Search results for: three phases
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1383

Search results for: three phases

873 U-Turn on the Bridge to Freedom: An Interaction Process Analysis of Task and Relational Messages in Totalistic Organization Exit Conversations on Online Discussion Boards

Authors: Nancy Di Tunnariello, Jenna L. Currie-Mueller

Abstract:

Totalistic organizations include organizations that operate by playing a prominent role in the life of its members through embedding values and practices. The Church of Scientology (CoS) is an example of a religious totalistic organization and has recently garnered attention because of the questionable treatment of members by those with authority, particularly when members try to leave the Church. The purpose of this study was to analyze exit communication and evaluate the task and relational messages discussed on online discussion boards for individuals with a previous or current connection to the totalistic CoS. Using organizational exit phases and interaction process analysis (IPA), researchers coded 30 boards consisting of 14,179 thought units from the Exscn.net website. Findings report all stages of exit were present, and post-exit surfaced most often. Posts indicated more tasks than relational messages, where individuals mainly provided orientation/information. After a discussion of the study’s contributions, limitations and directions for future research are explained.

Keywords: Bales' IPA, organizational exit, relational messages, scientology, task messages, totalistic organizations

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872 Strategy to Evaluate Health Risks of Short-Term Exposure of Air Pollution in Vulnerable Individuals

Authors: Sarah Nauwelaerts, Koen De Cremer, Alfred Bernard, Meredith Verlooy, Kristel Heremans, Natalia Bustos Sierra, Katrien Tersago, Tim Nawrot, Jordy Vercauteren, Christophe Stroobants, Sigrid C. J. De Keersmaecker, Nancy Roosens

Abstract:

Projected climate changes could lead to exacerbation of respiratory disorders associated with reduced air quality. Air pollution and climate changes influence each other through complex interactions. The poor air quality in urban and rural areas includes high levels of particulate matter (PM), ozone (O3) and nitrogen oxides (NOx), representing a major threat to public health and especially for the most vulnerable population strata, and especially young children. In this study, we aim to develop generic standardized policy supporting tools and methods that allow evaluating in future follow-up larger scale epidemiological studies the risks of the combined short-term effects of O3 and PM on the cardiorespiratory system of children. We will use non-invasive indicators of airway damage/inflammation and of genetic or epigenetic variations by using urine or saliva as alternative to blood samples. Therefore, a multi-phase field study will be organized in order to assess the sensitivity and applicability of these tests in large cohorts of children during episodes of air pollution. A first test phase was planned in March 2018, not yet taking into account ‘critical’ pollution periods. Working with non-invasive samples, choosing the right set-up for the field work and the volunteer selection were parameters to consider, as they significantly influence the feasibility of this type of study. During this test phase, the selection of the volunteers was done in collaboration with medical doctors from the Centre for Student Assistance (CLB), by choosing a class of pre-pubertal children of 9-11 years old in a primary school in Flemish Brabant, Belgium. A questionnaire, collecting information on the health and background of children and an informed consent document were drawn up for the parents as well as a simplified cartoon-version of this document for the children. A detailed study protocol was established, giving clear information on the study objectives, the recruitment, the sample types, the medical examinations to be performed, the strategy to ensure anonymity, and finally on the sample processing. Furthermore, the protocol describes how this field study will be conducted in relation with the prevision and monitoring of air pollutants for the future phases. Potential protein, genetic and epigenetic biomarkers reflecting the respiratory function and the levels of air pollution will be measured in the collected samples using unconventional technologies. The test phase results will be used to address the most important bottlenecks before proceeding to the following phases of the study where the combined effect of O3 and PM during pollution peaks will be examined. This feasibility study will allow identifying possible bottlenecks and providing missing scientific knowledge, necessary for the preparation, implementation and evaluation of federal policies/strategies, based on the most appropriate epidemiological studies on the health effects of air pollution. The research leading to these results has been funded by the Belgian Science Policy Office through contract No.: BR/165/PI/PMOLLUGENIX-V2.

Keywords: air pollution, biomarkers, children, field study, feasibility study, non-invasive

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871 A Neural Network Approach to Evaluate Supplier Efficiency in a Supply Chain

Authors: Kishore K. Pochampally

Abstract:

The success of a supply chain heavily relies on the efficiency of the suppliers involved. In this paper, we propose a neural network approach to evaluate the efficiency of a supplier, which is being considered for inclusion in a supply chain, using the available linguistic (fuzzy) data of suppliers that already exist in the supply chain. The approach is carried out in three phases, as follows: In phase one, we identify criteria for evaluation of the supplier of interest. Then, in phase two, we use performance measures of already existing suppliers to construct a neural network that gives weights (importance values) of criteria identified in phase one. Finally, in phase three, we calculate the overall rating of the supplier of interest. The following are the major findings of the research conducted for this paper: (i) linguistic (fuzzy) ratings of suppliers such as 'good', 'bad', etc., can be converted (defuzzified) to numerical ratings (1 – 10 scale) using fuzzy logic so that those ratings can be used for further quantitative analysis; (ii) it is possible to construct and train a multi-level neural network in order to determine the weights of the criteria that are used to evaluate a supplier; and (iii) Borda’s rule can be used to group the weighted ratings and calculate the overall efficiency of the supplier.

