Search results for: substitution effect
14818 Determinant Elements for Useful Life in Airports
Authors: Marcelo Müller Beuren, José Luis Duarte Ribeiro
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Studies point that Brazilian large airports are not managing their assets efficiently. Therefore, organizations seek improvements to raise their asset’s productivity. Hence, identification of assets useful life in airports becomes an important subject, since its accuracy leads to better maintenance plans and technological substitution, contribution to airport services management. However, current useful life prediction models do not converge in terms of determinant elements used, as they are particular to the studied situation. For that reason, the main objective of this paper is to identify the determinant elements for a useful life of major assets in airports. With that purpose, a case study was held in the key airport of the south of Brazil trough historical data analysis and specialist interview. This paper concluded that most of the assets useful life are determined by technical elements, maintenance cost, and operational costs, while few presented influence of technological obsolescence. As a highlight, it was possible to identify the determinant elements to be considered by a model which objective is to identify the useful life of airport’s major assets.Keywords: airports, asset management, asset useful life
Procedia PDF Downloads 52314817 Hydrogen Permeability of BSCY Proton-Conducting Perovskite Membrane
Authors: M. Heidari, A. Safekordi, A. Zamaniyan, E. Ganji Babakhani, M. Amanipour
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Perovskite-type membrane Ba0.5Sr0.5Ce0.9Y0.1O3-δ (BSCY) was successfully synthesized by liquid citrate method. The hydrogen permeation and stability of BSCY perovskite-type membranes were studied at high temperatures. The phase structure of the powder was characterized by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to characterize microstructures of the membrane sintered under various conditions. SEM results showed that increasing in sintering temperature, formed dense membrane with clear grains. XRD results for BSCY membrane that sintered in 1150 °C indicated single phase perovskite structure with orthorhombic configuration, and SEM results showed dense structure with clear grain size which is suitable for permeation tests. Partial substitution of Sr with Ba in SCY structure improved the hydrogen permeation flux through the membrane due to the larger ionic radius of Ba2+. BSCY membrane shows high hydrogen permeation flux of 1.6 ml/min.cm2 at 900 °C and partial pressure of 0.6.Keywords: hydrogen separation, perovskite, proton conducting membrane.
Procedia PDF Downloads 34214816 Pragmatics of Illness: A View from Jordanian Arabic
Authors: Marwan Jarrah, Nadia Nugrush, Sukainah Ali, Areej Allawzi
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This research article investigates how illnesses (different types and severity) are expressed in Arabic discourse with a particular focus on input coming from Colloquial Jordanian Arabic (CJA). Drawing on a corpus of naturally occurring conversations, this article offers evidence that illnesses are predominantly expressed through two different sets of expressive strategies, namely direct expressive strategies (DES) and indirect expressive strategies (IES). The latter are exclusively used when cancer and mental health disorders are targeted. IES include the substitution of the name of the illness with some religious expressions (e.g., ʔallah ʔijdʒi:rna ‘May Allah keeps us safe’) or certain terms especially when cancer is meant (e.g., haðˤa:k ʔil-maraðˤ ‘that disease’). On the other hand, DES are used in conjunction with other illnesses (e.g., heart, kidneys, diabetes, etc.), regardless of their severity. DES include specific formulas that remarkably mention the name of the inflicted organ (e.g., [with-SOMEONE the ORGAN] as in ʕinduh ʔil-qalb ‘lit. with-him the heart’ meaning ‘He has a heart disease). We discuss the effects of religious beliefs and local norms and values in determining the use of these strategies.Keywords: Illnesses, pragmatics, expressive strategies, religion
Procedia PDF Downloads 8314815 Potential of Grass Silage as a Source of Nutrients in Poultry Production
Authors: Hamim Abbas, Jean Luc-Hornick, Isabelle Dufrasne
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Feed costs constitute over 60% of total expenses in organic layer poultry production, with feed protein supply being a significant concern. Alfalfa-based dehydrated silage pellets are mainly diets composed of leaves (ABSP), which are non-conventional protein sources that could enhance profits by reducing feed costs and ensuring consistent availability. This experiment studied the effects on the performances of Novogen Brown light layers of a commercial control diet replaced with 10% ABSP. After a 21-day trial, this diet (ABSP) has improved the laying rate, yolk color of eggs, feed conversion rate, ω−3 (PUFAs) and ω−6/ω−3 ratio (P<0.05) while the body weight and egg weight were degraded with the substitution of the ABSP in the diet(P>0.05). The laying rate showed a tendency to increase (P=0.06). These findings suggest that ABSP can replace at least 10% of the feed in organic layer diets without compromising production parameters negatively.Keywords: alfalfa, silage, pellet, organic layers
