Search results for: 3D shape acquisition
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3219

Search results for: 3D shape acquisition

2799 Effect of the Support Shape on Fischer-Tropsch Cobalt Catalyst Performance

Authors: Jian Huang, Weixin Qian, Hongfang Ma, Haitao Zhang, Weiyong Ying

Abstract:

Cobalt catalysts were supported on extruded silica carrier and different-type (SiO2, γ-Al2O3) commercial supports with different shapes and sizes to produce heavy hydrocarbons for Fischer-Tropsch synthesis. The catalysts were characterized by N2 physisorption and H2-TPR. The catalytic performance of the catalysts was tested in a fixed bed reactor. The results of Fischer-Tropsch synthesis performance showed that the cobalt catalyst supported on spherical silica supports displayed a higher activity and a higher selectivity to C5+ products, due to the fact that the active components were only distributed in the surface layer of spherical carrier, and the influence of gas diffusion restriction on catalytic performance was weakened. Therefore, it can be concluded that the eggshell cobalt catalyst was superior to precious metals modified catalysts in the synthesis of heavy hydrocarbons.

Keywords: fischer-tropsch synthesis, cobalt catalyst, support shape, heavy hydrocarbons

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2798 A Comparative Study of the Alternatives to Land Acquisition: India

Authors: Aparna Soni

Abstract:

The much-celebrated foretold story of Indian city engines driving the growth of India has been scrutinized to have serious consequences. A wide spectrum of scholarship has brought to light the un-equalizing effects and the need to adopt a rights-based approach to development planning in India. Notably, these concepts and discourses ubiquitously entail the study of land struggles in the making of Urban. In fact, the very progression of the primitive accumulation theory to accumulation by dispossession, followed by ‘dispossession without development,’ thereafter Development without dispossession and now as Dispossession by financialization noticeably the last three developing in a span of mere three decades, is evidence enough to trace the centrality and evolving role of land in the making of urban India. India, in the last decade, has seen its regional governments actively experimenting with alternative models of land assembly (Amaravati and Delhi land pooling models, the loudly advertised ones). These are publicized as a replacement to the presumably cost and time antagonistic, prone to litigation land acquisition act of 2013. It has been observed that most of the literature treats these models as a generic large bracket of land expropriation and do not, in particular, try to differentially analyse to granularly find a pattern in these alternatives. To cater to this gap, this research comparatively studies these alternative land, assembly models. It categorises them based on their basic architecture, spatial and sectoral application, and governance frameworks. It is found that these alternatives are ad-hoc and fragmented pieces of legislation. These are fit for profit models commodifying land to ease its access by the private sector for real estate led growth. The research augments the literature on the privatization of land use planning in India. Further, it attempts to discuss the increasing role a landowner is expected to play in the future and suggests a way forward to safeguard them from market risks. The study involves a thematic analysis of the policy elements contained in legislative/policy documents, notifications, office orders. The study also derives from the various widely circulated print media information. With the present field-visit limitations, the study relies on documents accessed open-source in the public domain.

Keywords: commodification, dispossession, land acquisition, landowner

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2797 Effect of Three Instructional Strategies on Pre-service Teachers’ Learning Outcomes in Practical Chemistry in Niger State, Nigeria

Authors: Akpokiere Ugbede Roseline

Abstract:

Chemistry is an activity oriented subject in which many students achievement over the years are not encouraging. Among the reasons found to be responsible for student’s poor performance in chemistry are ineffective teaching strategies. This study, therefore, sought to determine the effect of guided inquiry, guided inquiry with demonstration, and demonstration with conventional approach on pre-service teachers’ cognitive attainment and practical skills acquisition on stoichiometry and chemical reactions in practical chemistry, Two research questions and hypotheses were each answered and tested respectively. The study was a quasi-experimental research involving 50 students in each of the experimental groups and 50 students in the control group. Out of the five instruments used for the study, three were on stimulus and two on response (Test of Cognitive Attainment and Test of Practical Skills in Chemistry) instruments administered, and dataobtained were analyzed with t-test and Analysis of Variance. Findings revealed, among others, that there was a significant effect of treatments on students' cognitive attainment and on practical skills acquisition. Students exposed to guided inquiry (with/without demonstration) strategies achieved better than those exposed to demonstration with conventional strategy. It is therefore recommended, among others, that Lecturers in Colleges of Education should utilize the guided inquiry strategy for teaching concepts in chemistry.

Keywords: instructional strategy, practical chemistry, learning outcomes, pre-service teachers

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2796 Beam Spatio-Temporal Multiplexing Approach for Improving Control Accuracy of High Contrast Pulse

Authors: Ping Li, Bing Feng, Junpu Zhao, Xudong Xie, Dangpeng Xu, Kuixing Zheng, Qihua Zhu, Xiaofeng Wei

Abstract:

In laser driven inertial confinement fusion (ICF), the control of the temporal shape of the laser pulse is a key point to ensure an optimal interaction of laser-target. One of the main difficulties in controlling the temporal shape is the foot part control accuracy of high contrast pulse. Based on the analysis of pulse perturbation in the process of amplification and frequency conversion in high power lasers, an approach of beam spatio-temporal multiplexing is proposed to improve the control precision of high contrast pulse. In the approach, the foot and peak part of high contrast pulse are controlled independently, which propagate separately in the near field, and combine together in the far field to form the required pulse shape. For high contrast pulse, the beam area ratio of the two parts is optimized, and then beam fluence and intensity of the foot part are increased, which brings great convenience to the control of pulse. Meanwhile, the near field distribution of the two parts is also carefully designed to make sure their F-numbers are the same, which is another important parameter for laser-target interaction. The integrated calculation results show that for a pulse with a contrast of up to 500, the deviation of foot part can be improved from 20% to 5% by using beam spatio-temporal multiplexing approach with beam area ratio of 1/20, which is almost the same as that of peak part. The research results are expected to bring a breakthrough in power balance of high power laser facility.

