Search results for: Thermal test

Authors: S.O. Shazlin, M.S. Nurulakmal

Abstract:

Studies have shown that the SnAgCu solder family has been widely used as a replacement for conventional Sn-Pb solders. An attractive approach is by introducing alloying additives (rare earth elements (RE), Zn, Co, Fe, Ni, Sb) into the SnAgCu solder, which helps in refining the microstructure also improving the mechanical and wetting properties of the solder. The present work focuses on the effect of additions of 0.5% Ce and Fe into Sn-3.0Ag-0.5Cu solder, in attempt to reduce the intermetallic compound (IMC) growth and reflow properties of the solder on Cu and Ni (P) surface finish, as well as effects thermal aging on the formation of intermetallic compound (IMC) on different surface finish. Excessive intermetallic compound growth may effect the interface and solder joint due to the brittle nature of the intermetallic compounds. Thus, by introducing alloying elements, IMC layer thickness can be decrease, resulting in better joint and solder reliability.

Keywords: Alloying Elements, Cu and Ni (P) Substrate, Intermetallic Compound (IMC), Reflow, Thermal Aging.

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Authors: Khashayar Jafari, Mostafa Jafarian Abyaneh, Vahab Toufigh

Abstract:

Polymer concrete (PC) is a distinct concrete with superior characteristics in comparison to ordinary cement concrete. It has become well-known for its applications in thin overlays, floors and precast components. In this investigation, the mechanical properties of PC with different epoxy resin contents, ordinary cement concrete (OCC) and lightweight concrete (LC) have been studied under uniaxial compression test. The study involves five types of concrete, with each type being tested four times. Their complete elastic-plastic behavior was compared with each other through the measurement of volumetric strain during the tests. According to the results, PC showed higher strength, ductility and energy absorption with respect to OCC and LC.

Keywords: Polymer concrete, ordinary cement concrete, lightweight concrete, uniaxial compression test, volumetric strain.

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Authors: M. O. Hamzah, M. R. M. Hasan

Abstract:

Binder drainage test is widely used to set an upper limit to the design binder content of porous asphalt. However, the presence of high amount of fine particles in the drained binder may affect the accuracy of the test result. This paper presents a study to characterize the composition and particle size distribution of fine particles accumulated in the drained binder. Fine aggregates and filler in the drained binder were extracted using a suitable solvent. Then, wet and dry sieve analysis was carried out to identify the actual composition of the extracted fine aggregates and filler. From the results, almost half of the drained binder consisted of fine aggregates and this significantly affects the accuracy of the design binder content of porous asphalt mix. This simple finding highlights the importance of taking into account the presence of fine aggregates in the calculation of drained binder.

Keywords: Porous asphalt, Binder drainage test, Drained binder, Fine particle proportion

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Authors: Simin Sadeghi-Saeb

Abstract:

Metacognitive strategies consistently play important roles in reading comprehension. The metacognitive strategies involve the active monitoring and consequent regulation and orchestration of the cognitive processes in relation to the cognitive objects or data on which they bear. In this paper, the effect of instruction in using metacognitive strategies on reading academic materials, type of metacognitive strategies were mostly used by college university students before and after the instruction and the level they use those strategies before and after the instruction were studied. For these aims, 50 female college students were chosen. Then, they were divided randomly into two groups, experimental and control groups. At first session, students in both groups took the standard TOFEL exam. After the pre-test had been administered, the instruction began. After treatment, a post-test was taken. It is useful to state that after pre-test and post-test the same questionnaire was handed to the students of experimental group. The results of this research show that the instruction of metacognitive strategies has positive effect on the students' scores in reading comprehension tests. Furthermore, it showed that before and after the instruction, the students' usage of metacognitive strategies changed. Also, it demonstrated that the instruction affected the students' level of metacognitive strategies' usage.

Keywords: EFL students, English reading comprehension, instruction, metacognitive strategies.

