Search results for: thermoelastic effect
8948 Opto-Electronic Properties of Novel Structures: Sila-Fulleranes
Authors: Farah Marsusi, Mohammad Qasemnazhand
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Density-functional theory (DFT) was applied to investigate the geometry and electronic properties H-terminated Si-fullerene (Si-fullerane). Natural bond orbital (NBO) analysis confirms sp3 hybridization nature of Si-Si bonds in Si-fulleranes. Quantum confinement effect (QCE) does not affect band gap (BG) so strongly in the size between 1 to 1.7 nm. In contrast, the geometry and symmetry of the cage have significant influence on BG. In contrast to their carbon analogues, pentagon rings increase the stability of the cages. Functionalized Si-cages are stable and can be chemically very active. The electronic properties are highly sensitive to the surface chemistry via functionalization with different chemical groups. As a result, BGs and chemical activities of these cages can be drastically tuned through the chemistry of the surface.Keywords: density functional theory, sila-fullerens, NBO analysis, opto-electronic properties
Procedia PDF Downloads 2928947 Impact of Globalization on Youth Bulge and Civil Unrest: An Empirical Approach
Authors: Swetasree Roy, Subaran Roy
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The contemporary literature documents globalization affects the stability of a country in three ways i) it increases peace ii) it decreases the likelihood of civil unrest, and iii) it creates employment. In this paper, we show that unemployment amongst youth plays a significant role in the effect of globalization and the internal stability of a country. Using recent data on globalization for 88 countries (2000-2014), we examine whether the presence of a large section of youth exacerbates the negative effects of globalization, thereby increasing chances of civil unrest. Using recent measures of globalization, we find globalization affect adversely on the stability of a country. Our results indicate that globalization in the presence of a high youth unemployment rate can create more instability in an economy. Results are robust in the presence of other socio-economic variables.Keywords: globalization, youth bulge, civil unrest, unemployment
Procedia PDF Downloads 1488946 The Analysis of TRACE/PARCS in the Simulation of Ultimate Response Guideline for Lungmen ABWR
Authors: J. R. Wang, W. Y. Li, H. T. Lin, B. H. Lee, C. Shih, S. W. Chen
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In this research, the TRACE/PARCS model of Lungmen ABWR has been developed for verification of ultimate response guideline (URG) efficiency. This ultimate measure was named as DIVing plan, abbreviated from system depressurization, water injection and containment venting. The simulation initial condition is 100% rated power/100% rated core flow. This research focuses on the estimation of the time when the fuel might be damaged with no water injection by using TRACE/PARCS first. Then, the effect of the reactor core isolation system (RCIC), control depressurization and ac-independent water addition system (ACIWA), which can provide the injection with 950 gpm are also estimated for the station blackout (SBO) transient.Keywords: ABWR, TRACE, safety analysis, PARCS
Procedia PDF Downloads 4518945 Financial Regulations and Insolvency Risk: Empirical Evidence from Commercial Banks of Pakistan
Authors: Shumaila Zeb
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The proposed study aims to investigate insolvency risk of commercial banks of Pakistan. Furthermore, it empirically estimates the effect of already implemented financial regulations on the insolvency risk of banks. To carry out the empirical analysis, a balanced bank-level panel data covering the period 2008-2016 is used. The Z-score is used for calculating the insolvency risk of each bank. The panel regression is used to investigate the relationship between financial regulations and insolvency risk of banks. The empirics reveal that the financial regulations enforced by State Bank of Pakistan have significant impacts on the insolvency risk of banks. The results further indicate that loan ratio and reserve ratio are positively and significantly related to the insolvency risk of banks.Keywords: insolvency risk, Z-score, financial regulations, banks
Procedia PDF Downloads 1928944 Gamma Irradiation Effects on the Magnetic Properties of Hard Ferrites
Authors: F. Abbas Pour Khotbehsara, B. Salehpour, A. Kianvash
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Many industrial materials like magnets need to be tested for the radiation environment expected at linear colliders (LC) where the accelerator and detectors will be subjected to large influences of beta, neutron and gamma’s over their life Gamma irradiation of the permanent sample magnets using a 60Co source was investigated up to an absorbed dose of 700Mrad shows a negligible effect on some magnetic properties of Nd-Fe-B. In this work, it has been tried to investigate the change of some important properties of Barium hexa ferrite. Results showed little decreases of magnetic properties at doses rang of 0.5 to 2.5 Mrad. But at the gamma irradiation dose up to 10 Mrad it is showed a few increase of properties. Also study of gamma irradiation of Nd-Fe-B showed considerably increase of magnetic properties.Keywords: gamma ray irradiation, hard ferrite, magnetic coefficient, magnetic material, radiation dose
Procedia PDF Downloads 2348943 Influence of Recycled Glass Content on the Properties of Concrete and Mortar
Authors: Bourmatte Nadjoua, Houari Hacène
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The effect of replacement of fine aggregates with recycled glass on the fresh and hardened properties of concrete and mortar is studied. Percentages of replacement are 0–25% and 50% of aggregates with fine waste glass to produce concrete and percentage of replacement of 100% to produce mortar. As a result of the conducted study, the slump flow increased with the increase of recycled glass content. On the other hand, the compressive strength and tensile strength of recycled glass mixtures were decreased with the increase in the recycled glass content. The results showed that recycled glass aggregate can successfully be used with limited level for producing concrete. Mortar based on glass shows a compressive strength with 50% lower than that of control mortar.Keywords: compressive strength, concrete, mortar, recycled glass
