Search results for: wake effects
4681 Hydrogen Embrittlement Properties of the Hot Stamped Carbon Steels
Authors: Mitsuhiro Okayasu, Lele Yang, Koji Shimotsu
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The effects of microstructural characteristics on the mechanical and hydrogen embrittlement properties of 1,800MPa grade hot stamping carbon steel were investigated experimentally. The tensile strength increased with increasing the hot stamping temperature until around 921°C, but that decreased with increasing the temperature in more than 921°C due to the increment of the size of lath martensite and prior austenite. With the hot stamping process, internal strain was slightly created in the sample, which led to the slight increment of the hardness value although no clear change of the microstructural formation was detected. Severity of hydrogen embrittlement was investigated using the hot stamped carbon steels after the immersion in a hydrogen gas, and that was directly attributed to the infiltration of the hydrogen into their grain boundaries. The high strength carbon steel with tiny lath martensite microstructure could make severe hydrogen brittleness as the hydrogen was strongly penetrated in the grain boundaries in the hydrogen gas for a month. Because of weak embrittlement for the as-received carbon (ferrite and pearlite), hydrogen embrittlement is caused by the high internal strain and high dislocation density. The hydrogen embrittlement for carbon steel is attributed to amount of the hydrogen immersed in-between grain boundaries, which is caused by the dislocation density and internal strain.Keywords: hydrogen embrittlement, hot stamping process, carbon steel, mechanical property
Procedia PDF Downloads 2014680 Mathematical Modeling of the Effect of Pretreatment on the Drying Kinetics, Energy Requirement and Physico-Functional Properties of Yam (Dioscorea Rotundata) and Cocoyam (Colocasia Esculenta)
Authors: Felix U. Asoiro, Kingsley O. Anyichie, Meshack I. Simeon, Chinenye E. Azuka
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The work was aimed at studying the effects of microwave drying (450 W) and hot air oven drying on the drying kinetics and physico-functional properties of yams and cocoyams species. The yams and cocoyams were cut into chips of thicknesses of 3mm, 5mm, 7mm, 9mm, and 11mm. The drying characteristics of yam and cocoyam chips were investigated under microwave drying and hot air oven temperatures (50oC – 90oC). Drying methods, temperature, and thickness had a significant effect on the drying characteristics and physico-functional properties of yam and cocoyam. The result of the experiment showed that an increase in the temperature increased the drying time. The result also showed that the microwave drying method took lesser time to dry the samples than the hot air oven drying method. The iodine affinity of starch for yam was higher than that of cocoyam for the microwaved dried samples over those of hot air oven-dried samples. The results of the analysis would be useful in modeling the drying behavior of yams and cocoyams under different drying methods. It could also be useful in the improvement of shelf life for yams and cocoyams as well as designs of efficient systems for drying, handling, storage, packaging, processing, and transportation of yams and cocoyams.Keywords: coco yam, drying, microwave, modeling, energy consumption, iodine affinity, drying ate
Procedia PDF Downloads 1064679 Identification of Biological Pathways Causative for Breast Cancer Using Unsupervised Machine Learning
Authors: Karthik Mittal
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This study performs an unsupervised machine learning analysis to find clusters of related SNPs which highlight biological pathways that are important for the biological mechanisms of breast cancer. Studying genetic variations in isolation is illogical because these genetic variations are known to modulate protein production and function; the downstream effects of these modifications on biological outcomes are highly interconnected. After extracting the SNPs and their effect on different types of breast cancer using the MRBase library, two unsupervised machine learning clustering algorithms were implemented on the genetic variants: a k-means clustering algorithm and a hierarchical clustering algorithm; furthermore, principal component analysis was executed to visually represent the data. These algorithms specifically used the SNP’s beta value on the three different types of breast cancer tested in this project (estrogen-receptor positive breast cancer, estrogen-receptor negative breast cancer, and breast cancer in general) to perform this clustering. Two significant genetic pathways validated the clustering produced by this project: the MAPK signaling pathway and the connection between the BRCA2 gene and the ESR1 gene. This study provides the first proof of concept showing the importance of unsupervised machine learning in interpreting GWAS summary statistics.Keywords: breast cancer, computational biology, unsupervised machine learning, k-means, PCA
Procedia PDF Downloads 1464678 Facile Synthesis and Structure Characterization of Europium (III) Tungstate Nanoparticles
Authors: Mehdi Rahimi-Nasrabadi, Seied Mahdi Pourmortazavi
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Taguchi robust design as a statistical method was applied for optimization of the process parameters in order to tunable, simple and fast synthesis of europium (III) tungstate nanoparticles. Europium (III) tungstate nanoparticles were synthesized by a chemical precipitation reaction involving direct addition of europium ion aqueous solution to the tungstate reagent solved in aqueous media. Effects of some synthesis procedure variables i.e., europium and tungstate concentrations, flow rate of cation reagent addition, and temperature of reaction reactor on the particle size of europium (III) tungstate nanoparticles were studied experimentally in order to tune particle size of europium (III) tungstate. Analysis of variance shows the importance of controlling tungstate concentration, cation feeding flow rate and temperature for preparation of europium (III) tungstate nanoparticles by the proposed chemical precipitation reaction. Finally, europium (III) tungstate nanoparticles were synthesized at the optimum conditions of the proposed method and the morphology and chemical composition of the prepared nano-material were characterized by means of X-Ray diffraction, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy, and fluorescence.Keywords: europium (III) tungstate, nano-material, particle size control, procedure optimization