Keywords: fuzzy data, neural network, supplier, supply chain

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870 Enhancement of Hardness and Corrosion Resistance of Plasma Nitrided Low Alloy Tool Steel

Authors: Kalimi Trinadh, Corinne Nouveau, A. S. Khanna, Karanveer S. Aneja, K. Ram Mohan Rao

Abstract:

This study concerns improving the corrosion resistance of low alloy steel after plasma nitriding performed at variable time and temperature. Nitriding carried out in the temperature range of 450-550ᵒC for a various time period of 1-8 hrs. at 500Pa in a glow discharge plasma of H₂ and N₂ (80:20). The substrate was kept biased negatively at 250V. Following nitriding the X-ray diffraction studies shown that the phases formed were mainly γ′ (Fe₄N) and ε (Fe₂₋₃N). The ε (Fe₂₋₃N) phase found to be the dominating phase. Cross sections of the samples under scanning electron microscope point analyses revealed the presence of nitrogen in the surface region. For the assessment of corrosion resistance property, potentiodynamic polarization tests were performed in 3.5% NaCl solution. It has been shown that the plasma nitriding significantly improved the corrosion resistance when compared to the as-received steel. Furthermore, it has also been found that nitriding for 6h has more corrosion resistance than nitriding for the 8h duration. The hardness of the nitrided samples was measured by Vicker’s microhardness tester. The hardness of the nitrided steel was found to be improved much above the hardness of the steel in the as-received condition. It was found to be around two-fold of the initial hardness.

Keywords: corrosion, steel, plasma nitriding, X-ray diffraction

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869 Flocculation on the Treatment of Olive Oil Mill Wastewater: Pre-Treatment

Authors: G. Hodaifa, J. A. Páez, C. Agabo, E. Ramos, J. C. Gutiérrez, A. Rosal

Abstract:

Currently, the continuous two-phase decanter process used for olive oil production is the more internationally widespread. The wastewaters generated from this industry (OMW) is a real environmental problem because of its high organic load. Among proposed treatments for these wastewaters, the advanced oxidation technologies (Fenton process, ozone, photoFenton, etc.) are the most favourable. The direct application of these processes is somewhat expensive. Therefore, the application of a previous stage based on a flocculation-sedimentation operation is of high importance. In this research five commercial flocculants (three cationic, and two anionic) have been used to achieve the separation of phases (liquid clarified-sludge). For each flocculant, different concentrations (0-1000 mg/L) have been studied. In these experiments, sludge volume formed over time and the final water quality were determined. The final removal percentages of total phenols (11.3-25.1%), COD (5.6-20.4%), total carbon (2.3-26.5%), total organic carbon (1.50-23.8%), total nitrogen (1.45-24.8%), and turbidity (27.9-61.4%) were obtained. Also, the variation on the electric conductivity reduction percentage (1-8%) was determined. Finally, the best flocculants with highest removal percentages have been determined (QG2001 and Flocudex CS49).

Keywords: flocculants, flocculation, olive oil mill wastewater, water quality

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868 Survey of Corrosion and Scaling of Urban Drinking Water Supply Reservoirs (Case Study: Ilam City)

Authors: Ehsan Derikvand, Hamid Kaykha, Rooholah Mansoori Yekta, Taleb Javanmard, Mohsen Mehdi Zadeh

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Corrosion and scaling are one of the most complicated and costly problems of drinking water supply. Corrosion has adverse effect on general health and public acceptance of water source and drinking water supply costs. The present study aimed to determine the potentials of corrosion and scaling of potable water supply reservoirs of Ilam city in June 2013 and August 2014 by Langelier Index (LI) and Reynar. The results of experiments and calculations show that the mean index of LSI in the first and second sampling stages is 0.34, 0.2, respectively and the mean index RSI in the first and second stages of sampling is 7.15 and 7.22, respectively. Based on LSI index of reservoirs water in the first phase, none of stations are corrosive and only one station in the second sampling phase has corrosive tendency. According to RSI index, there is no corrosive tendency in two phases. Based on the results, the water of drinking water reservoirs in Ilam city has no corrosion tendency and the analyses and results of Langelier Index (LI) and Ryznar are in relatively good condition.

Keywords: corrosion, scaling, water reservoirs, langelier and ryznar indices, Ilam city

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867 Nickel Catalyst Promoted with Lanthanum- Alumina for Dry Reforming of Methane

Authors: Radia Imane Fertout

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In recent years, the reaction of dry reforming of methane (DRM) has attracted much attention due to its environmental and industrial importance. Various catalysts, including Ni-based catalysts, have been investigated for the DRM. Doping Ni/Al₂O₃ by lanthanum and alkaline earth element may strongly influence solid-state reaction and increases the stability of catalysts due to the lower density and high basicity of these oxides. The effect of SrO on the activity and stability of Ni/Al₂O₃-La₂O₃ in dry reforming of methane was investigated. These catalysts have been prepared with the impregnation method, calcined in air at 450 and 650°C, then characterized by BET surface area, X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques and tested in DRM. The results showed that the addition of strontium to Ni/Al2O₃-La₂O₃ decreased the specific surface area. XRD results revealed the presence of different phases of Al₂O₃, La(OH)₃, La₂O₂CO₃, and SrCO₃. The catalytic evaluation results showed that adding SrO increased the catalytic activity and stability, that explained by the strong basicity of strontium. SEM analysis after the reaction indicates the formation of carbon over the spent catalyst and that the addition of strontium stabilized the surface of the catalyst.

