Search results for: resilience of compression (RC)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1724

Search results for: resilience of compression (RC)

944 Development of Web-Based Remote Desktop to Provide Adaptive User Interfaces in Cloud Platform

Authors: Shuen-Tai Wang, Hsi-Ya Chang

Abstract:

Cloud virtualization technologies are becoming more and more prevalent, cloud users usually encounter the problem of how to access to the virtualized remote desktops easily over the web without requiring the installation of special clients. To resolve this issue, we took advantage of the HTML5 technology and developed web-based remote desktop. It permits users to access the terminal which running in our cloud platform from anywhere. We implemented a sketch of web interface following the cloud computing concept that seeks to enable collaboration and communication among users for high performance computing. Given the development of remote desktop virtualization, it allows to shift the user’s desktop from the traditional PC environment to the cloud platform, which is stored on a remote virtual machine rather than locally. This proposed effort has the potential to positively provide an efficient, resilience and elastic environment for online cloud service. This is also made possible by the low administrative costs as well as relatively inexpensive end-user terminals and reduced energy expenses.

Keywords: virtualization, remote desktop, HTML5, cloud computing

Procedia PDF Downloads 333
943 Robust and Transparent Spread Spectrum Audio Watermarking

Authors: Ali Akbar Attari, Ali Asghar Beheshti Shirazi

Abstract:

In this paper, we propose a blind and robust audio watermarking scheme based on spread spectrum in Discrete Wavelet Transform (DWT) domain. Watermarks are embedded in the low-frequency coefficients, which is less audible. The key idea is dividing the audio signal into small frames, and magnitude of the 6th level of DWT approximation coefficients is modifying based upon the Direct Sequence Spread Spectrum (DSSS) technique. Also, the psychoacoustic model for enhancing in imperceptibility, as well as Savitsky-Golay filter for increasing accuracy in extraction, is used. The experimental results illustrate high robustness against most common attacks, i.e. Gaussian noise addition, Low pass filter, Resampling, Requantizing, MP3 compression, without significant perceptual distortion (ODG is higher than -1). The proposed scheme has about 83 bps data payload.

Keywords: audio watermarking, spread spectrum, discrete wavelet transform, psychoacoustic, Savitsky-Golay filter

Procedia PDF Downloads 190
942 Simulation Research of City Bus Fuel Consumption during the CUEDC Australian Driving Cycle

Authors: P. Kacejko, M. Wendeker

Abstract:

The fuel consumption of city buses depends on a number of factors that characterize the technical properties of the bus and driver, as well as traffic conditions. This parameter related to greenhouse gas emissions is regulated by law in many countries. This applies to both fuel consumption and exhaust emissions. Simulation studies are a way to reduce the costs of optimization studies. The paper describes simulation research of fuel consumption city bus driving. Parameters of the developed model are based on experimental results obtained on chassis dynamometer test stand and road tests. The object of the study was a city bus equipped with a compression-ignition engine. The verified model was applied to simulate the behavior of a bus during the CUEDC Australian Driving Cycle. The results of the calculations showed a direct influence of driving dynamics on fuel consumption.

Keywords: Australian Driving Cycle, city bus, diesel engine, fuel consumption

Procedia PDF Downloads 108
941 The Use of Biofeedback to Increase Resilience and Mental Health of Supersonic Pilots

Authors: G. Kloudova, S. Kozlova, M. Stehlik

Abstract:

Pilots are operating in a high-risk environment rich in potential stressors, which negatively affect aviation safety and the mental health of pilots. In the research conducted, the pilots were offered mental training biofeedback therapy. Biofeedback is an objective tool to measure physiological responses to stress. After only six sessions, all of the pilots tested showed significant differences between their initial condition and their condition after therapy. The biggest improvement was found in decreased heart rate (in 83.3% of tested pilots) and respiration rate (66.7%), which are the best indicators of anxiety states and panic attacks. To incorporate all of the variables, we correlated the measured physiological state of the pilots with their personality traits. Surprisingly, we found a high correlation with peripheral temperature and confidence (0.98) and with heart rate and aggressiveness (0.97). A retest made after a one-year interval showed that in majority of the subjects tested their acquired self-regulation ability had been internalized.

Keywords: aviation, biofeedback, mental workload, performance psychology

Procedia PDF Downloads 242
940 Finite Element Analysis of Reinforced Structural Walls

Authors: Mintesinot Teshome Mengsha

Abstract:

Reinforced concrete structural walls are provided in structures to decrease horizontal displacements under seismic loads. The cyclic lateral load resistance capacity of a structural wall is controlled by two parameters, the strength and the ductility; it is better to have the shear strength somewhat greater than the compression to prevent shear failure, which is brittle, sudden and of serious consequence. Due to architectural and functional reasons, small openings are provided in this important structural part. The main objective of this study is to investigate the finite element of RC structural walls with small openings subjected to cyclic load using the finite element approach. The experimental results in terms of load capacity, failure mode, crack pattern, flexural strength, shear strength, and deformation capacity.