Procedia PDF Downloads 4358942 The Relationship between the Speed of Light and Cosmic Background Potential
Authors: Youping Dai, Xinping Dai, Xiaoyun Li
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In this paper, the effect of Cosmic Background Gravitational Potential (CBGP) was discussed. It is helpful to reveal the equivalence of gravitational and inertial mass, and to understand the origin of inertia. The derivation is similar to the classic approach adopted by Landau in the book 'Classical Theory of Fields'.The main differences are that we used CBGP = Lambda^2 instead of c^2, and used CBGP energy E = m*Lambda^2 instead of kinetic energy E = (1/2)m*v^2 as initial assumptions (where Lambda has the same units for measuring velocity). It showed that Lorentz transformation, rest energy and Newtonian mechanics are all affected by $CBGP$, and the square of the speed of light is equal to CBGP too. Finally, the top value of cosmic mass density and cosmic radius were discussed.Keywords: the origin of inertia, Mach's principle, equivalence principle, cosmic background potential
Procedia PDF Downloads 3718941 The Efficacy of Motivation Management Training for Students’ Academic Achievement and Self-Concept
Authors: Ramazan Hasanzadeh, Leyla Vatandoust
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This study examined the efficacy of motivation management training for students’ academic achievement and self-concept. The pretest–posttest quasi-experimental study used a cluster random sampling method to select subjects for the experimental (20 subjects) and control (20 subjects) groups. posttest was conducted with both groups to determine the effect of the training. An academic achievement and academic self-concept questionnaire (grade point average requirement) was used for the pretest and posttest. The results showed that the motivation management training increased academic self-concept and academic achievement.Keywords: motivation management, academic self-concept, academic achievement, students
Procedia PDF Downloads 2518940 Anti-Apoptotic Effect of Pueraria tuberosa in Rats with Streptozotocin Induced Diabetic Nephropathy
Authors: Rashmi Shukla, Yamini Bhusan Tripathi
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Diabetic nephropathy (DN) is characterized as diabetic kidney disease which involves many pathways e.g. hyperactivated protein kinase c (PKC), polyol pathway, excess production of advanced glycation end product (AGEs) & free radical accumulation etc. All of them results to hypoxia followed by apoptosis of podocytes, glomerulosclerosis, extracellular matrix (ECM) accumulation and fibrosis resulting to irreversible changes in kidney. This is continuously rising worldwide and there are not enough specific drugs, to retard its progress. Due to increasing side effects of allopathic drugs, interest in herbal remedies is growing. Earlier, we have reported that PTY-2 (a phytomedicine, derived from Pueraria tuberosa Linn.) inhibits the accumulation of extracellular matrix (ECM) through activation of MMP-9. Present study exhibited the therapeutic potential of Pueraria tuberosa in the prevention of podocytes apoptosis and modulation of nephrin expression in streptozotocin (STZ) induced DN rats. DN rats were produced by maintaining persistent hyperglycemia for 8 weeks by intra-peritoneal injection of 55 mg/kg streptozotocin (STZ). These rats were randomly divided in 2 groups, i.e. DN control, and DN+ water extract of Pueraria tuberosa (PTW). One group of age-matched normal rats served as non-diabetic control (group-1), The STZ induced DN rats (group-2) and DN+PTW treated rats (group-3). The PTW was orally administered (0.3g/kg) daily to group-2 rats and drug vector (1 ml of 10% tween 20) in control rats. The treatments were continued for 20 days and blood and urine samples were collected. Rats were then sacrificed to investigate the expression Bcl2, Bax and nephroprotective protein i.e. nephrin in kidney glomerulus. The effect of PTW was evaluated, we have found that the PTW significantly(p < .001) reversed the raised serum urea, serum creatinine, urine protein and improved the creatinine clearance in STZ induce diabetic nephropathy in rats and also significantly(p < .001) prevented the rise in urine albumin excretion. The Western blot analysis of kidney tissue homogenate showed increased expression of Bcl2 in PTW treated rats. The RT-PCR showed the increased expression and accumulation of nephrin mRNA. The confocal photomicrographs also supported the reduction of Bax and a simultaneous increase in Bcl2 and nephrin in glomerular podocytes. Hence, our finding suggests that the nephroprotective role of PTW is mediated via restoration of nephrin thus prevents the podocytes apoptosis and ameliorates diabetic nephropathy. The clinical trial of PTW would prove to be a potential food supplement/ drug of alternative medicine for patients with diabetic nephropathy in early stage.Keywords: Pueraria tuberosa, diabetic nephropathy, anti-apoptosis, nephrin
Procedia PDF Downloads 2108939 Dynamical and Thermal Study of Twin Impinging Jets a Vertical Plate with Various Jet Velocities and Impinging Distance
Authors: Louaifi Hamaili Samira, Mataoui Amina, Cheraitia Tadjeddine
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This investigation proposes a numerical analysis of two turbulent parallel jets impinging a heated plate. The heat transfer enhancement is carried out according of the main parameters of the jet-wall interaction. The numerical solution of the stationary equations (RANS) is performed by the finite volume method using the k - ε model. A parametric study is performed to evaluate simultaneously the effect of nozzle-plate distance and velocity ratios in the range 0≤λ≤1. It is found that good local cooling is obtained for λ= 0.25 when the impinging distance is between 4w and 8w than for velocity ratios λ=1 and λ= 0.75. On the other hand, for impinging distances exceeding 8w, the velocity ratio λ =0.75 is more appropriate for good local cooling of the plate.Keywords: two unequal jets, turbulence, mixing, heat transfer, CFD