Keywords: dry reforming of methane, Ni/Al₂O₃-La₂O₃ catalyst, strontium, nickel

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866 Natural Frequency Analysis of a Porous Functionally Graded Shaft System

Authors: Natural Frequency Analysis of a Porous Functionally Graded Shaft System

Abstract:

The vibration characteristics of a functionally graded (FG) rotor model having porosities and micro-voids is investigated using three-dimensional finite element analysis. The FG shaft is mounted with a steel disc located at the midspan. The shaft ends are supported on isotropic bearings. The FG material is composed of a metallic (stainless-steel) and ceramic phase (zirconium oxide) as its constituent phases. The layer wise material property variation is governed by power law. Material property equations are developed for the porosity modelling. Python code is developed to assign the material properties to each layer including the effect of porosities. ANSYS commercial software is used to extract the natural frequencies and whirl frequencies for the FG shaft system. The obtained results show the influence of porosity volume fraction and power-law index, on the vibration characteristics of the ceramic-based FG shaft system.

Keywords: Finite element method, Functionally graded material, Porosity volume fraction, Power law

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865 Machine Learning Assisted Prediction of Sintered Density of Binary W(MO) Alloys

Authors: Hexiong Liu

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Powder metallurgy is the optimal method for the consolidation and preparation of W(Mo) alloys, which exhibit excellent application prospects at high temperatures. The properties of W(Mo) alloys are closely related to the sintered density. However, controlling the sintered density and porosity of these alloys is still challenging. In the past, the regulation methods mainly focused on time-consuming and costly trial-and-error experiments. In this study, the sintering data for more than a dozen W(Mo) alloys constituted a small-scale dataset, including both solid and liquid phases of sintering. Furthermore, simple descriptors were used to predict the sintered density of W(Mo) alloys based on the descriptor selection strategy and machine learning method (ML), where the ML algorithm included the least absolute shrinkage and selection operator (Lasso) regression, k-nearest neighbor (k-NN), random forest (RF), and multi-layer perceptron (MLP). The results showed that the interpretable descriptors extracted by our proposed selection strategy and the MLP neural network achieved a high prediction accuracy (R>0.950). By further predicting the sintered density of W(Mo) alloys using different sintering processes, the error between the predicted and experimental values was less than 0.063, confirming the application potential of the model.

Keywords: sintered density, machine learning, interpretable descriptors, W(Mo) alloy

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864 Developing Guidelines for Public Health Nurse Data Management and Use in Public Health Emergencies

Authors: Margaret S. Wright

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Background/Significance: During many recent public health emergencies/disasters, public health nursing data has been missing or delayed, potentially impacting the decision-making and response. Data used as evidence for decision-making in response, planning, and mitigation has been erratic and slow, decreasing the ability to respond. Methodology: Applying best practices in data management and data use in public health settings, and guided by the concepts outlined in ‘Disaster Standards of Care’ models leads to the development of recommendations for a model of best practices in data management and use in public health disasters/emergencies by public health nurses. As the ‘patient’ in public health disasters/emergencies is the community (local, regional or national), guidelines for patient documentation are incorporated in the recommendations. Findings: Using model public health nurses could better plan how to prepare for, respond to, and mitigate disasters in their communities, and better participate in decision-making in all three phases bringing public health nursing data to the discussion as part of the evidence base for decision-making.

Keywords: data management, decision making, disaster planning documentation, public health nursing

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863 Knowledge of Strategies to Teach Reading Components Among Teachers of Hard of Hearing Students

Authors: Khalid Alasim

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This study investigated Saudi Arabian elementary school teachers’ knowledge of strategies to teach reading components to hard-of-hearing students. The study focused on four of the five reading components the National Reading Panel (NPR, 2000) identified: phonemic awareness; phonics; vocabulary, and reading comprehension, and explored the relationship between teachers’ demographic characteristics and their knowledge of the strategies as well. An explanatory sequential mixed methods design was used that included two phases. The quantitative phase examined the knowledge of these Arabic reading components among 89 elementary school teachers of hard-of-hearing students, and the qualitative phase consisted of interviews with 10 teachers. The results indicated that the teachers have a great deal of knowledge (above the mean score) of strategies to teach reading components. Specifically, teachers’ knowledge of strategies to teach the vocabulary component was the highest. The results also showed no significant association between teachers’ demographic characteristics and their knowledge of strategies to teach reading components. The qualitative analysis revealed two themes: 1) teachers’ lack of basic knowledge of strategies to teach reading components, and 2) the absence of in-service courses and training programs in reading for teachers.

