Search results for: syphon effects.
2916 Production Optimization through Ejector Installation at ESA Platform Offshore North West Java Field
Authors: Arii Bowo Yudhaprasetya, Ario Guritno, Agus Setiawan, Recky Tehupuring, Cosmas Supriatna
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The offshore facilities condition of Pertamina Hulu Energi Offshore North West Java (PHE ONWJ) varies greatly from place to place, depending on the characteristics of the presently installed facilities. In some locations, such as ESA platform, gas trap is mainly caused by the occurrence of flash gas phenomenon which is known as mechanical-physical separation process of multiphase flow. Consequently, the presence of gas trap at main oil line would accumulate on certain areas result in a reduced oil stream throughout the pipeline. Any presence of discrete gaseous along continuous oil flow represents a unique flow condition under certain specific volume fraction and velocity field. From gas lift source, a benefit line is used as a motive flow for ejector which is designed to generate a syphon effect to minimize the gas trap phenomenon. Therefore, the ejector’s exhaust stream will flow to the designated point without interfering other systems.Keywords: Ejector, diffuser, multiphase flow, syphon effects.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9652915 Experimental Investigation of Heat Transfer on Vertical Two-Phased Closed Thermosyphon
Authors: M. Hadi Kusuma, Nandy Putra, Anhar Riza Antariksawan, Ficky Augusta Imawan
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Heat pipe is considered to be applied as a passive system to remove residual heat that generated from reactor core when incident occur or from spent fuel storage pool. The objectives are to characterized the heat transfer phenomena, performance of heat pipe, and as a model for large heat pipe will be applied as passive cooling system on nuclear spent fuel pool storage. In this experimental wickless heat pipe or two-phase closed thermosyphon (TPCT) is used. Variation of heat flux are 611.24 Watt/m2 - 3291.29 Watt/m2. Variation of filling ratio are 45 - 70%. Variation of initial pressure are -62 to -74 cm Hg. Demineralized water is used as working fluid in the TPCT. The results showed that increasing of heat load leads to an increase of evaporation of the working fluid. The optimum filling ratio obtained for 60% of TPCT evaporator volume, and initial pressure variation gave different TPCT wall temperature characteristic. TPCT showed best performance with 60% filling ratio and can be consider to be applied as passive residual heat removal system or passive cooling system on spent fuel storage pool.Keywords: Two-phase closed thermo syphon, heat pipe, passive cooling, spent fuel storage pool.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10612914 Characterization Non-Deterministic of Optical Channels
Authors: V. A. C. Vale, E. T. L. Cöuras Ford
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The use of optical technologies in the telecommunications has been increasing due to its ability to transmit large amounts of data over long distances. However, as in all systems of data transmission, optical communication channels suffer from undesirable and non-deterministic effects, being essential to know the same. Thus, this research allows the assessment of these effects, as well as their characterization and beneficial uses of these effects.Keywords: Optical communication, optical fiber, non-deterministic effects.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14462913 Assessment of the Environmental Destructive Effects of Building Dams
Authors: Mohammad Reza Pirestani, Mehdi Shafaghati, Amir Ahmad Dehghani
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From the beginning of creation, human being has ever fought against the ecosystem by changes has made in environment. The most environmental changes on the nature have been done after starting the concentrated life in the same region. Dams are one of the most important buildings in water resources and transferring. These buildings have been made from old times without access to hydrological, hydraulically, hydro mechanical information. Dams have positive and negative effects on environment. Constructing a dam relatively causes equal ecological consequences. According to different criteria, environmental effects of dams can lead short term and long term damages. These effects may influence on the situation and treatment of meteorology, biology, culture, ancient works, etc and severely causes to change and complicate it. So considering importance of positive effects of dam construction, it is necessary to minimize negative environmental effects of dams to achieve a stable development. In this article the considered effects and their solutions in influencing on assessment of destructive environmental effects of dams construction have been surveyed and presented.Keywords: Dam, Environment, Water Resources, Assessment
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 36082912 Engine Power Effects on Support Interference
Authors: B.J.C. Horsten, L.L.M. Veldhuis
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Renewed interest in propeller propulsion on aircraft configurations combined with higher propeller loads lead to the question how the effects of the propulsion on model support disturbances should be accounted for. In this paper, the determination of engine power effects on support interference of sting-mounted models is demonstrated by a measurement on a four-engine turboprop aircraft. CFD results on a more generic model are presented in order to clarify the possible mechanism behind engine power effects on support interference. The engine slipstream induces a local change in angle of sideslip at the model sting thereby influencing the sting near-field and far-field effects. Whether or not the net result of these changes in the disturbance pattern leads to a significant engine power effect depends on the configuration of the wind tunnel model and the test setup.Keywords: CFD, engine power effects, measurements, support interference.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14792911 A Case of Study for 3D Stereoscopic Conversion in Visual Effects Industry