Keywords: inertial confinement fusion, laser pulse control, beam spatio-temporal multiplexing, power balance

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2795 Pandemic-Related Disruption to the Home Environment and Early Vocabulary Acquisition

Authors: Matthew McArthur, Margaret Friend

Abstract:

The COVID-19 pandemic disrupted the stability of the home environment for families across the world. Potential disruptions include parent work modality (in-person vs. remote), levels of health anxiety, family routines, and caregiving. These disruptions may have interfered with the processes of early vocabulary acquisition, carrying lasting effects over the life course. Our justification for this research is as follows: First, early, stable, caregiver-child reciprocal interactions, which may have been disrupted during the pandemic, contribute to the development of the brain architecture that supports language, cognitive, and social-emotional development. Second, early vocabulary predicts several cognitive outcomes, such as numeracy, literacy, and executive function. Further, disruption in the home is associated with adverse cognitive, academic, socio-emotional, behavioral, and communication outcomes in young children. We are interested in how disruptions related to the COVID-19 pandemic are associated with vocabulary acquisition in children born during the first two waves of the pandemic. We are conducting a moderated online experiment to assess this question. Participants are 16 children (10F) ranging in age from 19 to 39 months (M=25.27) and their caregivers. All child participants were screened for language background, health history, and history of language disorders, and were typically developing. Parents completed a modified version of the COVID-19 Family Stressor Scale (CoFaSS), a published measure of COVID-19-related family stressors. Thirteen items from the original scale were replaced to better capture change in family organization and stability specifically related to disruptions in income, anxiety, family relations, and childcare. Following completion of the modified CoFaSS, children completed a Web-Based version of the Computerized Comprehension Task and the Receptive One Word Picture Vocabulary if 24 months or older or the MacArthur-Bates Communicative Development Inventory if younger than 24 months. We report our preliminary data as a partial correlation analysis controlling for age. Raw vocabulary scores on the CCT, ROWPVT-4, and MCDI were all negatively associated with pandemic-related disruptions related to anxiety (r12=-.321; r1=-.332; r9=-.509), family relations (r12=-.590*; r1=-.155; r9=-.468), and childcare (r12=-.294; r1=-.468; r9=-.177). Although the small sample size for these preliminary data limits our power to detect significance, this trend is in the predicted direction, suggesting that increased pandemic-related disruption across multiple domains is associated with lower vocabulary scores. We anticipate presenting data on a full sample of 50 monolingual English participants. A sample of 50 participants would provide sufficient statistical power to detect a moderate effect size, adhering to a nominal alpha of 0.05 and ensuring a power level of 0.80.

Keywords: COVID-19, early vocabulary, home environment, language acquisition, multiple measures

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2794 Examining Motivational Dynamics and L2 Learning Transitions of Air Cadets Between Year One and Year Two: A Retrodictive Qualitative Modelling Approach

Authors: Kanyaporn Sommeechai

Abstract:

Air cadets who aspire to become military pilots upon graduation undergo rigorous training at military academies. As first-year cadets are akin to civilian freshmen, they encounter numerous challenges within the seniority-based military academy system. Imposed routines, such as mandatory morning runs and restrictions on mobile phone usage for two semesters, have the potential to impact their learning process and motivation to study, including second language (L2) acquisition. This study aims to investigate the motivational dynamics and L2 learning transitions experienced by air cadets. To achieve this, a Retrodictive Qualitative Modelling approach will be employed, coupled with the adaptation of the three-barrier structure encompassing institutional factors, situational factors, and dispositional factors. Semi-structured interviews will be conducted to gather rich qualitative data. By analyzing and interpreting the collected data, this research seeks to shed light on the motivational factors that influence air cadets' L2 learning journey. The three-barrier structure will provide a comprehensive framework to identify and understand the institutional, situational, and dispositional factors that may impede or facilitate their motivation and language learning progress. Moreover, the study will explore how these factors interact and shape cadets' motivation and learning experiences. The outcomes of this research will yield fundamental data that can inform strategies and interventions to enhance the motivation and language learning outcomes of air cadets. By better understanding their motivational dynamics and transitions, educators and institutions can create targeted initiatives, tailored pedagogical approaches, and supportive environments that effectively inspire and engage air cadets as L2 learners.