Keywords: knowledge, reading, components, hard-of-hearing, phonology, vocabulary

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862 Mapping the Relationship between Elements of Urban Morphology Density of Crime

Authors: Fabio Salvador Aparecido Santos, Spencer Chainey, Richard Wortley

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Urban morphology can be understood as the study of the physical form of cities through its elements. Crime, at this turn, can be oversimplified as an action that breaks the rules established in a certain society. This study involves these two subjects through the relationship between elements of urban morphology and density of crime occurrences. We consider that there is a research gap about the influence of urban features on crime occurrences using statistic methods and mapping techniques on Geographic Information Systems. The investigation will comprehend three main phases. The first phase involves examining how theoretical principles associated with urban morphology can be viewed in terms of their influence on crime patterns. The second phase involves the development of tools to be used to model elements of urban morphology, and measure the relationship between these urban morphological elements and patterns of crime. The third phase involves determining the extent to which elements of the urban environment can contribute to crime reduction. Understanding the relationship between urban morphology and crime patterns in a Latin American context will help highlight the influence urban planning has on the crime problems that emerge in these settings, and how effectively urban planning can contribute to reducing crime.

Keywords: Agent-based Modelling, Environmental Criminology, Geographic Information System, Urban Morphology

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861 A New Method to Winner Determination for Economic Resource Allocation in Cloud Computing Systems

Authors: Ebrahim Behrouzian Nejad, Rezvan Alipoor Sabzevari

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Cloud computing systems are large-scale distributed systems, so that they focus more on large scale resource sharing, cooperation of several organizations and their use in new applications. One of the main challenges in this realm is resource allocation. There are many different ways to resource allocation in cloud computing. One of the common methods to resource allocation are economic methods. Among these methods, the auction-based method has greater prominence compared with Fixed-Price method. The double combinatorial auction is one of the proper ways of resource allocation in cloud computing. This method includes two phases: winner determination and resource allocation. In this paper a new method has been presented to determine winner in double combinatorial auction-based resource allocation using Imperialist Competitive Algorithm (ICA). The experimental results show that in our new proposed the number of winner users is higher than genetic algorithm. On other hand, in proposed algorithm, the number of winner providers is higher in genetic algorithm.

Keywords: cloud computing, resource allocation, double auction, winner determination

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860 Effects of Pre-Task Activities on the Writing Performance of Second Language Learners

Authors: Wajiha Fatima

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Based on Rod Ellis’s (2002) the methodology of task-based teaching, this study explored the effects of pre-task activities on the Job Application letter of 102 ESL students (who were female and undergraduate learners). For this purpose, students were divided among three groups (Group A, Group B, and Group C), kept in control and experimental settings as well. Pre-task phase motivates the learners to perform the actual task. Ellis reportedly discussed four pre-task phases: (1) performing a similar task; (2) providing a model; (3) non-task preparation activities and (4) strategic planning. They were taught through above given three pre-task activities. Accordingly, the learners in control setting were supposed to write without any teaching aid while learners in an experimental situation were provided three different pre-task activities in each group. In order to compare the scores of the pre-test and post-test of the three groups, sample paired t-test was utilized. The obtained results of the written job application by the female students revealed that pre-task activities improved their performance in writing. On the other hand, the comparison of the three pre-task activities revealed that 'providing a model' outperformed the other two activities. For this purpose, ANOVA was utilized.

Keywords: pre-task activities, second language learners, task based language teaching, writing

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859 Determination of Sintering Parameters of TiB₂ – Ti₃SiC₂ Composites

Authors: Bilge Yaman Islak, Erhan Ayas

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The densification behavior of TiB₂ – Ti₃SiC₂ composites is investigated for temperatures in the range of 1200°C to 1400°C, for the pressure of 40 and 50MPa, and for holding time between 15-30 min by spark plasma sintering (SPS) technique. Ti, Si, TiC and 5 wt.% TiB₂ were used to synthesize TiB₂ – Ti₃SiC₂ composites and the effect of different sintering parameters on the densification and phase evolution of these composites were investigated. The bulk densities were determined by using the Archimedes method. The polished and fractured surfaces of the samples were examined using a scanning electron microscope equipped with an energy dispersive spectroscopy (EDS). The phase analyses were accomplished by using the X-Ray diffractometer. Sintering temperature and holding time are found to play a dominant role in the phase development of composites. TiₓCᵧ and TiSi₂ secondary phases were found in 5 wt.%TiB₂ – Ti₃SiC₂ composites densified at 1200°C and 1400°C under the pressure of 40 MPa, due to decomposition of Ti₃SiC₂. The results indicated that 5 wt.%TiB₂ – Ti₃SiC₂ composites were densified into the dense parts with a relative density of 98.77% by sintering at 1300 °C, for 15 min, under a pressure of 50 MPa via SPS without the formation of any other ancillary phase. This work was funded and supported by Scientific Research Projects Commission of Eskisehir Osmangazi University with the Project Number 201915C103 (2019-2517).