Keywords: ABAQUS, finite element method, small openings, reinforced concrete structural walls

Procedia PDF Downloads 37
939 Development of Ferrous-Aluminum Alloys from Recyclable Material by High Energy Milling

Authors: Arnold S. Freitas Neto, Rodrigo E. Coelho, Erick S. Mendonça

Abstract:

This study aimed to obtain an alloy of Iron and Aluminum in the proportion of 50% of atomicity for each constituent. Alloys were obtained by processing recycled aluminum and chips of 1200 series carbon steel in a high-energy mill. For the experiment, raw materials were processed thorough high energy milling before mixing the substances. Subsequently, the mixture of 1200 series carbon steel and Aluminum powder was carried out a milling process. Thereafter, hot compression was performed in a closed die in order to obtain the samples. The pieces underwent heat treatments, sintering and aging. Lastly, the composition and the mechanical properties of their hardness were analyzed. In this paper, results are compared with previous studies, which used iron powder of high purity instead of Carbon steel in the composition.

Keywords: Fe-Al alloys, high energy milling, metallography characterization, powder metallurgy

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938 Piled Critical Size Bone-Biomimetic and Biominerizable Nanocomposites: Formation of Bioreactor-Induced Stem Cell Gradients under Perfusion and Compression

Authors: W. Baumgartner, M. Welti, N. Hild, S. C. Hess, W. J. Stark, G. Meier Bürgisser, P. Giovanoli, J. Buschmann

Abstract:

Perfusion bioreactors are used to solve problems in tissue engineering in terms of sufficient nutrient and oxygen supply. Such problems especially occur in critical size grafts because vascularization is often too slow after implantation ending up in necrotic cores. Biominerizable and biocompatible nanocomposite materials are attractive and suitable scaffold materials for bone tissue engineering because they offer mineral components in organic carriers – mimicking natural bone tissue. In addition, human adipose derived stem cells (ASCs) can potentially be used to increase bone healing as they are capable of differentiating towards osteoblasts or endothelial cells among others. In the present study, electrospun nanocomposite disks of poly-lactic-co-glycolic acid and amorphous calcium phosphate nanoparticles (PLGA/a-CaP) were seeded with human ASCs and eight disks were stacked in a bioreactor running with normal culture medium (no differentiation supplements). Under continuous perfusion and uniaxial cyclic compression, load-displacement curves as a function of time were assessed. Stiffness and energy dissipation were recorded. Moreover, stem cell densities in the layers of the piled scaffold were determined as well as their morphologies and differentiation status (endothelial cell differentiation, chondrogenesis and osteogenesis). While the stiffness of the cell free constructs increased over time caused by the transformation of the a-CaP nanoparticles into flake-like apatite, ASC-seeded constructs showed a constant stiffness. Stem cell density gradients were histologically determined with a linear increase in the flow direction from the bottom to the top of the 3.5 mm high pile (r2 > 0.95). Cell morphology was influenced by the flow rate, with stem cells getting more roundish at higher flow rates. Less than 1 % osteogenesis was found upon osteopontin immunostaining at the end of the experiment (9 days), while no endothelial cell differentiation and no chondrogenesis was triggered under these conditions. All ASCs had mainly remained in their original pluripotent status within this time frame. In summary, we have fabricated a critical size bone graft based on a biominerizable bone-biomimetic nanocomposite with preserved stiffness when seeded with human ASCs. The special feature of this bone graft was that ASC densities inside the piled construct varied with a linear gradient, which is a good starting point for tissue engineering interfaces such as bone-cartilage where the bone tissue is cell rich while the cartilage exhibits low cell densities. As such, this tissue-engineered graft may act as a bone-cartilage interface after the corresponding differentiation of the ASCs.

Keywords: bioreactor, bone, cartilage, nanocomposite, stem cell gradient

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937 Buckling Resistance of Basalt Fiber Reinforced Polymer Infill Panel Subjected to Elevated Temperatures

Authors: Viriyavudh Sim, Woo Young Jung

Abstract:

Performance of Basalt Fiber Reinforced Polymer (BFRP) sandwich infill panel system under diagonal compression was studied by means of numerical analysis. Furthermore, the variation of temperature was considered to affect the mechanical properties of BFRP, since their composition was based on polymeric material. Moreover, commercial finite element analysis platform ABAQUS was used to model and analyze this infill panel system. Consequently, results of the analyses show that the overall performance of BFRP panel had a 15% increase compared to that of GFRP infill panel system. However, the variation of buckling load in terms of temperature for the BFRP system showed a more sensitive nature compared to those of GFRP system.