Keywords: second language, education, motivational dynamics, learning transitions

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2793 Acoustic Emission Monitoring of Surface Roughness in Ultra High Precision Grinding of Borosilicate-Crown Glass

Authors: Goodness Onwuka, Khaled Abou-El-Hossein

Abstract:

The increase in the demand for precision optics, coupled with the absence of much research output in the ultra high precision grinding of precision optics as compared to the ultrahigh precision diamond turning of optical metals has fostered the need for more research in the ultra high precision grinding of an optical lens. Furthermore, the increase in the stringent demands for nanometric surface finishes through lapping, polishing and grinding processes necessary for the use of borosilicate-crown glass in the automotive and optics industries has created the demand to effectively monitor the surface roughness during the production process. Acoustic emission phenomenon has been proven as useful monitoring technique in several manufacturing processes ranging from monitoring of bearing production to tool wear estimation. This paper introduces a rare and unique approach with the application of acoustic emission technique to monitor the surface roughness of borosilicate-crown glass during an ultra high precision grinding process. This research was carried out on a 4-axes Nanoform 250 ultrahigh precision lathe machine using an ultra high precision grinding spindle to machine the flat surface of the borosilicate-crown glass with the tip of the grinding wheel. A careful selection of parameters and design of experiment was implemented using Box-Behnken method to vary the wheel speed, feed rate and depth of cut at three levels with a 3-center point design. Furthermore, the average surface roughness was measured using Taylor Hobson PGI Dimension XL optical profilometer, and an acoustic emission data acquisition device from National Instruments was utilized to acquire the signals while the data acquisition codes were designed with National Instrument LabVIEW software for acquisition at a sampling rate of 2 million samples per second. The results show that the raw and root mean square amplitude values of the acoustic signals increased with a corresponding increase in the measured average surface roughness values for the different parameter combinations. Therefore, this research concludes that acoustic emission monitoring technique is a potential technique for monitoring the surface roughness in the ultra high precision grinding of borosilicate-crown glass.

Keywords: acoustic emission, borosilicate-crown glass, surface roughness, ultra high precision grinding

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2792 Evaluation of Forming Properties on AA 5052 Aluminium Alloy by Incremental Forming

Authors: A. Anbu Raj, V. Mugendiren

Abstract:

Sheet metal forming is a vital manufacturing process used in automobile, aerospace, agricultural industries, etc. Incremental forming is a promising process providing a short and inexpensive way of forming complex three-dimensional parts without using die. The aim of this research is to study the forming behaviour of AA 5052, Aluminium Alloy, using incremental forming and also to study the FLD of cone shape AA 5052 Aluminium Alloy at room temperature and various annealing temperature. Initially the surface roughness and wall thickness through incremental forming on AA 5052 Aluminium Alloy sheet at room temperature is optimized by controlling the effects of forming parameters. The central composite design (CCD) was utilized to plan the experiment. The step depth, feed rate, and spindle speed were considered as input parameters in this study. The surface roughness and wall thickness were used as output response. The process performances such as average thickness and surface roughness were evaluated. The optimized results are taken for minimum surface roughness and maximum wall thickness. The optimal results are determined based on response surface methodology and the analysis of variance. Formability Limit Diagram is constructed on AA 5052 Aluminium Alloy at room temperature and various annealing temperature by using optimized process parameters from the response surface methodology. The cone has higher formability than the square pyramid and higher wall thickness distribution. Finally the FLD on cone shape and square pyramid shape at room temperature and the various annealing temperature is compared experimentally and simulated with Abaqus software.

Keywords: incremental forming, response surface methodology, optimization, wall thickness, surface roughness

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2791 Insights and Observation for Optimum Work Roll Cooling in Flat Hot Mills: A Case Study on Shape Defect Elimination

Authors: Uday S. Goel, G. Senthil Kumar, Biswajit Ghosh, V. V. Mahashabde, Dhirendra Kumar, H. Manjunath, Ritesh Kumar, Mahesh Bhagwat, Subodh Pandey

Abstract:

Tata Steel Bhushan Steel Ltd.(TSBSL)’s Hot Mill at Angul , Orissa , India, was facing shape issues in Hot Rolled (HR) coils. This was resulting in a defect called as ‘Ridge’, which was appearing in subsequent cold rolling operations at various cold mills (CRM) and external customers. A collaborative project was undertaken to resolve this issue. One of the reasons identified was the strange drop in thermal crown after rolling of 20-25 coils in the finishing mill (FM ) schedule. On the shop floor, it was observed that work roll temperatures in the FM after rolling were very high and non uniform across the work roll barrel. Jammed work roll cooling nozzles, insufficient roll bite lubrication and inadequate roll cooling water quality were found to be the main reasons. Regular checking was initiated to check roll cooling nozzles health, and quick replacement done if found jammed was implemented. Improvements on roll lubrication, especially flow rates, was done. Usage of anti-peeling headers and inter stand descaling was enhanced. A subsequent project was also taken up for improving the quality of roll cooling water. Encouraging results were obtained from the project with a reduction in rejection due to ridge at CRM’s by almost 95% of the pre project start levels. Poor profile occurrence of HR coils at HSM was also reduced from a high of 32% in May’19 to <1% since Apr’20.

