perspective is used to explore the challenges of creating opportunities that will foster lifelong education, inclusion, and equity for residents of rural communities in Ghana. The differentiated experiences of rural adults are under-researched and often unacknowledged in lifelong education literature and distance education policy. There is a need to examine carefully the structural inequalities that create disadvantages for residents of rural communities and women in pursuing distance education in designated cities in Ghana. The paper uses in-depth interviews to explore participants’ experiences of learning at a distance and to scrutinise the narratives of lifelong education. The paper reflects on the implications of the framework employed for educators and social justice in lifelong education. It further recommends the need to provide IT laboratories and fully online programs that would require stable and regular internet and access to ICT equipment for potential learning in rural communities. The social location approach presented a number of axes of diversity as comparatively more important than others; these included gender, age, education, work commitment, geography, and degree of social connectedness. This can inform lifelong education policy and programs to sustain quality education.

Keywords: equity, distance education, lifelong learning, social location, intersectionality, rural communities

Procedia PDF Downloads 74
11162 Characterizing the Diffused Double Layer Properties of Clay Minerals

Authors: N. Saranya

Abstract:

The difference in characteristic behavior of clay minerals for different electrolyte solution is dictated by the corresponding variation occurring at its diffused double layer thickness (DDL). The diffused double layer of clay mineral has two distinct regions; the inner region is termed as ‘Stern layer’ where ions are strongly attached to the clay surface. In the outer region, the ions are not strongly bonded with the clay surface, and this region is termed as ‘diffuse layer’. Within the diffuse layer, there is a plane that forms a boundary between the moving ions and the ions attached to the clay surface, which is termed as slipping or shear plane, and the potential of this plane is defined as zeta potential (ζ). Therefore, the variation in diffused double layer properties of clay mineral for different electrolyte solutions can be modeled if the corresponding variation in surface charge, surface potential, and zeta potential are computed. In view of this, the present study has attempted to characterize the diffused double layer properties of three different clay minerals interacting with different pore fluids by measuring the corresponding variation in surface charge, surface potential, and zeta potential. Further, the obtained variation in the diffused double layer property is compared with the Gouy-Chapman model, which is the widely accepted theoretical model to characterize the diffused double layer properties of clay minerals.

Keywords: DDL, surface charge, surface potential, zeta potential

Procedia PDF Downloads 154
11161 Selective Extraction of Couple Nickel(II) / Cobalt(II) by a Series of Schiff Bases in Sulfate Medium, in the Chloroforme-Water

Authors: N. Belhadj, M. Hadj Youcef, T. Benabdallah, Belbachir Ibtissem, N. Boceiri

Abstract:

This work deals with the synthesis, the structural elucidation and the exploration the extracting properties of a series of ortho-hydroxy Schiff base in sulfate medium. After the synthesis and characterization of their structures, the study of their behavior in solution was carried out by pH-metric titration in different media homogeneous and heterogeneous solution. This allowed to explore and to quantify in each of these media, some of their properties in solution such as, their acid-base behavior (determination and comparison of pKa), their distribution powers (determination and comparison of logKd), and their thermodynamic constants (determining ∆H°, ΔS° and ∆G°moy) by optimizing both the temperature and ionic strength. Study of the extraction of nickel (II) and cobalt(II) separately was undertaken in the aqueous-organic system, chloroform-water. Different extraction parameters have been thus optimized such, the pH, the concentration of extractant and the ionic strength, and the extraction constants established in each case. The extracted metal complexes have been isolated and their spatial configurations elucidated. The selective extraction of the couple cobalt (II)/nickel (II) was finally performed by our series of Schiff base in the chloroforme/water.

Keywords: selective extraction, Schiff base, distribution, cobalt(II), nickel(II)

Procedia PDF Downloads 450
11160 Approach for Demonstrating Reliability Targets for Rail Transport during Low Mileage Accumulation in the Field: Methodology and Case Study

Authors: Nipun Manirajan, Heeralal Gargama, Sushil Guhe, Manoj Prabhakaran

Abstract:

In railway industry, train sets are designed based on contractual requirements (mission profile), where reliability targets are measured in terms of mean distance between failures (MDBF). However, during the beginning of revenue services, trains do not achieve the designed mission profile distance (mileage) within the timeframe due to infrastructure constraints, scarcity of commuters or other operational challenges thereby not respecting the original design inputs. Since trains do not run sufficiently and do not achieve the designed mileage within the specified time, car builder has a risk of not achieving the contractual MDBF target. This paper proposes a constant failure rate based model to deal with the situations where mileage accumulation is not a part of the design mission profile. The model provides appropriate MDBF target to be demonstrated based on actual accumulated mileage. A case study of rolling stock running in the field is undertaken to analyze the failure data and MDBF target demonstration during low mileage accumulation. The results of case study prove that with the proposed method, reliability targets are achieved under low mileage accumulation.