Keywords: basalt fiber reinforced polymer (BFRP), buckling performance, numerical simulation, temperature dependent materials

Procedia PDF Downloads 195
936 A Passive Reaction Force Compensation for a Linear Motor Motion Stage Using Pre-Compressed Springs

Authors: Kim Duc Hoang, Hyeong Joon Ahn

Abstract:

Residual vibration of the system base due to a high-acceleration motion of a stage may reduce life and productivity of the manufacturing device. Although a passive RFC can reduce vibration of the system base, spring or dummy mass should be replaced to tune performance of the RFC. In this paper, we develop a novel concept of the passive RFC mechanism for a linear motor motion stage using pre-compressed springs. Dynamic characteristic of the passive RFC can be adjusted by pre-compression of the spring without exchanging the spring or dummy mass. First, we build a linear motor motion stage with pre-compressed springs. Then, the effect of the pre-compressed spring on the passive RFC is investigated by changing both pre-compressions and stiffness of springs. Finally, the effectiveness of the passive RFC using pre-compressed springs was verified with both simulations and experiments.

Keywords: linear motor motion stage, residual vibration, passive RFC, pre-compressed spring

Procedia PDF Downloads 343
935 The Walkway Project: An Exploration of Informal Public Space Upgrading in Gugulethu, Cape Town

Authors: Kathryn Ewing

Abstract:

Safe and accessible public spaces are vital elements of our South African cities. Public spaces hold the potential to act as important, vibrant places for learning, exchange, and practice. Public walkways, however, are some of the most neglected and extremely dangerous public spaces experienced in the local neighborhood of Gugulethu in Cape Town. Walkways feel insignificant, being recognized as informal and undetermined or retain complex fragments of formal erven. They are generally out of sight connecting minor streets and informal settlements. Community residents refer to the walkways as unsafe and dirty spaces. Local authorities allocate minimal to no municipal budgets nor maintenance plans resulting in a lack of basic services, particularly lighting and green infrastructure. ‘The Walkway Project’ presents a series of urban stories collected from co-design workshops, emotional mapping exercises, and fieldwork, including urban walks and urban talks. The narrative interprets the socio-spatial practice and complexity of informal public space in Gugulethu, Cape Town. The Walkway Project research, interrelated to the Master of Urban Design teaching and design-research studio, has a strong focus on participatory and engaged learning and action research methodology within a deliberate pedagogy. A consolidated urban design implementation plan exposes the impact and challenges of waste and water, opening the debate on relevant local solutions for resilience and safety in Cape Town. A small and neglected passage connecting two streets, commonly referred to as iThemba Walkway, is presented as a case study to show-case strategic urban design intervention strategies for urban upgrading. The iThemba walkway is a community-driven project that demonstrates active and responsible co-design and participatory development opportunities. In March 2021, when visited on an urban walk, the public space was covered by rubble and solid waste. By April 2021, the community cleaned the walkway and created an accessible passage for the school children to pass. Numerous co-design workshops have taken place over the past year. The walkway has emerged as a public space upgrading project facilitated, motivated, and implemented by multiple local partners and residents. Social maps from urban walks and talks illustrate the transformation of iThemba Walkway into an inclusive, safe, resilient, and sustainable urban space, linked to Sustainable Development Goal number 11, sustainable cities and communities. The outcomes of the upgrading project facilitate a deeper understanding of co-design methods, urban upgrading processes, and monitoring of public space and informal urbanism.

Keywords: informal, public space, resilience, safety, upgrade, walkways

Procedia PDF Downloads 87
934 Application of Model Tree in the Prediction of TBM Rate of Penetration with Synthetic Minority Oversampling Technique

Authors: Ehsan Mehryaar

Abstract:

The rate of penetration is (RoP) one of the vital factors in the cost and time of tunnel boring projects; therefore, predicting it can lead to a substantial increase in the efficiency of the project. RoP is heavily dependent geological properties of the project site and TBM properties. In this study, 151-point data from Queen’s water tunnel is collected, which includes unconfined compression strength, peak slope index, angle with weak planes, and distance between planes of weaknesses. Since the size of the data is small, it was observed that it is imbalanced. To solve that problem synthetic minority oversampling technique is utilized. The model based on the model tree is proposed, where each leaf consists of a support vector machine model. Proposed model performance is then compared to existing empirical equations in the literature.