Procedia PDF Downloads 3954677 How the Current Opioid Crisis Differs from the Heroin Epidemic of the 1960s-1970s: An Analysis of Drugs and Demographics
Authors: Donna L. Roberts
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Heroin has appeared on the drug scene before. Yet the current opioid crisis differs in significant ways. In order to address the grave challenges, this epidemic poses, the unique precipitating and sustaining conditions must be thoroughly examined. This research explored the various aspects of the political, economic, and social conditions that created a 'perfect storm' for the evolution and maintenance of the current opioid crisis. Specifically, the epidemiology, demographics, and progression of addiction inherent in the current crisis were compared to the patterns of past opioid use. Additionally, the role of pharmaceutical companies and prescribing physicians, the nature and pharmaceutical properties of the available substances and the changing socioeconomic climate were considered. Results indicated that the current crisis differs significantly with respect to its evolution, magnitude, prevalence, and widespread societal effects. Precipitated by a proliferation of prescription medication and sustained by the availability of cheaper, more potent street drugs, including new versions of synthetic opioids, the current crisis presents unprecedented challenges affecting a wider and more diverse segment of society. The unique aspects of this epidemic demand unique approaches to addressing the problem. Understanding these differences is a key step in working toward a practical and enduring solution.Keywords: addiction, drug abuse, opioids, opioid crisis
Procedia PDF Downloads 1524676 A Numerical Study on Electrophoresis of a Soft Particle with Charged Core Coated with Polyelectrolyte Layer
Authors: Partha Sarathi Majee, S. Bhattacharyya
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Migration of a core-shell soft particle under the influence of an external electric field in an electrolyte solution is studied numerically. The soft particle is coated with a positively charged polyelectrolyte layer (PEL) and the rigid core is having a uniform surface charge density. The Darcy-Brinkman extended Navier-Stokes equations are solved for the motion of the ionized fluid, the non-linear Nernst-Planck equations for the ion transport and the Poisson equation for the electric potential. A pressure correction based iterative algorithm is adopted for numerical computations. The effects of convection on double layer polarization (DLP) and diffusion dominated counter ions penetration are investigated for a wide range of Debye layer thickness, PEL fixed surface charge density, and permeability of the PEL. Our results show that when the Debye layer is in order of the particle size, the DLP effect is significant and produces a reduction in electrophoretic mobility. However, the double layer polarization effect is negligible for a thin Debye layer or low permeable cases. The point of zero mobility and the existence of mobility reversal depending on the electrolyte concentration are also presented.Keywords: debye length, double layer polarization, electrophoresis, mobility reversal, soft particle
Procedia PDF Downloads 3464675 Endemic Medicinal Plants in Eritrea: Scientific Name, Botanical Description and Geographical Location
Authors: Liya Abraham
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Medicinal plants are globally valuable sources of herbal products, either as lifesaving or life maintaining medicines. Studies reveal that more than 25% of modern drugs in the world are derived from plants. The Horn of Africa as a world hotspot; it has more than 1500 endemic plants. Eritrea, a country located in the Horn of Africa, is blessed with medicinal flora and fauna and marine and terrestrial biodiversity. Previous studies of flora of Ethiopia and Eritrea, incomplete species lists, indicate figures ranging between 6000 and 7000 species, with levels of endemism between 12–20%. In the past two decades, there has been growing interest in natural remedy herbal medicines owing to, but not limited to; resistance to antimicrobials, intolerance of side effects of modern drugs, and rise in chronic diseases like diabetes, hypertension, cancer, etc. Hence, owing to the rising demand for nature based health solutions, deforestation, construction purposes, grazing, and agricultural expansion; several medicinal plants in general and the endemic ones, in particular, are in the verge of extinction. Therefore, conservation strategies of endangered and endemic medicinal plants, especially those located in hot spot regions, must be promoted at global level. Thus, the author aims to share certain information regarding the endemic medicinal plants in Eritrea with the international scientific world.Keywords: endemic, eritrea, horn of Africa, medicinal plants, species
Procedia PDF Downloads 1734674 Theoretical and Experimental Investigation of the Interaction Behavior of a Bouncing Ball upon a Flexible Surface Impacted in Two Dimensions
Authors: Wiwat Chumai, Perawit Boonsomchua, Kanjana Ongkasin
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The ball bouncing problem is a well-known problem in physics involving a ball dropped from a height to the ground. In this paper, the work investigates the theoretical and experimental setup that describes the dynamics of a rigid body on a chaotic elastic surface under air-damp conditions. Examination of four different types of balls is made, including marble, metal ball, tennis ball, and ping-pong ball. In this experiment, the effect of impact velocities is not considered; the ball is dropped from a fixed height. The method in this work employs the Rayleigh Dissipation Function to specify the effects of dissipative forces in Lagrangian mechanics. Our discoveries reveal that the dynamics of the ball exhibit horizontal motion while damping oscillation occurs, forming the destabilization in vertical pinch-off motion. Moreover, rotational motion is studied. According to the investigation of four different balls, the outcomes illustrate that greater mass results in more frequent dynamics, and the experimental results at some points align with the theoretical model. This knowledge contributes to our understanding of the complex fluid system and could serve as a foundation for further developments in water droplet simulation.Keywords: droplet, damping oscillation, nonlinear damping oscillation, bouncing ball problem, elastic surface