Authors: Jin Zhi
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This paper covered a series of key points in terms of 2D to 3D stereoscopic conversion. A successfully applied stereoscopic conversion approach in current visual effects industry was presented. The purpose of this paper is to cover a detailed workflow and concept, which has been successfully used in 3D stereoscopic conversion for feature films in visual effects industry, and therefore to clarify the process in stereoscopic conversion production and provide a clear idea for those entry-level artists to improve an overall understanding of 3D stereoscopic in digital compositing field as well as to the higher education factor of visual effects and hopefully inspire further collaboration and participants particularly between academia and industry.
Keywords: Clean plates, Mattes, Stereoscopic conversion, 3Dprojection, Z-depth.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22322910 On the Optimality of Blocked Main Effects Plans
Authors: Rita SahaRay, Ganesh Dutta
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In this article, experimental situations are considered where a main effects plan is to be used to study m two-level factors using n runs which are partitioned into b blocks, not necessarily of same size. Assuming the block sizes to be even for all blocks, for the case n ≡ 2 (mod 4), optimal designs are obtained with respect to type 1 and type 2 optimality criteria in the class of designs providing estimation of all main effects orthogonal to the block effects. In practice, such orthogonal estimation of main effects is often a desirable condition. In the wider class of all available m two level even sized blocked main effects plans, where the factors do not occur at high and low levels equally often in each block, E-optimal designs are also characterized. Simple construction methods based on Hadamard matrices and Kronecker product for these optimal designs are presented.Keywords: Design matrix, Hadamard matrix, Kronecker product, type 1 criteria, type 2 criteria.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10522909 EEG Indices to Time-On-Task Effects and to a Workload Manipulation (Cueing)
Authors: A. T. Kamzanova, G. Matthews, A. M. Kustubayeva, S. M. Jakupov
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The aim of this study was to evaluate the sensitivity of a range of EEG indices to time-on-task effects and to a workload manipulation (cueing), during performance of a resource-limited vigilance task. Effects of task period and cueing on performance and subjective state response were consistent with previous vigilance studies and with resource theory. Two EEG indices – the Task Load Index (TLI) and global lower frequency (LF) alpha power – showed effects of task period and cueing similar to those seen with correct detections. Across four successive task periods, the TLI declined and LF alpha power increased. Cueing increased TLI and decreased LF alpha. Other indices – the Engagement Index (EI), frontal theta and upper frequency (UF) alpha failed to show these effects. However, EI and frontal theta were sensitive to interactive effects of task period and cueing, which may correspond to a stronger anxiety response to the uncued task.Keywords: brain activity, EEG, task engagement, vigilance task.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23222908 Theoretical Considerations of the Influence of Mechanical Uniaxial Stress on Pixel Readout Circuits
Authors: Georgios C. Dogiamis, Bedrich J. Hosticka, Anton Grabmaier
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In this work the effects of uniaxial mechanical stress on a pixel readout circuit are theoretically analyzed. It is the effects of mechanical stress on the in-pixel transistors do not arise at the output, when a correlated double sampling circuit is used. However, mechanical stress effects on the photodiode will directly appear at the readout chain output. Therefore, compensation techniques are needed to overcome this situation. Moreover simulation technique of mechanical stress is proposed and diverse layout as well as design recommendations are put forward, in order to minimize stress related effects on the output of a circuit. he shown, that wever, Moreover, a out
Keywords: mechanical uniaxial stress, pixel readout circuit
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15492907 Side Effects of Dental Tooth Whitening: Data from Literature
Authors: Saimir Heta, Ilma Robo, Emela Dalloshi, Nevila Alliu, Vera Ostreni
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The dental whitening process, beyond the fact that it is a mini-invasive dental treatment, has effects on the dental structure or on the pulp of the tooth where it is applied. The electronic search was performed using keywords to find articles published within the last 10 years about side effects, assessed as such, of the minimally invasive dental bleaching treatment. The aim of the study was to evaluate the side effects of bleaching based on the percentage and type of solution used, where the latter was evaluated on the basic solution used for bleaching. The side effects of bleaching are evaluated in selected articles depending on the method of bleaching application, which means it is carried out with recommended solutions, or with mixtures of alternative solutions or substances based on Internet information. The dental bleaching process has side effects which have not yet been definitively evaluated, experimentally in large samples of individuals or animals (mice or cattle) to arrive at accurate numerical conclusions. The trend of publications about this topic is increasing in recent years, as long as the trend for aesthetic facial treatments, including dental ones, is increasing.
