Search results for: compression binder

Authors: Nor-Edine Abriak, Mahfoud Benzerzour, Mouhamadou Amar, Abdeljalil Zri

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In this work, firstly we have studied the potential of raw sediments and sediments treated with lime or cement for use in a foundation layer and the base layer of a roadway. Secondly, we have examined mineral changes caused by the addition of lime or cement in order to explain the mechanical performance of stabilized sediments. After determining the amount of lime and cement required stabilizing the sediments, the compaction characteristics and Immediate Bearing Capacity (IBI) were studied using the Modified Proctor method. Then, the evolution of the three parameters, which are optimum water content, maximum dry density and IBI, were determined. Mechanical performances can be evaluated through resistance to compression, resistance under traction and the elasticity modulus. The resistances of the formulations treated with ROLAC®645 increase with the amount of ROLAC®645. Traction resistance and the elastic modulus were used to evaluate the potential of the formulations as road construction materials using the classification diagram. The results show that all the other formulations with ROLAC®645 can be used in subgrades and foundation layers for roads.

Keywords: sediment, lime, cement, roadway

Procedia PDF Downloads 267

Authors: Harisudha Kuresan, Dhanalakshmi Samiappan, T. Rama Rao

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In modern telecommunication applications, Glottal Closure Instants location finding is important and is directly evaluated from the speech waveform. Here, we study the GCI using Speech Event Detection using Residual Excitation and the Mean Based Signal (SEDREAMS) algorithm. Speech coding uses parameter estimation using audio signal processing techniques to model the speech signal combined with generic data compression algorithms to represent the resulting modeled in a compact bit stream. This paper proposes a sub-band coder SBC, which is a type of transform coding and its performance for GCI detection using SEDREAMS are evaluated. In SBCs code in the speech signal is divided into two or more frequency bands and each of these sub-band signal is coded individually. The sub-bands after being processed are recombined to form the output signal, whose bandwidth covers the whole frequency spectrum. Then the signal is decomposed into low and high-frequency components and decimation and interpolation in frequency domain are performed. The proposed structure significantly reduces error, and precise locations of Glottal Closure Instants (GCIs) are found using SEDREAMS algorithm.

Keywords: SEDREAMS, GCI, SBC, GOI

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Authors: Young Sik Kim, Tae Kwon Ha

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Effect of Zn addition on the microstructure and mechanical properties of Mg-Zn alloys with Zn contents from 6 to 10 weight percent was investigated in this study. Through calculation of phase equilibria of Mg-Zn alloys, carried out by using FactSage® and FTLite database, solution treatment temperature was decided as temperatures from 300 to 400oC, where supersaturated solid solution can be obtained. Solid solution treatment of Mg-Zn alloys was successfully conducted at 380oC and supersaturated microstructure with all beta phase resolved into matrix was obtained. After solution treatment, hot rolling was successfully conducted by reduction of 60%. Compression and tension tests were carried out at room temperature on the samples as-cast, solution treated, hot-rolled and recrystallized after rolling. After solid solution treatment, each alloy was annealed at temperatures of 180 and 200oC for time intervals from 1 min to 48 hrs and hardness of each condition was measured by micro-Vickers method. Peak aging conditions were deduced as at the temperature of 200oC for 10 hrs. By addition of Zn by 10 weight percent, hardness and strength were enhanced.

Keywords: Mg-Zn alloy, heat treatment, microstructure, mechanical properties, hardness

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Authors: Hlaing Zaw Oo, N. Kostromina, V. Osipchik, T. Kravchenko, K. Yakovleva

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The process of modification of ed-20 epoxy resin synthesized by vinyl-containing compounds is considered. It is shown that the introduction of vinyl-containing compounds into the composition based on epoxy resin ED-20 allows adjusting the technological and operational characteristics of the binder. For improvement of the properties of epoxy resin, following modifiers were selected: polyvinylformalethyl, polyvinyl butyral and composition of linear and aromatic amines (Аramine) as a hardener. Now the big range of hardeners of epoxy resins exists that allows varying technological properties of compositions, and also thermophysical and strength indicators. The nature of the aramin type hardener has a significant impact on the spatial parameters of the mesh, glass transition temperature, and strength characteristics. Epoxy composite materials based on ED-20 modified with polyvinyl butyral were obtained and investigated. It is shown that the composition of resins based on derivatives of polyvinyl butyral and ED-20 allows obtaining composite materials with a higher complex of deformation-strength, adhesion and thermal properties, better water resistance, frost resistance, chemical resistance, and impact strength. The magnitude of the effect depends on the chemical structure, temperature and curing time. In the area of concentrations, where the effect of composite synergy is appearing, the values of strength and stiffness significantly exceed the similar parameters of the individual components of the mixture. The polymer-polymer compositions form their class of materials with diverse specific properties that ensure their competitive application. Coatings with high performance under cyclic loading have been obtained based on epoxy oligomers modified with vinyl-containing compounds.