Procedia PDF Downloads 1004673 Banking Performance and Political Economy: Using ARDL Model
Authors: Marwen Ghouil, Jamel Eddine Mkadmi
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Banking performance is the pillar and goal of all banking activity and its impact on economic policy. First, researchers defined the principles for assessing and modeling bank performance, and then theories and models explaining bank performance were developed. The importance of credit as a means of financing businesses in most developing countries has led to questions about the effects of financial liberalisation on increased banking competition. In Tunisia, as in many other countries, the liberalization of financial services in general and of banks' activities has not ceased to evolve. The objective of this paper is to examine the determinants of banking performance for 8 Tunisian banks and their impact on economic policy during the Arab Spring. We used cointegration analysis and the ARDL Panel model, explaining using total assets, bank credits, guarantees, and bank size as performance drivers. The correlation analysis shows that there is a positive correlation relationship between total assets, bank credits, guarantees, and bank size and bank performance. Long-term empirical results show that bank loans, guarantees, bank size, and total assets have a positive and significant impact on bank performance. This means that bank credits, guarantees, bank size, and total assets are very important determinants of bank performance in Tunisia.Keywords: bank performance, economic policy, finance, economic
Procedia PDF Downloads 1344672 Numerical Simulation and Experimental Verification of Mechanical Displacements in Piezoelectric Transformer
Authors: F. Boukazouha, G. Poulin-Vittrant, M. Rguiti, M. Lethiecq
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Since its invention, by virtue of its remarkable features, the piezoelectric transformer (PT) has drawn the attention of the scientific community. In past years, it has been extensively studied and its performances have been continuously improved. Nowadays, such devices are designed in more and more sophisticated architectures with associated models describing their behavior quite accurately. However, the different studies usually carried out on such devices mainly focus on their electrical characteristics induced by direct piezoelectric effects such as voltage gain, efficiency or supplied power. In this work, we are particularly interested in the characterization of mechanical displacements induced by the inverse piezoelectric effect in a PT in vibration. For this purpose, a detailed three-dimensional finite element analysis is proposed to examine the mechanical behavior of a Rosen-type transformer made of a single bar of soft PZT (P191) and with dimensions 22mm×2.35mm×2.5mm. At the first three modes of vibration, output voltage and mechanical displacements ux, uy and uz along the length, the width and the thickness, respectively, are calculated. The amplitude of displacements varies in a range from a few nanometers to a few hundred nanometers. The validity of the simulations was successfully confirmed by experiments carried out on a prototype using a laser interferometer. A good match was observed between simulation and experimental results, especially for us at the second mode. Such 3D simulations thus appear as a helpful tool for a better understanding of mechanical phenomena in Rosen-type PT.Keywords: piezoelectricity, gain, dispalcement, simulations
Procedia PDF Downloads 314671 Large-Eddy Simulations for Aeronautical Systems
Authors: R. R. Mankbadi
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There are several technologically-important flow situations in which there is a need to control the outcome of the fluid flow. This could include flow separation, drag, noise, as well as particulate separations, to list only a few. One possible approach is the passive control, in which the design geometry is changed. An alternative approach is the Active Flow Control (AFC) technology in which an actuator is embedded in the flow field to change the outcome. Examples of AFC are pulsed jets, synthetic jets, plasma actuators, heating, and cooling, etc. In this work will present an overview of the development of this field. Some examples will include Airfoil Noise Suppression: Large-Eddy Simulations (LES) is used to simulate the effect of synthetic jet actuator on controlling the far field sound of a transitional airfoil. The results show considerable suppression of the noise if the synthetic jet is operated at frequencies. Mixing Enhancement and suppression: Results will be presented to show that imposing acoustic excitations at the nozzle exit can lead to enhancement or reduction of the jet plume mixing. In vertical takeoff of Aircrafts or in Space Launch, we will present results on the effects of water injection on reducing noise, and on protecting the structure and payload from fatigue damage. Other applications will include airfoil-gust interaction and propulsion systems optimizations.Keywords: aeroacoustics, flow control, aerodynamics, large eddy simulations
Procedia PDF Downloads 2884670 Induction Heating and Electromagnetic Stirring of Bi-Phasic Metal/Glass Molten Bath for Mixed Nuclear Waste Treatment
Authors: P. Charvin, R. Bourrou, F. Lemont, C. Lafon, A. Russello