Procedia PDF Downloads 5014814 Zinc (II) Complexes of Nitrogen, Oxygen and Sulfur Coordination Modes: Synthesis, Spectral Studies and Antibacterial Activities
Authors: Ayodele Odularu, Peter Ajibade, Albert Bolhuis
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This study aimed at assessing the antibacterial activities of four zinc (II) complexes. Zinc (II) complexes of nitrogen, oxygen and sulfur coordination modes were synthesized using direct substitution reaction. The characterization techniques involved physicochemical properties (molar conductivity) and spectroscopic techniques. The molar conductivity gave the non-electrolytic nature of zinc (II) complexes. The spectral studies of zinc (II) complexes were done using electronic spectra (UV-Vis) and Fourier Transform Infra-red Spectroscopy (FT-IR). Spectral data from the spectroscopic studies confirmed the coordination of the mixed ligands with zinc (II) ion. The antibacterial activities of zinc(II) complexes of were all in supportive of Overtone’s concept and Tweedy’s theory of chelation for bacterial strains of S. aureus MRSA252 and E coli MC4100 because the zones of inhibition were greater than the corresponding ligands. In summary, all zinc (II) complexes of ZEPY, ZE1PH, ZE1PY and ZE135PY all have potentials for antibacterial activities.Keywords: antibacterial activities, spectral studies, syntheses, zinc(II) complexes
Procedia PDF Downloads 28214813 Thermosalient Effect of an Organic Aminonitrile and its Derivatives
Authors: Lukman O. Alimi, Vincent J. Smith, Leonard J. Barbour
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The thermosalient effect is an extremely rare propensity of certain crystalline solids for self-actuation by elastic deformation or a ballistic event1. Thermosalient compounds, colloquially known as ‘jumping crystals’ are promising materials for fabrication of actuators that are also being considered as materials for clean energy conversion because of their capabilities to convert thermal energy into mechanical motion directly. Herein, an organic aminonitrile and its derivatives have been probed by a combination of structural, microscopic and thermoanalytical techniques. Crystals of these compounds were analysed by means of single crystal XRD and hotstage microscopy in the temperature range of 100 to 298 K and found to exhibit the thermosalient effect. We also carried out differential scanning calorimetric analysis at the temperature corresponding to that at which the crystal jumps as observed under a hotstage microscope.Keywords: aminonitrile, jumping crystal, self actuation, thermosalient effect
Procedia PDF Downloads 43614812 Characterization of Thixoformed AlSi12 Alloy with the Addition of Trace Amounts of Silver
Authors: Nursen Saklakoglu, Adnan Turker
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The main objective of this study is to reveal the effect of the Thixoforming process on the microstructure and mechanical properties of the AlSi12 alloy with trace amounts of silver. It is concluded that Thixoforming has an important effect on the morphology of intermetallics and Si formation, as well as globular α-Al morphology. The intermetallics have been fractured during thixoforming. It is believed that the fine distribution of the intermetallics is one mechanism for the improved mechanical properties of Thixoformed alloys. The discrete Si particles have been observed during both isothermal heating to the semi-solid range and Thixoforming, also have an important effect on mechanical properties. The Thixoforming process has a greater effect on hardness than the addition of Ag does.Keywords: AlSi alloys, intermetallic phases, mechanical properties trace element, silver, thixoforming
Procedia PDF Downloads 32614811 Design and Analysis of Shielding Magnetic Field for Active Space Radiation Protection
Authors: Chaoyan Huang, Hongxia Zheng
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For deep space exploration and long duration interplanetary manned missions, protection of astronauts from cosmic radiation is an unavoidable problem. However, passive shielding can be little effective for protecting particles which energies are greater than 1GeV/nucleon. In this study, active magnetic protection method is adopted. Taking into account the structure and size of the end-cap, eight shielding magnetic field configurations are designed based on the Hoffman configuration. The shielding effect of shielding magnetic field structure, intensity B and thickness L on H particles with 2GeV energy is compared by test particle simulation. The result shows that the shielding effect is better with the linear type magnetic field structure in the end-cap region. Furthermore, two magnetic field configurations with better shielding effect are investigated through H and He galactic cosmic spectra. And the shielding effect of the linear type configuration adopted in the barrel and end-cap regions is best.Keywords: galactic cosmic rays, active protection, shielding magnetic field configuration, shielding effect