Keywords: mean distance between failures, mileage-based reliability, reliability target appropriations, rolling stock reliability

Procedia PDF Downloads 253
11159 Investigation of Heat Conduction through Particulate Filled Polymer Composite

Authors: Alok Agrawal, Alok Satapathy

Abstract:

In this paper, an attempt to determine the effective thermal conductivity (keff) of particulate filled polymer composites using finite element method (FEM) a powerful computational technique is made. A commercially available finite element package ANSYS is used for this numerical analysis. Three-dimensional spheres-in-cube lattice array models are constructed to simulate the microstructures of micro-sized particulate filled polymer composites with filler content ranging from 2.35 to 26.8 vol %. Based on the temperature profiles across the composite body, the keff of each composition is estimated theoretically by FEM. Composites with similar filler contents are than fabricated using compression molding technique by reinforcing micro-sized aluminium oxide (Al2O3) in polypropylene (PP) resin. Thermal conductivities of these composite samples are measured according to the ASTM standard E-1530 by using the Unitherm™ Model 2022 tester, which operates on the double guarded heat flow principle. The experimentally measured conductivity values are compared with the numerical values and also with those obtained from existing empirical models. This comparison reveals that the FEM simulated values are found to be in reasonable good agreement with the experimental data. Values obtained from the theoretical model proposed by the authors are also found to be in even closer approximation with the measured values within percolation limit. Further, this study shows that there is gradual enhancement in the conductivity of PP resin with increase in filler percentage and thereby its heat conduction capability is improved. It is noticed that with addition of 26.8 vol % of filler, the keff of composite increases to around 6.3 times that of neat PP. This study validates the proposed model for PP-Al2O3 composite system and proves that finite element analysis can be an excellent methodology for such investigations. With such improved heat conduction ability, these composites can find potential applications in micro-electronics, printed circuit boards, encapsulations etc.

Keywords: analytical modelling, effective thermal conductivity, finite element method, polymer matrix composite

Procedia PDF Downloads 308
11158 Web-Based Cognitive Writing Instruction (WeCWI): A Hybrid e-Framework for Instructional Design

Authors: Boon Yih Mah

Abstract:

Web-based Cognitive Writing Instruction (WeCWI) is a hybrid e-framework that consolidates instructional design and language development towards the development of a web-based instruction (WBI). WeCWI divides instructional design into macro and micro perspectives. In macro perspective, a 21st century educator is encouraged to disseminate knowledge and share ideas with in-class and global learners. By leveraging the virtue of technology, WeCWI aims to transform the educator into an aggregator, curator, publisher, social networker and finally, a web-based instructor. Since the most notable contribution of integrating technology is being a tool of teaching as well as a stimulus for learning, WeCWI focuses on the use of contemporary web tools based on the multiple roles played by the 21st century educator. The micro perspective draws attention to the pedagogical approaches focussing on three main aspects: reading, discussion, and writing. With the effective use of pedagogical approaches, technology adds new dimensions and expands the bounds of learning capacity. Lastly, WeCWI also imparts the fundamental theoretical concepts for web-based instructors’ awareness such as interactionism, e-learning interactional-based model, computer-mediated communication (CMC), cognitive theories, and learning style model.

Keywords: web-based cognitive writing instruction, WeCWI, instructional design, e-framework, web-based instructor

Procedia PDF Downloads 427
11157 Change Detection of Vegetative Areas Using Land Use Land Cover of Desertification Vulnerable Areas in Nigeria

Authors: T. Garba, Y. Y. Sabo A. Babanyara, K. G. Ilellah, A. K. Mutari

Abstract:

This study used the Normalized Difference Vegetation Index (NDVI) and maps compiled from the classification of Landsat TM and Landsat ETM images of 1986 and 1999 respectively and Nigeria sat 1 images of 2007 to quantify changes in land use and land cover in selected areas of Nigeria covering 143,609 hectares that are threatened by the encroaching Sahara desert. The results of this investigation revealed a decrease in natural vegetation over the three time slices (1986, 1999 and 2007) which was characterised by an increase in high positive pixel values from 0.04 in 1986 to 0.22 and 0.32 in 1999 and 2007 respectively and, a decrease in natural vegetation from 74,411.60ha in 1986 to 28,591.93ha and 21,819.19ha in 1999 and 2007 respectively. The same results also revealed a periodic trend in which there was progressive increase in the cultivated area from 60,191.87ha in 1986 to 104,376.07ha in 1999 and a terminal decrease to 88,868.31ha in 2007. These findings point to expansion of vegetated and cultivated areas in in the initial period between 1988 and 1996 and reversal of these increases in the terminal period between 1988 and 1996. The study also revealed progressive expansion of built-up areas from 1, 681.68ha in 1986 to 2,661.82ha in 1999 and to 3,765.35ha in 2007. These results argue for the urgent need to protect and conserve the depleting natural vegetation by adopting sustainable human resource use practices i.e. intensive farming in order to minimize persistent depletion of natural vegetation.