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For nuclear waste treatment and confinement, a specific IN-CAN melting module based on low-frequency induction heating have been designed. The frequency of 50Hz has been chosen to improve penetration length through metal. In this design, the liquid metal, strongly stirred by electromagnetic effects, presents shape of a dome caused by strong Laplace forces developing in the bulk of bath. Because of a lower density, the glass phase is located above the metal phase and is heated and stirred by metal through interface. Electric parameters (Intensity, frequency) give precious information about metal load and composition (resistivity of alloy) through impedance modification. Then, power supply can be adapted to energy transfer efficiency for suitable process supervision. Modeling of this system allows prediction of metal dome shape (in agreement with experimental measurement with a specific device), glass and metal velocity, heat and motion transfer through interface. MHD modeling is achieved with COMSOL and Fluent. First, a simplified model is used to obtain the shape of the metal dome. Then the shape is fixed to calculate the fluid flow and the thermal part.Keywords: electromagnetic stirring, induction heating, interface modeling, metal load
Procedia PDF Downloads 2674669 Generativism in Language Design and Their Effects on String of Constructions
Authors: Christian Uchechukwu Gilbert
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Generativism in language design investigates the framework on which varying sentence structures are built in the English language. Propounded by Noam Chomsky in 1965, the theory transforms sentences from an active structure to a passive one by the application of established rules of the theory. Resident in the body of syntax, the rules include movement, insertion, substitution, and deletion rules. Using the movement rule, the analysis is armed with the qualitative research method, on which the works of scholars were duly consulted for more insight and in line with the academic practice in research activities. The investigation showed that the rules of competent grammar explain the formulation of sentences in a language and how transformation takes place among sentences from a deep structure to a surface structure with accurate results. The structural differences that could be got through dative movement and the deletion of the preposition; passivisation got from an active sentence by the insertion of the preposition “by” a “be verb” and the aspect tense marker “–en”, held as the creative aspect of language vocabulary and the subject-auxiliary inversion that exchanges the auxiliary of a sentence with the subject of the same sentence thereby transforming a kennel sentence to a polar question, viewed as an external argument under θ-theory. Generativism in language design, therefore, changes available types of sentences and relates one form of linguistic category with others in language design.Keywords: language, generate, transformation, structure, design
Procedia PDF Downloads 684668 The Effects of Different Parameters of Wood Floating Debris on Scour Rate Around Bridge Piers
Authors: Muhanad Al-Jubouri
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A local scour is the most important of the several scours impacting bridge performance and security. Even though scour is widespread in bridges, especially during flood seasons, the experimental tests could not be applied to many standard highway bridges. A computational fluid dynamics numerical model was used to solve the problem of calculating local scouring and deposition for non-cohesive silt and clear water conditions near single and double cylindrical piers with the effect of floating debris. When FLOW-3D software is employed with the Rang turbulence model, the Nilsson bed-load transfer equation and fine mesh size are considered. The numerical findings of single cylindrical piers correspond pretty well with the physical model's results. Furthermore, after parameter effectiveness investigates the range of outcomes based on predicted user inputs such as the bed-load equation, mesh cell size, and turbulence model, the final numerical predictions are compared to experimental data. When the findings are compared, the error rate for the deepest point of the scour is equivalent to 3.8% for the single pier example.Keywords: local scouring, non-cohesive, clear water, computational fluid dynamics, turbulence model, bed-load equation, debris
Procedia PDF Downloads 694667 Children and Parents Left behind in Transnational Families: The Problem of Care Deficit
Authors: Joanna Bielecka-Prus
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In the view of increasing number of labour migrations associated with broadly understood economic crisis, many families experience migration separation. Currently, in the era of globalization, migration movements include an increasing number of families, more and more frequently a new type of family, a transnational family. Accordingly, the functions of the family, family practice of care, and the relationships between members of the group change especially in the case of female migration. Sociologists highlight the emotional aspects of migrants’ family lives: managing emotions, coping with guilt, loneliness and rejection. Not without significance is the fact that today's public discourse often represents migrant women in a negative light. On the one hand, consumption and expanding material resources are assessed positively, on the other hand, deficits emotional and devastation of family life in the transnational families appear. Opinions expressed by different environments: the media, the political environment, etc. do not always take into account the context of mobility and their different effects on family life. The paper will present the analysis of qualitative studies of Polish female migrants’ families left-behind (children, parents, caregivers N = 100) and their coping strategies in different situations in the event of migration separation. The main area of care deficit will be defined and it will be showed who and how help to solve the problems.Keywords: care, children left behind, female migration, parents left behind
Procedia PDF Downloads 3954666 The Impacts of Civil War on Import and Export in Ethiopia: A Case Study of the Tigray Region Conflict
Authors: Simegn Alemayehu Ayele