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Authors: S. O. Adeosun, O. I. Sekunowo, O. P. Gbenebor, W. A. Ayoola, A. O. Odunade, T. A. Idowu

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Sand cast samples of the as-received 66/34Mg-Al alloy were first homogenized at 4900C and then divided into three groups on which annealing, normalising and artificial ageing were respectively carried out. Thermal ageing of the samples involved treatment at 5000C, soaked for 4 hours and quenched in water at ambient temperature followed by tempering at 2000C for 2 hours. Test specimens were subjected to microstructure and mechanical analyses and the results compared. Precipitation of significant volume of stable Mg17Al12 crystals in the aged specimen’s matrix conferred superior mechanical characteristics compared with the annealed, normalized and as-cast specimens. The ultimate tensile strength was 93.4MPa with micro-hardness of 64.9HRC and impact energy (toughness) of 4.05J. In particular, its Young modulus was 10.4GPa which compared well with that of cortical (trabecule) bone’s modulus that varies from 12-17GPa.

Keywords: Mg-Al alloy, artificial ageing, medical implant, cortical bone, mechanical properties.

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Authors: P. Hashim, M. S. Mohd Ridzwan, J. Bakar

Abstract:

Collagen was isolated from chicken feet by using papain and pepsin enzymes in acetic acid solution at 4°C for 24h with a yield of 18.16% and 22.94% by dry weight, respectively. Chemical composition and characteristics of chicken feet collagen such as amino acid composition, SDS-PAGE patterns, FTIR spectra and thermal properties were evaluated. The chicken feet collagen is rich in the amino acids glycine, glutamic acid, proline and hydroxyproline. Electrophoresis pattern demonstrated two distinct α-chains (α1 and α2) and β chain, indicating that type I collagen is a major component of chicken feet collagen. The thermal stability of collagen isolated by papain and pepsin revealed stable denaturation temperatures of 48.40 and 53.35°C, respectively. The FTIR spectra of both collagens were similar with amide regions in A, B, I, II and III. The study demonstrated that chicken feet collagen using papain isolation method is possible as commercial alternative ingredient. 

Keywords: Chicken feet, collagen, papain, pepsin.

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Authors: Andreas Theissler, Ian Dear

Abstract:

In the automotive industry test drives are being conducted during the development of new vehicle models or as a part of quality assurance of series-production vehicles. The communication on the in-vehicle network, data from external sensors, or internal data from the electronic control units is recorded by automotive data loggers during the test drives. The recordings are used for fault analysis. Since the resulting data volume is tremendous, manually analysing each recording in great detail is not feasible. This paper proposes to use machine learning to support domainexperts by preventing them from contemplating irrelevant data and rather pointing them to the relevant parts in the recordings. The underlying idea is to learn the normal behaviour from available recordings, i.e. a training set, and then to autonomously detect unexpected deviations and report them as anomalies. The one-class support vector machine “support vector data description” is utilised to calculate distances of feature vectors. SVDDSUBSEQ is proposed as a novel approach, allowing to classify subsequences in multivariate time series data. The approach allows to detect unexpected faults without modelling effort as is shown with experimental results on recordings from test drives.

Keywords: Anomaly detection, fault detection, test drive analysis, machine learning.

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Authors: K. Fraňa, M. Müller, F. Lemfeld

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The objective of this paper is to present a research study of the convectors that are used for heating or cooling of the living room or industrial halls. The key points are experimental measurement and comprehensive numerical simulation of the flow coming throughout the part of the convector such as heat exchanger, input from the fan etc.. From the obtained results, the components of the convector are optimized in sense to increase thermal power efficiency due to improvement of heat convection or reduction of air drag friction. Both optimized aspects are leading to the more effective service conditions and to energy saving. The significant part of the convector research is a design of the unique measurement laboratory and adopting measure techniques. The new laboratory provides possibility to measure thermal power efficiency and other relevant parameters under specific service conditions of the convectors.

Keywords: Heating, cooling, floor convectors, large eddy simulation, measurement techniques.

