Search results for: suitability tests

Authors: Gehan Aouf, Diala Tabbal, Abd El Rahim Sabsabi, Rashad Aouf

Abstract:

The aim of this study is to show the effect of adding cement municipal solid incineration fly ash and rubber as stabilizer materials on weak soil. A detailed experimental study was conducted in order to show the viability of using these admixtures in improving the maximum dry density and optimum moisture content of the composite soil. Soil samples were prepared by adding Rubber and Cement to municipal solid waste incineration fly-ash - oil mix at different percentages. Then, a series of laboratory tests were performed, namely: Sieve analysis, Atterberg limits tests, Unconfined compression test, and Proctor tests. Three different percentages of fly ash (10%, 20%, and 30%) MSWFA by total dry weight of soil and three different percentages of Portland cement (10%, 15%, and 20%) by total dry weight of the mix and 0%, 5%, 10% for Rubber by total dry weight of the mix were used to find the optimum value. The test results reveal that adding MSWIFA to the soil up to 20% increased the MDD of the mixture and decreased the OMC, then an opposite trend for results were found when the percentage of MSWIFA exceeded 20%. This is due to the low specific gravity of MSWIFA and to the greater water absorption of MSWIFA. The laboratory tests also indicate that adding Rubber to the mix Soil-MSWIFA-Cement decreases its MDD due to the low specific gravity of rubber and it affects a slight decrease in OMC because the rubber has low absorption of water.

Keywords: clayey soil, MSWIFA, proctor test, rubber

Procedia PDF Downloads 91

Authors: Hari Krishnan K. P., Anil Kumar M. V.

Abstract:

The Direct Strength Method (DSM) is used for the computation of the design strength of members whose behavior is governed by any form of buckling. DSM based semiempirical equations have been successfully used for cold-formed steel (CFS) members subjected to compression, bending, and shear. The DSM equations for the strength of a CFS member are based on the parameters accounting for strength [yield load (Py), yield moment (My), and shear yield load (Vy) for compression, bending, and shear respectively] and stability [buckling load (Pcr), buckling moment (Mcr), and shear buckling load (Vcr) for compression, bending and shear respectively]. The buckling of column and beam shall be governed by local, distortional, or global buckling modes and their interaction. Recently DSM-based methods are extended for the web crippling strength of CFS beams also. Numerous DSM-based expressions were reported in the literature, which is the function of loading case, cross-section shape, and boundary condition. Unlike members subjected to axial load, bending, or shear, no unified expression for the design web crippling strength irrespective of the loading case, cross-section shape, and end boundary conditions are available yet. This study, based on nonlinear finite element analysis results, shows that the slenderness of the web, which shall be represented either using web height to thickness ratio (h=t) or Pcr has negligible contribution to web crippling strength. Hence, the results in this paper question the suitability of DSM based approach for the web crippling strength of CFS beams.

Keywords: cold-formed steel, beams, DSM-based procedure, interior two flanged loading, web crippling

Procedia PDF Downloads 62

Authors: Qin Xvelian

Abstract:

organic renewal" based on the development of existing resources in high-density urban areas has become the mainstream of urban development in the new era. As an important stock resource of public space in high-density urban areas, promoting its value remodeling is an effective way to alleviate the shortage of public space resources. However, due to the lack of evaluation links in the process of underpass space renewal, a large number of underpass space resources have been left idle, facing the problems of low space conversion efficiency, lack of accuracy in development decision-making, and low adaptability of functional positioning to citizens' needs. Therefore, it is of great practical significance to construct the evaluation system of under-bridge space renewal potential and explore the renewal mode. In this paper, some of the under-bridge spaces in the main urban area of Chongqing are selected as the research object. Through the questionnaire interviews with the users of the built excellent space under the bridge, three types of six levels and twenty-two potential evaluation indexes of "objective demand factor, construction feasibility factor and construction suitability factor" are selected, including six levels of land resources, infrastructure, accessibility, safety, space quality and ecological environment. The analytical hierarchy process and expert scoring method are used to determine the index weight, construct the potential evaluation system of the space under the bridge in high-density urban areas of Chongqing, and explore the direction of renewal and utilization of its suitability. To provide feasible theoretical basis and scientific decision support for the use of under bridge space in the future.

Keywords: high density urban area, potential evaluation, space under bridge, updated using

Procedia PDF Downloads 34

Authors: Erkam Arslantas

Abstract:

Heat pipes one of the thermal control elements are used in communication satellites. A selection of the heat pipes of satellite thermal design will be emphasized how important and effective it is. In this article, manufacturing and performance control tests of heat pipes are reviewed from the current literature. The heat pipe is expected to function efficiently during all missions of the spacecraft from Beginning of Life (BOL) to End of Life (EOL). There are many parameters that are evaluated in manufacturing and performance control tests of the heat pipes which are used in satellites. These parameters are pressure design, leakage, noncondensable gas level (N.C.G), sine vibration, shock and static load capabilities, aging, bending, proof, final test etc. These parameters will be explained separately for the heat pipes in this review article and young researches working on the thermal control system of Geosynchronous Satellites systems can find easily related information in this article.