Keywords: hot rolling flat, shape, ridge, work roll, roll cooling nozzle, lubrication

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2790 Enhancing French Vocabulary Acquisition: The Impact of Explicit Instruction on Productive Non-Cognate Suffixes for Beginner Learners

Authors: Deborah Idowu

Abstract:

This research delves into the effectiveness of explicitly teaching productive non-cognate French suffixes to English beginner learners of the French language. It is widely accepted that cognates, especially orthographic ones, can be inferred by learners from their first language (in this case, English). The same is the case for derived French words with cognate suffixes, provided the learner is familiar with the lemma, which can either be cognate or non-cognate. However, the same cannot be said for derived French words with non-cognate suffixes. These suffixes often pose challenges to learners, even when the base word is familiar to them. The primary goal of this research is to enhance the vocabulary comprehension and expansion of English-speaking beginners in French by focusing on the recognition of derived French words that may not align with their L1 knowledge. The methodology employed in this study of derivational morphology involves an experimental group receiving explicit instruction on productive non-cognate suffixes, while a control group does not. By utilizing confidence ratings and other analytical tools, the analysis aims to measure the impact of this targeted instruction on the learners' ability to understand and incorporate non-cognate suffixes into their French vocabulary. Through this experimental approach, the research seeks to provide valuable insights into how explicit instruction on non-cognate suffixes can benefit beginner French learners, ultimately aiding them in navigating the intricacies of French derivational morphology. The objectives of this research are as follows: i. to investigate the impact of explicitly teaching productive non-cognate suffixes on the vocabulary comprehension and expansion of beginner learners of the French language; ii. to assess the effectiveness of targeted instruction on non-cognate suffixes in aiding English-speaking learners in recognizing and understanding derived French words that may not align with their native language knowledge, iii. to compare the vocabulary acquisition and retention of beginner French learners who receive explicit instruction on non-cognate suffixes with those who do not to determine the effectiveness of this instructional approach, iv. to analyze the confidence ratings and other analytical methods to gauge the learners' ability to integrate non-cognate suffixes into their French vocabulary and comprehend the meaning of derived words more effectively, v. to contribute insights into how explicit instruction on non-cognate suffixes can enhance the overall language learning experience for beginner learners of French, particularly in the area of French derivational morphology.

Keywords: suffixes, derivational morphology, non-cognates, vocabulary acquisition, French language learners

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2789 Flexural Behavior for Prefabricated Angle Truss Composite Beams Using Precast Concrete

Authors: Jo Kwang-Won, Lee Ho-Jun, Choi In-Rak, Park Hong-Gun

Abstract:

Prefabricated angle truss composited beam is a kind of concrete encased composite beam. It is prefabricated at factory as Pratt truss with steel members. Double angle is used for top, bottom chords and vertical web member. Moreover, diagonal web member is steel plate. Its sectional shape looks like I-shape. This beam system has two stages. The first is construction stage in which the beam is directly connected to the column for resist construction load. This stage beam consists of Pratt truss and precast concrete. The stability of the beam is verified. The second is service stage. After the connection, cast-in-place concrete is used for composite action. Ultimate flexural capacity is verified and show advantage than RC and steel. In this paper, the beam flexural capacity is verified in both stages. And examined the flexural behavior of the beam.

Keywords: composite beam, prefabrication, angle, precast concrete, pratt truss

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2788 Channel Characteristics and Morphometry of a Part of Umtrew River, Meghalaya

Authors: Pratyashi Phukan, Ranjan Saikia

Abstract:

Morphometry incorporates quantitative study of the area ,altitude,volume, slope profiles of a land and drainage basin characteristics of the area concerned.Fluvial geomorphology includes the consideration of linear,areal and relief aspects of a fluvially originated drainage basin. The linear aspect deals with the hierarchical orders of streams, numbers, and lenghts of stream segments and various relationship among them.The areal aspect includes the analysis of basin perimeters,basin shape, basin area, and related morphometric laws. The relief aspect incorporates besides hypsometric, climographic and altimetric analysis,the study of absolute and relative reliefs, relief ratios, average slope, etc. In this paper we have analysed the relationship among stream velocity, channel shape,sediment load,channel width,channel depth, etc.

Keywords: morphometry, hydraulic geometry, Umtrew river, Meghalaya

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2787 Evaluation of Particle Settling in Flow Chamber

Authors: Abdulrahman Alenezi, B. Stefan

Abstract:

Abstract— The investigation of fluids containing particles or filaments includes a category of complex fluids and is vital in both theory and application. The forecast of particle behaviors plays a significant role in the existing technology as well as future technology. This paper focuses on the prediction of the particle behavior through the investigation of the particle disentrainment from a pipe on a horizontal air stream. This allows for examining the influence of the particle physical properties on its behavior when falling on horizontal air stream. This investigation was conducted on a device located at the University of Greenwich's Medway Campus. Two materials were selected to carry out this study: Salt and Glass Beads particles. The shape of the Slat particles is cubic where the shape of the Glass Beads is almost spherical. The outcome from the experimental work were presented in terms of distance travelled by the particles according to their diameters as After that, the particles sizes were measured using Laser Diffraction device and used to determine the drag coefficient and the settling velocity.

Keywords: flow experiment, drag coefficient, Particle Settling, Flow Chamber

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2786 Studying the Effectiveness of Using Narrative Animation on Students’ Understanding of Complex Scientific Concepts

Authors: Atoum Abdullah

Abstract:

The purpose of this research is to determine the extent to which computer animation and narration affect students’ understanding of complex scientific concepts and improve their exam performance, this is compared to traditional lectures that include PowerPoints with texts and static images. A mixed-method design in data collection was used, including quantitative and qualitative data. Quantitative data was collected using a pre and post-test method and a close-ended questionnaire. Qualitative data was collected through an open-ended questionnaire. A pre and posttest strategy was used to measure the level of students’ understanding with and without the use of animation. The test included multiple-choice questions to test factual knowledge, open-ended questions to test conceptual knowledge, and to label the diagram questions to test application knowledge. The results showed that students on average, performed significantly higher on the posttest as compared to the pretest on all areas of acquired knowledge. However, the increase in the posttest score with respect to the acquisition of conceptual and application knowledge was higher compared to the increase in the posttest score with respect to the acquisition of factual knowledge. This result demonstrates that animation is more beneficial when acquiring deeper, conceptual, and cognitive knowledge than when only factual knowledge is acquired.

