bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Heating Rate and Cold Work on the Development of Dual-Phase Steel Microstructures
Authors: Thomas L.S. , Matlock David K. , Speer John G.
Published: May 2014

The effects of heating rate and prior cold work on the development of dual-phase steel microstructures in three low carbon steels were evaluated with samples processed on a Gleeble 3500 thermomechanical processing simulator. The nominally 0.2 wt pct carbon steels included a plain carbon steel and modified alloys incorporating higher manganese contents, boron additions, and microalloy additions. Each alloy was prepared with two different cold rolled reductions. Heating rates from 1 to 1000 oC/s were selected to span the rates typically experienced in conventional furnace heat treating up to rates for induction heating. Critical transformation temperatures were obtained from dilatometric curves. Dual-Phase microstructures after heat treatment with different heating rates were compared. Transformation temperatures decreased with an increase in cold work and increased with an increase in heating rate. The steels with higher manganese and carbon additions exhibited lower Ac3 values across all heating rates and the steels with higher silicon higher Ac1 temperatures across all heating rates. Ac1 increased less than Ac3 with increasing heating rate. The increase in transformation temperatures between 100 and 1000 °C/s was smaller than values exhibited over other increments in heating rate, and decreased in one steel; contributing factors were identified for this behavior.
Electrophoretic Deposition and Characterization of Biocomposites on Magnesium for Orthopedic Applications
Authors: Tian Qiao Mu , Liu Hui Nan
Published: May 2014

The objective of this study is to produce a uniform and consistent nanophase hydroxyapatite (nHA) and poly (lactic-co-glycolic acid) (PLGA) coating on three-dimensional magnesium (Mg) implants using electrophoretic deposition (EPD) process. Mg is biodegradable, mechanically strong, and promising for orthopedic implant and device applications. However, currently available Mg and its alloys degrade too rapidly to meet clinical needs. To control Mg degradation and promote bone ingrowth, nHA/PLGA composite microspheres were synthesized and deposited onto Mg substrates using EPD process. Annealing was applied to improve the coating adhesion. The surface morphology, composition, and coating cross-section were examined using a scanning electron microscope and energy dispersive X-ray spectrometer. The results showed the presence of calcium, phosphorous, carbon, and oxygen peaks, indicating the successful deposition of nHA/PLGA microspheres on Mg. The corrosion resistance of the coated Mg was evaluated using the Tafel test. The results showed that the nHA/PLGA composite coating improved the corrosion resistance of Mg.
Mechanical Properties of ZK60 Magnesium Alloy Processed by High-Pressure Torsion
Authors: Torbati-Sarraf Seyed Alireza , Langdon Terence
Published: May 2014

Severe plastic deformation routes such as high-pressure torsion (HPT) are capable of producing ultrafine grain sizes in various alloys, specifically in magnesium alloys which exhibit poor ductility due to their hexagonal close-packed (hcp) crystal structure. HPT was performed on ZK60 magnesium alloy samples at room temperature under a pressure of 2.0 GPa up to 5 turns. The Vickers microhardness values were obtained from the centre to the edge of the disc samples and they show a slight hardness gradient with values which are lower at the centre of the samples and higher towards the edge. By increasing the numbers of turns in HPT, the hardness values increase to a saturation level and the gradient is removed. Tensile tests were performed at high temperatures and the results reveal a significant increase in elongation to failure as the numbers of turns in HPT increases. It is shown that microstructural analysis is in agreement with the results obtained from mechanical testing.
In Situ Observation of Fracture Behavior of CrN/Cr Film during Three-Point Bending Test
Authors: Ushiro Yusuke , Okai Daisuke , Yamamoto Atsushi
Published: May 2014

The fracture behavior and adhesion strength of CrN/Cr and CrN films on SKD61 substrates were investigated by a three-point bending test. The SKD61 substrates were coated with a film with multilayer of CrN/Cr and a single film of CrN by a physical vapor deposition (PVD). The fracture behaviors of CrN/Cr and CrN films at three-point bending test were observed by scanning electron microscopy (SEM). Adhesions of the CrN/Cr/SKD61 and the CrN/SKD61 were also evaluated using a scratch tester. The scratch test resulted in no great difference in the adhesion strength between the CrN/Cr/SKD61 and the CrN/SKD61. On the other hand, the three-point bending test showed a high adhesion of the CrN/Cr with the intermediate layer of Cr film compared to the CrN on the SKD61.
TEM Observation for Precipitates Structure of Aged Al-Zn-Mg Series Al Alloys Addition of Cu or Ag
Authors: Watanabe Katsumi , Ikeno Susumu , Yoshida Tomoo , Murakami Satoshi , Matsuda Kenji
Published: May 2014