Keywords: communication satellite, heat pipe, performance test, thermal control

Procedia PDF Downloads 136

Authors: Vera Wilden, Benno Hoffmeister, Markus Feldmann

Abstract:

Glued laminated timber (glulam) is a preferred choice for long span girders, e.g., for gyms or storage halls. While the material provides sufficient strength to resist the bending moments, large spans lead to increased slenderness of such members and to a higher susceptibility to stability issues, in particular to lateral torsional buckling (LTB). Rules for the determination of the ultimate LTB resistance are provided by Eurocode 5. The verifications of the resistance may be performed using the so called equivalent member method or by means of theory 2nd order calculations (direct method), considering equivalent imperfections. Both methods have significant limitations concerning their applicability; the equivalent member method is limited to rather simple cases; the direct method is missing detailed provisions regarding imperfections and requirements for numerical modeling. In this paper, the results of a test series on slender glulam beams in three- and four-point bending are presented. The tests were performed in an innovative, newly developed testing rig, allowing for a very precise definition of loading and boundary conditions. The load was introduced by a hydraulic jack, which follows the lateral deformation of the beam by means of a servo-controller, coupled with the tested member and keeping the load direction vertically. The deformation-controlled tests allowed for the identification of the ultimate limit state (governed by elastic stability) and the corresponding deformations. Prior to the tests, the structural and geometrical imperfections were determined and used later in the numerical models. After the stability tests, the nearly undamaged members were tested again in pure bending until reaching the ultimate moment resistance of the cross-section. These results, accompanied by numerical studies, were compared to resistance values obtained using both methods according to Eurocode 5.

Keywords: experimental tests, glued laminated timber, lateral torsional buckling, numerical simulation

Procedia PDF Downloads 202

Authors: K. B. M. Islam, Syeeda Shiraj-Um-Mahmuda, Afroj Jahan, A. A. Bhuiyan

Abstract:

In Bangladesh, the use of imported probiotics in poultry is gradually being increased. But surprisingly, no probiotic bacteria have been isolated yet in Bangladesh despite the existence of scavenging native poultry as potential source that is seemingly more resistant to GIT infection as well as other diseases. Therefore, the study was undertaken to isolate, identify and characterize the potential probiotic Lactobacillus and Bifidobacteria strains from Bangladeshi indigenous poultry, and to evaluate their suitability to use in poultry industry. Crop and cecal samples from 61 healthy indigenous birds were used to isolate potential probiotics strains following conventional cultural methods. A total of 216 isolates were identified following physical, biochemical and molecular methods that belonged to the genus Lactobacillus and Bifidobacteria. An auto-aggregation test was performed for 180 and 136 isolated lactobacilli and bifidobacteria strains, respectively. Twelve lactobacilli isolates and 7 bifidobacteria isolates were selected because of their convenient aggregation. In vitro tests including antibacterial activity, resistance to low pH, hemolytic activities etc. were performed for evaluation of probiotic potential of each strain. Under the in vitro conditions and with respects to the probiotic traits, three lactobacilli; LS16, LS45, LS133 and two bifidobacteria, BS21 and BS90 were found to be potential probiotic strains. Thus, they are proposed to be evaluated for their in vivo probiotic properties. If the proposed strains are found suitable as the probiotics to be used in commercial poultry industry, it is expected that the local probiotics would be more beneficial and would save the huge amount of money that Bangladesh spends every year for the importation of such materials from abroad.

Keywords: Bangladeshi poultry, gut microbiota, lactic acid bacteria, scavenging chicken, GIT health

Procedia PDF Downloads 281

Authors: Areti Angeliki Veroniki, Sofia Tsokani, Evangelos Paraskevaidis, Dimitris Mavridis

Abstract:

The plethora of diagnostic test accuracy (DTA) studies has led to the increased use of systematic reviews and meta-analysis of DTA studies. Clinicians and healthcare professionals often consult DTA meta-analyses to make informed decisions regarding the optimum test to choose and use for a given setting. For example, the human papilloma virus (HPV) DNA, mRNA, and cytology can be used for the cervical intraepithelial neoplasia grade 2+ (CIN2+) diagnosis. But which test is the most accurate? Studies directly comparing test accuracy are not always available, and comparisons between multiple tests create a network of DTA studies that can be synthesized through a network meta-analysis of diagnostic tests (DTA-NMA). The aim is to summarize the DTA-NMA methods for at least three index tests presented in the methodological literature. We illustrate the application of the methods using a real data set for the comparative accuracy of HPV DNA, HPV mRNA, and cytology tests for cervical cancer. A search was conducted in PubMed, Web of Science, and Scopus from inception until the end of July 2019 to identify full-text research articles that describe a DTA-NMA method for three or more index tests. Since the joint classification of the results from one index against the results of another index test amongst those with the target condition and amongst those without the target condition are rarely reported in DTA studies, only methods requiring the 2x2 tables of the results of each index test against the reference standard were included. Studies of any design published in English were eligible for inclusion. Relevant unpublished material was also included. Ten relevant studies were finally included to evaluate their methodology. DTA-NMA methods that have been presented in the literature together with their advantages and disadvantages are described. In addition, using 37 studies for cervical cancer obtained from a published Cochrane review as a case study, an application of the identified DTA-NMA methods to determine the most promising test (in terms of sensitivity and specificity) for use as the best screening test to detect CIN2+ is presented. As a conclusion, different approaches for the comparative DTA meta-analysis of multiple tests may conclude to different results and hence may influence decision-making. Acknowledgment: This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning 2014-2020» in the context of the project “Extension of Network Meta-Analysis for the Comparison of Diagnostic Tests ” (MIS 5047640).

Keywords: colposcopy, diagnostic test, HPV, network meta-analysis

Procedia PDF Downloads 117

Authors: Mahmood Alsaadi, Alexei Lisitsa

Abstract:

Nowadays, medical devices rely completely on software whether as whole software or as embedded software, therefore, the organization that develops medical device software can benefit from adopting agile practices. Using agile practices in healthcare software development industries would bring benefits such as producing a product of a high-quality with low cost and in short period. However, medical device software development companies faced challenges in adopting agile practices. These due to the gaps that exist between agile practices and the requirements of healthcare regulations such as documentation, traceability, and formality. This research paper will conduct a study to investigate the adoption rate of agile practice in medical device software development, and they will extract and outline the requirements of healthcare regulations such as Food and Drug Administration (FDA), Health Insurance Portability and Accountability Act (HIPAA), and Medical Device Directive (MDD) that affect directly or indirectly on software development life cycle. Moreover, this research paper will evaluate the suitability of using agile practices in healthcare industries by analyzing the most popular agile practices such as eXtream Programming (XP), Scrum, and Feature-Driven Development (FDD) from healthcare industry point of view and in comparison with the requirements of healthcare regulations. Finally, the authors propose an agile mixture model that consists of different practices from different agile methods. As result, the adoption rate of agile practices in healthcare industries still low and agile practices should enhance with regard to requirements of the healthcare regulations in order to be used in healthcare software development organizations. Therefore, the proposed agile mixture model may assist in minimizing the gaps existing between healthcare regulations and agile practices and increase the adoption rate in the healthcare industry. As this research paper part of the ongoing project, an evaluation of agile mixture model will be conducted in the near future.

Keywords: adoption of agile, agile gaps, agile mixture model, agile practices, healthcare regulations

Procedia PDF Downloads 211

Authors: Elaheh Hosseini, Otmar Bock, Monika Thomas

Abstract:

The purpose of the present study was to determine the effect of climbing therapy on the components of attention of children with attention-deficit hyperactivity disorder (ADHD). Forty children with ADHD were assigned to either an intervention group or a control group. The exercise group participated in a climbing therapy program for ten weeks, whereas no intervention was administered to the control group. All two groups were then assessed with the same battery of attention tests used in our earlier study. We found that compared to the ‘intervention’ group, performance was higher in the ‘control’ group on tests of sustained, divided and distributed attention, on all four tests. The intervention group showed a significant improvement in components of attention after ten weeks. From this we conclude that climbing therapy can improve the attention of children with ADHD and can be considered as a promising intervention and a standalone treatment for children with ADHD.

Keywords: ADHD, climbing therapy, distributed attention, divided attention, selective attention, sustained attention

Procedia PDF Downloads 137

Authors: F. A. Hassona, M. M. Abu-Heleika, M. A. Hassan, A. E. Sidhom

Abstract:

Application of electrical measurements to evaluate engineering properties of soils has gained a wide, promising field of research in recent years. So, understanding of the relation between in-situ electrical resistivity of clay soil, and their mechanical and physical properties consider a promising field of research. This would assist in introducing a new technique for the determination of soil properties based on electrical resistivity. In this work soil physical and mechanical properties of clayey soil have been determined by experimental tests and correlated with the in-situ electrical resistivity. The research program was conducted through measuring fifteen vertical electrical sounding stations along with fifteen selected boreholes. These samples were analyzed and subjected to experimental tests such as physical tests namely bulk density, water content, specific gravity, and grain size distribution, and Attereberg limits tests. Mechanical test was also conducted such as direct shear test. The electrical resistivity data were interpreted and correlated with each one of the measured experimental parameters. Based on this study mathematical relations were extracted and discussed. These results exhibit an excellent match with the results reported in the literature. This study demonstrates the utility of the developed methodology for determining the mechanical properties of soils easily and rapidly depending on their electrical resistivity measurements.