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Authors: Nidal H. Abu-Zahra, Murtatha M. Jamel, Parisa Khoshnoud, Subhashini Gunashekar

Abstract:

Two types of glass fibers having different lengths (1/16" and 1/32") were added into rigid PVC foams to enhance the dimensional stability of extruded rigid Polyvinyl Chloride (PVC) foam at different concentrations (0-20 phr) using a single screw profile extruder. PVC foam-glass fiber composites (PVC-GF) were characterized for their dimensional stability, structural, thermal, and mechanical properties. Experimental results show that the dimensional stability, heat resistance, and storage modulus were enhanced without compromising the tensile and flexural strengths of the composites. Overall, foam composites which were prepared with longer glass fibers exhibit better mechanical and thermal properties than those prepared with shorter glass fibers due to higher interlocking between the fibers and the foam cells, which result in better load distribution in the matrix.

Keywords: Polyvinyl Chloride, PVC Foam, PVC Composites, Glass Fiber Composites.

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Authors: Bei Li, Qiu B. Chen, Chee H. Wong

Abstract:

In this work, we incorporated a quartic bond potential into a coarse-grained bead-spring model to study lubricant adsorption on a solid surface as well as depletion instability. The surface tension density and the number density profiles were examined to verify the solid-liquid and liquid-vapor interfaces during heat treatment. It was found that both the liquid-vapor interfacial thickness and the solid-vapor separation increase with the temperatureT* when T*is below the phase transition temperature Tc *. At high temperatures (T*>Tc *), the solid-vapor separation decreases gradually as the temperature increases. In addition, we evaluated the lubricant weight and bond loss profiles at different temperatures. It was observed that the lubricant desorption is favored over decomposition and is the main cause of the lubricant failure at the head disk interface in our simulations.

Keywords: Depletion instability, Lubricant film, Thermal adsorption, Molecular dynamics (MD).

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Authors: Yehia Manawi, Ahmad Kayvani Fard

Abstract:

Membrane distillation is an emerging technology which has been used to produce freshwater and purify different types of aqueous mixtures. Qatar is an arid country where almost 100% of its freshwater demand is supplied through the energy-intensive thermal desalination process. The country’s need for water has reached an all-time high which stipulates finding an alternative way to augment freshwater without adding any drastic affect to the environment. The objective of this paper was to investigate the potential of using the industrial low grade waste heat to produce freshwater using membrane distillation. The main part of this work was conducting a heat audit on selected Qatari chemical industries to estimate the amounts of freshwater produced if such industrial waste heat were to be recovered. By the end of this work, the main objective was met and the heat audit conducted on the Qatari chemical industries enabled us to estimate both the amounts of waste heat which can be potentially recovered in addition to the amounts of freshwater which can be produced if such waste heat were to be recovered.

By the end, the heat audit showed that around 605 Mega Watts of waste heat can be recovered from the studied Qatari chemical industries which resulted in a total daily production of 5078.7 cubic meter of freshwater.

This water can be used in a wide variety of applications such as human consumption or industry. The amount of produced freshwater may look small when compared to that produced through thermal desalination plants; however, one must bear in mind that this water comes from waste and can be used to supply water for small cities or remote areas which are not connected to the water grid. The idea of producing freshwater from the two widely-available wastes (thermal rejected brine and waste heat) seems promising as less environmental and economic impacts will be associated with freshwater production which may in the near future augment the conventional way of producing freshwater currently being thermal desalination. This work has shown that low grade waste heat in the chemical industries in Qatar and perhaps the rest of the world can contribute to additional production of freshwater using membrane distillation without significantly adding to the environmental impact.

Keywords: Membrane distillation, desalination, heat recovery, environment.