Keywords: Model tree, SMOTE, rate of penetration, TBM(tunnel boring machine), SVM

Procedia PDF Downloads 171
933 Importance of Remote Sensing and Information Communication Technology to Improve Climate Resilience in Low Land of Ethiopia

Authors: Hasen Keder Edris, Ryuji Matsunaga, Toshi Yamanaka

Abstract:

The issue of climate change and its impact is a major contemporary global concern. Ethiopia is one of the countries experiencing adverse climate change impact including frequent extreme weather events that are exacerbating drought and water scarcity. Due to this reason, the government of Ethiopia develops a strategic document which focuses on the climate resilience green economy. One of the major components of the strategic framework is designed to improve community adaptation capacity and mitigation of drought. For effective implementation of the strategy, identification of regions relative vulnerability to drought is vital. There is a growing tendency of applying Geographic Information System (GIS) and Remote Sensing technologies for collecting information on duration and severity of drought by direct measure of the topography as well as an indirect measure of land cover. This study aims to show an application of remote sensing technology and GIS for developing drought vulnerability index by taking lowland of Ethiopia as a case study. In addition, it assesses integrated Information Communication Technology (ICT) potential of Ethiopia lowland and proposes integrated solution. Satellite data is used to detect the beginning of the drought. The severity of drought risk prone areas of livestock keeping pastoral is analyzed through normalized difference vegetation index (NDVI) and ten years rainfall data. The change from the existing and average SPOT NDVI and vegetation condition index is used to identify the onset of drought and potential risks. Secondary data is used to analyze geographical coverage of mobile and internet usage in the region. For decades, the government of Ethiopia introduced some technologies and approach to overcoming climate change related problems. However, lack of access to information and inadequate technical support for the pastoral area remains a major challenge. In conventional business as usual approach, the lowland pastorals continue facing a number of challenges. The result indicated that 80% of the region face frequent drought occurrence and out of this 60% of pastoral area faces high drought risk. On the other hand, the target area mobile phone and internet coverage is rapidly growing. One of identified ICT solution enabler technology is telecom center which covers 98% of the region. It was possible to identify the frequently affected area and potential drought risk using the NDVI remote-sensing data analyses. We also found that ICT can play an important role in mitigating climate change challenge. Hence, there is a need to strengthen implementation efforts of climate change adaptation through integrated Remote Sensing and web based information dissemination and mobile alert of extreme events.

Keywords: climate changes, ICT, pastoral, remote sensing

Procedia PDF Downloads 301
932 Behavior of Square Reinforced-Concrete Columns Strenghtened with Carbon Fiber Reinforced Polymers (CFRP) under Concentric Loading

Authors: Dana Abed, Mu`Tasim Abdel-Jaber, Nasim Shatarat

Abstract:

This study aims at investigating the influence of cross-sectional size on axial compressive capacity of carbon fiber reinforced polymer (CFRP) wrapped square reinforced concrete short columns. Three sets of columns were built for this purpose: 200x200x1200 mm; 250x250x1500 mm and 300x300x1800 mm. Each set includes a control column and a strengthened column with one layer of CFRP sheets. All columns were tested under the effect of pure axial compression load. The results of the study show that using CFRP sheets resulted in capacity enhancement of 37%, 32% and 27% for the 200×200, 250×250, and 300×300 mm, respectively. The results of the experimental program demonstrated that the percentage of improvement in strength decreased by increasing the cross-sectional size of the column.

Keywords: CFRP, columns, concentric loading, cross-sectional

Procedia PDF Downloads 277
931 Development of 3D Particle Method for Calculating Large Deformation of Soils

Authors: Sung-Sik Park, Han Chang, Kyung-Hun Chae, Sae-Byeok Lee

Abstract:

In this study, a three-dimensional (3D) Particle method without using grid was developed for analyzing large deformation of soils instead of using ordinary finite element method (FEM) or finite difference method (FDM). In the 3D Particle method, the governing equations were discretized by various particle interaction models corresponding to differential operators such as gradient, divergence, and Laplacian. The Mohr-Coulomb failure criterion was incorporated into the 3D Particle method to determine soil failure. The yielding and hardening behavior of soil before failure was also considered by varying viscosity of soil. First of all, an unconfined compression test was carried out and the large deformation following soil yielding or failure was simulated by the developed 3D Particle method. The results were also compared with those of a commercial FEM software PLAXIS 3D. The developed 3D Particle method was able to simulate the 3D large deformation of soils due to soil yielding and calculate the variation of normal and shear stresses following clay deformation.