Keywords: electrical resistivity, clayey soil, physical properties, shear properties

Procedia PDF Downloads 254

Authors: Xu Jinsheng, Tong Xin, Zheng Jian, Zhou Changsheng

Abstract:

The NEPE (nitrate ester plasticized polyether) propellant is a kind of particle filling material with relatively high filling fraction. The experimental results show that the microcracks, microvoids and dewetting can cause the stress softening of the material. In this paper, a series of mechanical testing in inclusion with CCD technique were conducted to analyze the evolution of internal defects of propellant. The volume expansion function of the particle filling material was established by measuring of longitudinal and transverse strain with optical deformation measurement system. By analyzing the defects and internal damages of the material, a visco-hyperelastic constitutive model based on free energy theory was proposed incorporating damage function. The proposed constitutive model could accurately predict the mechanical properties of uniaxial tensile tests and tensile-relaxation tests.

Keywords: dewetting, constitutive model， uniaxial tensile tests, visco-hyperelastic, nonlinear

Procedia PDF Downloads 264

Authors: Xvelian Qin

Abstract:

Urban "organic renewal" based on the development of existing resources in high-density urban areas has become the mainstream of urban development in the new era. As an important stock resource of public space in high-density urban areas, promoting its value remodeling is an effective way to alleviate the shortage of public space resources. However, due to the lack of evaluation links in the process of underpass space renewal, a large number of underpass space resources have been left idle, facing the problems of low space conversion efficiency, lack of accuracy in development decision-making, and low adaptability of functional positioning to citizens' needs. Therefore, it is of great practical significance to construct the evaluation system of under-bridge space renewal potential and explore the renewal mode. In this paper, some of the under-bridge spaces in the main urban area of Chongqing are selected as the research object. Through the questionnaire interviews with the users of the built excellent space under the bridge, three types of six levels and twenty-two potential evaluation indexes of "objective demand factor, construction feasibility factor and construction suitability factor" are selected, including six levels of land resources, infrastructure, accessibility, safety, space quality and ecological environment. The analytical hierarchy process and expert scoring method are used to determine the index weight, construct the potential evaluation system of the space under the bridge in high-density urban areas of Chongqing, and explore the direction of renewal and utilization of its suitability. To provide feasible theoretical basis and scientific decision support for the use of under bridge space in the future.

Keywords: high density urban area, potential evaluation, space under bridge, updated using

Procedia PDF Downloads 35

Authors: Amirali Mahouti, Hooshang Katebi

Abstract:

Enlargement of Tabriz metropolis to the east and north-east caused urban construction to be built on Marl layers and because of increase in excavations depth, further information of this layer is inescapable. Looking at geotechnical investigation shows there is not enough information about Tabriz Marl and this soil has been classified only by color. Tabriz Marl is lacustrine carbonate sediment outcrops, surrounds eastern, northern and southern region of city in the East Azerbaijan Province of Iran and is known as bed rock of city under alluvium sediments. This investigation aims to characterize geotechnical parameters of this soil to identify and set it in classification system of carbonated soils. For this purpose, specimens obtained from 80 locations over the city and subjected to physical and mechanical tests, such as Atterberg limits, density, moisture content, unconfined compression, direct shear and consolidation. CaCO3 content, organic content, PH, XRD, XRF, TGA and geophysical downhole tests also have been done on some of them.

Keywords: carbonated soils, classification of soils, mineralogy, physical and mechanical tests for Marls, Tabriz Marl

Procedia PDF Downloads 298

Authors: Samar Raffoul, Martin Heywood, Dimitrios Moutaftsis, Michael Rowell

Abstract:

This paper comprises an experimental investigation into the structural performance of cold formed steel (CFS) and timber board composite floor systems. The tests include a series of small-scale pushout tests and full-scale bending tests carried out using a refined loading system to simulate uniformly distributed constant load. The influence of connection details (screw spacing and adhesives) on floor performance was investigated. The results are then compared to predictions from relevant existing models for composite floor systems. The results of this research demonstrate the significant benefits of considering the composite action of the boards in floor design. Depending on connection detail, an increase in flexural stiffness of up to 40% was observed in the floor system, when compared to designing joists individually.

Keywords: cold formed steel joists, composite action, flooring systems, shear connection

Procedia PDF Downloads 108

Authors: Nadine Ali Hassan, Ngoc Son Nguyen, Didier Marot, Fateh Bendahmane

Abstract:

This paper aims at presenting a study of the effect of scalping methods on the mechanical properties of coarse soils by resorting to numerical simulations based on the discrete element method (DEM) and experimental triaxial tests. Two reconstitution methods are used, designated as scalping method and substitution method. Triaxial compression tests are first simulated on a granular materials with a grap graded particle size distribution by using the DEM. We study the effect of these reconstitution methods on the stress-strain behavior of coarse soils with different fine contents and with different ways to control the densities of the scalped and substituted materials. Experimental triaxial tests are performed on original mixtures of sands and gravels with different fine contents and on their corresponding scalped and substituted samples. Numerical results are qualitatively compared to experimental ones. Agreements and discrepancies between these results are also discussed.