Keywords: densification, phase evolution, sintering, TiB₂ – Ti₃SiC₂ composites

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858 Use of Simultaneous Electron Backscatter Diffraction and Energy Dispersive X-Ray Spectroscopy Techniques to Characterize High-Temperature Oxides Formed on Nickel-Based Superalloys Exposed to Super-Critical Water Environment

Authors: Mohsen Sanayei, Jerzy Szpunar, Sami Penttilä

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Exposure of Nickel-based superalloys to high temperature and harsh environment such as Super-Critical Water (SCW) environment leads to the formation of oxide scales composed of multiple and complex phases that are difficult to differentiate with conventional analysis techniques. In this study, we used simultaneous Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-ray Spectroscopy (EDS) to analyze the complex oxide scales formed on several Nickel-based Superalloys exposed to high temperature SCW. Multi-layered structures of Iron, Nickel, Chromium and Molybdenum oxides and spinels were clearly identified using the simultaneous EBSD-EDS analysis technique. Furthermore, the orientation relationship between the oxide scales and the substrate has been investigated.

Keywords: electron backscatter diffraction, energy dispersive x-ray spectroscopy, superalloy, super-critical water

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857 The Effectiveness of Self-Compassion Training: A Field Trial Study

Authors: Esmaeil Sarikhani

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Objectives: Considering the importance of introducing new methods of improving self-compassion and compassion to the others in nursing students, this study intends to evaluate the effect of self-compassion training on nursing students. Methods: This is a field trial study in which 52 nursing interns from Isfahan University of Medical Sciences were selected using convenience sampling method and divided in two experimental and control groups. The sampling was done during two phases: before and after the intervention. The intervention consisted of eight sessions over eight weeks of self-compassion training. The data were collected using the self-compassion standard questionnaire with 26 questions before and after the intervention. Data were then analyzed by the SPSS18 software and independent and paired T-tests, and also Chi-square and Mann-Whitney tests. Results: The results obtained from the independent t-test showed that the mean score of self-compassion and its components in the experimental group was significantly increased compared to the control group (p < 0.001). Comparing the groups, the mean overall score difference of self-compassion and its components had also a statistically significant change after the intervention (p < 0.001). Conclusion: Self-compassion training program, leads to improving nursing students' self-compassion. As it seems, this method can be used as an important training course in order to improve compassion of nursing students to themselves and the others.

Keywords: self-compassion, student, nursing students, field trial

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856 Efficacy of Music for Improving Language in Children with Special Needs

Authors: Louisa Han Lin Tan, Poh Sim Kang, Wei Ming Loi, Susan Jane Rickard Liow

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The efficacy of music for improving speech and language has been shown across ages and diagnoses. Across the world, the wide range of therapy settings and increasing number of children diagnosed with special needs demand more cost and time effective service delivery. However, research exploring co-treatment models on children other than those with Autism Spectrum Disorder remains sparse. The aim of this research was to determine the efficacy of music for improving language in children with special needs, and generalizability of therapy effects. 25 children (7 to 12 years) were split into three groups – A, B and control. A cross-over design with direct therapy (storytelling) with or without music, and indirect therapy was applied with two therapy phases lasting 6 sessions each. Therapy targeted three prepositions in each phase. Baseline language abilities were assessed, with re-assessment after each phase. The introduction of music in therapy led to significantly greater improvement (p=.046, r=.53) in associated language abilities, with case studies showing greater effectiveness in developmentally appropriate target prepositions. However, improvements were not maintained once direct therapy ceased. As such, the incorporation of music could lead to greater efficiency and effectiveness of language therapy in children with special needs, but sustainability and generalizability of therapy effects both require further exploration.

Keywords: music, language therapy, children, special needs

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855 Processing and Characterization of Glass-Epoxy Composites Filled with Linz-Donawitz (LD) Slag

Authors: Pravat Ranjan Pati, Alok Satapathy

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Linz-Donawitz (LD) slag a major solid waste generated in huge quantities during steel making. It comes from slag formers such as burned lime/dolomite and from oxidizing of silica, iron etc. while refining the iron into steel in the LD furnace. Although a number of ways for its utilization have been suggested, its potential as a filler material in polymeric matrices has not yet been explored. The present work reports the possible use of this waste in glass fiber reinforced epoxy composites as a filler material. Hybrid composites consisting of bi-directional e-glass-fiber reinforced epoxy filled with different LD slag content (0, 7.5, 15, 22.5 wt%) are prepared by simple hand lay-up technique. The composites are characterized in regard to their density, porosity, micro-hardness and strength properties. X-ray diffractography is carried out in order to ascertain the various phases present in LDS. This work shows that LD slag, in spite of being a waste, possesses fairly good filler characteristics as it modifies the strength properties and improves the composite micro-hardness of the polymeric resin.