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Authors: Najmeh Bolbolamiri, Maryam Setayesh Sanai, Ahmad Mirabadi

Abstract:

This paper deals with condition monitoring of electric switch machine for railway points. Point machine, as a complex electro-mechanical device, switch the track between two alternative routes. There has been an increasing interest in railway safety and the optimal management of railway equipments maintenance, e.g. point machine, in order to enhance railway service quality and reduce system failure. This paper explores the development of Kolmogorov- Smirnov (K-S) test to detect some point failures (external to the machine, slide chairs, fixing, stretchers, etc), while the point machine (inside the machine) is in its proper condition. Time-domain stator Current signatures of normal (healthy) and faulty points are taken by 3 Hall Effect sensors and are analyzed by K-S test. The test is simulated by creating three types of such failures, namely putting a hard stone and a soft stone between stock rail and switch blades as obstacles and also slide chairs- friction. The test has been applied for those three faults which the results show that K-S test can effectively be developed for the aim of other point failures detection, which their current signatures deviate parametrically from the healthy current signature. K-S test as an analysis technique, assuming that any defect has a specific probability distribution. Empirical cumulative distribution functions (ECDF) are used to differentiate these probability distributions. This test works based on the null hypothesis that ECDF of target distribution is statistically similar to ECDF of reference distribution. Therefore by comparing a given current signature (as target signal) from unknown switch state to a number of template signatures (as reference signal) from known switch states, it is possible to identify which is the most likely state of the point machine under analysis.

Keywords: stator currents monitoring, railway points, point failures, fault detection and diagnosis, Kolmogorov-Smirnov test, time-domain analysis.

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Authors: M. Asato, C. Liu, N. Fujima, T. Hoshino, Y. Chen, T. Mohri

Abstract:

We study the temperature dependence of the interaction energies (IEs) of X (=Ru, Rh) impurities in Pd, due to the Fermi-Dirac (FD) distribution and the thermal vibration effect by the Debye-Grüneisen model. The n-body (n=2~4) IEs among X impurities in Pd, being used to calculate the internal energies in the free energies of the Pd-rich PdX alloys, are determined uniquely and successively from the lower-order to higher-order, by the full-potential Korringa-Kohn-Rostoker Green’s function method (FPKKR), combined with the generalized gradient approximation in the density functional theory. We found that the temperature dependence of IEs due to the FD distribution, being usually neglected, is very important to reproduce the X-concentration dependence of the observed solvus temperatures of the Pd-rich PdX (X=Ru, Rh) alloys.

Keywords: Full-potential KKR-Green’s function method, Fermi-Dirac distribution, GGA, phase diagram of Pd-rich PdX (X=Ru, Rh) alloys, thermal vibration effect.

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Authors: Thaniya Kaosol, Narumol Sohgrathok

Abstract:

In this paper, a Biochemical Methane Potential (BMP) test provides a measure of the energy production potential from codigestion between the frozen seafood wastewater and the decanter cake. The experiments were conducted in laboratory-scale. The suitable ratio of the frozen seafood wastewater and the decanter cake was observed in the BMP test. The ratio of the co-digestion between the frozen seafood wastewater and the decanter cake has impacts on the biogas production and energy production potential. The best performance for energy production potential using BMP test observed from the 180 ml of the frozen seafood wastewater and 10 g of the decanter cake ratio. This ratio provided the maximum methane production at 0.351 l CH4/g TCODremoval. The removal efficiencies are 76.18%, 83.55%, 43.16% and 56.76% at TCOD, SCOD, TS and VS, respectively. The result can be concluded that the decanter cake can improve the energy production potential of the frozen seafood wastewater. The energy provides from co-digestion between frozen seafood wastewater and decanter cake approximately 19x109 MJ/year in Thailand.

Keywords: Frozen seafood wastewater, decanter cake, biogas, methane, BMP test.

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Authors: Ravi V. Joat, Pravin S. Bodke, Shradha S. Binani, S. S. Wasnik

Abstract:

A phase diagram of the Ag₂SO₄ - CaSO₄ (Silver sulphate – Calcium Sulphate) binaries system using conductivity, XRD (X-Ray Diffraction Technique) and DTA (Differential Thermal Analysis) data is constructed. The eutectic reaction (liquid -» a-Ag₂SO₄ + CaSO₄) is observed at 10 mole% CaSO₄ and 645°C. Room temperature solid solubility limit up to 5.27 mole % of Ca ²⁺ in Ag₂SO₄ is set using X-ray powder diffraction and scanning electron microscopy results. All compositions beyond this limit are two-phase mixtures below and above the transition temperature (≈ 416°C). The bulk conductivity, obtained following complex impedance spectroscopy, is found decreasing with increase in CaSO₄ content. Amongst other binary compositions, the 80AgSO₄-20CaSO₄ gave improved sinterability/packing density.