Procedia PDF Downloads 14514810 Numerical Studies on 2D and 3D Boundary Layer Blockage and External Flow Choking at Wing in Ground Effect
Authors: K. Dhanalakshmi, N. Deepak, E. Manikandan, S. Kanagaraj, M. Sulthan Ariff Rahman, P. Chilambarasan C. Abhimanyu, C. A. Akaash Emmanuel Raj, V. R. Sanal Kumar
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In this paper using a validated double precision, density-based implicit standard k-ε model, the detailed 2D and 3D numerical studies have been carried out to examine the external flow choking at wing-in-ground (WIG) effect craft. The CFD code is calibrated using the exact solution based on the Sanal flow choking condition for adiabatic flows. We observed that at the identical WIG effect conditions the numerically predicted 2D boundary layer blockage is significantly higher than the 3D case and as a result, the airfoil exhibited an early external flow choking than the corresponding wing, which is corroborated with the exact solution. We concluded that, in lieu of the conventional 2D numerical simulation, it is invariably beneficial to go for a realistic 3D simulation of the wing in ground effect, which is analogous and would have the aspects of a real-time parametric flow. We inferred that under the identical flying conditions the chances of external flow choking at WIG effect is higher for conventional aircraft than an aircraft facilitating a divergent channel effect at the bottom surface of the fuselage as proposed herein. We concluded that the fuselage and wings integrated geometry optimization can improve the overall aerodynamic performance of WIG craft. This study is a pointer to the designers and/or pilots for perceiving the zone of danger a priori due to the anticipated external flow choking at WIG effect craft for safe flying at the close proximity of the terrain and the dynamic surface of the marine.Keywords: boundary layer blockage, chord dominated ground effect, external flow choking, WIG effect
Procedia PDF Downloads 27114809 Thermal End Effect on the Isotachophoretic Separation of Analytes
Authors: Partha P. Gopmandal, S. Bhattacharyya
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We investigate the thermal end effect on the pseudo-steady state behavior of the isotachophoretic transport of ionic species in a 2-D microchannel. Both ends of the channel are kept at a constant temperature which may lead to significant changes in electrophoretic migration speed. A mathematical model based on Nernst-Planck equations for transport of ions coupled with the equation for temperature field is considered. In addition, the charge conservation equations govern the potential field due to the external electric field. We have computed the equations for ion transport, potential and temperature in a coupled manner through the finite volume method. The diffusive terms are discretized via central difference scheme, while QUICK (Quadratic Upwind Interpolation Convection Kinematics) scheme is used to discretize the convective terms. We find that the thermal end effect has significant effect on the isotachophoretic (ITP) migration speed of the analyte. Our result shows that the ITP velocity for temperature dependent case no longer varies linearly with the applied electric field. A detailed analysis has been made to provide a range of the key parameters to minimize the Joule heating effect on ITP transport of analytes.Keywords: finite volume method, isotachophoresis, QUICK scheme, thermal effect
Procedia PDF Downloads 27414808 Effect of Elastic Modulus Anisotropy on Helical Piles Behavior in Sandy Soil
Authors: Reza Ziaie Moayed, Javad Shamsi Soosahab
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Helical piles are being used extensively in engineering applications all over the world. There are insufficient studies on the helical piles' behavior in anisotropic soils. In this paper, numerical modeling was adopted to investigate the effect of elastic modulus anisotropy on helical pile behavior resting on anisotropic sand by using a finite element limit analysis. The load-displacement behavior of helical piles under compression and tension loads is investigated in different relative densities of soils, and the effect of the ratio of horizontal elastic modulus with respect to vertical elastic modulus (EH/EV) is evaluated. The obtained results illustrate that in sandy soils, the anisotropic ratio of elastic modulus (EH/EV) has notable effect on bearing capacity of helical piles in different relative density. Therefore, it may be recommended that the effect of anisotropic condition of soil elastic modulus should be considered in helical piles behavior.Keywords: helical piles, bearing capacity, numerical modeling, soil anisotropy
Procedia PDF Downloads 16414807 Simulation and Study of the Effect of Paint Mineral Coating on Energy Saving