Keywords: particle method, large deformation, soil column, confined compressive stress

Procedia PDF Downloads 566
930 Poly(Methyl Methacrylate)/Graphene Microparticles Having a Core/Shell Structure Prepared with Carboxylated Graphene as a Pickering Stabilizer

Authors: Gansukh Erdenedelger, Doljinsuren Sukhbaatar, Trung Dung Dao, Byeong-Kyu Lee, Han Mo Jeong

Abstract:

Two kinds of carboxylated thermally reduced graphenes (C-TRGs) having different lateral sizes are examined as a Pickering stabilizer in the suspension polymerization of methyl methacrylate. The size and the shape of the prepared composite particles are irregular due to agglomeration, more evidently when the larger C-TRG is used. In addition, C-TRG is distributed not only on the surface but also inside the composite particles. It indicates that the C-TRG alone is not a stable Pickering agent. However, a very small dosage of acrylic acid remedies all these issues, because acrylic acid interacts with C-TRG and synergizes the stabilizing effect. The compression molded composite of the core/shell poly(methyl methacrylate)/C-TRG particles exhibits a very low percolation threshold of electrical conductivity of 0.03 vol%. It demonstrates that the C-TRG shells of the composite particles effectively form a segregated conductive network throughout the composite.

Keywords: pickering, graphene, polymerization, PMMA

Procedia PDF Downloads 287
929 Preparation of Carbon Monoliths from PET Waste and Their Use in Solar Interfacial Water Evaporation

Authors: Andrea Alfaro Barajas, Arturo I. Martinez

Abstract:

3D photothermal structure of carbon was synthesized using PET bottles waste and sodium chloride through controlled carbonization. Characterization techniques such as X-ray photoelectron spectroscopy, X-ray diffraction, BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, spectrophotometry, and mechanical compression were carried out. The carbon showed physical integrity > 90%, an absorbance > 90% between 300-1000nm of the solar spectrum, and a high specific surface area from 450 to 620 m2/g. The X-ray was employed to examine the phase structure; the obtained pattern shows an amorphous material. A higher intensity of band D with respect to band G was confirmed by Raman Spectroscopy. C-OH, COOH, C-O, and C-C bonds were obtained from the deconvolution of the high-resolution C1s orbital. Macropores of 160 to 180µm and micropores of 0.5 to 2nm were observed by SEM and TEM images, respectively. Such combined characteristics of carbon confer efficient evaporation of water under 1 sun irradiation > 60%.

Keywords: solar-absorber, carbon, water-evaporation, interfacial

Procedia PDF Downloads 142
928 The Effect of the Hexagonal Ring Interior Angle on Energy Absorption Capability

Authors: Shada Bennbaia, Elsadig Mahdi

Abstract:

In this paper, the effect of changing the interior angle of a hexagonal passive energy absorber is investigated. Aluminum hexagonal structures have been tested under in-plane quasi-static compression tests. These hexagonal structures are designed to have varying interior angle values to study their crushing behavior and the relationship between the angle and the energy absorption capability. It was found that the structures with angles 40° and 45° showed an almost perfectly stable crushing mechanism with low initial peak force. Thus, hexagonal structures with these angels can be used in the vehicle's crumple zones to absorb energy during collisions. The larger angles required high initial peak force to start crushing, which indicates that these structures are best suited in applications where high load carrying capacity is needed.

Keywords: energy absorption, crushing force efficiency, crushing mechanism, hexagonal angle, peak force

Procedia PDF Downloads 187
927 Urban Landscape Sustainability Between Past and Present: Toward a Future Vision

Authors: Dina Salem

Abstract:

A variety of definitions and interpretations for sustainable development has been offered since the widely known definition of the World Commission on Environment and Development in 1987, the perspectives have ranged from deep ecology to better life quality for people. Sustainable landscape is widely understood as a key contributor to urban sustainability for the fact that all landscapes has a social, economic, cultural and ecological function for the community’s well-being and urban development, that was evident even before the emergence of sustainability concept. In this paper, the concepts of landscape planning and sustainable development are briefly reviewed; visions for landscape sustainability are demonstrated and classified. Challenges facing sustainable landscape planning are discussed. Finally, the paper investigates how our future urban open space could be sustainable and how does this contribute to urban sustainability, by creating urban landscapes that takes into account the social and cultural values of users of urban open space besides the ecological balance of urban open spaces as an integrated network.