Procedia PDF Downloads 218938 Effect of Xylophagous On The Productivity Of The Trees Of The Fruit-bearing Pistachio Tree In Algeria
Authors: Chebouti-meziou Nadjiba1, And Chebouti Yahia2:
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the cultivation of Pistachios Pistacia vera of rare plants in Algeria and this point to see the lack of knowledge of techniques, which resulted in the proliferation of the tree to obtain a limited benefit does not exceed 0.75 tons / hectare, in addition to the enemy that lead to poor product on the one hand, one of which buds into wood and fruit Chaetoptelius vestitus. Since the tree is the raw sound production, while 25 kg of infected tree produces about 15 kg of any shortage of fact that this insect Chaetoptelius vestitus spend the amount of trouble going in the summer the young twigs of the trees into a sound the product by20% and due to the composition by the problem of spending in the newly formed branches, which lead to this loss in yieldKeywords: chaetoptelius vestitus, pistacia vera, spending, return, poor product.
Procedia PDF Downloads 658937 Experimental Investigation of the Effect of Temperature on A PEM Fuel Cell Performance
Authors: Remzi Şahin, Sadık Ata, Kevser Dincer
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In this study, performance of proton exchange membrane (PEM) fuel cell was experimentally investigated. The efficiency of energy conversion in PEM fuel cells is dependent on the catalytic activities of the catalysts used in the cathode and anode of membrane electrode assemblies. Membrane is considered the heart of PEM fuel cells without which they cannot produce electricity. PEM fuel cell performance increased with coating carbon nanotube (CNT). CNT show a unique combination of stiffness, strength, and tenacity compared to other fiber materials which usually lack one or more of these properties. Two different experiments were performed and the membrane performance has been determined by repeating the two experiments that were done before coating. The purposes of these experiments are the observation of power change due to a temperature change in the same voltage value.Keywords: carbon nanotube (CNT), proton exchange membrane (PEM), fuel cell, spin method
Procedia PDF Downloads 3728936 Smart Technology for Hygrothermal Performance of Low Carbon Material Using an Artificial Neural Network Model
Authors: Manal Bouasria, Mohammed-Hichem Benzaama, Valérie Pralong, Yassine El Mendili
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Reducing the quantity of cement in cementitious composites can help to reduce the environmental effect of construction materials. By-products such as ferronickel slags (FNS), fly ash (FA), and Crepidula fornicata (CR) are promising options for cement replacement. In this work, we investigated the relevance of substituting cement with FNS-CR and FA-CR on the mechanical properties of mortar and on the thermal properties of concrete. Foraging intervals ranging from 2 to 28 days, the mechanical properties are obtained by 3-point bending and compression tests. The chosen mix is used to construct a prototype in order to study the material’s hygrothermal performance. The data collected by the sensors placed on the prototype was utilized to build an artificial neural network.Keywords: artificial neural network, cement, circular economy, concrete, by products
Procedia PDF Downloads 1098935 Effect of Precursor’s Grain Size on the Conversion of Microcrystalline Gallium Antimonide GaSb to Nanocrystalline Gallium Nitride GaN
Authors: Jerzy F. Janik, Mariusz Drygas, Miroslaw M. Bucko
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A simple precursor system has been recently developed in our laboratory for the conversion of affordable microcrystalline gallium antimonide GaSb to a range of nanocrystalline powders of gallium nitride GaN – a wide bandgap semiconductor indispensable in modern optoelectronics. The process relies on high temperature nitridation reactions of GaSb with ammonia. Topochemical relationships set up by the cubic lattice of GaSb result in some metastable cubic GaN formed in addition to the stable hexagonal GaN. A prior application of high energy ball milling to the initially microcrystalline GaSb precursor is shown to alter the nitridation output.Keywords: nanocrystalline, gallium nitride, GaN, gallium antimonide, GaSb, nitridation, ball milling
Procedia PDF Downloads 3928934 Definition of Aerodynamic Coefficients for Microgravity Unmanned Aerial System
Authors: Gamaliel Salazar, Adriana Chazaro, Oscar Madrigal
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The evolution of Unmanned Aerial Systems (UAS) has made it possible to develop new vehicles capable to perform microgravity experiments which due its cost and complexity were beyond the reach for many institutions. In this study, the aerodynamic behavior of an UAS is studied through its deceleration stage after an initial free fall phase (where the microgravity effect is generated) using Computational Fluid Dynamics (CFD). Due to the fact that the payload would be analyzed under a microgravity environment and the nature of the payload itself, the speed of the UAS must be reduced in a smoothly way. Moreover, the terminal speed of the vehicle should be low enough to preserve the integrity of the payload and vehicle during the landing stage. The UAS model is made by a study pod, control surfaces with fixed and mobile sections, landing gear and two semicircular wing sections. The speed of the vehicle is decreased by increasing the angle of attack (AoA) of each wing section from 2° (where the airfoil S1091 has its greatest aerodynamic efficiency) to 80°, creating a circular wing geometry. Drag