Authors: A. A. Azemati, H. Hosseini
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By using an adequate paint in buildings, energy consumption can be decreased. In this research, a range of wall paints in different climatic conditions has been investigated to observe its effect on energy consumption. In the current study, the researchers have investigated the effect of different parameters including climatic condition, absorption coefficient, and thermal loads on paint coating. In order to study these effects, heating and cooling loads of a typical building with different color paints have been calculated. The effect of building paint in different climatic condition was studied and a comparison was drawn between paints and painting coats with inorganic micro particles in temperate climate to obtain optimized energy consumption.Keywords: climate, energy consumption, inorganic, painting coats
Procedia PDF Downloads 29014806 Leverage Effect for Volatility with Generalized Laplace Error
Authors: Farrukh Javed, Krzysztof Podgórski
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We propose a new model that accounts for the asymmetric response of volatility to positive ('good news') and negative ('bad news') shocks in economic time series the so-called leverage effect. In the past, asymmetric powers of errors in the conditionally heteroskedastic models have been used to capture this effect. Our model is using the gamma difference representation of the generalized Laplace distributions that efficiently models the asymmetry. It has one additional natural parameter, the shape, that is used instead of power in the asymmetric power models to capture the strength of a long-lasting effect of shocks. Some fundamental properties of the model are provided including the formula for covariances and an explicit form for the conditional distribution of 'bad' and 'good' news processes given the past the property that is important for the statistical fitting of the model. Relevant features of volatility models are illustrated using S&P 500 historical data.Keywords: heavy tails, volatility clustering, generalized asymmetric laplace distribution, leverage effect, conditional heteroskedasticity, asymmetric power volatility, GARCH models
Procedia PDF Downloads 38614805 Analysis of Cyclic Elastic-Plastic Loading of Shaft Based on Kinematic Hardening Model
Authors: Isa Ahmadi, Ramin Khamedi
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In this paper, the elasto-plastic and cyclic torsion of a shaft is studied using a finite element method. The Prager kinematic hardening theory of plasticity with the Ramberg and Osgood stress-strain equation is used to evaluate the cyclic loading behavior of the shaft under the torsional loading. The material of shaft is assumed to follow the non-linear strain hardening property based on the Prager model. The finite element method with C1 continuity is developed and used for solution of the governing equations of the problem. The successive substitution iterative method is used to calculate the distribution of stresses and plastic strains in the shaft due to cyclic loads. The shear stress, effective stress, residual stress and elastic and plastic shear strain distribution are presented in the numerical results.Keywords: cyclic loading, finite element analysis, Prager kinematic hardening model, torsion of shaft
Procedia PDF Downloads 41014804 Discussing Concept Gratitude of Muslim Consumers Based on Islamic Law: A Confirmation on the Theory of Consumer Satisfaction through Imam Al-Ghazali's Thought
Authors: Suprihatin Soewarto
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The background of writing this paper is to assess the truth of rejection of some Muslim scholars who develop Islamic economics on the concept of consumer satisfaction and replace it with the concept of maslahah. In the perspective of Islamic law, this rejection attitude needs to be verified in order to know the accuracy of the replacement of this concept of satisfaction with maslahah as part of consumer behavior. This is done so that replacement of rejection of the term satisfaction with maslahah is objective. This objective replacement of the term will surely be more enlightening and more just than the subjective substitution. Therefore the writing of this paper aims to get an answer whether the concept of satisfaction needs to be replaced? is it possible for Islamic law to confirm the theory of consumer satisfaction? The method of writing this paper using the method of literature with a critical analysis approach. The results of this study is an explanation of the similarities and differences of consumer satisfaction theory and consumer theory maslahah according to Islamic law. disclosure of the concept of consumer gratitude according to Islamic law and its implementation in Muslim consumer demand theory.Keywords: consumer's gratitude, islamic law, confirmation, satisfaction consumer's
Procedia PDF Downloads 20914803 Biostimulation and Muscular Ergogenic Effect of Ozone Therapy on Buttock Augmentation: A Case Report and Literature Review
Authors: Ferreira R., Rocha K.