Keywords: Ag2SO4-CaSO4 (Silver sulphate–Calcium Sulphate) binaries system, XRD (X-Ray Diffraction Technique) and DTA (Differential Thermal Analysis).

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Authors: Chang S. Woo, Hyun S. Park, Wan D. Kim

Abstract:

Fatigue life prediction and evaluation are the key technologies to assure the safety and reliability of automotive rubber components. The objective of this study is to develop the fatigue analysis process for vulcanized rubber components, which is applicable to predict fatigue life at initial product design step. Fatigue life prediction methodology of vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter of maximum strain appearing at the critical location determined from fatigue test. In order to develop an appropriate fatigue damage parameter of the rubber material, a series of displacement controlled fatigue test was conducted using threedimensional dumbbell specimen with different levels of mean displacement. It was shown that the maximum strain was a proper damage parameter, taking the mean displacement effects into account. Nonlinear finite element analyses of three-dimensional dumbbell specimens were performed based on a hyper-elastic material model determined from the uni-axial tension, equi-biaxial tension and planar test. Fatigue analysis procedure employed in this study could be used approximately for the fatigue design.

Keywords: Rubber, Material test, Finite element analysis, Strain, Fatigue test, Fatigue life prediction.

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Authors: Yong F. Li, Yi X. Liu, Xiang M. Wang, Feng H. Wang

Abstract:

Wood as a natural renewable material is vulnerable to degradation by microorganisms and susceptible to change in dimension by water. In order to effectively improve the durability of wood, an active reagent, maleic anhydride (Man) was selected for wood modification. Man was first dissolved into a solvent, and then penetrated into wood porous structure under a vacuum/pressure condition. After a final catalyst-thermal treatment, wood modification was finished. The test results indicate that acetone is a good solvent for transporting Man into wood matrix. SEM observation proved that wood samples treated by Man kept a good cellular structure, indicating a well penetration of Man into wood cell walls. FTIR analysis suggested that Man reacted with hydroxyl groups on wood cell walls by its ring-ether group, resulting in reduction of amount of hydroxyl groups and resultant good dimensional stability as well as fine decay resistance. Consequently, Man modifying wood to improve its durability is an effective method.

Keywords: Wood, porous structure, durability improvement, maleic anhydride

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Authors: Muhammed A. Ahmed, Sidra A. Shaikh

Abstract:

Global Solar Radiation (H) for Dubai and Sharjah, Latitude 25.25oN, Longitude 55oE and 25.29oN, Longitude 55oE respectively have been studied using sunshine hour data (n) of the areas using various methods. These calculated global solar radiation values are then compared to the measured values presented by NASA. Furthermore, the extraterrestrial (H0), diffuse (Hd) and beam radiation (Hb) are also calculated. The diffuse radiation is calculated using methods proposed by Page and Liu and Jordan (L-J). Diffuse Radiation from the Page method is higher than the L-J method. Moreover, the clearness index (KT) signifies a clear sky almost all year round. Rainy days are hardly a few in a year and limited in the months December to March. The temperature remains between 25oC in winter to 44oC in summer and is desirable for thermal applications of solar energy. From the estimated results, it appears that solar radiation can be utilized very efficiently throughout the year for photovoltaic and thermal applications.