Keywords: urban landscape, urban sustainability, resilience, open spaces

Procedia PDF Downloads 538
926 Nondestructive Monitoring of Atomic Reactions to Detect Precursors of Structural Failure

Authors: Volodymyr Rombakh

Abstract:

This article was written to substantiate the possibility of detecting the precursors of catastrophic destruction of a structure or device and stopping operation before it. Damage to solids results from breaking the bond between atoms, which requires energy. Modern theories of strength and fracture assume that such energy is due to stress. However, in a letter to W. Thomson (Lord Kelvin) dated December 18, 1856, J.C. Maxwell provided evidence that elastic energy cannot destroy solids. He proposed an equation for estimating a deformable body's energy, equal to the sum of two energies. Due to symmetrical compression, the first term does not change, but the second term is distortion without compression. Both types of energy are represented in the equation as a quadratic function of strain, but Maxwell repeatedly wrote that it is not stress but strain. Furthermore, he notes that the nature of the energy causing the distortion is unknown to him. An article devoted to theories of elasticity was published in 1850. Maxwell tried to express mechanical properties with the help of optics, which became possible only after the creation of quantum mechanics. However, Maxwell's work on elasticity is not cited in the theories of strength and fracture. The authors of these theories and their associates are still trying to describe the phenomena they observe based on classical mechanics. The study of Faraday's experiments, Maxwell's and Rutherford's ideas, made it possible to discover a previously unknown area of electromagnetic radiation. The properties of photons emitted in this reaction are fundamentally different from those of photons emitted in nuclear reactions and are caused by the transition of electrons in an atom. The photons released during all processes in the universe, including from plants and organs in natural conditions; their penetrating power in metal is millions of times greater than that of one of the gamma rays. However, they are not non-invasive. This apparent contradiction is because the chaotic motion of protons is accompanied by the chaotic radiation of photons in time and space. Such photons are not coherent. The energy of a solitary photon is insufficient to break the bond between atoms, one of the stages of which is ionization. The photographs registered the rail deformation by 113 cars, while the Gaiger Counter did not. The author's studies show that the cause of damage to a solid is the breakage of bonds between a finite number of atoms due to the stimulated emission of metastable atoms. The guarantee of the reliability of the structure is the ratio of the energy dissipation rate to the energy accumulation rate, but not the strength, which is not a physical parameter since it cannot be measured or calculated. The possibility of continuous control of this ratio is due to the spontaneous emission of photons by metastable atoms. The article presents calculation examples of the destruction of energy and photographs due to the action of photons emitted during the atomic-proton reaction.

Keywords: atomic-proton reaction, precursors of man-made disasters, strain, stress

Procedia PDF Downloads 81
925 Effect of Elastic Modulus Varieties on Helical Pile Behavior in Sand

Authors: Javad Shamsi Soosahab, Reza Ziaie Moayed

Abstract:

The compressive and tensile bearing capacity of helical piles in sand is investigated by means of numerical modeling. The analyses are carried out using two-dimensional finite-element software, Optum G2. The load–displacement behavior under compression and tension is compared in different relative densities for constant and various elastic modulus. The criterion used to find the ultimate axial load is the load corresponding to 5% of the helical diameter. The results show that relative density of sand plays an essential role in the response of ultimate capacities towards various condition. Increase in elastic modulus with depth is found to play a relatively more significant role to the increase in ultimate compressive load capacities, however tension bearing capacity decreases.

Keywords: helical piles, Optum G2, relative density, constant and various elastic modulus

Procedia PDF Downloads 141
924 Formulation and Evaluation of Dispersible Tablet of Furosemide for Pediatric Use

Authors: O. Benaziz, A. Dorbane, S. Djeraba

Abstract:

The objective of this work is to formulate a dry dispersible form of furosemide in the context of pediatric dose adjustment. To achieve this, we have produced a set of formulas that will be tested in process and after compression. The formula with the best results will be improved to optimize the final shape of the product. Furosemide is the most widely used pediatric diuretic because of its low toxicity. The manufacturing process was chosen taking into account all the data relating to the active ingredient and the excipients used and complying with the specifications and requirements of dispersible tablets. The process used to prepare these tablets was wet granulation. Different excipients were used: lactose, maize starch, magnesium stearate and two superdisintegrants. The mode of incorporation of super-disintegrant changes with each formula. The use of super-disintegrant in the formula allowed optimization of the disintegration time. Prepared tablets were evaluated for weight, content uniformity, hardness, disintegration time, friability and in vitro dissolution test. 