coefficients (Cd) and forces (Fd) are obtained employing CFD analysis. A simplified 3D model of the vehicle is analyzed using Ansys Workbench 16. The distance between the object of study and the walls of the control volume is eight times the length of the vehicle. The domain is discretized using an unstructured mesh based on tetrahedral elements. The refinement of the mesh is made by defining an element size of 0.004 m in the wing and control surfaces in order to figure out the fluid behavior in the most important zones, as well as accurate approximations of the Cd. The turbulent model k-epsilon is selected to solve the governing equations of the fluids while a couple of monitors are placed in both wing and all-body vehicle to visualize the variation of the coefficients along the simulation process. Employing a statistical approximation response surface methodology the case of study is parametrized considering the AoA of the wing as the input parameter and Cd and Fd as output parameters. Based on a Central Composite Design (CCD), the Design Points (DP) are generated so the Cd and Fd for each DP could be estimated. Applying a 2nd degree polynomial approximation the drag coefficients for every AoA were determined. Using this values, the terminal speed at each position is calculated considering a specific Cd. Additionally, the distance required to reach the terminal velocity at each AoA is calculated, so the minimum distance for the entire deceleration stage without comprising the payload could be determine. The Cd max of the vehicle is 1.18, so its maximum drag will be almost like the drag generated by a parachute. This guarantees that aerodynamically the vehicle can be braked, so it could be utilized for several missions allowing repeatability of microgravity experiments.Keywords: microgravity effect, response surface, terminal speed, unmanned system
Procedia PDF Downloads 1688933 Effect of Phosphorus Solubilizing Bacteria on Yield and Seed Quality of Camelina (Camelina sativa L.) under Drought Stress
Authors: Muhammad Naeem Chaudhry, Fahim Nawaz, Rana Nauman Shabbir
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New strategies aimed at increasing the resilience of crop plants to the negative effects of climate change represent important research priorities of plant scientists. The use of soil microorganisms to alleviate abiotic stresses like drought has gained particular importance in recent past. A field experiment was planned to investigate the effect of phosphorous solubilizing bacteria on yield and seed quality of Camelina (Camelina sativa L.) under water deficit conditions. The study was conducted at Agronomic Research Farm, University College of Agriculture and Environmental Sciences, The Islamia University Bahawalpur, during 4th week of November, 2013. The available seeds of Camelina sativa were inoculated with two bacterial strains (pseudomonas and Bacillus spp.) and grown under various water stress levels i.e. D0, (four irrigations), D3 (three irrigation), D2 (two irrigations), and D1 (one irrigation). The results revealed that drought stress significantly reduced the plant growth and yield, consequently reducing protein contents and oil concentration in camelina. The exposure to drought stress decreased plant height (16%), plant population (27%), number of fertile branches (41-59%), number of pods per plant (35%) and seed per pod (33%). Drought stress also exerted a negative impact on yield characteristics by reducing the 1000-seed weight (65%), final seed yield (52%), biological yield (22%) and harvest index (39%) of camelina. However, the inoculation of seeds with Pseudomonas and Bacillus spp. promoted the plant growth characterized by increased plant height and enhanced plant population. It was noted that inoculation of seeds with Pseudomonas resulted in the maximum plant population (113.4 cm), primary branches (19 plant-1), and number of pods (664 plant-1), whereas Bacillus inoculation resulted in maximum plant height (113.4 cm), seeds per pod (15.9), 1000-seed weight (1.85 g), and seed yield (3378.8 kg ha-1). Moreover, the inoculation with Bacillus also significantly improved the quality attributes of camelina and gave 3.5% and 2.1% higher oil contents than Pseudomonas and control (no-inoculation), respectively. Similarly, the same strain also resulted in maximum protein contents (33.3%). Our results confirmed the hypothesis that inoculation of seeds with phosphorous solubilizing bacterial strains is an effective, viable and environment-friendly approach to improve yield and quality of camelina under water deficit conditions. However, further studies are suggested to investigate the physiological and molecular processes, stimulated by bacterial strains, for increasing drought tolerance in food crops.Keywords: Camelina, drought stress, phosphate solubilizing bacteria, seed quality
Procedia PDF Downloads 2578932 Evaluation of Moringa oleifera in Decolourization of Dyes in Textile Wastewater
Authors: Nagia Ali, R. S. R. El-Mohamedy
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The purpose of this paper is to irradiate the dyes biologically through the use of Moreinga oleifera. The study confirms the potential use of Moringa oleifera in decolourization of dyes and thus opens up a scope for future analysis pertaining to its performance in treatment of textile effluent. In this paper, the ability of natural products in removing dyes was tested using two reactive dyes and one acid dye. After a preliminary screening for dye removal capacity, a vegetal protein extract derived from Moeringa oleifera seed was fully studied. The influences of several parameters such as pH, temperature or initial dye concentration were tested and the behavior of coagulants was compared. It was found that dye removal decreased as pH increased. Temperature did not seem to have a considerable effect, while initial dye concentration appeared to be a very important variable.Keywords: Moreinga oleifera, decolourization, waste water, reactive dyes, acid dyes
Procedia PDF Downloads 3608931 Using the Structural Equation Model to Explain the Effect of Supervisory Practices on Regulatory Density