Al-Zn-Mg alloy has been known as one of the aluminum alloys with the good age-hardening ability and the high strength among commercial aluminum alloys. The mechanical property of the limited ductility, however, is required to further improvement. In this work, three alloys, which were added Cu or Ag into the Al-Zn-Mg alloy, were prepared to compare the effect of the additional elements on the aging behavior. Ag or Cu added alloy showed higher maximum hardness than Ag or Cu free alloy. The η’ phase were observed in all alloys peak-aged at 423K. According to addition of Ag or Cu, the number density of the precipitates increased than Ag or Cu free alloy.
Mechanical Properties at Elevated Temperatures of an S304H-Type Austenitic Stainless Steel Processed by Warm Rolling
Authors: Yanushkevich Zhanna , Belyakov Andrey , Kaibyshev Rustam
Published: May 2014

The effect of multiple warm to hot rolling in the temperature interval of 673 – 1273 K on the microstructures and mechanical properties of an S304H-type austenitic stainless steel was studied. The structural changes during multiple rolling are characterized by the elongation of original grains towards the rolling direction and the development of new fine grains. The average spacing between high-angle boundaries in the transverse section of the rolled samples decreases from about 0.95 to 0.4 μm with decrease in the rolling temperature from 1273 to 773 K. The multiple rolling leads to significant strengthening as revealed by tensile tests at ambient and elevated temperatures. The offset yield strength evaluated at ambient temperature increased from 480 to 1120 MPa, while the rolling temperature decreased from 1273 to 673 K. The effect of the rolling temperature on the strength becomes less pronounced with an increase of the temperature of tensile tests.
Improving Energy Efficiency by Classroom Scheduling: A Case Study in a Thai University
Authors: Sethanan Kanchana , Theerakulpisut Somnuk , Benjapiyaporn Chatchai
Published: May 2014

In an attempt to improve energy efficiency in classrooms by classroom scheduling, an algorithm was developed to solve the timetabling problem in a Thai university. The algorithm using Tabu Search, unlike all other algorithms for time tabling, aims at reducing classroom energy consumption. The algorithm took into account the number of students in each class, class time, class size, time available for both students enrolling in each class and faculty members in charge of the classes, and energy consumption in each time period of the classroom. The algorithm was used to solve the past timetabling problem of a Thai university over the academic year 2006 to 2012 and the results were compared with those of the trial-and-error traditional timetabling. It was found that the algorithm can be used to significantly lower energy consumption of the classrooms.
Densified Fuels from Mixed Plastic Wastes and Corn Stover
Authors: Auprakul Unchana , Promwungkwa Anucha , Tippayawong Nakorn , Chaiklangmuang Suparin
Published: May 2014

Mixed plastic wastes recovered from dumpsites may be utilized as densified solid fuel. However, it is commonly known that plastic materials may not bind together under compaction. Corn stover can be used as natural binder in this case. It can improve chemical composition (reducing sulfur and chlorine content) and mechanical strength of the fuel pellet. In this paper, densification of mixed plastic wastes and corn stover was investigated. Compression pressure was conducted at 150 MPa. The pellet size was 8 mm in diameter and 20 mm long. Effects of moisture content (5-20%), types of material, and preheating temperatures (75 and 100°C) on the fuel properties were studied. The pellets from mixed materials were found to have higher calorific value, carbon content and durability index than corn stover pellet.
Air Change Rate Efficiency Improvement for a Broiler House in a Minimum Ventilation Situation
Authors: Wisate Chayanon , Suntivarakorn Ratchaphon , Radpakdee Thana , Winitchai Sorayut
Published: May 2014

This research presents an improvement of the air change rate efficiency for a closed system broiler house in minimum ventilation situation. The multi inlet system was installed in the broiler house in order to improve the air change rate. Two closed system broiler house, which were a 14x120x2.4 m3 rectangular cross-section, were used to test in the experiment. The experiment and simulation were conducted in order to know the air velocity, and the comparison of both results was done. From the experimental result, it was found that the air velocity of broiler house with the multi-inlets system was higher than the house without multi-inlets system. The mathematical simulation result was also showed the similar result with that of experiment. The multi-inlet system can increase the area, where the air velocity was in standard and above standard duration. Thus, the air change rate was increased from 0.26 to 0.29 air change/min for the broiler house.
Electrical Conduction Mechanisms in n-CdS/p-CuFeO2 Heterojunction Diode
Authors: Gaewdang Thitinai , Wongcharoen Ngamnit
Published: May 2014