Keywords: formulation, dispersible tablets, wet granulation, superdisintegrants, disintegration

Procedia PDF Downloads 337
923 Use of Residues from Water Treatment and Porcelain Coatings Industry for Producing Eco-Bricks

Authors: Flavio Araujo, Fabiolla Lima, Julio Lima, Paulo Scalize, Antonio Albuquerque, Heitor Reis

Abstract:

One of the great environmental problems in the management of water treatment (WTP) is on the disposal of waste generated during the treatment process. The same occurs with the waste generated during rectification of porcelain tiles. Despite environmental laws in Brazil the residues does not have an ecologically balanced destination. Thus, with the purpose to identify an environmentally sustainable disposal, residues were used to replace part of the soil, for production soil-cement bricks. It was used the residues from WTP and coatings industry Cecrisa (Brazil). Consequently, a greater amount of fine aggregate in the two samples of residues was found. The residue affects the quality of bricks produced, compared to the sample without residues. However, the results of compression and water absorption tests were obtained values that meet the standards, respectively 2.0 MPa and 20% absorption.

Keywords: water treatment residue, porcelain tile residue, WTP, brick

Procedia PDF Downloads 472
922 Promotion of Lipid Syntheses of Microalgae by Microfluidic-Assisted Membrane Distortion

Authors: Seul Ki Min, Gwang Heum Yoon, Jung Hyun Joo, Hwa Sung Shin

Abstract:

Cellular membrane distortion is known as a factor to change intracellular signaling. However, progress of relevant studies is difficult because there are no facilities that can control membrane distortion finely. In this study, we developed microfluidic device which can inflict mechanical stress on cell membrane of Chlamydomonas reinhardtii using regular height of the channels. And cellular physiological changes were analyzed from cells cultured in the device. Excessive calcium ion influx through into cytoplasm was induced from mechanical stress. The results revealed that compressed cells had up-regulated Mat3 mRNA which regulates cell size and cell cycle from a prolonged G1 phase. Additionally, TAG used for the production of biodiesel was raised rapidly from 4 h after compression. Taken together, membrane distortion can be considered as an attractive inducer for biofuel production.

Keywords: mechanical stress, membrane distortion, Chlamydomonas reinhardtii, deflagellation, cell cycle, lipid metabolism

Procedia PDF Downloads 367
921 Soil Reinforcement by Fibers Using Triaxial Compression Test

Authors: Negadi Kheira, Arab Ahmed, Kamal Elbokl Mohamed, Setti Fatima

Abstract:

In order to evaluate influences of roots on soil shear strength, monotonic drained and undrained triaxial laboratory tests were carried out on reconstituted specimens at various confining pressure (σc’=50, 100, 200, 300, 400 kPa) and a constant relative density (Dr = 50%). Reinforcement of soil by fibrous roots is crucial for preventing soil erosion and degradation. Therefore, we investigated soil reinforcement by roots of acacia planted in the area of Chlef where shallow landslides and slope instability are frequent. These roots were distributed in soil in two forms: vertically and horizontally. The monotonic test results showed that roots have more impacts on the soil shear strength than the friction angle, and the presence of roots in soil substantially increased the soil shear strength. Also, the results showed that the contribution of roots on the shear strength mobilized increases with increase in the confining pressure.

Keywords: soil, monotonic, triaxial test, root fiber, undrained

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920 Lung Parasites in Stone Martens (Martes foina L.) from Bulgaria

Authors: Vassilena Dakova, Mariana Panayotova-Pencheva

Abstract:

The present work focused on the study of pulmonary helminth-fauna of the stone marten in Bulgaria in terms of which the data are little. For the purpose, four stone martens were helminthologically necropsied according to the common technique. In addition, some of the injured lung parts were investigated after their boiling in lactic acid and subsequent compression. Four nematode species from different families of order Strongylida and Trichocephalida were found in the lungs. These were Crenosoma petrowi Morosov, 1939; Eucoleus aerophilus Creplin, 1839; Filaroides martis Werner, 1782 and Sobolevingylus petrowi Romanov, 1952. Some of the parasite structures with taxonomic importance were measured and described. According to our best knowledge, the species F. martis and S. petrowi are recorded for the first time as a part of the helminth-fauna of Southeast Europe and Bulgaria in particular.

Keywords: Bulgaria, Crenosoma petrowi, Eucoleus aerophilus, Filaroides martis, lung parasites, Sobolevingylus petrowi, stone martens

Procedia PDF Downloads 134
919 Future trends of MED-TVC Desalination Technology

Authors: Irfan Wazeer

Abstract:

Desalination has become one of the major water treatment process in several countries around the world where shortage of water is a serious problem. Energy consumption is a vital economic factor in selecting the type of desalination processes because current desalination processes require large amount of energy which is costly. Multi-effect desalination system with thermal vapor compression (MED-TVC) is particularly more attractive than other thermal desalination systems due to its low energy consumption. MED-TVC is characterized by high performance ratio (PR), easier operation, low maintenance requirements and simple geometry. These attractive features make MED-TVC highly competitive to other well established desalination techniques that include the reverse osmosis (RO) and multi-stage flash desalination (MSF). The primary goal of this paper is to present a preview of some aspects related with the theory of the technology, parametric study of the MED-TVC systems and its development. It will analyzed the current and future aspects of the MED-TVC technology in view of latest installed plants.