Authors: Jill Round
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In the economic system, the financial sector plays a crucial role as an intermediary between market participants, other financial institutions, and customers. Financial institutions such as banks have to make decisions to satisfy the demands of all the participants by keeping abreast of regulatory change. In recent years, progress has been made regarding frameworks, development of rules, standards, and processes to manage risks in the banking sector. The increasing focus of regulators and policymakers placed on risk management, corporate governance, and the organization’s culture is of special interest as it requires a well-resourced risk controlling function, compliance function, and internal audit function. In the past years, the relevance of these functions that make up the so-called Three Lines of Defense has moved from the backroom to the boardroom. The approach of the model can vary based on the various organizational characteristics. Due to the intense regulatory requirements, organizations operating in the financial sector have more mature models. In less regulated industries there is more cloudiness about what tasks are allocated where. All parties strive to achieve their objectives through the effective management of risks and serve the identical stakeholders. Today, the Three Lines of Defense model is used throughout the world. The research looks at trends and emerging issues in the professions of the Three Lines of Defense within the banking sector. The answers are believed to helping to explain the increasing regulatory requirements for the banking sector. While the number of supervisory practices increases the risk management requirements intensify and demand more regulatory compliance at the same time. The Structural Equation Modeling (SEM) is applied by making use of conducted surveys in the research field. It aims to describe (i) the theoretical model regarding the applicable linearity relationships, (ii) the causal relationship between multiple predictors (exogenous) and multiple dependent variables (endogenous), (iii) taking into consideration the unobservable variables and (iv) the measurement errors. The surveys conducted on the research field suggest that the observable variables are caused by various latent variables. The SEM consists of the 1) measurement model and the 2) structural model. There is a detectable correlation regarding the cause-effect relationship among the performed supervisory practices and the increasing scope of regulation. Supervisory practices reinforce the regulatory density. In the past, controls were placed after supervisory practices were conducted or incidents occurred. In further research, it is of interest to examine, whether risk management is proactive, reactive to incidents and supervisory practices or can be both at the same time.Keywords: risk management, structural equation model, supervisory practice, three lines of defense
Procedia PDF Downloads 2158930 Observation of Laminar to Turbulent Transition in Micro-Propellers
Authors: Dake Wang, Ellis Edinkrah, Brian Wang
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Micro-propellers can operate in regimes of small Reynolds numbers where the effect of viscous friction becomes important. In this work, the transition from laminar to turbulent regime in micro-propellers driven by electric motors was observed. The analysis revealed that the lift force was linearly proportional to propeller output power when systems operate in the laminar/viscous regime, while a sublinear relation between the force and the output power was observed in the turbulent/inertial regime. These behaviors appeared to be independent of motor-propeller specifications. The Reynolds number that marks the regime transition was found to be at around 10000.Keywords: UAV, micro-propeller, laminar-turbulent, Reynolds number
Procedia PDF Downloads 928929 A Stochastic Approach to Extreme Wind Speeds Conditions on a Small Axial Wind Turbine
Authors: Nkongho Ayuketang Arreyndip, Ebobenow Joseph
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In this paper, to model a real life wind turbine, a probabilistic approach is proposed to model the dynamics of the blade elements of a small axial wind turbine under extreme stochastic wind speeds conditions. It was found that the power and the torque probability density functions even though decreases at these extreme wind speeds but are not infinite. Moreover, we also found that it is possible to stabilize the power coefficient (stabilizing the output power) above rated wind speeds by turning some control parameters. This method helps to explain the effect of turbulence on the quality and quantity of the harness power and aerodynamic torque.Keywords: probability, probability density function, stochastic, turbulence
Procedia PDF Downloads 5788928 The Moderation Effect of Critical Item on the Strategic Purchasing: Quality Performance Relationship
Authors: Kwong Yeung
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Theories about strategic purchasing and quality performance are underdeveloped. Understanding the evolving role of purchasing from reactive to proactive is a pressing strategic issue. Using survey responses from 176 manufacturing and electronics industry professionals, we study the relationships between strategic purchasing and supply chain partners’ quality performance to answer the following questions: Can transaction cost economics be used to elucidate the strategic purchasing-quality performance relationship? Is this strategic purchasing-quality performance relationship moderated by critical item analysis? The findings indicate that critical item analysis positively and significantly moderates the strategic purchasing-quality performance relationship.Keywords: critical item analysis, moderation, quality performance, strategic purchasing, transaction cost economics
Procedia PDF Downloads 5568927 The Antimicrobial Activity of Marjoram Essential Oil Against Some Antibiotic Resistant Microbes Isolated from Hospitals