Keywords: Teeth whitening, side effects, permanent teeth, formed dental apex.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 202906 Health Effects of Trihalomethanes as Chlorinated Disinfection by Products: A Review Article
Authors: M. R. Mohamadshafiee, L. Taghavi
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Trihalomethanes (THMs) were among the first disinfection byproducts to be discovered in chlorinated water. The substances form during a reaction between chlorine and organic matter in the water. Trihalomethanes are suspected to have negative effects on birth such as, low birth weight, intrauterine growth retardation in term births, as well as gestational age and preterm delivery. There are also some evidences showing these by-products to be mutagenic and carcinogenic, the greatest amount of evidence being related to the bladder cancer. However, there exist inconsistencies regarding such effects of THMs as different studies have provided different results in this regard. The aim of the present study is to provide a review of the related researches about the above mentioned health effects of THMs.Keywords: Trihalomethans, by-products, disinfection, carcinogenic
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 47262905 Effects of FAU Zeolites on the Crystallization of Chloronitrobenzenes above the Eutectic Composition
Authors: Jeeranun Neaungjumnong, Sasikarn Yairit, Sudarat Pattanapaiboonkul, Pramoch Rangsunvigit, Santi Kulprathipanja
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Crystallization has been used for the separation of chloronitrobenzene or CNBs, which are isomeric substances (o-, mand p-CNB) and important intermediates in chemical productions. Effects of feed composition on the crystallization of m- and p-CNB was first studied. The results conform to the binary phase diagram of m- and p-CNB. After that, effects of FAU zeolites (NaX, CaX, BaX, NaY and CaY) above the eutectic composition (63.5 and 65.0 wt% m-CNB in the feed) was also investigated. The results showed that the FAU zeolites significantly affected the precipitates, the composition of which was shifted from being rich in m-CNB to rich in p-CNB. Effects of the number of FAU zeolites on the precipitate composition was then studied. The results revealed that the precipitates from the lower number of the zeolites had higher p-CNB purity than those from the higher number of zeolite.Keywords: Chloronitrobenzenes, crystallization, separation, eutectic
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16492904 Perturbative Analysis on a Lunar Free Return Trajectory
Authors: Emre Ünal, Hasan Başaran
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In this study, starting with a predetermined Lunar free-return trajectory, an analysis of major near-Earth perturbations is carried out. Referencing to historical Apollo-13 flight, changes in the mission’s resultant perimoon and perigee altitudes with each perturbative effect are evaluated. The perturbations that were considered are Earth oblateness effects, up to the 6th order, atmospheric drag, third body perturbations consisting of solar and planetary effects and solar radiation pressure effects. It is found that for a Moon mission, most of the main perturbative effects spoil the trajectory significantly while some came out to be negligible. It is seen that for apparent future request of constructing low cost, reliable and safe trajectories to the Moon, most of the orbital perturbations are crucial.