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Abstract: On November 4, 2020, the Ethiopian government launched a military operation against the Tigray People's Liberation Front (TPLF) in Ethiopia's Tigray Province, sparking the beginning of the Tigray War. This study focuses on the most recent Tigray War as it explores the effects of the civil war on Ethiopia's import and export activity. This study examines the consequences of violence on Ethiopia's trade relations, including its trading partners, export volume, and import requirements, using a combination of qualitative and quantitative data. The research outcome showed that Ethiopia's trade activities have suffered significantly as a result of the Tigray conflict, with both imports and exports declining. Particularly, the violence has hampered logistics and transportation networks, which has reduced the number of products exported and imported. Furthermore, the conflict has weakened Ethiopia's trading relationships and reduced demand for Ethiopian commodities. The survey also reveals that some of Ethiopia's major trade routes have been closed as a result of the conflict, severely restricting trade activities. These findings underline the necessity for political stability and conflict resolution procedures to support the nation's import and export activity by indicating that civil war has substantial repercussions for Ethiopia's economic development and trade activities.Keywords: import demands, logistic networks, trade partiners, trade relatinships
Procedia PDF Downloads 854665 Effects of Cerium Oxide Nanoparticle Addition in Diesel and Diesel-Biodiesel Blends on the Performance Characteristics of a CI Engine
Authors: Abbas Ali Taghipoor Bafghi, Hosein Bakhoda, Fateme Khodaei Chegeni
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An experimental investigation is carried out to establish the performance characteristics of a compression ignition engine while using cerium oxide nano particles as additive in neat diesel and diesel-bio diesel blends. In the first phase of the experiments, stability of neat diesel and diesel-bio diesel fuel blends with the addition of cerium oxide nano particles are analyzed. After series of experiments, it is found that the blends subjected to high speed blending followed by ultrasonic bath stabilization improves the stability.In the second phase, performance characteristics are studied using the stable fuel blends in a single cylinder four stroke engine coupled with an electrical dynamo meter and a data acquisition system. The cerium oxide acts as an oxygen donating catalyst and provides oxygen for combustion. The activation energy of cerium oxide acts to burn off carbon deposits within the engine cylinder at the wall temperature and prevents the deposition of non-polar compounds on the cylinder wall results reduction in HC emissions. The tests revealed that cerium oxide nano particles can be used as additive in diesel and diesel-bio diesel blends to improve complete combustion of the fuel significantly.Keywords: engine, cerium oxide, biodiesel, deposit
Procedia PDF Downloads 3464664 Serum Anti-Oxidation Enzymes Response to L-Carnitine Supplementation
Authors: Farah Nameni, Hamidreza Poursadra, Maasumeh Nurani Pilehrud
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Exercise training induced Inflammation and stress. Antioxidant, for example L- Carnitine has beneficial effects in immune system and increased antioxidant enzymes activity. L- Carnitine protects the tissue against the oxidative side effect and helps the body to protect against stress during and after acute exercise. The aim of this study was to determine the effect of L-Carnitine on the blood enzymes: GPX SOD, CAT and GR response. In this study, 20 basketball players girls participated. Subjects were randomly assigned into two groups; placebo and supplementation. Antioxidadision enzymes (Superoxide Dismutase, Catalase, Glutathione Reductase, Glutathione Peroxidase) evaluated. L-Carnitine supplement group orally daily received 3000 mg powder for 14 dys. Then all participates trained basketball exercise acute. Blood samples were drawn vein before and immediately after exercise. Superoxide Dismutase, Catalase, Glutathione Reductase, Glutathione Peroxidase were measured, and data was analyzed using repeated measure ANOVA, Bonferroni and t-test. Our results showed: SOD, GPX and GPX (P < 0.05) have a significant increase. These results suggest L-Carnitine supplementation may increase GPX SOD, CAT, and basal anti oxidative capacity. L-Carnitine can modulate the alterations of exercise oxidative damage in girl basketball players.Keywords: l-carnitine, GPX, SOD, CAT, exercise, GR, anti-oxidant
Procedia PDF Downloads 1904663 Reliability and Cost Focused Optimization Approach for a Communication Satellite Payload Redundancy Allocation Problem
Authors: Mehmet Nefes, Selman Demirel, Hasan H. Ertok, Cenk Sen
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A typical reliability engineering problem regarding communication satellites has been considered to determine redundancy allocation scheme of power amplifiers within payload transponder module, whose dominant function is to amplify power levels of the received signals from the Earth, through maximizing reliability against mass, power, and other technical limitations. Adding each redundant power amplifier component increases not only reliability but also hardware, testing, and launch cost of a satellite. This study investigates a multi-objective approach used in order to solve Redundancy Allocation Problem (RAP) for a communication satellite payload transponder, focusing on design cost due to redundancy and reliability factors. The main purpose is to find the optimum power amplifier redundancy configuration satisfying reliability and capacity thresholds simultaneously instead of analyzing respectively or independently. A mathematical model and calculation approach are instituted including objective function definitions, and then, the problem is solved analytically with different input parameters in MATLAB environment. Example results showed that payload capacity and failure rate of power amplifiers have remarkable effects on the solution and also processing time.Keywords: communication satellite payload, multi-objective optimization, redundancy allocation problem, reliability, transponder