Keywords: Dubai, Sharjah, Global Solar Radiation, Diffuse Radiation

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Authors: Kyoung Hoon Kim

Abstract:

Turbine blade cooling is considered as the most effective way of maintaining high operating temperature making use of the available materials, and turbine systems with wet compression have a potential for future power generation because of high efficiency and high specific power with a relatively low cost. In this paper performance analysis of wet-compression gas turbine cycle with turbine blade cooling is carried out. The wet compression process is analytically modeled based on non-equilibrium droplet evaporation. Special attention is paid for the effects of pressure ratio and water injection ratio on the important system variables such as ratio of coolant fluid flow, fuel consumption, thermal efficiency and specific power. Parametric studies show that wet compression leads to insignificant improvement in thermal efficiency but significant enhancement of specific power in gas turbine systems with turbine blade cooling.

Keywords: Water injection, wet compression, gas turbine, turbine blade cooling.

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Authors: Kitti Leangkrua

Abstract:

This paper presents a risk-based maintenance strategy of a power transformer in order to optimize operating and maintenance costs. The methodology involves the study and preparation of a database for the collection the technical data and test data of a power transformer. An evaluation of the overall condition of each transformer is performed by a program developed as a result of the measured results; in addition, the calculation of the main equipment separation to the overall condition of the transformer (% HI) and the criteria for evaluating the importance (% ImI) of each location where the transformer is installed. The condition assessment is performed by analysis test data such as electrical test, insulating oil test and visual inspection. The condition of the power transformer will be classified from very poor to very good condition. The importance is evaluated from load criticality, importance of load and failure consequence. The risk matrix is developed for evaluating the risk of each power transformer. The high risk power transformer will be focused firstly. The computerized program is developed for practical use, and the maintenance strategy of a power transformer can be effectively managed.

Keywords: Asset management, risk-based maintenance, power transformer, health index.

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Authors: I. Parkova, A. Vališevskis, A. Viļumsone

Abstract:

Nocturnal enuresis or bed-wetting is intermittent incontinence during sleep of children after age 5 that may precipitate wide range of behavioral and developmental problems. One of the non-pharmacological treatment methods is the use of a bed-wetting alarm system. In order to improve comfort conditions of nocturnal enuresis alarm system, modular moisture sensor should be replaced by a textile sensor. In this study behavior and moisture detection speed of woven and sewn sensors were compared by analyzing change in electrical resistance after solution (salt water) was dripped on sensor samples. Material of samples has different structure and yarn location, which affects solution detection rate. Sensor system circuit was designed and two sensor tests were performed: system activation test and false alarm test to determine the sensitivity of the system and activation threshold. Sewn sensor had better result in system’s activation test – faster reaction, but woven sensor had better result in system’s false alarm test – it was less sensitive to perspiration simulation. After experiments it was found that the optimum switching threshold is 3V in case of 5V input voltage, which provides protection against false alarms, for example – during intensive sweating.

Keywords: Conductive yarns, moisture textile sensor.

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Authors: M. M. Seraj, M. S. Gadala

Abstract:

This study presents a systematic analysis of wetted region due to cooling of aluminum plate by water spray impingement with respect to different water flow rates, spray nozzle heights, and subcooling. Unlike jet impingement, the wetting is not commenced upon spray impingement and there is a delay in wetness of hot test surface. After initiation, the wetting (black zone) progresses gradually to cover all test plate and provides efficient cooling in nucleate boiling regime. Generally, spray cooling is found function of spray flow rate, spray-to-surface distance and water subcooling. Wetting delay is decreasing by increasing of spray flow rate until spray impact area is not become bigger that test surface. Otherwise, higher spray flow rate is not practically accelerated start of wetting. Very fast wetting due to spray cooling can be obtained by dense spray (high floe rate) discharged from adjacent nozzle to the test surface. Highly subcooling water spray also triggers earlier wetting of hot aluminum plate.

Keywords: Water spray, wetting, aluminum plate, flow rate.