In this work, n-CdS/p-CuFeO2 heterojunction diode was fabricated by thermal evaporating CdS thin films on 1 mm thick-CuFeO2 ceramic substrate with substrate temperature kept at 373 K during evaporation process. The forward current-voltage characteristics of n-CdS/p-CuFeO2 heterojunction in a temperature range of 100-300 K were investigated to determine the electrical parameters and conduction mechanism. It was found that, at forward bias below 0.5 V, the conduction mechanism of the diode is dominated by thermionic emission (TE) mechanism. At bias voltage above 0.5 V, the current transport is due to space charge limited current (SCLC) controlled by an exponential trap distribution in the band gap of CdS. The temperature dependence of the saturation current and ideality factor are well described by tunneling enhanced recombination at junction interface with activation and characteristic tunneling energy values as about 1.79 eV and E00 = 86 meV, respectively. The value of interface state density (Nss) evaluated from capacitance spectroscopy increases from 2.09x1011 eV-1cm-2 (at 300 K) to 2.70x1011 eV-1cm-2 (at 363 K). Free carrier concentration of 5.80x1013 cm-3 at room temperature was estimated from capacitance-voltage measurements at 50 kHz.
Pressure Drop and Water Holdup of Malaysian Crude Oil and Water Two-Phase Flow in Pipes
Authors: Ismail Issham , Misnan Shahir , Izwan Ismail Ahmad Shamsul , Mohsin Rahmat
Published: May 2014

Understanding the pressure drop and water holdup of crude oil-water flow in a pipe is crucial to many engineering applications. Free water in contact with the pipes wall can cause erosion or corrosion problems. An experimental research was conducted at the Malaysia Petroleum Resources Corporation Institute for Oil and Gas, Universiti Teknologi Malaysia to study the pressure drop and water holdup of the Malaysian waxy crude oil-water flowing in a closed-loop system at ambient condition through a 5.08 cm ID stainless steel horizontal pipeline. In the research work, water cuts were varied from 0 - 90% with mixture velocities ranging from 0.1 0.8 m/s. The research works comprised fluid characterization, pressure drop, and liquid holdup measurement.The investigations proved that pressure drop increased with flow rates, while the water holdup was found to have decreased slightly at higher water cuts due to the presence of emulsion in the crude oil a challenge when using a waxy crude oil in a two phase flow system. The experimental results can be used as a platform to understand better a more complex case of liquid-liquid two phase flow.
Tuning PID Controller Using Genetic Algorithms for Electro-Hydraulic System with Tracking Force Control
Authors: Moonumca Pisan , Depaiwa Nattawoot , Yamamoto Yoshio
Published: May 2014

The aim of this paper is design a controller for force control of an Electro-Hydraulic System and selection of a PID gains are using genetic algorithm. The mathematical model is considered as the Newton second law and compressible fluid flow theory. This paper compares two kinds of tuning methods for PID controller. One is the controller design by the genetic algorithm, second is the controller design by the Ziegler and Nichols method. Each PID gains are tested with step input function, square signal, half-sine signal and half-saw signal. And results show performance index with rise time, settling time and Maximum %OS. It was found that the proposed PID gains tuning by the genetic algorithm is better than the Ziegler & Nichols method.
Fabrication of Al2O3/ZrO2 Micro/Nano Composites Using Powder Alkoxide Mixtures
Authors: Boonsorn Wathun , Watcharamaisakul Sukasem , Golman Boris
Published: May 2014

Al2O3/ZrO2 composites have been investigated as the bio-inert material. In the present work Al2O3/ZrO2 Micro/Nano composites were prepared by colloidal method. The effects of the concentration of zirconium propoxide and the sintering temperature were studied on the distribution of ZrO2 nano-grainsin Al2O3 matrix and mechanical properties of composites. XRD patterns for all compositions showed a single phase of a-Al2O3, and the tetragonal and monoclinic ZrO2 phases. Samples sintered at 1650°C demonstrated the high bulk density with value of 86-92% of theoretical density. ZrO2 nano-grains were dispersed within Al2O3 grain and the grain boundary. The sample of the highest flexural strength of 710 MPa was synthesized using 100% Zr propoxide solution and sintered at 1650o C. The flexural strength was found to increase with increasing the concentration of Zr propoxide and sintering temperature.
Automatic Feature Weight Assignment Based on Image Retrieval Using Genetic Algorithm
Authors: Srisook Purichaya , Praditwong Kata
Published: May 2014