Keywords: epoxy resins, modification, vinyl-containing compounds, deformation, strength properties

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Authors: A. Hamma, A. Pegoretti

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The paper focuses on the evaluation of mechanical performances and viscoelastic behaviour of starch-grafted-PP reinforced with kenaf fibres. Investigations were carried out on composites prepared by melt compounding and compression molding. Two aspects have been taken into account, the effects of various fibres loading rates (10, 20 and 30 wt.%) and the fibres aspect ratios (L/D=30 and 160). Good fibres/matrix interaction has been evidenced by SEM observations. However, processing induced variation of fibre length quantified by optical microscopy observations. Tensile modulus and ultimate properties, hardness and tensile impact stress, were found to remarkably increase with fibre loading. Moreover, short term tensile creep tests have proven that kenaf fibres improved considerably the creep stability. Modelling of creep behaviour by a four parameter Burger model was successfully used. An empirical equation involving Halpin-Tsai semi empirical model was also used to predict the elastic modulus of composites.

Keywords: mechanical properties, creep, fibres, thermoplastic composites, starch-grafted-PP

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Authors: Essam Shalaby, Alexander Churyumov, Malak Abou El-Khair, Atef Daoud

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A comparative study of the thermal and mechanical behavior of squeezed A359 composites containing 5, 10 and 15 wt.% SiC, (SiC+ Si3N4) and AlN particulates was investigated. Stir followed by squeeze casting techniques are used to produce A359 composites. It was noticed that, A359/AlN composites have high thermal conductivity as compared to A359 alloy and even to A359/SiC or A359/(SiC+Si3N4) composites. Microstructures of the composites have shown homogeneous and even distribution of reinforcements within the matrix. Interfacial reactions between particles and matrix were investigated using X-ray diffraction and energy dispersive X-ray analysis. The presence of particles led not only to increase peak hardness of the composites but also to accelerate the aging kinetics. As compared with A359 matrix alloy, compression test of the composites has exhibited a significant increase in the yield and the ultimate compressive strengths with a relative reduction in the failure strain. Those light weight composites have a high potential to be used for automotive and aerospace applications.

Keywords: metal-matrix composite, squeeze, microstructure, thermal conductivity, compressive properties

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Authors: Abu Salim Mustafa

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Rv3873 is a relatively large size protein (371 amino acids in length) and its gene is located in the immunodominant genomic region of difference (RD)1 that is present in the genome of Mycobacterium tuberculosis but deleted from the genomes of all the vaccine strains of Bacillus Calmette Guerin (BCG) and most other mycobacteria. However, when tested for cellular immune responses using peripheral blood mononuclear cells from tuberculosis patients and BCG-vaccinated healthy subjects, this protein was found to be a major stimulator of cell mediated immune responses in both groups of subjects. In order to further identify the sequence of immunodominant epitopes and explore their Human Leukocyte Antigen (HLA)-restriction for epitope recognition, 24 peptides (25-mers overlapping with the neighboring peptides by 10 residues) covering the sequence of Rv3873 were synthesized chemically using fluorenylmethyloxycarbonyl chemistry and tested in cell mediated immune responses. The results of these experiments helped in the identification of an immunodominant peptide P9 that was recognized by people expressing varying HLA-DR types. Furthermore, it was also predicted to be a promiscuous binder with multiple epitopes for binding to HLA-DR, HLA-DP and HLA-DQ alleles of HLA-class II molecules that present antigens to T helper cells, and to HLA-class I molecules that present antigens to T cytotoxic cells. In addition, the evaluation of peptide P9 using an immunogenicity predictor server yielded a high score (0.94), which indicated a greater probability of this peptide to elicit a protective cellular immune response. In conclusion, P9, a peptide with multiple epitopes and ability to bind several HLA class I and class II molecules for presentation to cells of the cellular immune response, may be useful as a peptide-based vaccine against tuberculosis.