Keywords: changes, classification, desertification, vegetation changes

Procedia PDF Downloads 373
11156 Impact of Drought on Agriculture in the Upper Middle Gangetic Plain in India

Authors: Reshmita Nath

Abstract:

In this study, we investigate the spatiotemporal characteristics of drought in India and its impact on agriculture during the summer season (April to September). For our analysis, we have used Standardized Precipitation Evapotranspiration Index (SPEI) datasets between 1982 and 2012 at six-month timescale. Based on the criteria SPEI<-1 we obtain the vulnerability map and have found that the Humid subtropical Upper Middle Gangetic Plain (UMGP) region is highly drought prone with an occurrence frequency of 40-45%. This UMGP region contributes at least 18-20% of India’s annual cereal production. Not only the probability, but the region becomes more and more drought-prone in the recent decades. Moreover, the cereal production in the UMGP has experienced a gradual declining trend from 2000 onwards and this feature is consistent with the increase in drought affected areas from 20-25% to 50-60%, before and after 2000, respectively. The higher correlation coefficient (-0.69) between the changes in cereal production and drought affected areas confirms that at least 50% of the agricultural (cereal) losses is associated with drought. While analyzing the individual impact of precipitation and surface temperature anomalies on SPEI (6), we have found that in the UMGP region surface temperature plays the primary role in lowering of SPEI. The linkage is further confirmed by the correlation analysis between the SPEI (6) and surface temperature rise, which exhibits strong negative values in the UMGP region. Higher temperature might have caused more evaporation and drying, which therefore increases the area affected by drought in the recent decade.

Keywords: drought, agriculture, SPEI, Indo-Gangetic plain

Procedia PDF Downloads 246
11155 In-silico Analysis of Plumbagin against Cancer Receptors

Authors: Arpita Roy, Navneeta Bharadvaja

Abstract:

Cancer is an uncontrolled growth of abnormal cells in the body. It is one of the most serious diseases on which extensive research work has been going on all over the world. Structure-based drug designing is a computational approach which helps in the identification of potential leads that can be used for the development of a drug. Plumbagin is a naphthoquinone derivative from Plumbago zeylanica roots and belongs to one of the largest and diverse groups of plant metabolites. Anticancer and antiproliferative activities of plumbagin have been observed in animal models as well as in cell cultures. Plumbagin shows inhibitory effects on multiple cancer-signaling proteins; however, the binding mode and the molecular interactions have not yet been elucidated for most of these protein targets. In this investigation, an attempt to provide structural insights into the binding mode of plumbagin against four cancer receptors using molecular docking was performed. Plumbagin showed minimal energy against targeted cancer receptors, therefore suggested its stability and potential towards different cancers. The least binding energies of plumbagin with COX-2, TACE, and CDK6 are -5.39, -4.93, -and 4.81 kcal/mol, respectively. Comparison studies of plumbagin with different receptors showed that it is a promising compound for cancer treatment. It was also found that plumbagin obeys the Lipinski’s Rule of 5 and computed ADMET properties which showed drug likeliness and improved bioavailability. Since plumbagin is from a natural source, it has reduced side effects, and these results would be useful for cancer treatment.

Keywords: cancer, receptor, plumbagin, docking

Procedia PDF Downloads 131
11154 Investigating Salience Theory’s Implications for Real-Life Decision Making: An Experimental Test for Whether the Allais Paradox Exists under Subjective Uncertainty

Authors: Christoph Ostermair

Abstract:

We deal with the effect of correlation between prospects on human decision making under uncertainty as proposed by the comparatively new and promising model of “salience theory of choice under risk”. In this regard, we show that the theory entails the prediction that the inconsistency of choices, known as the Allais paradox, should not be an issue in the context of “real-life decision making”, which typically corresponds to situations of subjective uncertainty. The Allais paradox, probably the best-known anomaly regarding expected utility theory, would then essentially have no practical relevance. If, however, empiricism contradicts this prediction, salience theory might suffer a serious setback. Explanations of the model for variable human choice behavior are mostly the result of a particular mechanism that does not come to play under perfect correlation. Hence, if it turns out that correlation between prospects – as typically found in real-world applications – does not influence human decision making in the expected way, this might to a large extent cost the theory its explanatory power. The empirical literature regarding the Allais paradox under subjective uncertainty is so far rather moderate. Beyond that, the results are hard to maintain as an argument, as the presentation formats commonly employed, supposably have generated so-called event-splitting effects, thereby distorting subjects’ choice behavior. In our own incentivized experimental study, we control for such effects by means of two different choice settings. We find significant event-splitting effects in both settings, thereby supporting the suspicion that the so far existing empirical results related to Allais paradoxes under subjective uncertainty may not be able to answer the question at hand. Nevertheless, we find that the basic tendency behind the Allais paradox, which is a particular switch of the preference relation due to a modified common consequence, shared by two prospects, is still existent both under an event-splitting and a coalesced presentation format. Yet, the modal choice pattern is in line with the prediction of salience theory. As a consequence, the effect of correlation, as proposed by the model, might - if anything - only weaken the systematic choice pattern behind the Allais paradox.

Keywords: Allais paradox, common consequence effect, models of decision making under risk and uncertainty, salience theory

Procedia PDF Downloads 180