The work proposes the new method to increase an efficiency of a Content-based Image Retrieval (CBIR) system. For combining many image features, the optimal weight of each feature is required. To find the optimal value of the feature, this work uses Genetic Algorithm (GA). An image is represented as color, shape and texture features. The experiment compares the results from the system with equal weight values and the system with the weights provided by GA. Evaluation shows the robustness and efficiency of the proposed technique.
A Hybrid Technique of Noise Reduction with Periductal Fibrosis Ultrasound Images for Periductal Fibrosis Detection System of Cholangiocarcinoma Surveillance
Authors: Wayalun Pichet , Saiyod Saiyan , Chamadol Nittaya
Published: May 2014

The Cholangiocarcinoma (CCA) is a serious public health problem. The Periductal fibrosis (PDF) ultrasound images are applied for CCA surveillance because it is no side effect of radiation with patients, easy to portability and low cost. In contrast, the common problem of ultrasound images are speckle noise in which decreases the PDF detection performance. In this paper proposes a hybrid noise reduction method in the PDF detection system. The proposed noise reduction method by applying the Median filter and Fast Fourier transform based on PDF ultrasound images. The experimental results give the best performance for PDF detection system. A success rate of proposed method achieved at 70.89%.
The Construction of ElGamal over Koblitz Curve
Authors: Kamthawee Krissanee , Chiewthanakul Bhichate
Published: May 2014

Recently elliptic curve cryptosystems are widely accepted for security applications key generation, signature and verification. Cryptographic mechanisms based on elliptic curves depend on arithmetic involving the points of the curve. it is possible to use smaller primes, or smaller finite fields, with elliptic curves and achieve a level of security comparable to that for much larger integers. Koblitz curves, also known as anomalous binary curves, are elliptic curves defined over F2. The primary advantage of these curves is that point multiplication algorithms can be devised that do not use any point doublings. The ElGamal cryptosystem, which is based on the Discrete Logarithm problem can be implemented in any group. In this paper, we propose the ElGamal over Koblitz Curve Scheme by applying the arithmetic on Koblitz curve to the ElGamal cryptosystem. The advantage of this scheme is that point multiplication algorithms can be speeded up the scalar multiplication in the affine coodinate of the curves using Frobenius map. It has characteristic two, therefore it’s arithmetic can be designed in any computer hardware. Moreover, it has more efficient to employ the TNAF method for scalar multiplication on Koblitz curves to decrease the number of nonzero digits. It’s security relies on the inability of a forger, who does not know a private key, to compute elliptic curve discrete logarithm.
New Key Factors Discovery to Enhance Dengue Fever Forecasting Model
Authors: Ongruk Phatsavee , Siriyasatien Padet , Kesorn Kraisak
Published: May 2014

There are several factors that can be used to predict a dengue fever outbreak. Almost all existing research approaches, however, usually exploit the use of a basic set of core attributes to forecast an outbreak, e.g. temperature, humidity, wind speed, and rainfall. In contrast, this research identifies new attributes to improve the prediction accuracy of the outbreak. The experimental results are analyzed using a correlation analysis and demonstrate that the density of dengue virus infection rate in female mosquitoes and seasons have strong correlation with a dengue fever outbreak. In addition, the research constructs a forecast model using Poisson regression analysis. The result shows the proposed model obtains significantly low forecasting error rate when compared it against the conventional model using only temperature, humidity, wind speed, and rainfall parameters.
Influence of Hydrophilic Polymer on Pure Water Permeation, Permeability Coefficient, and Porosity of Polysulfone Blend Membranes
Authors: Ali Asmadi , Awang Mohamad , Mat Ramli , Johari Anwar , Kamaruddin Mohd Johari , Sulaiman Wan Rosli Wan
Published: May 2014