Keywords: characterization, glass-epoxy composites, LD slag, waste utilization

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854 Voltage Sag Characteristics during Symmetrical and Asymmetrical Faults

Authors: Ioannis Binas, Marios Moschakis

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Electrical faults in transmission and distribution networks can have great impact on the electrical equipment used. Fault effects depend on the characteristics of the fault as well as the network itself. It is important to anticipate the network’s behavior during faults when planning a new equipment installation, as well as troubleshooting. Moreover, working backwards, we could be able to estimate the characteristics of the fault when checking the perceived effects. Different transformer winding connections dominantly used in the Greek power transfer and distribution networks and the effects of 1-phase to neutral, phase-to-phase, 2-phases to neutral and 3-phase faults on different locations of the network were simulated in order to present voltage sag characteristics. The study was performed on a generic network with three steps down transformers on two voltage level buses (one 150 kV/20 kV transformer and two 20 kV/0.4 kV). We found that during faults, there are significant changes both on voltage magnitudes and on phase angles. The simulations and short-circuit analysis were performed using the PSCAD simulation package. This paper presents voltage characteristics calculated for the simulated network, with different approaches on the transformer winding connections during symmetrical and asymmetrical faults on various locations.

Keywords: Phase angle shift, power quality, transformer winding connections, voltage sag propagation

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853 Smart Card Technology Adaption in a Hospital Setting

Authors: H. K. V. Narayan

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This study was conducted at Tata Memorial Hospital (TMH), Mumbai, India. The study was to evaluate the impact of adapting Smart Card (SC) for clinical and business transactions in order to reduce Lead times and to enforce business rules of the hospital. The objective for implementing the Smart Card was to improve the patient perception of quality in terms of structures process and outcomes and also to improve the productivity of the Institution. The Smart Card was implemented in phases from 2011 and integrated with the Hospital Information System (HIS/EMR). The implementation was a learning curve for all the stake holders as software obviated the need to use hardcopies of transactions. The acceptability to the stake holders was challenge in change management. The study assessed the impact 3 years into the implementation and the observed trends have suggested that it has decreased the lead times for services and increased the no of transactions and thereby the productivity. Patients who used to complain of multiple queues and cumbersome transactions now compliment the administration for effective use of Information and Communication Technology.

Keywords: smart card, high availability of health care information, reduction in potential medical errors due to elimination of transcription errors, reduction in no of queues, increased transactions, augmentation of revenue

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852 Structural and Electrical Properties of VO₂/ZnO Nanostructures

Authors: Sang-Wook Han, Zhenlan Jin, In-Hui Hwang, Chang-In Park

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We examined structural and electrical properties of uniformly-oriented VO₂/ZnO nanostructures. VO₂ was deposited on ZnO templates by using a direct current-sputtering deposition. Scanning electron microscope and transmission electron microscope measurements indicated that b-oriented VO₂ were uniformly crystallized on ZnO templates with different lengths. VO₂/ZnO formed nanorods on ZnO nanorods with length longer than 250 nm. X-ray absorption fine structure at V K edge of VO₂/ZnO showed M1 and R phases of VO₂ at 30 and 100 ℃, respectively, suggesting structural phase transition between temperatures. Temperature-dependent resistance measurements of VO₂/ZnO nanostructures revealed metal-to-insulator transition at 65 ℃ and 55 ℃ during heating and cooling, respectively, regardless of ZnO length. The bond lengths of V-O and V-V pairs in VO₂/ZnO nanorods were somewhat distorted, and a substantial amount of structural disorder existed in the atomic pairs, compared to those of VO₂ films without ZnO. Resistance from VO₂/ZnO nanorods revealed a sharp MIT near 65 ℃ during heating and a hysteresis behavior. The resistance results suggest that microchannel for charge carriers exist nearly room temperature during cooling. VO₂/ZnO nanorods are quite stable and reproducible so that they can be widely used for practical applications to electronic devices, gas sensors, and ultra-fast switches, as examples.

Keywords: metal-to-insulator transition, VO₂, ZnO, XAFS, structural-phase transition

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851 Grain Refinement of Al-7Si-0.4Mg Alloy by Combination of Al-Ti-B and Mg-Al2Ca Mater Alloys and Their Effects on Tensile Property

Authors: Young-Ok Yoon, Su-Yeon Lee, Seong-Ho Ha, Gil-Yong Yeom, Bong-Hwan Kim, Hyun-Kyu Lim, Shae K. Kim

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Al-7Si-0.4Mg alloy (designated A356) is widely used in the automotive and aerospace industries as structural components due to an excellent combination of castability and mechanical properties. Grain refinement has a significant effect on the mechanical properties of castings, mainly since the distribution of secondary phase is changed. As a grain refiner, the Al-Ti-B master alloys containing TiAl3 and TiB2 particles have been widely used in Al foundries. The Mg loss and Mg based inclusion formation by the strong affinity of Mg to oxygen in the melting process of Mg contained alloys have been an issue. This can be significantly improved only by Mg+Al2Ca master alloy as an alloying element instead of pure Mg. Moreover, the eutectic Si modification and grain refinement is simultaneously obtained because Al2Ca behaves as Ca, a typical Si modifier. The present study is focused on the combined effects of Mg+Al2Ca and Al-Ti-B master alloys on the grain refiment of Al-7Si-0.4Mg alloy and their proper ratio for the optimum effect. The aim of this study, therefore, is to investigate the change of the microstructure in Al-7Si-0.4Mg alloy with different ratios of Ti and Al2Ca (detected Ca content) and their effects on the tensile property. The distribution and morphology of the secondary phases by the grain refinement will be discussed.