Keywords: coarse soils, mechanical behavior, scalping, replacement, triaxial devices

Procedia PDF Downloads 173

Authors: Xuelian Qin

Abstract:

Urban "organic renewal" based on the development of existing resources in high-density urban areas has become the mainstream of urban development in the new era. As an important stock resource of public space in high-density urban areas, promoting its value remodeling is an effective way to alleviate the shortage of public space resources. However, due to the lack of evaluation links in the process of underpass space renewal, a large number of underpass space resources have been left idle, facing the problems of low space conversion efficiency, lack of accuracy in development decision-making, and low adaptability of functional positioning to citizens' needs. Therefore, it is of great practical significance to construct the evaluation system of under-bridge space renewal potential and explore the renewal mode. In this paper, some of the under-bridge spaces in the main urban area of Chongqing are selected as the research object. Through the questionnaire interviews with the users of the built excellent space under the bridge, three types of six levels and twenty-two potential evaluation indexes of "objective demand factor, construction feasibility factor and construction suitability factor" are selected, including six levels of land resources, infrastructure, accessibility, safety, space quality and ecological environment. The analytical hierarchy process and expert scoring method are used to determine the index weight, construct the potential evaluation system of the space under the bridge in high-density urban areas of Chongqing, and explore the direction of renewal and utilization of its suitability. To provide feasible theoretical basis and scientific decision support for the use of under bridge space in the future.

Keywords: high density urban area, potential evaluation, space under bridge, updated using

Procedia PDF Downloads 55

Authors: Muhammad Arslan Usman, Muhammad Rehan Usman, Soo Young Shin

Abstract:

Live video streaming is one of the most widely used service among end users, yet it is a big challenge for the network operators in terms of quality. The only way to provide excellent Quality of Experience (QoE) to the end users is continuous monitoring of live video streaming. For this purpose, there are several objective algorithms available that monitor the quality of the video in a live stream. Subjective tests play a very important role in fine tuning the results of objective algorithms. As human perception is considered to be the most reliable source for assessing the quality of a video stream, subjective tests are conducted in order to develop more reliable objective algorithms. Temporal impairments in a live video stream can have a negative impact on the end users. In this paper we have conducted subjective evaluation tests on a set of video sequences containing temporal impairment known as frame freezing. Frame Freezing is considered as a transmission error as well as a hardware error which can result in loss of video frames on the reception side of a transmission system. In our subjective tests, we have performed tests on videos that contain a single freezing event and also for videos that contain multiple freezing events. We have recorded our subjective test results for all the videos in order to give a comparison on the available No Reference (NR) objective algorithms. Finally, we have shown the performance of no reference algorithms used for objective evaluation of videos and suggested the algorithm that works better. The outcome of this study shows the importance of QoE and its effect on human perception. The results for the subjective evaluation can serve the purpose for validating objective algorithms.

Keywords: objective evaluation, subjective evaluation, quality of experience (QoE), video quality assessment (VQA)

Procedia PDF Downloads 581

Authors: Bulus Kpame, Mukhtar Mohammed Alhaji, Garba Jibril

Abstract:

In any team sport, the most important variables that should be used to measure performance are physical condition, and technical and tactical performance. In a complex game like football, it is extremely difficult to measure the relative importance of each of these variables. However, physical fitness itself has been shown to consist of several components, like endurance, strength, flexibility, agility, coordination and speed. Each of these components has been shown to consist of several subcomponents. This paper attempts to describe a test battery to assess and evaluate physical performance in football players. This battery comprises a functional, structured training session of about 2.5hrs. it consists of quality rating of the warm-up procedure, tests of flexibility, football skills, power, speed, and endurance. Acceptable values for performance in each of the tests are also presented under each test. It is hoped that this battery of tests will be helpful to the coach in determining the effect of a specific training program. It would also be helpful to train physician and trainer, to monitor progress during rehabilitation after sustaining any injury.