Procedia PDF Downloads 2614662 Influence of Procurement Methods on Cost Performance of Building Projects in Gombe State, Nigeria
Authors: S. U. Kunya, S. Abdulkadir, M. A. Anas, L. Z. Adam
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Procurement methods is described as systems of contractual arrangements used by the contractor in order to secure the design and construction services based on the stipulated cost and within the required time and quality. Despite that, major projects in the Nigerian construction industry failed because of wrong procurement methods with major consequences leads to cost overrun which needs to find lasting solution. The aim of the study is to evaluate the influence of procurement methods on cost performance of building projects in Gombe State, Nigeria. Study adopts descriptive and explorative design approach. Data were collected through administering of one hundred questionnaire using convenient sampling techniques. Data analyses using percentages, mean value and Anova analysis. Major finding show that more than fifty percent (50%) of procurement methods available are mainly utilized in the study area and the top procurement methods that have high impacts on cost performance as compare with the other methods is project management and direct labour procurement methods. The results of hypothesis’ tests with pvalue 0.12 and 0.07 validated that there was no significant variation in the perception of stakeholders’ on the impacts of procurements methods on cost performance. Therefore, the study concluded that projects management and direct labour are the most appropriate procurement methods that will ensure successful completion of project at stipulated cost in building projects.Keywords: cost, effects, performance, procurement, projects
Procedia PDF Downloads 2244661 The Impact of a Sustainable Solar System on the Growth of Strawberry Plants in an Agricultural Greenhouse
Authors: Ilham Ihoume, Rachid Tadili, Nora Arbaoui
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This study examines the effects of a solar-based heating system, in a north-south oriented agricultural greenhouse on the development of strawberry plants during winter. This system relies on the circulation of water as a heat transfer fluid in a closed circuit installed on the greenhouse roof to store heat during the day and release it inside at night. A comparative experimental study was conducted in two greenhouses, one experimental with the solar heating system and the other for control without any heating system. Both greenhouses are located on the terrace of the Solar Energy and Environment Laboratory of the Mohammed V University in Rabat, Morocco. The devel-oped heating system consists of a copper coil inserted in double glazing and placed on the roof of the greenhouse, a water pump circulator, a battery, and a photovoltaic solar panel to power the electrical components. This inexpen-sive and environmentally friendly system allows the greenhouse to be heated during the winter and improves its microclimate system. This improvement resulted in an increase in the air temperature inside the experimental green-house by 6 °C and 8 °C, and a reduction in its relative humidity by 23% and 35% compared to the control greenhouse and the ambient air, respectively, throughout the winter. For the agronomic performance, it was observed that the production was 17 days earlier than in the control greenhouse.Keywords: sustainability, solar energy, thermal energy storage., greenhouse heating
Procedia PDF Downloads 374660 The Influence of Positive and Negative Affect on Perception and Judgement
Authors: Annamarija Paula
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Modern psychology is divided into three distinct domains: cognition, affect, and conation. Historically, psychology devalued the importance of studying the effect in order to explain human behavior as it supposedly lacked both rational thought and a scientific foundation. As a result, affect remained the least studied domain for years to come. However, the last 30 years have marked a significant change in perspective, claiming that not only is affect highly adaptive, but it also plays a crucial role in cognitive processes. Affective states have a crucial impact on human behavior, which led to fundamental advances in the study of affective states on perception and judgment. Positive affect and negative affect are distinct entities and have different effects on social information processing. In addition, emotions of the same valence are manifested in distinct and unique physiological reactions indicating that not all forms of positive or negative affect are the same or serve the same purpose. The effect plays a vital role in perception and judgments, which impacts the validity and reliability of memory retrieval. The research paper analyzes key findings from the past three decades of observational and empirical research on affective states and cognition. The paper also addresses the limitations connected to the findings and proposes suggestions for possible future research.Keywords: memory, affect, perception, judgement, mood congruency effect
Procedia PDF Downloads 1304659 Numerical Resolving of Net Faradaic Current in Fast-Scan Cyclic Voltammetry Considering Induced Charging Currents
Authors: Gabriel Wosiak, Dyovani Coelho, Evaldo B. Carneiro-Neto, Ernesto C. Pereira, Mauro C. Lopes
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In this work, the theoretical and experimental effects of induced charging currents on fast-scan cyclic voltammetry (FSCV) are investigated. Induced charging currents arise from the effect of ohmic drop in electrochemical systems, which depends on the presence of an uncompensated resistance. They cause the capacitive contribution to the total current to be different from the capacitive current measured in the absence of electroactive species. The paper shows that the induced charging current is relevant when the capacitive current magnitude is close to the total current, even for systems with low time constant. In these situations, the conventional background subtraction method may be inaccurate. A method is developed that separates the faradaic and capacitive currents by using a combination of voltametric experimental data and finite element simulation, by the obtention of a potential-dependent capacitance. The method was tested in a standard electrochemical cell with Platinum ultramicroelectrodes, in different experimental conditions as well in previously reported data in literature. The proposed method allows the real capacitive current to be separated even in situations where the conventional background subtraction method is clearly inappropriate.Keywords: capacitive current, fast-scan cyclic voltammetry, finite-element method, electroanalysis