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Ozone therapy is indicated for improving skin aesthetics, bio-stimulating and ergogenic effect. This paper aims to carry out a case report that demonstrates the positive results of ozone therapy in buttock augmentation. The application showed positive results for skin bio stimulating, neocollagenesis, adipogenesis, and ergogenic muscle effect in the reported case, demonstrating to be a viable clinical technique. Buttock augmentation with ozone therapy is a promising aesthetic therapeutic modality with fast and safe results as an aesthetic therapeutic option for buttock augmentation.Keywords: bio-stimulating effect, ozone therapy, muscular ergogenic, buttock augmentation
Procedia PDF Downloads 29414802 Critical Activity Effect on Project Duration in Precedence Diagram Method
Authors: Salman Ali Nisar, Koshi Suzuki
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Precedence Diagram Method (PDM) with its additional relationships i.e., start-to-start, finish-to-finish, and start-to-finish, between activities provides more flexible schedule than traditional Critical Path Method (CPM). But, changing the duration of critical activities in PDM network will have anomalous effect on critical path. Researchers have proposed some classification of critical activity effects. In this paper, we do further study on classifications of critical activity effect and provide more information in detailed. Furthermore, we determine the maximum amount of time for each class of critical activity effect by which the project managers can control the dynamic feature (shortening/lengthening) of critical activities and project duration more efficiently.Keywords: construction project management, critical path method, project scheduling, precedence diagram method
Procedia PDF Downloads 51214801 Physical Characteristics of Cookies Enriched with Microencapsulated Cherry Pomace Extract
Authors: Jovana Petrović, Ivana Lončarević, Vesna Tumbas Šaponjac, Biljana Pajin, Danica Zarić
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Pomace, a by-product from fruit processing industry is the potential source of valuable bioactive. Cookies are popular, ready to eat and low price foods; therefore, enrichment of these products is of great importance. In this work, bioactive compounds extracted from cherry pomace, encapsulated in soy and whey proteins, have been incorporated in cookies, replacing 10 (SP10 and WP10) and 15% of wheat flour (SP15 and WP15). Cookie geometry (diameter (D), thickness (T) and spread ratio (D/T)), cookie weight, cookie hardness and cookie surface colour were measured. Sensory characteristics are also examined. The results show that encapsulated cherry pomace bioactives have positively influenced the cookie mass. Diameter, redness (a* value) and cookie hardness increased. Sensory evaluation of cookies, revealed that up to 15% substitution of wheat flour with WP encapsulate produced acceptable cookies similar to the control (100% wheat flour) cookies.Keywords: cherry pomace, polyphenols, microencapsulation, cookies, physical characteristics
Procedia PDF Downloads 47014800 Investigations of Metals and Metal-Antibrowning Agent Effects on Polyphenol Oxidase Activity from Red Poppy Leaf
Authors: Gulnur Arabaci
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Heavy metals are one of the major groups of contaminants in the environment and many of them are toxic even at very low concentration in plants and animals. However, some metals play important roles in the biological function of many enzymes in living organisms. Metals such as zinc, iron, and cooper are important for survival and activity of enzymes in plants, however heavy metals can inhibit enzyme which is responsible for defense system of plants. Polyphenol oxidase (PPO) is a copper-containing metalloenzyme which is responsible for enzymatic browning reaction of plants. Enzymatic browning is a major problem for the handling of vegetables and fruits in food industry. It can be increased and effected with many different futures such as metals in the nature and ground. In the present work, PPO was isolated and characterized from green leaves of red poppy plant (Papaver rhoeas). Then, the effect of some known antibrowning agents which can form complexes with metals and metals were investigated on the red poppy PPO activity. The results showed that glutathione was the most potent inhibitory effect on PPO activity. Cu(II) and Fe(II) metals increased the enzyme activities however, Sn(II) had the maximum inhibitory effect and Zn(II) and Pb(II) had no significant effect on the enzyme activity. In order to reduce the effect of heavy metals, the effects of metal-antibrowning agent complexes on the PPO activity were determined. EDTA and metal complexes had no significant effect on the enzyme. L-ascorbic acid and metal complexes decreased but L-ascorbic acid-Cu(II)-complex had no effect. Glutathione–metal complexes had the best inhibitory effect on Red poppy leaf PPO activity.Keywords: inhibition, metal, red poppy, poly phenol oxidase (PPO)
Procedia PDF Downloads 32914799 Characterization of Edible Film from Uwi Starch (Dioscorea alata L.)