Keywords: mycobacterium tuberculosis, PPE68, peptides, vaccine

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Authors: Raed H. Allawi

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Formation pressure is the most critical parameter in hydrocarbon exploration and exploitation. Specifically, predicting abnormal pressures (high formation pressures) and subnormal pressure zones can provide valuable information to minimize uncertainty for anticipated drilling challenges and risks. This study aims to interpret and delineate the pore and fracture pressure of the Mishrif reservoir in the southern Iraq Oilfield. The data required to implement this study included acoustic compression wave, gamma-ray, bulk density, and drilling events. Furthermore, supporting these models needs the pore pressure measurement from the Modular Formation Dynamics Tester (MDT). Many measured values of pore pressure were used to validate the accurate model. Using sonic velocity approaches, the mean absolute percentage error (MAPE) was about 4%. The fracture pressure results were consistent with the measurement data, actual drilling report, and events. The model's results will be a guide for successful drilling in future wells in the same oilfield.

Keywords: pore pressure, fracture pressure, overburden pressure, effective stress, drilling events

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Authors: Berkay Ergene, Çağın Bolat

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In this study, we mainly focused on a simulation study regarding composite footbed in order to contribute to shoe industry. As a footbed, e-glass fiber reinforced polyurethane was determined since polyurethane based materials are already used for footbed in shoe manufacturing frequently. Flat, elliptical and rectangular grooved shoe soles were modeled and analyzed separately as TPU, 10% glass fiber reinforced, 30% glass fiber reinforced and 50% glass fiber reinforced materials according to their properties under three point bending and compression situations to determine the relationship between model, material type and mechanical behaviours of composite model. ANSYS 14.0 APDL mechanical structural module is utilized in all simulations and analyzed stress and strain distributions for different footbed models and materials. Furthermore, materials constants like young modulus, shear modulus, Poisson ratio and density of the composites were calculated theoretically by using composite mixture rule and interpreted for mechanical aspects.

Keywords: composite, elastic behaviour, footbed, simulation

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Authors: Heshalini Rajagopal, Li Sze Chow, Raveendran Paramesran

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Magnetic Resonance Imaging (MRI) is one of the most important medical imaging modality. Subjective assessment of the image quality is regarded as the gold standard to evaluate MR images. In this study, a database of 210 MR images which contains ten reference images and 200 distorted images is presented. The reference images were distorted with four types of distortions: Rician Noise, Gaussian White Noise, Gaussian Blur and DCT compression. The 210 images were assessed by ten subjects. The subjective scores were presented in Difference Mean Opinion Score (DMOS). The DMOS values were compared with four FR-IQA metrics. We have used Pearson Linear Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) to validate the DMOS values. The high correlation values of PLCC and SROCC shows that the DMOS values are close to the objective FR-IQA metrics.

Keywords: medical resonance (MR) images, difference mean opinion score (DMOS), full reference image quality assessment (FR-IQA)

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Authors: Taboka Motlhabane, Pradeep Sahoo

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The global demand for cooling has grown exponentially over the past century to meet economic development and social needs, accounting for approximately 10% of the global electricity consumption. As global temperatures continue to rise, the demand for cooling and heating, ventilation and air-conditioning (HVAC) equipment is set to rise with it. The increased use of HVAC equipment has significantly contributed to the growth of greenhouse gas (GHG) emissions which aid the climate crisis- one of the biggest challenges faced by the current generation. The need to address emissions caused directly by HVAC equipment and electricity generated to meet the cooling or heating demand is ever more pressing. Currently, developed countries account for the largest cooling and heating demand, however developing countries are anticipated to experience a huge increase in population growth in 10 years, resulting in a shift in energy demand. Developing countries, which are projected to account for nearly 60% of the world's GDP by 2030, are rapidly building infrastructure and economies to meet their growing needs and meet these projections. Cooling, a very energy-intensive process that can account for 20 % to 75% of a building's energy, depending on the building's use. Solar photovoltaic (PV) driven air-conditioning offers a great cost-effective alternative for adoption in both residential and non-residential buildings to offset grid electricity, particularly in countries with high irradiation, such as Botswana. This research paper explores the potential of a grid-connected solar photovoltaic vapor-compression air-conditioning system for the Peter-Smith herbarium at the Okavango Research Institute (ORI) University of Botswana campus in Maun, Botswana. The herbarium plays a critical role in the collection and preservation of botanical data, dating back over 100 years, with pristine collection from the Okavango Delta, a UNESCO world heritage site and serves as a reference and research site. Due to the herbarium’s specific needs, it operates throughout the day and year in an attempt to maintain a constant herbarium temperature of 16°?. The herbarium model studied simulates a variable-air-volume HVAC system with a system rating of 30 kW. Simulation results show that the HVAC system accounts for 68.9% of the building's total electricity at 296 509.60 kWh annually. To offset the grid electricity, a 175.1 kWp nominal power rated PV system requiring 416 modules to match the required power, covering an area of 928 m2 is used to meet the HVAC system annual needs. An economic assessment using PVsyst found that for an installation priced with average solar PV prices in Botswana totalled to be 787 090.00 BWP, with annual operating costs of 30 500 BWP/year. With self-project financing, the project is estimated to have recouped its initial investment within 6.7 years. At an estimated project lifetime of 20 years, the Net Present Value is projected at 1 565 687.00 BWP with a ROI of 198.9%, with 74 070.67 tons of CO2 saved at the end of the project lifetime. This study investigates the performance of the HVAC system to meet the indoor air comfort requirements, the annual PV system performance, and the building model has been simulated using DesignBuilder Software.