It is well known that membrane with hydrophobic property is a fouling membrane. Polysulfone (PSf) membrane has hydrophobic characteristic was blended with a hydrophilic polymer, cellulose acetate phthalate (CAP) in order to increase hydrophilicity property of pure PSf membrane. In this study, membrane casting solutions containing 17 wt% of polymer was prepared via wet phase inversion process. The pure PSf membrane was coded as PC-0. PSf/CAP blend membranes with blend composition of 95/5, 90/10, 85/15 and 80/20 wt% of total polymer concentration in the membrane casting solutions were marked as PC-5, PC-10, PC-15 and PC-20 respectively. All of the membranes were characterized in terms of pure water flux and permeability coefficient in order to study their hydrophilicity properties. The investigated results shows that increased of CAP composition in PSf blend membranes has increased pure water flux, permeability coefficient and porosity of the blend membrane which in turn formed membrane with anti-fouling property.
Methanol Synthesis in a Slurry Phase Reactor over Cu/ZnO/Al2O3 Catalyst
Authors: Krekkeitsakul Kuntima , Utistham Thanes , Hartley Unalome Wetwatana
Published: May 2014

Methanol synthesis from synthesis gas (syngas, a mixture of hydrogen (H2) and carbon monoxide (CO)) in the presence of copper/zinc oxide/alumina catalyst (Cu/ZnO/Al2O3) was investigated using semi-batch reactor. The process was operated at 280 °C under pressure 40 bar in a slurry reactor (Parr reactor model 4848). The catalyst weight, syngas molar ratio and residence time were optimized for methanol synthesis. Cu/ZnO/Al2O3catalyst was prepared by a two-step surfactant assisted precipitation method using polyethylene glycol (PEG 6000). The catalysts surface area, crystallinity, reducibility and morphology were characterized by BET, XRD, H2-TPR and SEM-EDS, respectively. The BET analysis indicated that the catalyst calcined at 300 °C gave the highest surface area (99.67 m2/g). The crystallite size of Cu in Cu/ZnO/Al2O3catalyst was estimated to be 14.14 nm., after adding the surfactants. The maximum methanol yield (607.53) was achieved after 24 hours of residence time using 5 g of the catalyst under a stream of 2 to 1 molar ratio of H2and CO reactive mixed gas. Under these conditions, 38.26% of CO conversion and 93.11% of selectivity to methanol were achieved. When the residence time was decreased to 12 hours with molar ratio of 0.5 H2to 1 CO, the yield of methanol was 388.11, with a CO conversion of 38.53% and selectivity to methanol of 90.77%.
Compressive Response of Polyurethane Open-Cell Foam with Electrodeposited Copper Coatings
Authors: Janphongsri Wisut , Boonyongmaneerat Yuttanant , Jearanaisilawong Petch
Published: May 2014

Mechanical response of polyurethane open-cell foam with electrodeposited copper coatings under compressive loads is investigated via experimental characterization. Commercially available open-cell polyurethane foam specimens are copper deposited using electroless and electro-deposition techniques. Thickness and composition of the coating are controlled by varying the deposition time to 30, 60 and 90 minutes. Micrographs of the coated foam structure show that the coating thickness is higher at the outer surface, and the averaged thickness linearly depends on the deposition time. The coated foam exhibits a stiffer compressive response than that of the uncoated one. When unloaded, the copper coating layers fracture at the center of foams ligaments, and fall off from the foam structure.
The Carbonation of Calcium-Silicate-Hydrate C-S-H in Cement Mortar Studied Using Thermal Analysis and Gas Pycnometer: Determination of the Quantity of Calcium Carbonate Produced and the Increase in Molar Volume
Authors: Pham Son Tung , Prince William
Published: May 2014

The objective of this work was to examine the microstructural changes caused by the carbonation of normalised cement mortar. Samples were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO2 concentration. The main contributions of this study were: 1) a new way to determine separately the amount of calcium carbonate CaCO3 produced by the carbonation of portlandite Ca (OH)2 and that associated with the carbonation of calcium-silicate-hydrate C-S-H using only thermal analysis; 2) determination of the increase in the molar volume of the calcium-silicate-hydrate C-S-H due to carbonation using gas pycnometer, which indicated an increase of about 39 cm3 for 1 mole of C3S2H3 carbonated. The results indicated that the amount of CaCO3 produced by the carbonation of C-S-H is higher than that produced by the carbonation of portlandite.
Efficiency Factors for Reinforced Concrete Deep Beams: Part 1 - Improved Models
Authors: Chetchotisak Panatchai , Teerawong Jaruek , Chetchotsak Danaipong , Yindeesuk Sukit
Published: May 2014