Keywords: Al-7Si-0.4Mg alloy, Al2Ca, Al-Ti-B alloy, grain refinement

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850 Feature Extractions of EMG Signals during a Constant Workload Pedaling Exercise

Authors: Bing-Wen Chen, Alvin W. Y. Su, Yu-Lin Wang

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Electromyography (EMG) is one of the important indicators during exercise, as it is closely related to the level of muscle activations. This work quantifies the muscle conditions of the lower limbs in a constant workload exercise. Surface EMG signals of the vastus laterals (VL), vastus medialis (VM), rectus femoris (RF), gastrocnemius medianus (GM), gastrocnemius lateral (GL) and Soleus (SOL) were recorded from fourteen healthy males. The EMG signals were segmented in two phases: activation segment (AS) and relaxation segment (RS). Period entropy (PE), peak count (PC), zero crossing (ZC), wave length (WL), mean power frequency (MPF), median frequency (MDF) and root mean square (RMS) are calculated to provide the quantitative information of the measured EMG segments. The outcomes reveal that the PE, PC, ZC and RMS have significantly changed (p<.001); WL presents moderately changed (p<.01); MPF and MDF show no changed (p>.05) during exercise. The results also suggest that the RS is also preferred for performance evaluation, while the results of the extracted features in AS are usually affected directly by the amplitudes. It is further found that the VL exhibits the most significant changes within six muscles during pedaling exercise. The proposed work could be applied to quantify the stamina analysis and to predict the instant muscle status in athletes.

Keywords: electromyographic feature extraction, muscle status, pedaling exercise, relaxation segment

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849 3D Interferometric Imaging Using Compressive Hardware Technique

Authors: Mor Diama L. O., Matthieu Davy, Laurent Ferro-Famil

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In this article, inverse synthetic aperture radar (ISAR) is combined with compressive imaging techniques in order to perform 3D interferometric imaging. Interferometric ISAR (InISAR) imaging relies on a two-dimensional antenna array providing diversities in the elevation and azimuth directions. However, the signals measured over several antennas must be acquired by coherent receivers resulting in costly and complex hardware. This paper proposes to use a chaotic cavity as a compressive device to encode the signals arising from several antennas into a single output port. These signals are then reconstructed by solving an inverse problem. Our approach is demonstrated experimentally with a 3-elements L-shape array connected to a metallic compressive enclosure. The interferometric phases estimated from a unique broadband signal are used to jointly estimate the target’s effective rotation rate and the height of the dominant scattering centers of our target. Our experimental results show that the use of the compressive device does not adversely affect the performance of our imaging process. This study opens new perspectives to reduce the hardware complexity of high-resolution ISAR systems.

Keywords: interferometric imaging, inverse synthetic aperture radar, compressive device, computational imaging

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848 The Exploration of Preschool Teachers' Understanding of the Role of Socio-Emotional Development in School Readiness

Authors: A. Pedro, T. Goldschmidt

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Socio-emotional development is considered to be an essential prerequisite for school readiness. To our best knowledge, research on socio-emotional development specifically from the views of teachers in the South African context is limited. This study explored preschool teachers’ understanding of the role that socio-emotional development plays in preparing the child for school. Using the social learning theory, a qualitative approach with an exploratory design was used for the study. A total of 12 preschool teachers from both community-based and school-based preschools were purposively recruited. Upon receiving ethics clearance from the University of the Western Cape and the Western Cape Education Department, semi-structured interviews were conducted and analysed by utilizing Braun and Clarke’s (2006) six phases of thematic analysis. Participants’ rights, anonymity, and confidentiality were upheld throughout the research process. Findings reveal that preschool teachers emphasise the importance of holistic development for school readiness. Teachers deemed socio-emotional development as absolutely crucial for preparing children for school as it eases the transition to formal schooling and adaptation to the classroom environment.

Keywords: early childhood, preschool teachers, school readiness, socio-emotional development

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847 Development of High Temperature Mo-Si-B Based In-situ Composites

Authors: Erhan Ayas, Buse Katipoğlu, Eda Metin, Rifat Yılmaz

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The search for new materials has begun to be used even higher than the service temperature (~1150ᵒC) where nickel-based superalloys are currently used. This search should also meet the increasing demands for energy efficiency improvements. The materials studied for aerospace applications are expected to have good oxidation resistance. Mo-Si-B alloys, which have higher operating temperatures than nickel-based superalloys, are candidates for ultra-high temperature materials used in gas turbine and jet engines. Because the Moss and Mo₅SiB₂ (T2) phases exhibit high melting temperature, excellent high-temperature creep strength and oxidation resistance properties, however, low fracture toughness value at room temperature is a disadvantage for these materials, but this feature can be improved with optimum Moss phase and microstructure control. High-density value is also a problem for structural parts. For example, in turbine rotors, the higher the weight, the higher the centrifugal force, which reduces the creep life of the material. The density value of the nickel-based superalloys and the T2 phase, which is the Mo-Si-B alloy phase, is in the range of 8.6 - 9.2 g/cm³. But under these conditions, T2 phase Moss (density value 10.2 g/cm³), this value is above the density value of nickel-based superalloys. So, with some ceramic-based contributions, this value is enhanced by optimum values.