Keywords: vapor compression refrigeration, solar cooling, renewable energy, herbarium

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Authors: E. Dehghan, R. Dehghan

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Generally, the slender structural walls have flexural behavior. Since behavior of bending members can be explained by moment–curvature relation, therefore, an analytical model is proposed based on moment–curvature relation for slender structural walls. The moment–curvature relationships of RC sections are constructed through section analysis. Governing equations describing the bond-slip behavior in walls are derived and applied to moment–curvature relations. For the purpose of removing the imprecision in analytical results, the plastic hinge length is included in the finite element modeling. Finally, correlation studies between analytical and experimental results are conducted with the objective to establish the validity of the proposed algorithms. The results show that bond-slip effect is more significant in walls subjected to larger axial compression load. Moreover, preferable results are obtained when ultimate strain of concrete is assumed conservatively.

Keywords: nonlinear analysis, slender structural walls, moment-curvature relation, bond-slip, plastic hinge length

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Authors: Claudineia Brazil, Luciane Salvi, Margareth Haubrich

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The research aims to understand the determinants of Quality of Life at Work (QWL) and the main indicators that influence the productivity of employees working in construction. The methodology is based on the qualitative theoretical approach, in which information is collected in works that have already been carried out, providing a more detailed compression of the research from the point of view of other authors. In this research, pioneering models for assessing Quality of Life at Work (QWL) were investigated, seeking to find the best quality of life indicators in the work environment. The elements investigated in the research were classified into three main groups: Organizational, Environmental and Behavioral. In order to obtain the results, the information obtained through bibliographic research was compared and it was possible to conclude that the focus on the quality of life at work influences the individual and collective productivity of employees, causing the company to be positively impacted. This advocates the need for strategic actions in the area of people management, which will meet these needs. Therefore, it is hoped that this study can contribute to the more effective management of human resources in organizations, reflecting on increased productivity.

Keywords: construction, management, productivity, quality of life at work

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Authors: Soheil Heydari, Ailar Hajimohammadi, Nasser Khalili

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Polystyrene, being made from a monomer called styrene, is a rigid and easy-to mould polymer that is widely used for many applications, from foam packaging to disposable containers. Considering that the degradation of waste polystyrene takes up to 500 years, there is an urgent need for a sustainable application for waste polystyrene. This study evaluates the application of waste polystyrene as an asphalt modifier. The inclusion of waste plastics in asphalt is either practised by the dry process or the wet process. In the dry process, plastics are added straight into the asphalt mixture and in the wet process, they are mixed and digested into bitumen. In this article, polystyrene was used as an asphalt modifier in a dry process. However, the mixing process is precisely designed to make sure that the polymer is melted and modified in the binder. It was expected that, due to the rigidity of polystyrene, it will have positive effects on the permanent deformation of the asphalt mixture. Therefore, different mixtures were manufactured with different contents of polystyrene and Marshall specimens were manufactured, and dynamic creep tests were conducted to evaluate the permanent deformation of the modification. This is a commonly repeated loading test conducted at different stress levels and temperatures. Loading cycles are applied to the AC specimen until failure occurs; with the amount of deformation constantly recorded the cumulative, permanent strain is determined and reported as a function of the number of cycles. Also, to our best knowledge, hybrid mixes of polystyrene with crumb rubber and low-density polyethylene were made and compared with a polystyrene-modified mixture. The test results of this study showed that the hybrid mix of polystyrene and low-density polyethylene has the highest resistance against permanent deformation. However, the polystyrene-modified mixture outperformed the hybrid mix of polystyrene and crumb rubber, and both demonstrated way lower permanent deformation than the unmodified specimen.