Authors: Miksusanti, Herlina, Wiwin
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The research about modification uwi starch (Dioscorea alata L) by using propylene oxide has been done. Concentration of propylene oxide were 6%(v/w), 8%(v/w), and 10%(v/w). The amilograf parameters after modification were characteristic breakdown viscosity 43 BU and setback viscosity 975 BU. The modification starch have edible properties according to FDA (Food and Drug Administration) which have degree of modification < 7%, degree of substitution < 0,1 and propylene oxide concentration < 10%(v/w). The best propylene oxide in making of edible film was 8 %( v/w). The starch control can be made into edible film with thickness 0,136 mm, tensile strength 20,4605 MPa and elongation 22%. Modification starch of uwi can be made into edible film with thickness 0,146 mm, tensile strength 25, 3521 Mpa, elongation 30% and water vapor transmission 7, 2651 g/m2/24 hours. FTIR characterization of uwi starch showed the occurrence of hydroxypropylation. The peak spectrum at 2900 cm-1 showed bonding of C-H from methyl group, which is characteristic for modification starch with hydroxypropyl. Characterization with scanning electron microscopy showed that modification of uwi starch has turned the granule of starch to be fully swallon.Keywords: uwi starch, edible film, propylen oxide, modification
Procedia PDF Downloads 30014798 The New Propensity Score Method and Assessment of Propensity Score: A Simulation Study
Authors: Azam Najafkouchak, David Todem, Dorothy Pathak, Pramod Pathak, Joseph Gardiner
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Propensity score (PS) methods have recently become the standard analysis tool for causal inference in observational studies where exposure is not randomly assigned. Thus, confounding can impact the estimation of treatment effect on the outcome. Due to the dangers of discretizing continuous variables, the focus of this paper will be on how the variation in cut-points or boundaries will affect the average treatment effect utilizing the stratification of the PS method. In this study, we will develop a new methodology to improve the efficiency of the PS analysis through stratification and simulation study. We will also explore the property of empirical distribution of average treatment effect theoretically, including asymptotic distribution, variance estimation and 95% confident Intervals.Keywords: propensity score, stratification, emprical distribution, average treatment effect
Procedia PDF Downloads 9914797 The Effect of Molybdate on Corrosion Behaviour of AISI 316Ti Stainless Steel in Chloride Environment
Authors: Viera Zatkalíková, Lenka Markovičová, Aneta Tor-Swiatek
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The effect of molybdate addition to chloride environment on resistance of AISI 316Ti stainless steel to pitting corrosion was studied. Potentiodynamic polarisation tests were performed in 1 M and 0.1 M chloride acidified solutions with various additions of sodium molybdate at room temperature. The presented results compare the effect of molybdate anions on quality of passive film (expressed by the pitting potential) in both chloride solutions. The pitting potential increases with the increase inhibitor concentration. The inhibitive effect of molybdate ions is stronger in chloride solution of lower aggressiveness (0.1M).Keywords: AISI 316Ti steel, molybdate inhibitor, pitting corrosion, pitting potential, potentiodynamic polarisation
Procedia PDF Downloads 39114796 Degradation of the Mechanical Properties of the Polypropylene Talc Nanocomposite in Chemical Environment
Authors: Ahmed Ouadah Bouakkaz, Mohamed Elmeguenni, Bel Abbes Bachir Bouiadjra, Mohamed Belhouari, Abdulmohsen Albedah
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In this study, the effect of the chemical environment on the mechanical properties of the polypropylene-talc composite was analyzed. The talc proportion was varied in order to highlight the combined effects of time of immersion in the chemical environment 'benzene' and talc concentration on the mechanical properties of the composite. Tensile test was carried out to evaluate the mechanical properties of PP-talc composite and to analyze the effect of the immersion time on the variation of these properties. The obtained results show that increasing the time of immersion has a very negative effect on the mechanical strength of the PP-talc composite, but this effect can be significantly reduced by the augmentation of the talc proportion.Keywords: polypropylene (PP), talc, nanocomposite, degradation
Procedia PDF Downloads 38514795 The Effect of Damper Attachment on Tennis Racket Vibration: A Simulation Study
Authors: Kuangyou B. Cheng