Keywords: animation, narration, science, teaching

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2785 Reduction of Dynamic Influences in Composite Rubber-Concrete Block Designed to Walls Construction

Authors: Maciej Major, Izabela Major

Abstract:

The aim of this paper is a numerical analysis of three-layered block design to walls construction subjected to the dynamic load. The block consists of the layers: concrete with rubber pads in shape of crosses, space filled with air and concrete with I-shape rubber pads. The main purpose of rubber inserts embedded during the production process is additional protection against the transversal dynamic load. For the analysis, as rubber, the Zahorski hyperelastic incompressible material model was assumed. A concentrated force as dynamic load applied to the external block surface was investigated. The results for the considered block observed as the stress distribution plot were compared to the results obtained for the solid concrete block. In order to estimate the percentage damping of proposed composite, rubber-concrete block in relation to the solid block the numerical analysis with the use of finite element method based on ADINA software was performed.

Keywords: dynamics, composite, rubber, Zahorski

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2784 The Chemical Transport Mechanism of Emitter Micro-Particles in Tungsten Electrode: A Metallurgical Study

Authors: G. Singh, H.Schuster, U. Füssel

Abstract:

The stability of electric arc and durability of electrode tip used in Tungsten Inert Gas (TIG) welding demand a metallurgical study about the chemical transport mechanism of emitter oxide particles in tungsten electrode during its real welding conditions. The tungsten electrodes doped with emitter oxides of rare earth oxides such as La₂O₃, Th₂O₃, Y₂O₃, CeO₂ and ZrO₂ feature a comparatively lower work function than tungsten and thus have superior emission characteristics due to lesser surface temperature of the cathode. The local change in concentration of these emitter particles in tungsten electrode due to high temperature diffusion (chemical transport) can change its functional properties like electrode temperature, work function, electron emission, and stability of the electrode tip shape. The resulting increment in tip surface temperature results in the electrode material loss. It was also observed that the tungsten recrystallizes to large grains at high temperature. When the shape of grain boundaries are granular in shape, the intergranular diffusion of oxide emitter particles takes more time to reach the electrode surface. In the experimental work, the microstructure of the used electrode's tip surface will be studied by scanning electron microscope and reflective X-ray technique in order to gauge the extent of the diffusion and chemical reaction of emitter particles. Besides, a simulated model is proposed to explain the effect of oxide particles diffusion on the electrode’s microstructure, electron emission characteristics, and electrode tip erosion. This model suggests metallurgical modifications in tungsten electrode to enhance its erosion resistance.

Keywords: rare-earth emitter particles, temperature-dependent diffusion, TIG welding, Tungsten electrode

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2783 Measurements of Recovery Stress and Recovery Strain of Ni-Based Shape Memory Alloys

Authors: W. J. Kim

Abstract:

The behaviors of the recovery stress and strain of an ultrafine-grained Ni-50.2 at.% Ti alloy prepared by high-ratio differential speed rolling (HRDSR) were examined by a specially designed tensile-testing set up, and the factors that influence the recovery stress and strain were studied. After HRDSR, both the recovery stress and strain were enhanced compared to the initial condition. The constitutive equation showing that the maximum recovery stress is a sole function of the recovery strain was developed based on the experimental data. The recovery strain increased as the yield stress increased. The maximum recovery stress increased with an increase in yield stress. The residual recovery stress was affected by the yield stress as well as the austenite-to-martensite transformation temperature. As the yield stress increased and as the martensitic transformation temperature decreased, the residual recovery stress increased.

Keywords: high-ratio differential speed rolling, tensile testing, severe plastic deformation, shape memory alloys

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2782 Experimental and Numerical Studies of Droplet Formation

Authors: Khaled Al-Badani, James Ren, Lisa Li, David Allanson

Abstract:

Droplet formation is an important process in many engineering systems and manufacturing procedures, which includes welding, biotechnologies, 3D printing, biochemical, biomedical fields and many more. The volume and the characteristics of droplet formation are generally depended on various material properties, microfluidics and fluid mechanics considerations. Hence, a detailed investigation of this process, with the aid of numerical computational tools, are essential for future design optimization and process controls of many engineering systems. This will also improve the understanding of changes in the properties and the structures of materials, during the formation of the droplet, which is important for new material developments to achieve different functions, pending the requirements of the application. For example, the shape of the formed droplet is critical for the function of some final products, such as the welding nugget during Capacitor Discharge Welding process, or PLA 3D printing, etc. Although, most academic journals on droplet formation, focused on issued with material transfer rate, surface tension and residual stresses, the general emphasis on the characteristics of droplet shape has been overlooked. The proposed work for this project will examine theoretical methodologies, experimental techniques, and numerical modelling, using ANSYS FLUENT, to critically analyse and highlight optimization methods regarding the formation of pendant droplet. The project will also compare results from published data with experimental and numerical work, concerning the effects of key material parameters on the droplet shape. These effects include changes in heating/cooling rates, solidification/melting progression and separation/break-up times. From these tests, a set of objectives is prepared, with an intention of improving quality, stability and productivity in modelling metal welding and 3D printing.