Keywords: permanent deformation, waste plastics, polystyrene, hybrid plastics, hybrid mix, hybrid modification, dry process

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Authors: Harkaranjit Singh, Arun Kumar

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Depletion of natural resources is a common phenomenon in developing countries like India due to rapid urbanization and industrialization involving construction of infrastructure and other amenities. In view of this, people have started searching for suitable other viable alternative materials for concrete so that the existing natural resources could be preserved to the possible extent for the future generation. In this process, different industrial waste materials such as fly ash, blast furnace slag, quarry dust, tile waste, bricks, broken glass waste, waste aggregate from demolition of structures, ceramic insulator waste, etc. have been tried as a viable substitute material to the conventional materials in concrete and has also been succeeded. This paper describes the studies conducted on strength characteristics of concrete made with utilizing of crushed tiles as a coarse aggregate. The waste crushed tiles can be used as coarse aggregates with the replacement ratio of 0, 50, 75 and 100% were used. Mechanical and physical tests were conducted on specimens. It was found that, the concrete made of waste ceramic tile aggregate produced more strength in compression, and flexure.

Keywords: compressive strength, flexural strength, waste crushed tile, concrete

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Authors: Pahirangan Sivapatham, , Esser Barbara

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The impacts of the asphalt mix design, the properties of aggregates and quality differences in the same type of bitumen, as well as the dosage rate of reclaimed asphalt on the relevant material parameter of the analytical pavement design method are not known. Due to that, in this study, the influence of the above mentioned characteristics on relevant material parameters has been determined and analyzed by means of the analytical pavement calculations method. Therefore, material parameters for several asphalt mixes for asphalt wearing course, asphalt binder course and asphalt base course have been determined. Thereby several bitumens of the same type from different producer’s have been used. In addition, asphalt base course materials with three different dosages of reclaimed asphalt have been produced and tested. As material parameter according to the German analytical pavement design guide(RDO Asphalt), the stiffness’s at different temperatures and fatigue behavior have been determined. The findings of asphalt base course materials produced with several pen graded bitumen from different producers and different dosages of reclaimed asphalt indicate the distinct impact on fatigue behaviors and mechanical properties. The calculated test results of the analytical pavement design method show significant differences in the lifetimes. The pavement design calculation is to carry out by means of the actual material parameter. The calculated lifetime of the asphalt base course materials differentiates by the factor 3.2. The determining test results of bitumen characteristics meet the requirement according to the German Standards. But, further investigations of bitumen in different aging conditions show significant differences in their quality. The fatigue behavior and stiffness of asphalt pavement improves with increasing dosage of reclaimed asphalt. Furthermore, the type of aggregates used shows no significant influences.

Keywords: reclaimed asphalt pavement, quality differences in the bitumen, life time calculation, Asphalt mix with RAP

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Authors: WooYoung Jung, V. Sim

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This paper presents numerical analysis in terms of buckling resistance strength of polymer matrix composite (PMC) infill panels system under the influence of temperature on the foam core. Failure mode under in-plane compression is investigated by means of numerical analysis with ABAQUS platform. Parameters considered in this study are contact length and both the type of foam for core and the variation of its Young's Modulus under the thermal influence. Variation of temperature is considered in static cases and only applied to core. Indeed, it is shown that the effect of temperature on the panel system mechanical properties is significance. Moreover, the variations of temperature result in the decrements of the system strength. This is due to the polymeric nature of this material. Additionally, the contact length also displays the effect on performance of infill panel. Their significance factors are based on type of polymer for core. Hence, by comparing difference type of core material, the variation can be reducing.

Keywords: buckling, contact length, foam core, temperature dependent

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Authors: Ankur Mundhra, Shubhadeep Chakraborty, Y. R. Singh, Vishal Das

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Seismic data scaling affects the dynamic range of a data and with present day lower costs of storage and higher reliability of Hard Disk data, scaling is not suggested. However, in dealing with data of different vintages, which perhaps were processed in 16 bits or even 8 bits and are need to be processed with 32 bit available data, scaling is performed. Also, scaling amplifies low amplitude events in deeper region which disappear due to high amplitude shallow events that saturate amplitude scale. We have focused on significance of scaling data to aid interpretation. This study elucidates a proper seismic loading procedure in workstations without using default preset parameters as available in most software suites. Differences and distribution of amplitude values at different depth for seismic data are probed in this exercise. Proper loading parameters are identified and associated steps are explained that needs to be taken care of while loading data. Finally, the exercise interprets the un-certainties which might arise when correlating scaled and unscaled versions of seismic data with synthetics. As, seismic well tie correlates the seismic reflection events with well markers, for our study it is used to identify regions which are enhanced and/or affected by scaling parameter(s).