Authors: R. A. Abdel Rahman, A. E. Abdel Wahab, E. A. Goghneimy, H. F. Mohamed, E. M. Salama
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Infectious diseases are a major cause of death worldwide. The treatment of infections continues to be problematic in modern time because of the severe side effects of some drugs and the growing resistance to antimicrobial agents. Hence, the search for newer, safer and more potent antimicrobials is a pressing need. Herbal medicines have received much attention as a source of new antibacterial drugs since they are considered time-tested and comparatively safe both for human use and the environment. In the present study, the antimicrobial activity of marjoram (Origanum majorana L.) essential oil on some gram positive and gram negative reference bacteria, as well as some hospital resistant microbes, was tested. Marjoram oil was extracted and the oil chemical constituents were identified using GC/MS analysis. Staphylococcus aureas ATCC 6923, Pseudomonus auregonosa ATCC 9027, Bacillus subtilis ATCC 6633, E. coli ATCC 8736 and two hospital resistant microbes isolates 16 and 21 were used. The two isolates were identified by biochemical tests and 16s rRNA as proteus spp. and Enterococcus facielus. The effect of different concentrations of essential oils on bacterial growth was tested using agar disk diffusion assay method to determine the minimum inhibitory concentrations and using micro dilution method to determine the minimum bactericidal concentrations. Marjoram oil was found to be effective against both reference and hospital resistance strains. Hospital strains were more resistant to marjoram oil than reference strains. P. auregonosa growth was completely inhibited at a low concentration of oil (4µl/ml). The other reference strains showed sensitivity to marjoram oil at concentrations ranged from 5 to 7µl/ml. The two hospital strains showed sensitivity at media containing 10 and 15µl/ml oil. The major components of oil were terpineol, cis-beta (23.5%), 1,6 – octadien –3-ol,3,7-dimethyl, 2 aminobenzoate (10.9%), alpha terpieol (8.6%) and linalool (6.3%). Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis were used to determine the difference between treated and untreated hospital strains. SEM results showed that treated cells were smaller in size than control cells. TEM data showed that cell lysis has occurred to treated cells. Treated cells have ruptured cell wall and appeared empty of cytoplasm compared to control cells which shown to be intact with normal volume of cytoplasm. The results indicated that marjoram oil has a positive antimicrobial effect on hospital resistance microbes. Natural crude extracts can be perfect resources for new antimicrobial drugs.Keywords: antimicrobial activity, essential oil, hospital resistance microbes, marjoram
Procedia PDF Downloads 4418926 An Analysis of Oil Price Changes and Other Factors Affecting Iranian Food Basket: A Panel Data Method
Authors: Niloofar Ashktorab, Negar Ashktorab
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Oil exports fund nearly half of Iran’s government expenditures, since many years other countries have been imposed different sanctions against Iran. Sanctions that primarily target Iran’s key energy sector have harmed Iran’s economy. The strategic effects of sanctions might be reduction as Iran adjusts to them economically. In this study, we evaluate the impact of oil price and sanctions against Iran on food commodity prices by using panel data method. Here, we find that the food commodity prices, the oil price and real exchange rate are stationary. The results show positive effect of oil price changes, real exchange rate and sanctions on food commodity prices.Keywords: oil price, food basket, sanctions, panel data, Iran
Procedia PDF Downloads 3498925 The Effects of Stoke's Drag, Electrostatic Force and Charge on Penetration of Nanoparticles through N95 Respirators
Authors: Jacob Schwartz, Maxim Durach, Aniruddha Mitra, Abbas Rashidi, Glen Sage, Atin Adhikari
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NIOSH (National Institute for Occupational Safety and Health) approved N95 respirators are commonly used by workers in construction sites where there is a large amount of dust being produced from sawing, grinding, blasting, welding, etc., both electrostatically charged and not. A significant portion of airborne particles in construction sites could be nanoparticles created beside coarse particles. The penetration of the particles through the masks may differ depending on the size and charge of the individual particle. In field experiments relevant to this current study, we found that nanoparticles of medium size ranges are penetrating more frequently than nanoparticles of smaller and larger sizes. For example, penetration percentages of nanoparticles of 11.5 – 27.4 nm into a sealed N95 respirator on a manikin head ranged from 0.59 to 6.59%, whereas nanoparticles of 36.5 – 86.6 nm ranged from 7.34 to 16.04%. The possible causes behind this increased penetration of mid-size nanoparticles through mask filters are not yet explored. The objective of this study is to identify causes behind this unusual behavior of mid-size nanoparticles. We have considered such physical factors as Boltzmann distribution of the particles in thermal equilibrium with the air, kinetic energy of the particles at impact on the mask, Stoke’s drag force, and electrostatic forces in the mask stopping the particles. When the particles collide with the mask, only the particles that have enough kinetic energy to overcome the energy loss due to the electrostatic forces and the Stokes’ drag in the mask can pass through the mask. To understand this process, the following assumptions were made: (1) the effect of Stoke’s drag depends on the particles’ velocity at entry into the mask; (2) the electrostatic force is proportional to the charge on the particles, which in turn is proportional to the surface area of the particles; (3) the general dependence on electrostatic charge and thickness means that for stronger electrostatic