Keywords: computer modelling, droplet formation, material distortion, materials forming, welding

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2781 Learning Activities in Teaching Nihon-Go in the Philippines: Basis for a Proposed Action Plan

Authors: Esperanza C. Santos

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Japanese Language was traditionally considered as a means of imparting culture and training aesthetic experience in students and therefore as something beyond the practical aims of language teaching and learning. Due to the complexity of foreign languages, lots of language learners and teachers shared deep reservations about the potentials of foreign language in enhancing the communication skills of the students. In spite of the arguments against the use of Foreign Language (Nihon-go) in the classroom, the researcher strongly support the use of Nihon-go in teaching communication skills as the researcher believes that Nihon-go is a valuable resource to be exploited in the classroom in order to help the students explore the language in an interesting and challenging way. The focus of this research is to find out the relationship between the preferences, opinions, and perceptions with the communication skills. This study also identifies the significance of the relationship between preferences, opinions and perceptions and communications skills in the activities employed in Foreign language (Nihon-go) among the junior and senior students in Foreign Language 2 at the Imus Institute, Imus Cavite during the academic year 2013-2014. The results of the study are expected to encourage further studies that particularly focused on the communication skills as brought about by the identified factors namely: preferences, opinions, and perceptions on the benefits factor namely the language acquisition; access to Japanese culture and students' interpretative ability. Therefore, this research is in its quest for the issues and concerns on how to effectively teach different learning activities in a Nihon-go class.

Keywords: preferences, opinions, perceptions, language acquisition

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2780 Free Vibration Analysis of Gabled Frame Considering Elastic Supports and Semi-Rigid Connections

Authors: A. Shooshtari, A. R. Masoodi, S. Heyrani Moghaddam

Abstract:

Free vibration analysis of a gabled frame with elastic support and semi-rigid connections is performed by using a program in OpenSees software. Natural frequencies and mode shape details of frame are obtained for two states, which are semi-rigid connections and elastic supports, separately. The members of this structure are analyzed as a prismatic nonlinear beam-column element in software. The mass of structure is considered as two equal lumped masses at the head of two columns in horizontal and vertical directions. Note that the degree of freedom, allocated to all nodes, is equal to three. Furthermore, the mode shapes of frame are achieved. Conclusively, the effects of connections and supports flexibility on the natural frequencies and mode shapes of structure are investigated.

Keywords: natural frequency, mode shape, gabled frame, semi-rigid connection, elastic support, OpenSees software

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2779 Role of Cellulose Fibers in Tuning the Microstructure and Crystallographic Phase of α-Fe₂O₃ and α-FeOOH Nanoparticles

Authors: Indu Chauhan, Bhupendra S. Butola, Paritosh Mohanty

Abstract:

It is very well known that properties of material changes as their size approach to nanoscale level due to the high surface area to volume ratio. However, in last few decades, a tenet ‘structure dictates function’ is quickly being adopted by researchers working with nanomaterials. The design and exploitation of nanoparticles with tailored shape and size has become one of the primary goals of materials science researchers to expose the properties of nanostructures. To date, various methods, including soft/hard template/surfactant assisted route hydrothermal reaction, seed mediated growth method, capping molecule-assisted synthesis, polyol process, etc. have been adopted to synthesize the nanostructures with controlled size and shape and monodispersity. However controlling the shape and size of nanoparticles is an ultimate challenge of modern material research. In particular, many efforts have been devoted to rational and skillful control of hierarchical and complex nanostructures. Thus in our research work, role of cellulose in manipulating the nanostructures has been discussed. Nanoparticles of α-Fe₂O₃ (diameter ca. 15 to 130 nm) were immobilized on the cellulose fiber surface by a single step in situ hydrothermal method. However, nanoflakes of α-FeOOH having thickness ca. ~25 nm and length ca. ~250 nm were obtained by the same method in absence of cellulose fibers. A possible nucleation and growth mechanism of the formation of nanostructures on cellulose fibers have been proposed. The covalent bond formation between the cellulose fibers and nanostructures has been discussed with supporting evidence from the spectroscopic and other analytical studies such as Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The role of cellulose in manipulating the nanostructures has been discussed.

Keywords: cellulose fibers, α-Fe₂O₃, α-FeOOH, hydrothermal, nanoflakes, nanoparticles

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2778 Non-Linear Load-Deflection Response of Shape Memory Alloys-Reinforced Composite Cylindrical Shells under Uniform Radial Load

Authors: Behrang Tavousi Tehrani, Mohammad-Zaman Kabir

Abstract:

Shape memory alloys (SMA) are often implemented in smart structures as the active components. Their ability to recover large displacements has been used in many applications, including structural stability/response enhancement and active structural acoustic control. SMA wires or fibers can be embedded with composite cylinders to increase their critical buckling load, improve their load-deflection behavior, and reduce the radial deflections under various thermo-mechanical loadings. This paper presents a semi-analytical investigation on the non-linear load-deflection response of SMA-reinforced composite circular cylindrical shells. The cylinder shells are under uniform external pressure load. Based on first-order shear deformation shell theory (FSDT), the equilibrium equations of the structure are derived. One-dimensional simplified Brinson’s model is used for determining the SMA recovery force due to its simplicity and accuracy. Airy stress function and Galerkin technique are used to obtain non-linear load-deflection curves. The results are verified by comparing them with those in the literature. Several parametric studies are conducted in order to investigate the effect of SMA volume fraction, SMA pre-strain value, and SMA activation temperature on the response of the structure. It is shown that suitable usage of SMA wires results in a considerable enhancement in the load-deflection response of the shell due to the generation of the SMA tensile recovery force.