A strut-and-tie model (STM) has been used as a rational and simple method for analysis and design of reinforced concrete deep beams. The STM idealizes the discontinuity regions in such members as a truss-like structure consisting of compression struts and tension ties. The strength of a deep beam is usually controlled by the capacity of the diagonal concrete struts which is generally proposed in terms of the concrete strength and the efficiency factor. The efficiency factor accounts for the variation of the concrete material and the compression softening effect. One has been used in many STMs and often exhibit biases and uncertain errors in prediction of the shear strengths of deep beams. This uncertainty is due to the imperfection of formulation, missing parameters, and insufficient experimental data. Based on a database of 406 test results and six state-of-the-art formulations of the efficiency factors found in the international building codes and literature, this paper proposes improved STMs for accurate prediction of shear strength of simply supported reinforced concrete deep beams by correcting the bias and quantifying the scatter using a Bayesian parameter estimation method.
Statistical Analysis on Satisfaction of Residents Living in Prefabricated Concrete Buildings in Thailand
Authors: Witchayangkoon Boonsap , Budsaba Kamon , Buddhawanna Saharat , Sirimontree Sayan , Lertpocasombut Krittiya
Published: May 2014

Sample survey has been conducted to evaluate satisfaction of residents living in prefabricated concrete buildings (dormitories, detached houses, and townhouses) in Thailand. Nine criteria have been determined including moisture protection, noise prevention, safety of structures, thermal prevention, air flow, external appearance, interior, facility, and overall satisfaction. The t-test indicates that the satisfaction score mean between males and females for each criterion is not significantly different. The Levenes test shows that our survey data do not follow homogeneity of variance assumption for ANOVA F-test for most criteria, except for airflows and overall satisfaction criteria. Welch and Brown-Forsythe tests are then used under non-homogeneity of variances. The tests reveal that all criteria show a significant difference among habitats groups, but not for the thermal prevention criterion. Some multiple comparisons also show many pairs of significant mean difference among habitat groups.
A Multi-Period Evacuation Vehicle Routing Problem Model
Authors: Chanta Sunarin , Sangsawang Ornurai
Published: May 2014

In this paper, we proposed an optimization model that addresses the evacuation routing problem for flood disaster when evacuees trying to move from affected areas to safe places using public transportation. A focus is on the situation of evacuating during high water level when special high vehicles are needed. The objective is to minimize the total traveled distance through evacuation periods where a limited number of vehicles is given. We formulated the problem as a mixed integer programming model based on the capacitated vehicle routing problem with multiple evcuation periods where demand changing by the time. The proposed model has been tested on a real-world case study affected by the severe flooding in Thailand, 2011.
The Relationship between Diurnal Temperature Range (DTR) and Rainfall over Northern Thailand
Authors: Beule Lukas , Tantanee Sarintip
Published: May 2014

Since 1950, it has been found that the global diurnal temperature range (DTR), the difference between the minimum temperature (Tmin) and the maximum temperature (Tmax) of daily surface air temperature, has been temporally decreasing in several places all over the world. The aim of this study is to investigate the effect of DTR on the amount of total monthly rainfall (TRF) and the number of rainy days per month (RD), as well as to evaluate the possibility of using DTR as a parameter in the rainfall prediction process. The study area is in northern Thailand, which covers about one third of the total area of the country. The impact of DTR on rainfall over the studied area is evaluated from the relationship between DTR and TRF, as well as DTR and RD, by using long-term meteorological monthly data over 30 years (1978-2007). Besides, the relationships of RD, TRF, and the temperature of mean monthly Tmax and Tmin are also analysed. The significance of the correlation between the two parameters is identified by the coefficient of correlation. The possibility of using DTR is evaluated by estimating the relationships between DTR and a one month-lag time of RD and TRF. It is found that the DTR has a strong statistically significant ( > 99%) negative correlation with TRF and RD, as well as with the one month-lag time of TRF and RD. Therefore, it is possible to consider DTR as a significant parameter for rainfall prediction.
Preparation and Properties of Poly(ether imide) Ultrafiltration Membrane Modified with Polyether Diamine
Authors: Phomdum Pattama , Chinpa Watchanida
Published: May 2014