Procedia PDF Downloads 754658 Gut-Microbiota-Brain-Axis, Leaky Gut, Leaky Brain: Pathophysiology of Second Brain Aging and Alzheimer’s Disease- A Neuroscientific Riddle
Authors: Bilal Ahmad
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Alzheimer’s disease (AD) is one of the most common neurodegenerative illnesses. However, how Gut-microbiota plays a role in the pathogenesis of AD is not well elucidated. The purpose of this literature review is to summarize and understand the current findings that may elucidate the gut microbiota's role in the development of AD. Methods: A literature review of all the relevant papers known to the author was conducted. Relevant articles, abstracts and research papers were collected from well-accepted web sources like PubMed, PMC, and Google Scholar. Results: Recent studies have shown that Gut-microbiota has an important role in the progression of AD via Gut-Microbiota-Brain Axis. The onset of AD supports the ‘Hygiene Hypothesis’, which shows that AD might begin in the Gut, causing dysbiosis, which interferes with the intestinal barrier by releasing pro-inflammatory cytokines and making its way up to the brain via the blood-brain barrier (BBB). Molecular mechanisms lipopolysaccharides and serotonin kynurenine (tryptophan) pathways have a direct association with inflammation, the immune system, neurodegeneration, and AD. Conclusion: The studies helped to analyze the molecular basis of AD, other neurological conditions like depression, autism, and Parkinson's disease and how they are linked to Gut-microbiota. Further, studies to explore the therapeutic effects of probiotics in AD and cognitive enhancement should be warranted to provide significant clinical and practical value.Keywords: gut-microbiota, Alzheimer’s disease, second brain aging, lipopolysaccharides, short-chain fatty acids
Procedia PDF Downloads 444657 Exploring Social Impact of Emerging Technologies from Futuristic Data
Authors: Heeyeul Kwon, Yongtae Park
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Despite the highly touted benefits, emerging technologies have unleashed pervasive concerns regarding unintended and unforeseen social impacts. Thus, those wishing to create safe and socially acceptable products need to identify such side effects and mitigate them prior to the market proliferation. Various methodologies in the field of technology assessment (TA), namely Delphi, impact assessment, and scenario planning, have been widely incorporated in such a circumstance. However, literatures face a major limitation in terms of sole reliance on participatory workshop activities. They unfortunately missed out the availability of a massive untapped data source of futuristic information flooding through the Internet. This research thus seeks to gain insights into utilization of futuristic data, future-oriented documents from the Internet, as a supplementary method to generate social impact scenarios whilst capturing perspectives of experts from a wide variety of disciplines. To this end, network analysis is conducted based on the social keywords extracted from the futuristic documents by text mining, which is then used as a guide to produce a comprehensive set of detailed scenarios. Our proposed approach facilitates harmonized depictions of possible hazardous consequences of emerging technologies and thereby makes decision makers more aware of, and responsive to, broad qualitative uncertainties.Keywords: emerging technologies, futuristic data, scenario, text mining
Procedia PDF Downloads 4914656 Enrichment and Flux of Heavy Metals along the Coastal Sediments of Pakistan
Authors: Asmat Siddiqui, Noor Us Saher
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Heavy metal contamination in the marine environment is a global issue, and in past decades, this problem has intensified due to an increase in urbanization and industrialization, especially in developing countries. Marine sediments act as a preliminary indicator of heavy metal contamination in the coastal and estuarine environment, which has adverse effects on biota as well as in the marine system. The aim of the current study was to evaluate the contamination status, enrichment, and flux of heavy metals in two monitoring years from coastal sediments of Pakistan. A total of 74 sediment samples were collected from seven coastal areas of Pakistan in two monitoring years, 2001-03 (MY-I) and 2011-13 (MY-II). The geochemical properties (grain size analysis, organic contents and eight heavy metals, i.e. Fe, Zn, Cu, Cr, Ni, Co, Pb, and Cd) of all sediment samples were analyzed. A significant increase in Fe, Ni and Cr concentrations detected between the years, whereas no significant differences were exhibited in Cu, Zn, Co, Pb and Cd concentrations. The extremely high enrichment (>50) of Cu, Zn, Pb and Cd were scrutinized in both monitoring years. The annual deposition flux of heavy metals ranged from 0.63 to 66.44 and 0.78 to 68.27 tons per year in MY-I and MY-II, respectively, with the lowest flux evaluated for Cd and highest for Zn in both monitoring years. A significant increase (p <0.05) was observed in the burial flux of Cr and Ni during the last decade in coastal sediments. The use of geo-indicators is helpful to assess the contamination analysis for management and conservation of the marine environment.Keywords: coastal contamination, enrichment factor, geo-indicator, heavy metal flux
Procedia PDF Downloads 3804655 Urinary Neutrophil Gelatinase Associated Lipocalin as Diagnostic Biomarkers for Lupus Nephritis
Authors: Lorena GóMez Escorcia, Gustavo Aroca MartíNez, Jose Luiz Villarreal, Elkin Navarro Quiroz