resistance in the masks and thicker the masks’ fiber layers the penetration of particles is reduced, which is a sensible conclusion. In sampling situations where one mask was soaked in alcohol eliminating electrostatic interaction the penetration was much larger in the mid-range than the same mask with electrostatic interaction. The smaller nanoparticles showed almost zero penetration most likely because of the small kinetic energy, while the larger sized nanoparticles showed almost negligible penetration most likely due to the interaction of the particle with its own drag force. If there is no electrostatic force the fraction for larger particles grows. But if the electrostatic force is added the fraction for larger particles goes down, so diminished penetration for larger particles should be due to increased electrostatic repulsion, may be due to increased surface area and therefore larger charge on average. We have also explored the effect of ambient temperature on nanoparticle penetrations and determined that the dependence of the penetration of particles on the temperature is weak in the range of temperatures in the measurements 37-42°C, since the factor changes in the range from 3.17 10-3K-1 to 3.22 10-3K-1.Keywords: respiratory protection, industrial hygiene, aerosol, electrostatic force
Procedia PDF Downloads 1898924 The Unsteady Non-Equilibrium Distribution Function and Exact Equilibrium Time for a Dilute Gas Affected by Thermal Radiation Field
Authors: Taha Zakaraia Abdel Wahid
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The behavior of the unsteady non-equilibrium distribution function for a dilute gas under the effect of non-linear thermal radiation field is presented. For the best of our knowledge this is done for the first time at all. The distinction and comparisons between the unsteady perturbed and the unsteady equilibrium velocity distribution functions are illustrated. The equilibrium time for the dilute gas is determined for the first time. The non-equilibrium thermodynamic properties of the system (gas+the heated plate) are investigated. The results are applied to the Argon gas, for various values of radiation field intensity. 3D-Graphics illustrating the calculated variables are drawn to predict their behavior. The results are discussed.Keywords: dilute gas, radiation field, exact solutions, travelling wave method, unsteady BGK model, irreversible thermodynamics, unsteady non-equilibrium distribution functions
Procedia PDF Downloads 4908923 Homoeopathy with Integrative Approach in the World of Attention Deficit Hyperactivity Disorder
Authors: Mansi Chinchanikar
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Homoeopathy is the second most widely used medical system in the world, yet the homoeopaths of India and around the world are sick of reading or hearing about how homoeopathy is only a placebo effect and cannot cure or even manage any disease. However, individuals making such unfounded claims should explain to the group how a homoeopathic placebo, particularly one for a neurodevelopmental disease like Attention Deficit Hyperactivity Disorder (ADHD), can be effective in children, with studies to back it up their skeptics. This literary review work exhibits how homoeopathy with a multimodal approach may show a considerable proportion of ADHD patients in India and throughout the world successfully manageable and treatable according to growing study evidence, ruling out the hazardous conventional medicines. Indeed, homeopathy can help cure ADHD symptoms either on its own or in combination with other types of integrative systems.Keywords: ADHD, adult ADHD, homoeopathy, integrative approach
Procedia PDF Downloads 778922 What are Parents of Teacher Candidates’ Belief Towards Teaching as a Profession?
Authors: Chua Lee Chuan
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This study was conducted to explore parents’ beliefs towards the teaching profession. This survey was conducted on 51 parents of teacher candidates in a teacher training institute. A research instrument, using questionnaires, adapted from FIT-Choice scale developed by Richardson and Watt (2006) was used to collect data from the population. The findings showed that parents, in general, have positive attitudes towards the teaching profession. They perceived teaching as a career highly valued by the society. Though the teaching job was viewed as difficult and requiring high expertise, the salary received commensurate their hard work and heavy workload. In terms of gender, male and female parents did not differ in their beliefs about the teaching profession. However, results indicated that educational attainment and income level had significant effect on parents’ beliefs on teaching as a profession. Implications and recommendations in relation to the findings are also included.Keywords: beliefs, teaching profession, parents, teacher candidates
Procedia PDF Downloads 3918921 Comparison of Effect of Group Counseling with Cognitive Therapy Approach and Interactive Lectures on Anxiety during Pregnancy in Primiparas: A Clinical Trial
Authors: Zohre Shahhosseini, Mehdi Pourasghar, AliReza Khalilian, Fariba Salehi
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Objective: The prevalence of anxiety during pregnancy, particularly in developing countries, and its adverse effects on mother and baby, can make pregnancy unpleasant for pregnant women. The effect of anxiety during pregnancy on birth outcomes and children can be a justification for screening of anxious pregnant women in periodic pregnancy care and helping them. In this study, researchers have investigated effects and comparison of group counseling (Cognitive therapy) and interactive lectures on anxiety during pregnancy of primiparas. Methods: The population studied in this semi-experimental trail was nulliparous pregnant women with backgrounds in health care centers in Sari city .They were studied during a period of 3 months from early March to end May 2016. Sample size in this study was 91 patients, who were randomly assigned to three groups: group counseling, interactive lecture, and