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Authors: Abiodun M. Lawal, Benjamin O. Olley

Abstract:

Long Distance Truck Drivers (LDTDs) have been found to be a high risk group in the spread of HIV/AIDS globally; perhaps, due to their high Sexual Risk Behaviours (SRBs). Interventions for reducing SRBs in trucking population have not been fully exploited. A quasi-experimental control group pretest-posttest design was used to assess the efficacy of psycho-education and behavioural skills training in reducing SRBs among LDTDs. Sixteen drivers rivers were randomly assigned into either experimental or control groups using balloting technique. Questionnaire was used as an instrument for data collection. Repeated measures t-test and independent t-test were used to test hypotheses. Intervention had significant effect on the SRBs among LDTDs at post-test (t{7}= 6.01, p<.01) and at follow up (t{7} = 6.42, p<.01). No significant difference in sexual risk behaviour of LDTDs at post-test and at follow-up stage. Similarly, intervention had significant effects on sexual risk behaviour at post-test (t {14} = - 4.69, p<.05) and at follow-up (t {14} = -9.56, p<.05) respectively. At post-test and follow-up stages, drivers in experimental group reported reduced SRBs than those in control group. Drivers in experimental group reported lower sexual risk behaviour a week after intervention as well as at three months follow-up than those in control group. It is concluded that HIV/AIDS preventive intervention that provides the necessary informational and behavioural skills content can significantly impact long distance truck drivers’ sexual risk behaviours.

Keywords: HIV/AIDS interventions, Long distance truck drivers, Nigeria, Sexual risk behaviours.

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Authors: Wonsim Cha, Kibum Kim, Kyungwook Choi, Kihyung Lee

Abstract:

A co-generation system in automobile can improve thermal efficiency of vehicle in some degree. The waste heat from the engine exhaust and coolant is still attractive energy source that reaches around 60% of the total energy converted from fuel. To maximize the effectiveness of heat exchangers for recovering the waste heat, it is vital to select the most suitable working fluid for the system, not to mention that it is important to find the optimum design for the heat exchangers. The design of heat exchanger is out of scoop of this study; rather, the main focus has been on the right selection of working fluid for the co-generation system. Simulation study was carried out to find the most suitable working fluid that can allow the system to achieve the optimum efficiency in terms of the heat recovery rate and thermal efficiency.

Keywords: Cycle Analysis, Heat Recovery, Rankine Cycle, Waste Heat Recovery, Working Fluid.

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Authors: Daniel L. Clinciu, Ikrom Abdulaev, Brian D. Oscar

Abstract:

Various personality profile tests are used to identify personality strengths and limits in individuals, helping both individuals and managers to optimize work and team effort in organizations. One such test, the Hartman’s personality profile, emphasizes four driving "core motives" influenced or affected by both strengths and limitations classified into four colors: Red - motivated by power; Blue - discipline and loyalty; White - peace; and Yellow – fun loving. Two shortcomings of Hartman’s personality test are noted; 1) only one selection for every item / situation allowed and 2) selection of an item / option even if not applicable. A test taker may be as much nurturing as he is opinionated but since “opinionated” seems less attractive the individual would likely select nurturing, causing a misidentification in personality strengths and limits. Since few individuals have a “strong” personality, it is difficult to assess their true personality strengths and limits allowing only one choice or requiring unwanted choices, undermining the potential of the test. We modified Hartman’s personality profile allowing test takers to make either multiple choices for any item / situation or leave them blank if applicable. Sixty-eight participants (38 males and 30 females), 17 - 49 years old, from countries in Asia, Europe, N. America, CIS, Africa, Latin America, and Oceania were included. 58 participants (85.3%) reported the modified test, allowing multiple / no choices better identified their personality strengths and limits, while 10 participants (14.7%) expressed the original (one choice version) was sufficient. The overall results show that our modified test enhanced the identification and balance of core personalities’ strengths and limits, aiding test takers, managers and organizations to better assess individual characteristics, particularly useful in making task-related, teamwork, and management decisions.

Keywords: Organizational behavior, personality tests, personality limitations, personality strengths, task management, team work.