Keywords: assessment, evaluation, performance, programs

Procedia PDF Downloads 374

Authors: Gehan Aouf, Diala Tabbal, Abd El Rahim Sabsabi, Rashad Aouf

Abstract:

The aim of this study is to assess the viability of utilizing Municipal Solid Waste Incineration Fly Ash (MSWIFA) with Ordinary Portland cement as soil reinforcement materials for geotechnical engineering applications. A detailed experimental program is carried out, followed by analysis of results. Soil samples were prepared by adding Cement to MSWIFA-soil mix at different percentages. Then, a series of laboratory tests were performed, namely: Sieve analysis, Atterberg limits tests, Unconfined compression test, and Proctor tests. A parametric study is conducted to investigate the effect of adding the cement at different percentages on the unconfined compression strength, maximum dry density, and optimum moisture content of clayey soil-MSWIFA The variation of contents of admixtures were 10%, 20%, and 30% for MSWIFA by dry total weight of soil and 10%, 15%, and 20% for Portland cement by dry total weight of the mix. The test results reveal that adding MSWIFA to the soil up to 20% increased the MDD of the mixture and decreased the OMC, then an opposite trend for results were found when the percentage of MSWIFA exceeds 20%. This is due to the low specific gravity of MSWIFA and to the greater water absorption of MSWIFA. The laboratory tests also indicate that the UCS values were found to be increased for all the mixtures with curing periods of 7, 14, and 28 days. It is also observed that the cement increased the strength of the finished product of the mix of soil and MSWIFA.

Keywords: clayey soil, cement, MSWIFA, unconfined compression strength

Procedia PDF Downloads 107

Authors: Hina Javed

Abstract:

This study investigated the different strategies used by Pakistani students learning English as a second language at secondary level school. The basic premise of the study is that ESL students face tremendous difficulty while they are reading a text in English. It also purports to dig into the different causes of their slow reading. They might range from word reading accuracy, mental translation, lexical density, cultural gaps, complex syntactic constructions, and back skipping. Sixty Grade 7 students from two secondary mainstream schools in Lahore were selected for the study, thirty being boys and thirty girls. They were administered reading-related and reading speed pre and post-tests. The purpose of the tests was to gauge their performance on different reading tasks so as to be able to see how they used strategies, if any, and also to ascertain the causes hampering their performance on those tests. In the pretests, they were given simple texts with considerable lexical density and moderately complex sentential layout. In the post-tests, the reading tasks contained comic strips, texts with visuals, texts with controlled vocabulary, and an evenly distributed varied range of simple, compound, and complex sentences. Both the tests were timed. The results gleaned through the data gathered corroborated the researchers’ basic hunch that they performed significantly better than pretests. The findings suggest that the morphological structure of words and lexical density are the main sources of reading comprehension difficulties in poor ESL readers. It is also confirmed that if the texts are accompanied by pictorial visuals, it greatly facilitates students’ reading speed and comprehension. There is no substantial evidence that ESL readers adopt any specific strategy while reading in English.

Keywords: slow ESL reading speed, mental translation, complex syntactic constructions, back skipping

Procedia PDF Downloads 43

Authors: Ionel Zagan, Vasile Gheorghita Gaitan

Abstract:

The development of CPUs and of real-time systems based on them made it possible to use time at increasingly low resolutions. Together with the scheduling methods and algorithms, time organizing has been improved so as to respond positively to the need for optimization and to the way in which the CPU is used. This presentation contains both a detailed theoretical description and the results obtained from research on improving the performances of the nMPRA (Multi Pipeline Register Architecture) processor by implementing specific functions in hardware. The proposed CPU architecture has been developed, simulated and validated by using the FPGA Virtex-7 circuit, via a SoC project. Although the nMPRA processor hardware structure with five pipeline stages is very complex, the present paper presents and analyzes the tests dedicated to the implementation of the CPU and of the memory on-chip for instructions and data. In order to practically implement and test the entire SoC project, various tests have been performed. These tests have been performed in order to verify the drivers for peripherals and the boot module named Bootloader.

Keywords: hardware scheduler, nMPRA processor, real-time systems, scheduling methods

Procedia PDF Downloads 245

Authors: Ana P. R. N. Barroso, Maurício N. Kleinberg, Frederico R. Silva, Rodrigo F. Guimarães, Marcelo M. V. Parente, Walney S. Araújo

Abstract:

The fight against accelerated wear of the equipment used in the oil and gas sector is a challenge for minimizing maintenance costs. Corrosion being one of the main agents of equipment deterioration, we seek alternative materials that exhibit improved corrosion resistance at low cost of production. This study aims to evaluate the corrosion behavior of experimental alloys containing 15% and 17% of chromium (Cr) and 5% of molybdenum (Mo) in comparison with an AISI 444 commercial alloy. Microstructural analyzes were performed on samples of the alloys before and after the electrochemical tests. Two samples of each solubilized alloy were also taken for analysis of the corrosion behavior by testing potentiodynamic polarization (PP) and Electrochemical Impedance Spectroscopy (EIS) with immersion time of 24 hours in electrolytic solution with acidic character. The graphics obtained through electrochemical tests of PP and EIS indicated that among the experimental alloys, the alloy with higher chromium content (17%) had a higher corrosion resistance, confirming the beneficial effect of adding chromium. When comparing the experimental alloys with the AISI 444 commercial alloy, it is observed that the AISI 444 commercial alloy showed superior corrosion resistance to that of the experimental alloys for both assays, PP and EIS. The microstructural analyzes performed after the PP and EIS tests confirmed the results previously described. These results suggest that the addition of these levels of molybdenum did not favor the electrochemical behavior of experimental ferritic alloys for the electrolytic medium studied.