Keywords: Apollo-13 trajectory, atmospheric drag, lunar trajectories, oblateness effect, perturbative effects, solar radiation pressure, third body perturbations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4722903 Searching the Stabilizing Effects of Neutron Shell Closure via Fusion Evaporation Residue Studies
Authors: B. R. S. Babu, E. Prasad, P. V. Laveen, A. M. Vinodkumar
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Searching the “Island of stability” is a topic of extreme interest in theoretical as well as experimental modern physics today. This “island of stability” is spanned by superheavy elements (SHE's) that are produced in the laboratory. SHE's are believed to exist primarily due to the “magic” stabilizing effects of nuclear shell structure. SHE synthesis is extremely difficult due to their very low production cross section, often of the order of pico barns or less. Stabilizing effects of shell closures at proton number Z=82 and neutron number N=126 are predicted theoretically. Though stabilizing effects of Z=82 have been experimentally verified, no concluding observations have been made with N=126, so far. We measured and analyzed the total evaporation residue (ER) cross sections for a number of systems with neutron number around 126 to explore possible shell closure effects in ER cross sections, in this work.Keywords: Superheavy element, fusion evaporation, evaporation reside, compound nucleus.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16222902 Study on the Influence of Physical Effort on the Mental Processes of Preteen Students
Authors: Constantin Pehoiu, Cristian Savu, Silviu Badea, Cristian Borida
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The physiological effects of physical exercise on human body are relatively well known in literature, which describes in detail the changes that occur in the cardiovascular system, the respiratory one, in bones and other systems, both during exercise and after its delivery. However, the effects of exercise on mental processes are less treated. From the literature reviews discussed in this study, it can be detached the idea that we can not exactly say that physical exercise has beneficial effects on mental processes, but neither that it would have potentially negative effects. This uncertainty, reflected in the inability to indicate precise and unequivocal meaning, favorable-unfavorable physical effort in acting on mental processes, is a prime reason to undertake a study of the phenomenon influence effort administered physical education classes on the dynamics of mental processes like attention and memory.Keywords: management, exercise, mental process, lesson.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16652901 Effects of Repetitive Strain/Stress Injury on the Human Body
Authors: Mohd Abdullah
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This review describes some of the effects of repetitive strain/stress injury (RSI) on the human body especially among computer professionals today that spend extended hours of prolonged sitting in front of a computer day in and day out. The review briefly introduces the main factors that contribute to an increase of RSI among such computer professionals. The review briefly discusses how the human spinal column and knees are mainly affected by the onset of RSI resulting in poor posture. The root and secondary causes and effects of RSI are reviewed. The importance and value of the various breathing techniques are reviewed in an attempt to alleviate some of the effects of RSI. The review concludes with a small sample of suggested office stretches and poses geared towards at reducing RSI follows in this review. Readers will learn about the effects of RSI, as well as ways to cope with it. A better understanding of coping strategies may lead to well-being and a healthier overall lifestyle. Ultimately, the investment of time to connect with oneself with the poses and the power of the breath would promote a well-being that is overall healthier thus resulting in a better ability to cope/manage life stresses.
Keywords: Health, wellness, repetitive, chairs.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10702900 Spatio-Temporal Analysis and Mapping of Malaria in Thailand
Authors: Krisada Lekdee, Sunee Sammatat, Nittaya Boonsit
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This paper proposes a GLMM with spatial and temporal effects for malaria data in Thailand. A Bayesian method is used for parameter estimation via Gibbs sampling MCMC. A conditional autoregressive (CAR) model is assumed to present the spatial effects. The temporal correlation is presented through the covariance matrix of the random effects. The malaria quarterly data have been extracted from the Bureau of Epidemiology, Ministry of Public Health of Thailand. The factors considered are rainfall and temperature. The result shows that rainfall and temperature are positively related to the malaria morbidity rate. The posterior means of the estimated morbidity rates are used to construct the malaria maps. The top 5 highest morbidity rates (per 100,000 population) are in Trat (Q3, 111.70), Chiang Mai (Q3, 104.70), Narathiwat (Q4, 97.69), Chiang Mai (Q2, 88.51), and Chanthaburi (Q3, 86.82). According to the DIC criterion, the proposed model has a better performance than the GLMM with spatial effects but without temporal terms.