Keywords: clipping, compression, resolution, seismic scaling

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Authors: Fatiha Teklal, Bachir Kacimi, Arezki Djebbar

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The study and application of composite materials are a truly interdisciplinary endeavor that has been enriched by contributions from chemistry, physics, materials science, mechanics and manufacturing engineering. The understanding of the interface (or interphase) in composites is the central point of this interdisciplinary effort. From the early development of composite materials of various nature, the optimization of the interface has been of major importance. Even more important, the ideas linking the properties of composites to the interface structure are still emerging. In our study, we need a direct characterization of the interface; the micromechanical tests we are addressing seem to meet this objective and we chose to use two complementary tests simultaneously. The microindentation test that can be applied to real composites and the drop test, preferred to the pull-out because of the theoretical possibility of studying systems with high adhesion (which is a priori the case with our systems). These two tests are complementary because of the principle of the model specimen used for both the first "compression indentation" and the second whose fiber is subjected to tensile stress called the drop test. Comparing the results obtained by the two methods can therefore be rewarding.

Keywords: Fiber, Interface, Matrix, Micromechanics, Pull-out

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Authors: Tahar Ayadat

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The undrained shear strength is an essential parameter for determining the consistency and the ultimate bearing capacity of a clay layer. The undrained shear strength can be determined by field tests such as the in situ vane test or in laboratory, including hand vane test, triaxial, simple compression test, and the consistency penetrometer (i.e. Swedish cone). However, the field vane test and the Swedish cone are the most commonly used tests by geotechnical experts. In this technical note, a comparison between the shear strength results obtained by the in situ vane test and the cone penetration test (Swedish cone) was conducted. A correlation between the results of these two tests, concerning the undrained shear strength of the Champlain sea clay, has been developed. Moreover, some applications of the proposed correlation on some geotechnical problems have been included, such as the determination of the consistency and the bearing capacity of a clay layer.

Keywords: correlation, shear strength, clay, vane test, Swedish cone

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Authors: Shiuh-Jer Huang, Yun-Han Yeh

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A four-wheel drive electric vehicle was built with hub DC motors and FPGA embedded control structure. A 40 steps manual adjusting motorcycle shock absorber was refitted with DC motor driving mechanism to construct as a semi-active suspension system. Accelerometer and potentiometer sensors are installed to measure the sprung mass acceleration and suspension system compression or rebound states for control purpose. An intelligent fuzzy logic controller was proposed to real-time search appropriate damping ratio based on vehicle running condition. Then, a robust fuzzy sliding mode controller (FSMC) is employed to regulate the target damping ratio of each wheel axis semi-active suspension system. Finally, different road surface conditions are chosen to evaluate the control performance of this semi-active suspension and compare with that of passive system based on wheel axis acceleration signal.

Keywords: acceleration, FPGA, Fuzzy sliding mode control, semi-active suspension

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Authors: J. O. Idoko, C. N. Michael, T. O. Fasuan

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This study investigated the effects of cooking time, seed-to-water ratio and soaking time on proximate and functional properties of African walnut seed using Box-Behnken design and Response Surface Methodology (BBD-RSM) with a view to increase its utilization in the food industry. African walnut seeds were sorted washed, soaked, cooked, dehulled, sliced, dried and milled. Proximate analysis and functional properties of the samples were evaluated using standard procedures. Data obtained were analyzed using descriptive and inferential statistics. Quadratic models were obtained to predict the proximate and functional qualities as a function of cooking time, seed-to-water ratio and soaking time. The results showed that the crude protein ranged between 11.80% and 23.50%, moisture content ranged between 1.00% and 4.66%, ash content ranged between 3.35% and 5.25%, crude fibre ranged from 0.10% to 7.25% and carbohydrate ranged from 1.22% to 29.35%. The functional properties showed that soluble protein ranged from 16.26% to 42.96%, viscosity ranged from 23.43 mPas to 57 mPas, emulsifying capacity ranged from 17.14% to 39.43% and water absorption capacity ranged from 232% to 297%. An increase in the volume of water used during cooking resulted in loss of water soluble protein through leaching, the length of soaking time and the moisture content of the dried product are inversely related, ash content is inversely related to the cooking time and amount of water used, extraction of fat is enhanced by increase in soaking time while increase in cooking and soaking times result into decrease in fibre content. The results obtained indicated that African walnut could be used in several food formulations as protein supplement and binder.