Keywords: MED-TVC, parallel feed, performance ratio, GOR

Procedia PDF Downloads 249
918 H.264 Video Privacy Protection Method Using Regions of Interest Encryption

Authors: Taekyun Doo, Cheongmin Ji, Manpyo Hong

Abstract:

Like a closed-circuit television (CCTV), video surveillance system is widely placed for gathering video from unspecified people to prevent crime, surveillance, or many other purposes. However, abuse of CCTV brings about concerns of personal privacy invasions. In this paper, we propose an encryption method to protect personal privacy system in H.264 compressed video bitstream with encrypting only regions of interest (ROI). There is no need to change the existing video surveillance system. In addition, encrypting ROI in compressed video bitstream is a challenging work due to spatial and temporal drift errors. For this reason, we propose a novel drift mitigation method when ROI is encrypted. The proposed method was implemented by using JM reference software based on the H.264 compressed videos, and experimental results show the verification of our proposed methods and its effectiveness.

Keywords: H.264/AVC, video encryption, privacy protection, post compression, region of interest

Procedia PDF Downloads 333
917 A Qualitative Study About a Former Professional Baseball Player with Dyslexia

Authors: Matthias Grunke

Abstract:

In this qualitative study, we interviewed a young man with learning disabilities who played professional baseball for two years. Individuals with severe academic challenges constitute one of the most vulnerable groups of our society. Science has to find ways on how to arm them against life’s challenges and help them to cope with the many risk factors that they are usually confronted with. Team sports like baseball seem to be a suitable means for that purpose. In the interview, our participant talked about his life as a student with severe learning difficulties and related how his career in baseball made his academic challenges appear much less significant. He gave some meaningful insights into what helped him to build a happy and fulfilling life for himself, not only in spite of his challenges but also because of what he's learning disabilities taught him. Support from significant others, a sense of purpose, his fighting spirit ignited by sports, and the success that he experienced on the baseball field were among the most relevant factors. Overall, this study highlights the importance of finding an outlet for young people with learning disabilities where their academic difficulties retreat into the background and their talents are validated.

Keywords: baseball, inclusion, learning disabilities, resilience

Procedia PDF Downloads 90
916 Vibration Analysis of Functionally Graded Engesser-Timoshenko Beams Subjected to Axial Load Located on a Continuous Elastic Foundation

Authors: M. Karami Khorramabadi, A. R. Nezamabadi

Abstract:

This paper studies free vibration of functionally graded beams Subjected to Axial Load that is simply supported at both ends lies on a continuous elastic foundation. The displacement field of beam is assumed based on Engesser-Timoshenko beam theory. The Young's modulus of beam is assumed to be graded continuously across the beam thickness. Applying the Hamilton's principle, the governing equation is established. Resulting equation is solved using the Euler's Equation. The effects of the constituent volume fractions and foundation coefficient on the vibration frequency are presented. To investigate the accuracy of the present analysis, a compression study is carried out with a known data.

Keywords: functionally graded beam, free vibration, elastic foundation, Engesser-Timoshenko beam theory

Procedia PDF Downloads 409
915 Damage Micromechanisms of Coconut Fibers and Chopped Strand Mats of Coconut Fibers

Authors: Rios A. S., Hild F., Deus E. P., Aimedieu P., Benallal A.

Abstract:

The damage micromechanisms of chopped strand mats manufactured by compression of Brazilian coconut fiber and coconut fibers in different external conditions (chemical treatment) were used in this study. Mechanical analysis testing uniaxial traction were used with Digital Image Correlation (DIC). The images captured during the tensile test in the coconut fibers and coconut fiber mats showed an uncertainty of measurement in order centipixels. The initial modulus (modulus of elasticity) and tensile strength decreased with increasing diameter for the four conditions of coconut fibers. The DIC showed heterogeneous deformation fields for coconut fibers and mats and the displacement fields showed the rupture process of coconut fiber. The determination of poisson’s ratio of the mat was performed through of transverse and longitudinal deformations found in the elastic region.

Keywords: coconut fiber, mechanical behavior, digital image correlation, micromechanism

Procedia PDF Downloads 454