Keywords: airy stress function, cylindrical shell, Galerkin technique, load-deflection curve, recovery stress, shape memory alloy

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2777 Modeling of Single Bay Precast Residential House Using Ruaumoko 2D Program

Authors: N. H. Hamid, N. M. Mohamed, S. A. Anuar

Abstract:

Precast residential houses are normally constructed in Malaysia using precast shear-key wall panel and precast wall panel are designed using BS8110 where there is no provision for earthquake. However, the safety of this house under moderate and strong earthquake is still questionable. Consequently, the full-scale of residential house are designed, constructed, tested and analyzed under in-plane lateral cyclic loading. Hysteresis loops are plotted based on the experimental work and compared with modeling of hysteresis loops using HYSTERES in RUAUMOKO 2D program. Modified Takeda hysteresis model is chosen to behave a similar pattern with experimental work. This program will display the earthquake excitations, spectral displacements, pseudo spectral acceleration, and deformation shape of the structure. It can be concluded that this building is suffering severe cracks and damage under moderate and severe earthquake.

Keywords: precast shear-key, hysteresis loops, spectral displacements, deformation shape

Procedia PDF Downloads 443
2776 Automatic Censoring in K-Distribution for Multiple Targets Situations

Authors: Naime Boudemagh, Zoheir Hammoudi

Abstract:

The parameters estimation of the K-distribution is an essential part in radar detection. In fact, presence of interfering targets in reference cells causes a decrease in detection performances. In such situation, the estimate of the shape and the scale parameters are far from the actual values. In the order to avoid interfering targets, we propose an Automatic Censoring (AC) algorithm of radar interfering targets in K-distribution. The censoring technique used in this work offers a good discrimination between homogeneous and non-homogeneous environments. The homogeneous population is then used to estimate the unknown parameters by the classical Method of Moment (MOM). The AC algorithm does not need any prior information about the clutter parameters nor does it require both the number and the position of interfering targets. The accuracy of the estimation parameters obtained by this algorithm are validated and compared to various actual values of the shape parameter, using Monte Carlo simulations, this latter show that the probability of censing in multiple target situations are in good agreement.

Keywords: parameters estimation, method of moments, automatic censoring, K distribution

Procedia PDF Downloads 362
2775 A Parasitic Resonator-Based Diamond Shape Microstrip Antenna for Ultra-Wide-Band Applications

Authors: M. Zulfiker Mahmud, M. Naimur Rahman, Farhad Bin Ashraf, Norbahiah Misran, Mohammad Tariqul Islam

Abstract:

This study proposes a diamond-shaped microstrip patch antenna for ultra-wideband applications. The antenna is made up of a diamond shape radiating patch, partial ground plane, and three asterisk-shaped parasitic elements. The parasitic elements are positioned above the ground plane to enhance the bandwidth and gain. The proposed antenna has a compact dimension of 30 x 25 x 1.6 mm3 and achieves an overall bandwidth (S11<-10dB) is 5.8 GHz from 2.7 GHz to 8.5 GHz. The antenna attains more than 4 dBi realized the gain and 80% efficiency over the bandwidth with omnidirectional radiation pattern. The design and simulation of the proposed antenna are performed in Computer Simulation Technology (CST) Microwave Studio. The observation during the analysis of the simulated data reveals that the proposed antenna is suitable for Ultra wide-band (UWB) applications where high gain is required.

Keywords: diamond-shaped antenna, microstrip antenna, parasitic resonator, UWB applications

Procedia PDF Downloads 207
2774 Optimization of High Flux Density Design for Permanent Magnet Motor

Authors: Dong-Woo Kang

Abstract:

This paper presents an optimal magnet shape of a spoke-shaped interior permanent magnet synchronous motor by using ferrite magnets. Generally, the permanent magnet motor used the ferrite magnets has lower output power and efficiency than a rare-earth magnet motor, because the ferrite magnet has lower magnetic energy than the rare-earth magnet. Nevertheless, the ferrite magnet motor is used to many industrial products owing to cost effectiveness. In this paper, the authors propose a high power density design of the ferrite permanent magnet synchronous motor. Furthermore, because the motor design has to be taken a manufacturing process into account, the design is simulated by using the finite element method for analyzing the demagnetization, the magnetizing, and the structure stiffness. Especially, the magnet shape and dimensions are decided for satisfying these properties. Finally, the authors design an optimal motor for applying our system. That final design is manufactured and evaluated from experimentations.

Keywords: demagnetization, design optimization, magnetic analysis, permanent magnet motors

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2773 Breeding Performance and Egg Quality of Red Jungle Fowl (Gallus Gallus L.) Mated with Native Hens (Gallus galus domesticus) in Selected Areas of Leyte under Confinement System

Authors: Francisco F. Buctot Jr.