Keywords: African walnut, functional properties, proximate analysis, response surface methodology

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Authors: Mohamed Mesbah, Bruce Janson

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An interchange is the most important component of freeway and highway facilities. It is working as a connector between the highway’s elements. The main goal of designing interchanges is to provide an acceptable level of service and delay to make vehicles move smoothly when they are entering and exiting the interchange. There are many factors that can have a significant impact on the level of service; the main factors are traffic volumes, and type of interchange. This paper will discuss interchange with roundabouts under various values of traffic volumes to determine the level of service of the interchanges that will be studied in this paper and replace the system of interchange from roundabout to traffic signal to make a significant compression between these systems. A secondary goal is to propose improvements for scenarios where the level of service is deemed unacceptable. This will be achieved using Synchro traffic simulation software, which facilitates the simulation and optimization of interchanges to enhance operational efficiency and safety.

Keywords: interchange, roundabout, traffic signal, Synchro, delay, level of service, traffic volumes, vehicles, simulation, optimization, adjustment

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Authors: Mantas Sakalas, Paulius Sakalas

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This paper presents an analysis and design of a ultrawideband 1.8GHz to 43GHz Low Noise Amplifier (LNA) in 0.1 μm Galium Arsenide (GaAs) pseudomorphic High Electron Mobility Transistor (pHEMT) technology. The feedback based bandwidth extension techniques is analyzed and based on the outcome, a two stage LNA is designed. The impedance fine tuning is implemented by using Transmission Line (TL) structures. The measured performance shows a good agreement with simulation results and an outstanding wideband noise matching. The measured small signal gain was 12 dB, whereas a 3 dB gain flatness in range from 1.8 - 43 GHz was reached. The noise figure was below 4 dB almost all over the entire frequency band of 1.8GHz to 43GHz, the output power at 1 dB compression point was 6 dBm and the DC power consumption was 95 mW. To the best knowledge of the authors the designed LNA outperforms the State of the Art (SotA) reported LNA designs in terms of combined parameters of noise figure within the addressed ultra-wide 3 dB bandwidth, linearity and DC power consumption.

Keywords: feedback amplifiers, GaAs pHEMT, monolithic microwave integrated circuit, LNA, noise matching

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Authors: Shanxiong Chen, Xu Han, Xiaolong Wang, Hui Ma

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Yi is an ethnic group mainly living in mainland China, with its own spoken and written language systems, after development of thousands of years. Ancient Yi is one of the six ancient languages in the world, which keeps a record of the history of the Yi people and offers documents valuable for research into human civilization. Recognition of the characters in ancient Yi helps to transform the documents into an electronic form, making their storage and spreading convenient. Due to historical and regional limitations, research on recognition of ancient characters is still inadequate. Thus, deep learning technology was applied to the recognition of such characters. Five models were developed on the basis of the four-layer convolutional neural network (CNN). Alpha-Beta divergence was taken as a penalty term to re-encode output neurons of the five models. Two fully connected layers fulfilled the compression of the features. Finally, at the softmax layer, the orthographic features of ancient Yi characters were re-evaluated, their probability distributions were obtained, and characters with features of the highest probability were recognized. Tests conducted show that the method has achieved higher precision compared with the traditional CNN model for handwriting recognition of the ancient Yi.

Keywords: recognition, CNN, Yi character, divergence

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Authors: M. Naeimi, H. Aghazadeh, E. Afjei, A. Siadatan

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In this paper, a novel view of air gap magnetic field analysis of synchronous reluctance motor and permanent magnet assisted synchronous reluctance motor under static eccentricity to provide the precise fault diagnosis based on three-dimensional finite element method is presented. Analytical nature of this method makes it possible to simulate reliable and precise model by considering the end effects and axial fringing effects. The results of the three-dimensional finite element analysis of synchronous reluctance motor and permanent magnet synchronous reluctance motor such as flux linkage, flux density, and compression both of SynRM and PM-SynRM for various eccentric motor conditions are obtained and analyzed. These results present useful information regarding to the detection of static eccentricity.