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Authors: V. Nikkhah Rashidabad, M. Manteghian, M. Masoumi, S. Mousavian, D. Ashouri

Abstract:

In this research, the capability of neural networks in  modeling and learning complicated and nonlinear relations has been  used to develop a model for the prediction of changes in the diameter  of bubbles in pool boiling distilled water. The input parameters used  in the development of this network include element temperature, heat  flux, and retention time of bubbles. The test data obtained from the  experiment of the pool boiling of distilled water, and the  measurement of the bubbles form on the cylindrical element. The  model was developed based on training algorithm, which is  typologically of back-propagation type. Considering the correlation  coefficient obtained from this model is 0.9633. This shows that this  model can be trusted for the simulation and modeling of the size of  bubble and thermal transfer of boiling.

Keywords: Bubble Diameter, Heat Flux, Neural Network, Training Algorithm.

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Authors: Wael M. El-Mamlouk, Metwally A. El-Sharkawy, Hossam. E. Mostafa

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In this paper, we analyze and test a scheme for the estimation of electrical fundamental frequency signals from the harmonic load current and voltage signals. The scheme was based on using two different Multi Layer Artificial Neural Networks (ML-ANN) one for the current and the other for the voltage. This study also analyzes and tests the effect of choosing the optimum artificial neural networks- sizes which determine the quality and accuracy of the estimation of electrical fundamental frequency signals. The simulink tool box of the Matlab program for the simulation of the test system and the test of the neural networks has been used.

Keywords: Harmonics, Neural Networks, Modeling, Simulation, Active filters, electric Networks.

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Authors: Wen-Chi Liu

Abstract:

This study applies a simple and powerful nonlinear unit root test to test the validity of long-run purchasing power parity (PPP)  in a sample of 10 East-Asian countries (i.e., China, Hong Kong,  Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Taiwan  and Thailand) over the period of March 1985 to September 2008. The empirical results indicate that PPP holds true for half of these 10  East-Asian countries under study, and the adjustment toward PPP is found to be nonlinear and in an asymmetric way. 

 

Keywords: Purchasing Power Parity, East-Asian Countries, Nonlinear Unit Root Test, Asymmetry.

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Authors: Paramet Nualmuenwai, Chutima Prommak

Abstract:

This paper presents the IP traffic analysis. The traffic was collected from the network of Suranaree University of Technology using the software based on the Simple Network Management Protocol (SNMP). In particular, we analyze the distribution of the aggregated traffic during the hours of peak load and light load. The traffic profiles including the parameters described the traffic distributions were derived. From the statistical analysis applying three different methods, including the Kolmogorov Smirnov test, Anderson Darling test, and Chi-Squared test, we found that the IP traffic distribution is a non-normal distribution and the distributions during the peak load and the light load are different. The experimental study and analysis show high uncertainty of the IP traffic.

Keywords: IP traffic analysis, IP traffic distribution, Traffic uncertainty

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Authors: J. M. Counsell, Y. Khalid, M. J. Stewart

Abstract:

Achieving nearly zero carbon heating continues to be identified by UK government analysis as an important feature of any lowest cost pathway to reducing greenhouse gas emissions. Heat currently accounts for 48% of UK energy consumption and approximately one third of UK’s greenhouse gas emissions. Heat Networks are being promoted by UK investment policies as one means of supporting hybrid heat pump based solutions. To this effect the RISE (Renewable Integrated and Sustainable Electric) heating system project is investigating how an all-electric heating sourceshybrid configuration could play a key role in long-term decarbonisation of heat.  For the purposes of this study, hybrid systems are defined as systems combining the technologies of an electric driven air source heat pump, electric powered thermal storage, a thermal vessel and micro-heat network as an integrated system.  This hybrid strategy allows for the system to store up energy during periods of low electricity demand from the national grid, turning it into a dynamic supply of low cost heat which is utilized only when required. Currently a prototype of such a system is being tested in a modern house integrated with advanced controls and sensors. This paper presents the virtual performance analysis of the system and its design for a micro heat network with multiple dwelling units. The results show that the RISE system is controllable and can reduce carbon emissions whilst being competitive in running costs with a conventional gas boiler heating system.

Keywords: Gas boilers, heat pumps, hybrid heating and thermal storage, renewable integrated& sustainable electric.

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