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Lupus nephritis (LN) is a high-cost disease, occurring in about half of patients with Systemic Lupus Erythematosus (SLE). Renal biopsy constitutes the only protocol that, to date, allows a correct diagnosis of the level of renal involvement in these patients. However, this procedure can have various adverse effects such as kidney bleeding, muscle bleeding, infection, pain, among others. Therefore, the development of new diagnostic alternatives is required. The neutrophil gelatinase-associated lipocalin (NGAL) has been emerging as a novel biomarker of acute kidney injury. The aim of this study was to assess urinary NGAL levels as a marker for disease activity in patients with lupus nephritis. For this work included 50 systemic lupus erythematosus (SLE) patients, 50 with active lupus nephritis (LN), and 50 without autoimmune and renal disease as controls. TNGAL in urine samples was measured by enzyme-linked immunosorbent assay (ELISA). The results revealed that patients with kidney damage had an elevated urinary NGAL as compared to patients with lupus without kidney damage and controls (p <0.005), and the mean of uNGAL was (28.72 ± 4.53), (19.51 ± 4.72), (8.91 ± 3.37) respectively. Measurement of urinary NGAL levels showed a very good diagnostic performance for discriminating patients with Lupus nephritis from SLE without renal damage and of control individuals.Keywords: lupus nephritis, biomarker, NGAL, urine samples
Procedia PDF Downloads 2074654 Active Learning Management for Teacher's Professional Courses in Curriculum and Instruction, Faculty of Education Thaksin University
Authors: Chuanphit Chumkhong
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This research aimed 1) to study the effects of the management of Active Learning among 3rd year students enrolled in teacher’s profession courses and 2) to assess the satisfaction of the students with courses using the Active Learning approach. The population for the study consisted of 442 3rd year undergraduate students enrolled in two teacher education courses in 2015: Curriculum Development and Learning Process Management. They were 442 from 11 education programs. Respondents for evaluation of satisfaction with Active Learning management comprised 432 students. The instruments used in research included a detailed course description and rating scale questionnaire on Active Learning. The data were analyzed using arithmetic mean and standard deviation. The results of the study reveal the following: 1. Overall, students gain a better understanding of the Active Learning due to their actual practice on the activity of course. Students have the opportunity to exchange learning knowledge and skills. The AL teaching activities make students interested in the contents and they seek to search for knowledge on their own. 2. Overall, 3rd year students are satisfied with the Active Learning management at a ‘high’ level with a mean score (μ) of 4.12 and standard deviation (σ) of. 51. By individual items, students are satisfied with the 10 elements in the two courses at a ‘high’ level with the mean score (μ) between 3.79 to 4.41 and a standard deviation (σ) between to 68. 79.Keywords: active learning teaching model, teacher’s professional courses, professional courses, curriculum and instruction teacher's
Procedia PDF Downloads 2484653 English Title Adaptive Comparison of Outdoor and Indoor Social Security in Damaged Area and New Residential Complex with Two-Way Anova Case Study: Qasr-Al-Dasht and Moalem District in Shiraz
Authors: Homa Parmoon, Narges Hamzeh
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Since today's urban spaces are disposed towards behavioral disorders and lack of security, both qualitative and quantitative aspects of security especially social and physical security are considered as basic necessities in urban planning. This research focused on the variable of place of living, examined social security in the old and new textures, and investigated the amount of residents’ social security in Shiraz including safety, financial, emotional and moral security. To this end, two neighborhoods in region 1 of Shiraz- Qasr-Al-Dasht (old texture) and Moalem (new texture)- were examined through a comparative study of 60 samples lived in two neighborhoods. Data were gathered through two-way ANOVA between the variables of residential context and internal and external security. This analysis represents the significance or insignificance of the model as well as the individual effects of each independent variable on the dependent variable. It was tested by ANCOVA and F-test. Research findings indicated place of living has a significant effect on families’ social security. The safety, financial, emotional, and moral security also represented a great impact on social security. As a result, it can be concluded that social security changes with the changing in place of living.Keywords: social security, damaged area, two-way ANOVA, Shiraz
Procedia PDF Downloads 1394652 Effect of Dietary Supplementation of Allium Hookeri Root and Processed Sulfur on the Growth Performance of Guinea Pigs
Authors: Nayeon, Lee, Won-Young, Cho, Hyun Joo, Jang, Chi-Ho, Lee
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This study investigated the effects of the dietary supplementation of the Allium hookeri root, and processed sulfur, on the growth performance of guinea pigs. The guinea pigs were fed a control diet (CON), as well as the control diet including 1% freeze-dried Allium hookeri root (AH), or 0.1% processed sulfur (S), or including both the freeze-dried Allium hookeri root and the processed sulfur (AHS). The weight of perirenal adipose tissue (PAT) and the epididymal adipose tissue (EAT) in the AH were significantly lower than CON (p < 0.05). The serum cholesterols levels of the AH and the AHS were significantly lower than the S (p < 0.05). While the total saturated fatty acid content in the serum of the AH and AHS groups showed a tendency to decrease, the total monounsaturated fatty acid increased. The results of this study suggested that dietary consumption of Allium hookeri root may help to decrease fat accumulation, lower serum cholesterol levels, and control serum free fatty acid contents in the guinea pigs.Keywords: Allium hookeri, dietary supplementation, growth performance, processed sulfur, Guinea pig
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