Abstract:

This study was conducted to assess the breeding performance and egg quality traits of Red Jungle Fowls in selected areas of Leyte mated to Native hens under confinement system. A total of six Red Jungle Fowl roosters, two native roosters and 16 native hens were randomly assigned to four treatments with eight replications; each composed of one rooster and two hens randomly laid out in a Randomized Complete Block Design set up. Result on egg weight showed highly significant difference at p<0.01 and revealed heaviest weight (39.0 g) and lightest weight (35.75 g) on Native x Native and Baybay RJF x Native, respectively. While comparable number of eggs per clutch, fertility and hatchability rates, yolk and albumen weights, shell weight, egg length and width, egg shape index and yolk color score were obtained.

Keywords: egg clutch, egg shape index, native chicken, hatchability rate

Procedia PDF Downloads 349
2772 Using iPads and Tablets in Language Teaching and Learning Process

Authors: Ece Sarigul

Abstract:

It is an undeniable fact that, teachers need new strategies to communicate with students of the next generation and to shape enticing educational experiences for them. Many schools have launched iPad/ Tablets initiatives in an effort to enhance student learning. Despite their rapid adoption, the extent to which iPads / Tablets increase student engagement and learning is not well understood. This presentation aims to examine the use of iPads and Tablets in primary and high schools in Turkey as well as in the world to increase academic achievement through promotion of higher order thinking skills. In addition to explaining the ideas of school teachers and students who use the specific iPads or Tablets , various applications in schools and their use will be discussed and demonstrated in this study. The specific” iPads or Tablets” applications discussed in this presentation can be incorporated into the curriculum to assist in developing transformative practices and programs to meet the needs of a diverse student population. In the conclusion section of the presentation, there will be some suggestions for teachers about the effective use of technological devices in the classroom. This study can help educators understand better how students are currently using iPads and Tablets and shape future use.

Keywords: ipads, language teaching, tablets, technology

Procedia PDF Downloads 239
2771 Effect of Phonological Complexity in Children with Specific Language Impairment

Authors: Irfana M., Priyandi Kabasi

Abstract:

Children with specific language impairment (SLI) have difficulty acquiring and using language despite having all the requirements of cognitive skills to support language acquisition. These children have normal non-verbal intelligence, hearing, and oral-motor skills, with no history of social/emotional problems or significant neurological impairment. Nevertheless, their language acquisition lags behind their peers. Phonological complexity can be considered to be the major factor that causes the inaccurate production of speech in this population. However, the implementation of various ranges of complex phonological stimuli in the treatment session of SLI should be followed for a better prognosis of speech accuracy. Hence there is a need to study the levels of phonological complexity. The present study consisted of 7 individuals who were diagnosed with SLI and 10 developmentally normal children. All of them were Hindi speakers with both genders and their age ranged from 4 to 5 years. There were 4 sets of stimuli; among them were minimal contrast vs maximal contrast nonwords, minimal coarticulation vs maximal coarticulation nonwords, minimal contrast vs maximal contrast words and minimal coarticulation vs maximal coarticulation words. Each set contained 10 stimuli and participants were asked to repeat each stimulus. Results showed that production of maximal contrast was significantly accurate, followed by minimal coarticulation, minimal contrast and maximal coarticulation. A similar trend was shown for both word and non-word categories of stimuli. The phonological complexity effect was evident in the study for each participant group. Moreover, present study findings can be implemented for the management of SLI, specifically for the selection of stimuli.

Keywords: coarticulation, minimal contrast, phonological complexity, specific language impairment

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2770 In vitro Study on Characterization and Viability of Vero Cell Lines after Supplementation with Porcine Follicular Fluid Proteins in Culture Medium

Authors: Mayuva Youngsabanant, Suphaphorn Rabiab, Hatairuk Tungkasen, Nongnuch Gumlungpat, Mayuree Pumipaiboon

Abstract:

The porcine follicular fluid proteins (pFF) of healthy small size ovarian follicles (1-3 mm in diameters) of Large White pig ovaries were collected by sterile technique. They were used for testing the effect on cell viability and characterization of Vero cell lines using MTT assay. Two hundred microliter of round shape Vero cell lines were culture in 96 well plates with DMEM for 24 h. After that, they were attachment to substrate and some changed into fibroblast shape and spread over the surface after culture for 48 h. Then, Vero cell lines were treated with pFF at concentration of 2, 4, 20, 40, 200, 400, 500, and 600 µg proteins/mL for 24 h. Yields of the best results were analyzed by using one-way ANOVA. MTT assay reviewed an increasing in percentage of viability of Vero cell lines indicated that at concentration of 400-600 µg proteins/mL showed higher percentage of viability (115.64 ± 6.95, 106.91 ± 5.27 and 116.73 ± 20.15) than control group. They were significantly different from the control group (p < 0.05) but lower than the positive control group (DMEM with 10% heat treated fetal bovine serum). Cell lines showed normal character in fibroblast elongate shape after treated with pFF except in high concentration of pFF. This result implies that pFF of small size ovarian follicle at concentration of 400-600 µg proteins/mL could be optimized concentration for using as a supplement in Vero cell line culture medium to promote cell viability instead of growth hormone from fetal bovine serum. This merit could be applied in other cell biotechnology researches. Acknowledgements: This work was funded by a grant from Silpakorn University and Faculty of Science, Silpakorn University, Thailand.

Keywords: cell viability, porcine follicular fluid, MTT assay, Vero cell line

Procedia PDF Downloads 117