Keywords: Bayesian method, generalized linear mixed model (GLMM), malaria, spatial effects, temporal correlation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21472899 Estimation of Stress Intensity Factors from Near Crack Tip Field
Authors: Zhuang He, Andrei Kotousov
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All current experimental methods for determination of stress intensity factors are based on the assumption that the state of stress near the crack tip is plane stress. Therefore, these methods rely on strain and displacement measurements made outside the near crack tip region affected by the three-dimensional effects or by process zone. In this paper, we develop and validate an experimental procedure for the evaluation of stress intensity factors from the measurements of the out-of-plane displacements in the surface area controlled by 3D effects. The evaluation of stress intensity factors is possible when the process zone is sufficiently small, and the displacement field generated by the 3D effects is fully encapsulated by K-dominance region.Keywords: Digital image correlation, stress intensity factors, three-dimensional effects, transverse displacement.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32212898 Self-Adaptive Differential Evolution Based Power Economic Dispatch of Generators with Valve-Point Effects and Multiple Fuel Options
Authors: R.Balamurugan, S.Subramanian
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This paper presents the solution of power economic dispatch (PED) problem of generating units with valve point effects and multiple fuel options using Self-Adaptive Differential Evolution (SDE) algorithm. The global optimal solution by mathematical approaches becomes difficult for the realistic PED problem in power systems. The Differential Evolution (DE) algorithm is found to be a powerful evolutionary algorithm for global optimization in many real problems. In this paper the key parameters of control in DE algorithm such as the crossover constant CR and weight applied to random differential F are self-adapted. The PED problem formulation takes into consideration of nonsmooth fuel cost function due to valve point effects and multi fuel options of generator. The proposed approach has been examined and tested with the numerical results of PED problems with thirteen-generation units including valve-point effects, ten-generation units with multiple fuel options neglecting valve-point effects and ten-generation units including valve-point effects and multiple fuel options. The test results are promising and show the effectiveness of proposed approach for solving PED problems.Keywords: Multiple fuels, power economic dispatch, selfadaptivedifferential evolution and valve-point effects.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18932897 The Students' Learning Effects on Dance Domain of Arts Education
Authors: Sheng-Min Cheng
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The purpose of this study was to explore the learning effects on dance domain in Arts Curriculum at junior and senior high levels. A total of 1,366 students from 9th to 11th grade of different areas from Taiwan were administered a self-designed dance achievement test. Data were analyzed through descriptive analysis, independent sample t test, one-way ANOVA and Post hoc comparison analysis using Scheffé Test. The results showed (1) female studentsKeywords: arts education, dance learning effects, secondary level students, dance talented students
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21102896 Microwave Shielding of Magnetized Hydrogen Plasma in Carbon Nanotubes
Authors: Afshin Moradi, Mohammad Hosain Teimourpour
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We derive simple sets of equations to describe the microwave response of a thin film of magnetized hydrogen plasma in the presence of carbon nanotubes, which were grown by ironcatalyzed high-pressure disproportionation (HiPco). By considering the interference effects due to multiple reflections between thin plasma film interfaces, we present the effects of the continuously changing external magnetic field and plasma parameters on the reflected power, absorbed power, and transmitted power in the system. The simulation results show that the interference effects play an important role in the reflectance, transmittance and absorptance of microwave radiation at the magnetized plasma slab. As a consequence, the interference effects lead to a sinusoidal variation of the reflected intensity and can greatly reduce the amount of reflection power, but the absorption power increases.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14012895 A Study on Bilingual Semantic Processing: Category Effects and Age Effects
Authors: Lai Yi-Hsiu
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The present study addressed the nature of bilingual semantic processing in Mandarin Chinese and Southern Min and examined category effects and age effects. Nineteen bilingual adults of Mandarin Chinese and Southern Min, nine monolingual seniors of Mandarin Chinese, and ten monolingual seniors of Southern Min in Taiwan individually completed two semantic tasks: Picture naming and category fluency tasks. The instruments for the naming task were sixty black-and-white pictures, including thirty-five object pictures and twenty-five action pictures. The category fluency task also consisted of two semantic categories – objects (or nouns) and actions (or verbs). The reaction time for each picture/question was additionally calculated and analyzed. Oral productions in Mandarin Chinese and in Southern Min were compared and discussed to examine the category effects and age effects. The results of the category fluency task indicated that the content of information of these seniors was comparatively deteriorated, and thus they produced a smaller number of semantic-lexical items. Significant group differences were also found in the reaction time results. Category effects were significant for both adults and seniors in the semantic fluency task. The findings of the present study will help characterize the nature of the bilingual semantic processing of adults and seniors, and contribute to the fields of contrastive and corpus linguistics.