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Tennis is among the most popular sports worldwide. During ball-racket impact, substantial vibration transmitted to the hand/arm may be the cause of “tennis elbow”. Although it is common for athletes to attach a “vibration damper” to the spring-bed, the effect remains unclear. To avoid subjective factors and errors in data recording, the effect of damper attachment on racket handle end vibration was investigated with computer simulation. The tennis racket was modeled as a beam with free-free ends (similar to loosely holding the racket). Finite difference method with 40 segments was used to simulate ball-racket impact response. The effect of attaching a damper was modeled as having a segment with increased mass. It was found that the damper has the largest effect when installed at the spring-bed center. However, this is not a practical location due to interference with ball-racket impact. Vibration amplitude changed very slightly when the damper was near the top or bottom of the spring-bed. The damper works only slightly better at the bottom than at the top of the spring-bed. In addition, heavier dampers work better than lighter ones. These simulation results were comparable with experimental recordings in which the selection of damper locations was restricted by ball impact locations. It was concluded that mathematical model simulations were able to objectively investigate the effect of damper attachment on racket vibration. In addition, with very slight difference in grip end vibration amplitude when the damper was attached at the top or bottom of the spring-bed, whether the effect can really be felt by athletes is questionable.Keywords: finite difference, impact, modeling, vibration amplitude
Procedia PDF Downloads 26214794 Performance of Self-Compacting Mortars Containing Foam Glass Granulate
Authors: Brahim Safi, Djamila Aboutaleb, Mohammed Saidi, Abdelbaki Benmounah, Fahima Benbrahim
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The inorganic wastes are currently used in the manufacture of concretes as mineral additions by cement substitution or as fine/coarse aggregates by replacing traditional aggregates. In this respect, this study aims to valorize the mineral wastes in particular glass wastes to produce granulated foam glass (as fine aggregates). Granulated foam glasses (GFG) were prepared from the glass powder (glass cullet) and foaming agent (limestone) according to applied manufacturing of GFG (at a heat treatment 850 ° C for 20min). After, self-compacting mortars were elaborated with fine aggregate (sand) and other variant mortars with granulated foam glass at volume ratio (0, 30, 50 and 100 %). Rheological characterization tests (fluidity) and physic-mechanical (density, porosity /absorption of water and mechanical tests) were carried out on studied mortars. The results obtained show that a slightly decreasing of compressive strength of mortars having lightness very important for building construction.Keywords: glass wastes, lightweight aggregate, mortar, fluidity, density, mechanical strength
Procedia PDF Downloads 22914793 Mutations in MTHFR Gene Associated with Mental Retardation and Cerebral Palsy Combined with Mental Retardation in Erbil City
Authors: Hazha Hidayat, Shayma Ibrahim
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Folate metabolism plays a crucial role in the normal development of the neonatal central nervous system. It is regulated by MTHFR gene polymorphism. Any factors, which will affect this metabolism either by hereditary or gene mutation will lead to many mental disorders. The purpose of this study was to investigate whether MTHFR gene mutation contributes to the development of mental retardation and CP combined with mental retardation in Erbil city. DNA was isolated from the peripheral blood samples of 40 cases suffering from mental retardation (MR) and CP combined with MR were recruited, sequence the 4, 6, 7, 8 exons of the MTHFR gene were done to identify the variants. Exons were amplified by PCR technique and then sequenced according to Sanger method to show the differences with MTHFR reference sequences. We observed (14) mutations in 4, 6, 7, 8 exons in the MTHFR gene associated with Cerebral Palsy combined with mental retardation included deletion, insertion, Substitution. The current study provides additional evidence that multiple variations in the MTHFR gene are associated with mental retardation and Cerebral Palsy.Keywords: methylenetetrahydrofolate reductase (MTHFR) gene, SNPs, homocysteine, sequencing
Procedia PDF Downloads 30914792 FDI, Environmental Regulations and Innovation Performance of Chinese Enterprises
Authors: Yan Chen, Hongbing Li, Ruirui Zhai