Keywords: synchronous reluctance motor (SynRM), permanent magnet assisted synchronous reluctance motor (PMaSynRM), finite element method, static eccentricity, fault analysis

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Authors: Adil Elrayah, Jie Weng, Esra Suliman

Abstract:

The mineral in human bone is not pure stoichiometric calcium phosphate (Ca/P) as it is partially substituted by in organic elements. In this study, the copper ions (Cu²⁺) substituted hydroxyapatite (CuHA) powder has been synthesized by the co-precipitation method. The CuHA powder has been used to fabricate CuHA fiber scaffolds by sol-gel process and the following sinter process. The resulted CuHA fibers have slightly different microstructure (i.e. porosity) compared to HA fiber scaffold, which is denser. The mechanical properties test was used to evaluate CuHA, and the results showed decreases in both compression strength and hardness tests. Moreover, the in vitro used endothelial cells to evaluate the angiogenesis of CuHA. The result illustrated that the viability of endothelial cell on CuHA fiber scaffold surfaces tends to antigenic behavior. The results obtained with CuHA scaffold give this material benefit in biological applications such as antimicrobial, antitumor, antigens, compacts, filling cavities of the tooth and for the deposition of metal implants anti-tumor, anti-cancer, bone filler, and scaffold.

Keywords: fiber scaffold, copper ions, hydroxyapatite, in vitro, mechanical property

Procedia PDF Downloads 156

Authors: Nazish Saleem Abbas, Muhammad Haris Jamil, Hamid Sharif

Abstract:

Digital watermarking is a technique that allows an individual to add and hide secret information, copyright notice, or other verification message inside a digital audio, video, or image. Today, with the advancement of technology, modern healthcare systems manage patients’ diagnostic information in a digital way in many countries. When transmitted between hospitals through the internet, the medical data becomes vulnerable to attacks and requires security and confidentiality. Digital watermarking techniques are used in order to ensure the authenticity, security and management of medical images and related information. This paper proposes a watermarking technique that embeds a watermark in medical images imperceptibly and securely. In this work, digital watermarking on medical images is carried out using the Least Significant Bit (LSB) with the Discrete Cosine Transform (DCT). The proposed methods of embedding and extraction of a watermark in a watermarked image are performed in the frequency domain using LSB by XOR operation. The quality of the watermarked medical image is measured by the Peak signal-to-noise ratio (PSNR). It was observed that the watermarked medical image obtained performing XOR operation between DCT and LSB survived compression attack having a PSNR up to 38.98.

Keywords: watermarking, image processing, DCT, LSB, PSNR

Procedia PDF Downloads 50

Authors: Wen-Lih Chen, Chao-Kuang Chen, Mao-Ju Fang, Hsiang-Cheng Hsu

Abstract:

In this study, we conducted CFD simulation to study the gas cycle of a medium-temperature-differential (MTD) γ-type Stirling engine. Mesh compression and expansion as well as overset mesh techniques are employed to simulate the moving parts of the engine. Shear-Stress Transport (SST) k-ω turbulence model has been adopted because the model is not prone to generate excessive turbulence upon impingement regions. Hence, wall heat transfer rates at the hot and cold ends will not be overestimated. The effects of several different displacer-cylinder-wall temperature setups, including smooth and finned walls, on engine performance are investigated. The results include temperature contours, pressure versus volume diagrams, and variations of heat transfer rates, indicated power, and efficiency. It is found that displacer-wall heat transfer is one of the most important factors on engine performance, and some wall-temperature setups produce better results than others.

Keywords: CFD, finned wall, MTD Stirling engine, heat transfer

Procedia PDF Downloads 378

Authors: Shibo Wei, Ting Jiang

Abstract:

Convolutional-recurrent neural networks (CRN) have achieved much success recently in the speech enhancement field. The common processing method is to use the convolution layer to compress the feature space by multiple upsampling and then model the compressed features with the LSTM layer. At last, the enhanced speech is obtained by deconvolution operation to integrate the global information of the speech sequence. However, the feature space compression process may cause the loss of information, so we propose to model the upsampling result of each step with the residual LSTM layer, then join it with the output of the deconvolution layer and input them to the next deconvolution layer, by this way, we want to integrate the global information of speech sequence better. The experimental results show the network model (RES-CRN) we introduce can achieve better performance than LSTM without residual and overlaying LSTM simply in the original CRN in terms of scale-invariant signal-to-distortion ratio (SI-SNR), speech quality (PESQ), and intelligibility (STOI).

Keywords: convolutional-recurrent neural networks, speech enhancement, residual LSTM, SI-SNR

Procedia PDF Downloads 202