Keywords: Bilingual semantic processing, aging, Mandarin Chinese, Southern Min.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12942894 Modeling Brand Alliance Effects Professional Services
Authors: Kristina Maiksteniene
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Various formal and informal brand alliances are being formed in professional service firms. Professional service corporate brand is heavily dependent on brands of professional employees who comprise them, and professional employee brands are in turn dependent on the corporate brand. Prior work provides limited scientific evidence of brand alliance effects in professional service area – i.e., how professional service corporate-employee brand allies are affected by an alliance, what are brand attitude effects after alliance formation and how these effects vary with different strengths of an ally. Scientific literature analysis and theoretical modeling are the main methods of the current study. As a result, a theoretical model is constructed for estimating spillover effects of professional service corporate-employee brand alliances and for comparison among different professional service firm expertise practice models – from “brains" to “procedure" model. The resulting theoretical model lays basis for future experimental studies.
Keywords: Brand alliances, professional services, corporatebrand, employee brand.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17622893 Effects of Arcing in Air on the Microstructure, Morphology and Photoelectric Work Function of Ag- Ni (60/40) Contact Materials
Authors: Mohamed Akbi
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The present work aims to throw light on the effects of arcing in air on the surface state of contact pastilles made of silvernickel Ag-Ni (60/40). Also, the photoelectric emission from these electrical contacts has been investigated in the spectral range of 196- 256 nm. In order to study the effects of arcing on the EWF, the metallic samples were subjected to electrical arcs in air, at atmospheric pressure and room temperature, after that, they have been introduced into the vacuum chamber of an experimental UHV set-up for EWF measurements. Both Fowler method of isothermal curves and linearized Fowler plots were used for the measurement of the EWF by the photoelectric effect. It has been found that the EWF varies with the number of applied arcs. Thus, after 500 arcs in air, the observed EWF increasing is probably due to progressive inclusion of oxide on alloy surface. Microscopic examination is necessary to get better understandings on EWF of silver alloys, for both virgin and arced electrical contacts.
Keywords: Ag-Ni contact materials, arcing effects, electron work function, Fowler methods, photoemission.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23752892 Numerical Simulation of Lightning Strike Direct Effects on Aircraft Skin Composite Laminate
Authors: Muhammad Khalil, Nader Abuelfoutouh, Gasser Abdelal, Adrian Murphy
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Nowadays, the direct effects of lightning to aircrafts are of great importance because of the massive use of composite materials. In comparison with metallic materials, composites present several weaknesses for lightning strike direct effects. Especially, their low electrical and thermal conductivities lead to severe lightning strike damage. The lightning strike direct effects are burning, heating, magnetic force, sparking and arcing. As the problem is complex, we investigated it gradually. A magnetohydrodynamics (MHD) model is developed to simulate the lightning strikes in order to estimate the damages on the composite materials. Then, a coupled thermal-electrical finite element analysis is used to study the interaction between the lightning arc and the composite laminate and to investigate the material degradation.