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Innovation driven and innovation in the process of new-type urbanization is a major strategic choice for the introduction of foreign capital and the process of economic development. This research investigates the effect of urbanization, FDI and environmental regulations on innovation performance of enterprises, based on Chinese Industrial Statistics Database of 2004 to 2007 and data at province-level. It is found that the FDI from U.S. and environmental regulations will hinder the creativity of Chinese industry through reducing the R&D of them. However, the FDI from U.S. enhances the ability of domestic enterprises to attain “compensation from innovation” following the environmental regulations. Meanwhile, we confirm that environmental regulation can contribute to the innovation spillover of FDI from U.S. Furthermore, the channel of effect is discussed. In addition, FDI from EU and Japan are further examined. Unlike the FDI from U.S., the FDI from EU and Japan both have the positive innovation spillover effect, but through the same channel referred above which exist in FDI. Further analysis based on "innovation-driven effect" of urbanization is developed, and it is found that urbanization has an innovation-driven effect on environmental regulation and FDI spillover. The regulation of FDI from the United States and the European Union outperforms the FDI from Japan at a restrained degree.Keywords: environmental regulations, FDI, innovation-driven, innovation performance
Procedia PDF Downloads 44214791 Effect of Sub Supercritical CO2 Processing on Microflora and Shelf Life Tempe
Authors: M. Kustyawati, F. Pratama, D. Saputra, A. Wijaya
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Tempe composes of not only molds but also bacteria and yeasts. The structure of microorganisms needs to be in balance number in order the tempe to be an acceptable quality for an extended time. Sub supercritical carbon dioxide can be a promising preservation method for tempe as it induces microbial inactivation avoiding alterations of its quality attributes. Fresh tempe were processed using supercritical and sub supercritical CO2 for a defined holding times, then the growth ability of molds and bacteria were analyzed. The results showed that the supercritical CO2 processing for 5 minutes reduced the number of bacteria and molds to 0.30 log cycle and 1.17 log cycles, respectively. In addition, sub supercritical CO2 processing for 20 minutes had fungicidal effect against mold tempe; whereas, the sub supercritical CO2 for 10 minutes had reducing effect against bacteria tempe, and had fungistatic affect against mold tempe. It suggested that sub-supercritical CO2 processing for 10 min could be useful alternative technique for preservation of tempe.Keywords: tempe, sub supercritical CO2, fungistatic effect, preservation
Procedia PDF Downloads 27114790 Power Reduction of Hall-Effect Sensor by Pulse Width Modulation of Spinning-Current
Authors: Hyungil Chae
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This work presents a method to reduce spinning current of a Hall-effect sensor for low-power magnetic sensor applications. Spinning current of a Hall-effect sensor changes the direction of bias current periodically and can separate signals from DC-offset. The bias current is proportional to the sensor sensitivity but also increases the power consumption. To achieve both high sensitivity and low power consumption, the bias current can be pulse-width modulated. When the bias current duration Tb is reduced by a factor of N compared to the spinning current period of Tₛ/2, the total power consumption can be saved by N times. N can be large as long as the Hall-effect sensor settles down within Tb. The proposed scheme is implemented and simulated in a 0.18um CMOS process, and the power saving factor is 9.6 when N is 10. Acknowledgements: This work was supported by Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (20160001360022003, Development of Hall Semi-conductor for Smart Car and Device).Keywords: chopper stabilization, Hall-effect sensor, pulse width modulation, spinning current
Procedia PDF Downloads 48414789 Structural, Magnetic and Electrical Properties of Gd3+ Doped CoFe2O4 Nanoparticles Synthesized by Sonochemical Method
Authors: Raghvendra Singh Yadav, Ivo Kuřitka
Abstract:
In this report, we studied the impact of Gd3+ substitution on structural, magnetic and electrical properties of CoFe2O4 nanoparticles synthesized by sonochemical method. X-ray diffraction pattern confirmed the formation of cubic spinel structure at low concentration of Gd3+ ions, however, GdFeO3 additional phase was observed at higher concentration of Gd3+ ions. Raman and Fourier Transform Infrared spectroscopy study also confirmed cubic spinel structure of Gd3+ substituted CoFe2O4 nanoparticles. The field emission scanning electron microscopy study revealed that Gd3+ substituted CoFe2O4 nanoparticles were in the range of 5-20 nm. The magnetic properties of Gd3+ substituted CoFe2O4 nanoparticles were investigated by using vibrating sample magnetometer. The variation in saturation magnetization, coercivity and remanent magnetization with Gd3+ concentration in CoFe2O4 nanoparticles was observed. The variation of real and imaginary part of dielectric constant, tan δ, and AC conductivity were studied at room temperature.Keywords: spinel ferrites, nanoparticles, sonochemical method, magnetic properties
Procedia PDF Downloads 295