Keywords: molybdenum, composites, in-situ, mmc

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846 Two Coordination Polymers Synthesized from Various N-Donor Clusters Spaced by Terephtalic Acid for Efficient Photocatalytic Degradation of Ibuprofen in Water under Solar and Artificial Irradiation

Authors: Amina Adala, Nadra Debbache, Tahar Sehili

Abstract:

Coordination polymers and uniformly {[Zn(II)(BIPY)(Pht)]n} (1), {[Zn (HYD)(Pht)]n} (2) (BIPY = 4,4’ bipyridine, Pht = terephtalic acid, HYD = 8-hydroxyquinoline) have been successfully synthesized by a hydrothermal process using aqueous zinc solution. The as-prepared compounds phases were characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy, UV-visible spectroscopy, thermogravimetric analysis (TGA), and the electrochemistry study by the voltammetry cyclic. The results showed a crystalline phase for CP1 however, CP2 requires recrystallization; the FTIR showed the presence of characteristic bands of all ligands; besides that, TGA shows thermal stability up to 300°C. The electrochemistry study showed a good charge transfer between the ligands and Zn metal for the two components. UV-Vis measurement showed strong absorption in a wide range from UV to visible light with a band gap of 2.69 eV for CP1 and 2.56 eV for CP2, smaller than that of ZnO. This represents an alternative to using ZnO. The Ibuprofen IBP decomposition kinetics of 5.10⁻⁵ mol.L⁻¹ under solar and artificial light were studied for different irradiation conditions. Good photocatalytic properties were observed due to their high surface area.

Keywords: metal-organic frameworks, photocatalysis, photodegradation, organic pollutant, ibuprofen

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845 Comparing Repaired and Undamaged Specimens Test Results of Post-Tensioned Beam to Column Connections

Authors: Mustafa Kaya

Abstract:

After the 1999 Marmara earthquake in Turkey research by the Turkish Precast Union stated that 24.50% of the precast structures were damaged with some of this damage being observed in the beam to column connections of the structures. Since it is essential to provide those rendered homeless by the earthquake with safe, habitable accommodation repairing medium and slight levels of damage at the connection parts should be undertaken. In order to prove that a repaired connection was sufficiently strong, a precast beam to column post tensioned connection was tested in three phases. In phase one, the middle level damage was observed at 6% drift at these connections. As a result of the extra loads applied, little damage was observed. In the last phase, the four connections tested in the first phase were repaired using epoxy resin and then retested. The results from the tests on the repaired precast and the undamaged specimens showed that the repaired specimens were sufficiently strong, thus proving that repair to damaged precast beam to column post tensioned connections can be undertaken.

Keywords: precast beam to column connection, moment-resisting connection, post-tensioned connections, repair of precast connections

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844 Dielectric, Energy Storage and Impedance Spectroscopic Studies of Tin Doped Ba₀.₉₈Ca₀.₀₂TiO₃ Lead-Free Ceramics

Authors: Ramovatar, Neeraj Panwar

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Lead free Ba₀.₉₈Ca₀.₀₂SnxTi₁₋ₓO₃ (x = 0.01 and 0.05 mole %) ferroelectric ceramics have been synthesized by the solid-state reaction method with sintering at 1400 °C for 2 h. The room temperature x-ray diffraction (XRD) patterns identified the tetragonal phase for x = 0.01 composition whereas co-existence of tetragonal and orthorhombic phases for x =0.05 composition. Raman spectroscopy results corroborated with the XRD results at room temperature. The maximum dielectric properties (ɛm ~ 8591, tanδ ~ 0.018) were obtained for the compound with x = 0.01 at 5 kHz. Further, the tetragonal to cubic (TC) transition temperature was observed at 122 °C and 102 °C for the ceramics with x =0.01 and x = 0.05, respectively. The temperature dependent P-E loops also revealed the existence of TC at these particular temperature values. The energy storage density (Ed) of both compounds was calculated from room temperature P – E loops at an applied electric field of 20 kV/cm. The maximum Ed ~ 224 kJ/m³ was achieved for the sample with x = 0.01 as compared to 164 kJ/m³ for the x =0.05 composition. The value of Ed is comparable to other BaTiO₃ based lead free ferroelectric systems. Impedance spectroscopy analysis exhibited the bulk and grain boundary contributions above 300 °C under the frequency range 100 Hz to 1 MHz. The above properties make these ceramics suitable for energy storage devices.

Keywords: dielectric properties, energy storage properties, impedance spectroscopy, lead free ceramics

Procedia PDF Downloads 153