Keywords: corrosion, molybdenum, electrochemical tests, experimental alloys

Procedia PDF Downloads 550

Authors: Glaucia Maricato

Abstract:

Our research deals with specific use of DNA tests in Brazil – aimed at financial reparation for the institutionalized and otherwise scattered offspring of leprosy patients who, from the 1920s up through the 1980s, were subjected to compulsory internment in the 'hospital-colonies', specialized in the containment of Hansen’s disease. Through a social movement, the ex-patients themselves gained the right, in 2007, to financial compensations. At the moment, the movement is seeking reparation for the (now adult) children of these people as well. Many of these children grew up in orphanages, in adopted families, or do not have official documents to prove their family belonging. In 2011, a team of Brazilian geneticists had volunteered their services, applying DNA tests in order to ascertain the connection of certain individuals to an ex-internee of the leprosarium. We have accompanied the activities in four different ex-colonies in order to understand how the DNA test was being signified by those being tested, and how the test fit into already existent notions of family. Inspired in the writings of scholars such as Sheila Jasanoff and Helena Machado, we examine the possibility of a 'geneticization of family ties' when people are obliged to back their claim for human rights by producing legal proof based on blood tests. However, in like fashion to other ethnographic studies on this theme, we encountered among tested adults a number of creative strategies that allow for the co-existence of the idea of 'scientifically-based' blood ties alongside other more traditional ways of signifying kinship.

Keywords: human rights, social movements, DNA tests, Hansen's disease

Procedia PDF Downloads 110

Authors: Duanlei Yuan, Guangchao Yan, Zhanqing Chen, Xian Cheng

Abstract:

This paper mainly focuses on the problem that high voltage circuit breaker’s closing and opening operation at random phase brings harmful electromagnetic transient effects on the power system. To repress the negative transient effects, a 35 kV SF6 phase-control circuit breaker equipped with electromagnetic force driving actuator is designed in this paper. Based on the constructed mathematical and structural models, the static magnetic field distribution and dynamic properties of the under loading actuator are simulated. The prototype of 35 kV SF6 phase-control circuit breaker is developed based on theories analysis and simulation. Tests are carried on to verify the operating reliability of the prototype. The developed circuit breaker can control its operating speed intelligently and switches with phase selection. Results of the tests and simulation prove that the phase-control circuit breaker is feasible for industrial applications.

Keywords: phase-control, circuit breaker, electromagnetic force driving actuator, tests and simulation

Procedia PDF Downloads 372

Authors: Siti Nur Afifah Azraai, Lim Kar Sing, Nordin Yahaya, Norhazilan Md Noor

Abstract:

This experimental study consists of a characterization of epoxy grout where an amount of 2% of graphene nanoplatelets particles were added to commercial epoxy resin to evaluate their behavior regarding neat epoxy resin. Compressive tests, tensile tests and flexural tests were conducted to study the effect of graphene nanoplatelets on neat epoxy resin. By comparing graphene-based and neat epoxy grout, there is no significant increase of strength due to weak interface in the graphene nanoplatelets/epoxy composites. From this experiment, the tension and flexural strength of graphene-based epoxy grouts is slightly lower than ones of neat epoxy grout. Nevertheless, the addition of graphene has produced more consistent results according to a smaller standard deviation of strength. Furthermore, the graphene has also improved the ductility of the grout, hence reducing its brittle behaviour. This shows that the performance of graphene-based grout is reliably predictable and able to minimize sudden rupture. This is important since repair design of damaged pipeline is of deterministic nature.

Keywords: composite, epoxy resin, graphene nanoplatelets, pipeline

Procedia PDF Downloads 459

Authors: Ji Hun Choi, Seung Un Chae, Kyeong Suk Cho

Abstract:

Synthetic resins are widely used in various fields including electricity, engineering, construction and agriculture. Many of interior and exterior finishing materials for buildings are synthetic resin products. In this study, full-scale fire tests were conducted on polyvinyl chloride, polypropylene and urethane in accordance with the “ISO 9705: Fire test - Full-scale room test for surface products” to measure heat release rate, toxic gas emission and smoke production rate. Based on the tests, fire growth pattern and fire risk were analyzed. Findings from the tests conducted on polyvinyl chloride and urethane are as follows. The total heat release rate and total smoke production rate of polyvinyl chloride were 98.89MW and 5284.41m2, respectively and its highest CO2 concentration was 0.149%. The values obtained from the test with urethane were 469.94 MW, 3396.28 m2 and 1.549%. While heat release rate and CO2 concentration were higher in urethane implying its high combustibility, smoke production rate was 1.5 times higher in polyvinyl chloride. Follow-up tests are planned to be conducted to accumulate data for the evaluation of heat emission and fire risk associated with synthetic resins.