control group. Demographic questionnaire and Speilberger State –Trait Anxiety Inventory (SPAI) was completed for all three groups after obtaining letter of consent and completing the initial checklist. Then interventions included 4 sessions for group counseling and 4 sessions for interactive lecture which were implemented in two sessions a week. 4 weeks after interventions, Speilberger State – Trait Anxiety Inventory (SPAI), completed by both group counseling and interactive lectures groups again. In control group, the second questionnaire was also completed 4 weeks after completing the initial questionnaire. Data analysis was performed using spss software version 18. At first, the Kalmogorov-Smiranov test was carried out and then chi square tests, Independent t-test, paired t-test, ANOVA test, and Dunnett's post hoc test were applied. Results: Findings show that group counseling and interactive lecture with reducing state and trait anxiety in significant level of P=0/000 contribute to reduction of anxiety in nulliparous pregnant mothers. However, in this study, group counseling was more effective than an interactive lecture in reducing participants' anxiety, but this difference was not significant (P≥0/05). Conclusions: According to the results of this study, it is suggested that by screening of psychological - mental problems of pregnant women in periodic care during pregnancy be considered by revised prenatal care plans and creation of counseling and training units at health centers. Besides owing to the fact that both interactive lecture and group counseling method were effective in reducing anxiety, these methods should be used proportionate to situations and facilities.Keywords: anxiety, group counseling, cognitive therapy, interactive lecture, nulliparous
Procedia PDF Downloads 2908920 The Effect of Mental Workload Towards Mental Fatigue on Customer Care Agent Using Electroencephalogram
Authors: Maya Arlini Puspasari, Shafira Karamina Alifah, Hardianto Iridiastadi
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High mental workload can lead to fatigue and further result in decreased concentration and work performance. This study is conducted to see the effects of mental workload towards mental fatigue. Mental fatigue measurement was conducted at the first and the last 10 minutes of the working time using electroencephalogram, while mental workload measurement was conducted after the work is completed using the NASA-TLX questionnaire. The result shows that there is an increase in alpha band which indicates an increase in mental fatigue. This study also shows absolute alpha is more sensitive compared to the relative alpha. This study proves that there is a relationship between mental workload and mental fatigue although not relatively strong.Keywords: mental workload, electroencephalogram, customer care agents, NASA-TLX
Procedia PDF Downloads 2158919 Evaluation of Antimicrobial and Anti-Inflammatory Activity of Doani Sidr Honey and Madecassoside against Propionibacterium Acnes
Authors: Hana Al-Baghaoi, Kumar Shiva Gubbiyappa, Mayuren Candasamy, Kiruthiga Perumal Vijayaraman
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Acne is a chronic inflammatory disease of the sebaceous glands characterized by areas of skin with seborrhea, comedones, papules, pustules, nodules, and possibly scarring. Propionibacterium acnes (P. acnes), plays a key role in the pathogenesis of acne. Their colonization and proliferation trigger the host’s inflammatory response leading to the production of pro-inflammatory cytokines such as interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α). The usage of honey and natural compounds to treat skin ailments has strong support in the current trend of drug discovery. The present study was carried out evaluate antimicrobial and anti-inflammatory potential of Doani Sidr honey and its fractions against P. acnes and to screen madecassoside alone and in combination with fractions of honey. The broth dilution method was used to assess the antibacterial activity. Also, ultra structural changes in cell morphology were studied before and after exposure to Sidr honey using transmission electron microscopy (TEM). The three non-toxic concentrations of the samples were investigated for suppression of cytokines IL 8 and TNF α by testing the cell supernatants in the co-culture of the human peripheral blood mononuclear cells (hPBMCs) heat killed P. acnes using enzyme immunoassay kits (ELISA). Results obtained was evaluated by statistical analysis using Graph Pad Prism 5 software. The Doani Sidr honey and polysaccharide fractions were able to inhibit the growth of P. acnes with a noteworthy minimum inhibitory concentration (MIC) value of 18% (w/v) and 29% (w/v), respectively. The proximity of MIC and MBC values indicates that Doani Sidr honey had bactericidal effect against P. acnes which is confirmed by TEM analysis. TEM images of P. acnes after treatment with Doani Sidr honey showed completely physical membrane damage and lysis of cells; whereas non honey treated cells (control) did not show any damage. In addition, Doani Sidr honey and its fractions significantly inhibited (> 90%) of secretion of pro-inflammatory cytokines like TNF α and IL 8 by hPBMCs pretreated with heat-killed P. acnes. However, no significant inhibition was detected for madecassoside at its highest concentration tested. Our results suggested that Doani Sidr honey possesses both antimicrobial and anti-inflammatory effects against P. acnes and can possibly be used as therapeutic agents for acne. Furthermore, polysaccharide fraction derived from Doani Sidr honey showed potent inhibitory effect toward P. acnes. Hence, we hypothesize that fraction prepared from Sidr honey might be contributing to the antimicrobial and anti-inflammatory activity. Therefore, this polysaccharide fraction of Doani Sidr honey needs to be further explored and characterized for various phytochemicals which are contributing to antimicrobial and anti-inflammatory properties.Keywords: Doani sidr honey, Propionibacterium acnes, IL-8, TNF alpha
Procedia PDF Downloads 393