Keywords: Composite structures, lightning multiphysics, magnetohydrodynamics, coupled thermal-electrical analysis, thermal plasmas.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26232891 Study on the Characteristics of the Measurement System for pH Array Sensors
Authors: Jung-Chuan Chou, Wei-Lun Hsia
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A measurement system for pH array sensors is introduced to increase accuracy, and decrease non-ideal effects successfully. An array readout circuit reads eight potentiometric signals at the same time, and obtains an average value. The deviation value or the extreme value is counteracted and the output voltage is a relatively stable value. The errors of measuring pH buffer solutions are decreased obviously with this measurement system, and the non-ideal effects, drift and hysteresis, are lowered to 1.638mV/hr and 1.118mV, respectively. The efficiency and stability are better than single sensor. The whole sensing characteristics are improved.Keywords: Array sensors, measurement system, non-ideal effects, pH sensor, readout circuit.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16942890 Zno Nanocomposites: Control of Enviromental Effects for Preservation of old Manuscripts
Authors: Maryam Afsharpour, Saleh Imani, Shahrzad Abdolmohammadi
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We investigate the ZnO role in the inherent protection of old manuscripts to protect them against environmental damaging effect of ultraviolet radiation, pollutant gasses, mold and bacteria. In this study a cellulosic nanocomposite of ZnO were used as protective coating on the surface of paper fibers. This layered nanocomposite can act as a consolidate materials too. Furthermore, to determine how well paper works screen objects from the damaging effects, two accelerated aging mechanisms due to light and heat are discussed. Results show good stability of papers with nanocomposite coating. Also, a good light stability was shown in the colored paper that treated with this nanocomposite. Furthermore, to demonstrate the degree of antifungal and antibacterial properties of coated papers, papers was treated with four common molds and bacteria and the good preventive effects of coated paper against molds and bacteria are described.Keywords: Enviromental effects, Manuscript, Nanocomposite, Zinc oxide.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20402889 Left Ventricular Model to Study the Combined Viscoelastic, Heart Rate, and Size Effects
Authors: Elie H. Karam, Antoine B. Abche
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It is known that the heart interacts with and adapts to its venous and arterial loading conditions. Various experimental studies and modeling approaches have been developed to investigate the underlying mechanisms. This paper presents a model of the left ventricle derived based on nonlinear stress-length myocardial characteristics integrated over truncated ellipsoidal geometry, and second-order dynamic mechanism for the excitation-contraction coupling system. The results of the model presented here describe the effects of the viscoelastic damping element of the electromechanical coupling system on the hemodynamic response. Different heart rates are considered to study the pacing effects on the performance of the left-ventricle against constant preload and afterload conditions under various damping conditions. The results indicate that the pacing process of the left ventricle has to take into account, among other things, the viscoelastic damping conditions of the myofilament excitation-contraction process. The effects of left ventricular dimensions on the hemdynamic response have been examined. These effects are found to be different at different viscoelastic and pacing conditions.Keywords: Myocardial sarcomere, cardiac pump, excitationcontractioncoupling, viscoelasicity
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16542888 Investigation of Multiple Material Gate Impact on Short Channel Effects and Reliability of Nanoscale SOI MOSFETs
Authors: Paniz Tafakori, Ali A. Orouji
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In this paper the features of multiple material gate silicon-on-insulator MOSFETs are presented and compared with single material gate silicon-on-insulator MOSFET structures. The results indicate that the multiple material gate structures reduce short channel effects such as drain induce barrier lowering, hot electron effect and better current characteristics in comparison with single material structuresKeywords: Short-channel effects (SCEs), Dual material gate (DMG), Triple material gate (TMG), Pentamerous material gate (PMG).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20052887 Shading Percentage Effects on Energy Consumption for Bahraini Residential Buildings
Authors: Saad F. Al Nuaimi
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Energy consumption is a very important topic these days especially regarding air conditioning in residential buildings, since this takes the biggest amount of energy in buildings total consumption, residential buildings constitute the biggest percentage of energy consumption in Bahrain. This research reflects on the effects of shading percentage in different solar orientations on the energy consumption inside residential buildings (domestic dwellings). The research as found that, there are different effects of shading in changing building orientation: • 0.69% for the shading percentage 25% when the building is oriented to the north (0º); • 18.59% for 75% of shading in north-west orientation (325º); • The best effect for shading is in north-west orientation (315º); • The less effect for shading was in case of the building orientation is the north (0º).Keywords: Bahraini buildings, Building shading, energy consumption, residential buildings, shading effects.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1924