Keywords: synthetic resins, fire test, full-scale test, heat release rate, smoke production rate, polyvinyl chloride, polypropylene, urethane

Procedia PDF Downloads 407

Authors: Hamed Tohidi, James W. Mahar

Abstract:

One of the unknowns in the design of zoned earth dams is the percentage of sand which can be present in a clay core and still retain the necessary plasticity to prevent cracking in response to deformation. Cracks in the clay core of a dam caused by differential settlement can lead to failure of the dam. In this study, a series of Atterberg Limit tests and unconfined compression strength tests have been conducted in the ISU soil mechanics laboratory on prepared mixes of quartz sand and commercial clays (Kaolin and Smectite) to determine the relationship between sand content, plasticity and squeezing behavior. The prepared mixes have variable percentages of sand ranging between 10 and 90% by weight. Plastic limit test results in which specimens can be rolled into 1/8 in. threads without crumbling and plasticity index values which represent the range of water content over which the specimens can be remolded without cracking were used to evaluate the plasticity of the sand-clay mixtures. The test results show that the design mixes exhibit plastic behavior with sand contents up to 80% by weight. However, the plasticity of the mixes decreases with increasing sand content. For unconfined compression strength tests, the same mixtures of sand and clay (Kaolin) were made in plastic limit. The results which were concluded from the UCC tests represent the relationship between sand-clay content and chance of having squeezing behavior, also according to the results from UCC, strength of different samples and stress-strain curves can be obtained.

Keywords: clay's behaviour, plasticity, sand content, Kaolin clay

Procedia PDF Downloads 218

Authors: Shumani Ramuhaheli, Christopher C. Enweremadu, Hilary L. Rutto

Abstract:

In this study, biodiesel from used cooking oil was produced as purified by washing with water (water wash) and amberlite (dry wash). The work presents the results of short term tests on performance characteristics of diesel engine using both biodiesel-fuel samples. In this investigation, the water wash biodiesel and dry wash biodiesel and diesel were compared for performance using a four-cylinder diesel engine. The torque, brake power, specific fuel consumption and brake thermal efficiency were analyzed. The tests showed that in all cases, dry wash biodiesel performed marginally poorer compared to water wash biodiesel. Except for brake thermal efficiency, diesel fuel had better engine performance characteristics compared to the biodiesel-fuel samples. According to these results, dry washing of biodiesel has a marginal effect on engine performance.

Keywords: biodiesel, engine performance, used cooking oil, water wash, dry wash

Procedia PDF Downloads 333

Authors: Navid Khayat

Abstract:

This study investigates the retrofitting of schools in Ahvaz City. Three schools, namely, Enghelab, Sherafat, and Golchehreh, in Ahvaz City are initially examined through Schmidt hammer and ultrasonic tests. Given the tests and controls on the structures of these schools, the methods are presented for their reconstruction. The plan is presented for each school by estimating the cost and generally the feasibility and estimated the duration of project reconstruction. After reconstruction, the mentioned tests are re-performed for rebuilt parts and the results indicate a significant improvement in performance of structure because of reconstruction. According to the results, despite the fact that the use of fiber reinforced polymers (FRP) for structure retrofitting is costly, due to the low executive costs and also other benefits of FRP, it is generally considered as one of the most effective ways of retrofitting. Building the concrete coating on walls is another effective method in retrofitting the buildings. According to this method, a grid of horizontal and vertical bars is installed on the wall and then the concrete is poured on it. The use of concrete coating on the concrete and brick structures leads to the useful results and the experience indicates that the poured concrete filled the joints well and provides the appropriate binding and adhesion.

Keywords: renovation, retrofitting, masonry structures, old school

Procedia PDF Downloads 257

Authors: Hanbey Hazar, Hakan Gul

Abstract:

In this study; piston, exhaust, and suction valves of a diesel engine were coated in 300 mm thickness with Tungsten Carbide (WC) by using the HVOF coating method. Mathematical modeling of a coated and uncoated (standardized) engine was performed by using ANN (Artificial Neural Networks). The purpose was to decrease the number of repetitions of tests and reduce the test cost through mathematical modeling of engines by using ANN. The results obtained from the tests were entered in ANN and therefore engines' values at all speeds were estimated. Results obtained from the tests were compared with those obtained from ANN and they were observed to be compatible. It was also observed that, with thermal barrier coating, hydrocarbon (HC), carbon monoxide (CO), and smoke density values of the diesel engine decreased; but nitrogen oxides (NOx) increased. Furthermore, it was determined that results obtained through mathematical modeling by means of ANN reduced the number of test repetitions. Therefore, it was understood that time, fuel and labor could be saved in this way.

Keywords: Artificial Neural Network, Diesel Engine, Mathematical Modelling, Thermal Barrier Coating

Procedia PDF Downloads 500