In this study, the morphologies, the hydrophilicity, and the anti-fouling of poly (ether imide) (PEI) membrane modified with an aqueous solution of polyether diamine predominantly PEO backbone (PEO-diamine) were investigated. A decrease in water contact angle and an increase in water absorption ratio indicated the hydrophilicity of modified membrane. Scanning Electron Microscope (SEM) showed a thinner skin layer of membrane and pores on the membrane surface for modified PEI membrane providing an increment of pure water flux and a reduction of BSA rejection of membrane. Under the protein filtration study, it was found that the flux recovery ratio of modified PEI membrane was higher than that of the unmodified PEI membrane.
Estimation of Missing GPS Precipitable Water Vapor Data by Zenith Wet Delay and Meteorological Data
Authors: Uang-Aree Prawit , Kingpaiboon Sununtha , Khuanmar Kulyakorn
Published: May 2014

This article presents a statistical correlation between GPS precipitable water vapor and meteorological data, i.e., surface temperature, air pressure, relative humidity, dew point temperature, and water vapor pressure by using linear regression. The data, recorded over a 4-year period, was used as an estimation of missing GPS precipitable water vapor data from discontinuous recordings. A multiple linear regression equation showed a correlation among zenith wet delay (ZWD), water vapor pressure (e) and surface temperature (T) was ZWD(e,T) = 17.4952e-0.8281T-93.164, with a coefficient of determination (R2) of 0.725, a mean absolute error of 8.71 mm, a root mean square error of 10.39 mm, and a mean absolute percentage error of 18.63%. The equation obtained can be used to estimate GPS precipitable water vapor data which is missing from recordings due to accident or technological error.
Preparation of Graft Copolymer of Natural Rubber and Polystyrene by Electron Beam Irradiation
Authors: Khamplod Thammarit , Loykulnant Surapich , Kongkaew C. , Prapainainar P.
Published: May 2014

The simultaneous graft copolymerization between natural rubber (NR) and styrene monomer (St) was induced by electron beam irradiation. The grafted polystyrene in graft copolymer was characterized by Fourier Transform Infrared Spectroscopy (FT-IR). This research investigated the influence of three factors (radiation dose, type of emulsifier and adding of sensitizer; normal butyl acrylate (n-BA)). It was found that the appropriated emulsifier was ammonium laurate which lead to higher monomer conversion and grafting efficiency. The adding of n-BA could notably enhance monomer conversion and crosslink density. Moreover increasing radiation dose, the monomer conversion and crosslink density increased. This technique was a cleaner and faster technology suitable for grafting application.
Analytical Model for Effect of Polymer Composite Membrane Properties on Direct Methanol Fuel Cell Performance
Authors: Apichaya Theampetch , Prapainainar Paweena , Prapainainar Chaiwat
Published: May 2014

Abstract. Performance of direct methanol fuel cell (DMFC), using polymer composite membrane, can be directly affected by membrane properties, including permeability, proton conductivity and membrane thickness. In order to obtain high DMFC performance, methanol permeability of the membrane should be low, while keeping high proton conductivity. This may be achieved by modification of incorporating inorganic filler into high proton conducting membrane. In this work, the analytical modeling for DMFC performance prediction was developed to be a guideline for Nafion based membrane improvement. Methanol permeability and proton conductivity were set at 0.30 – 5.60 cm2×S-1 and 0.08 – 0.15 S×cm-1 with the thickness of 25 – 1000 μm. The results show that DMFC performance strongly depends on the methanol permeability especially with thin membrane giving maximum power density of 1034 and 100mW×cm-2 at the permeability of 0.30 and 5.60 cm2×S-1, respectively, with thickness of 45 μm, while with thick membrane the permeability has negligibly effect. However, the proton conductivity mainly affects DMFC performance only with thick membrane as a result of ohmic resistance.
Compressive Strength and Hydration Process of Self Compacting Concrete (SCC) Mixed with Sea Water, Marine Sand and Portland Composite Cement
Authors: Tjaronge M. Wihardi , Irmawaty Rita , Adisasmita Sakti Adji , Amiruddin Arwin , Hartini
Published: May 2014

In order to eliminate the main problems of clean water shortage and fine aggregate in the low land areas and the distant islands, it is purpose to utilized the sea water, marine sand and Portland composite cement to produce the high performance Self-Compacting Concrete (SCC), where Portland composite cement containing of fly ash. The evaluation result on the mix design, workability (slump flow, segregation), mechanical properties (compressive strength-static modulus) and hydration process of SCC were discussed.
Experimental Study on Permeable Asphalt Pavement Used Domato Stone (Quartzite Dolomite) as Course Agregate for Surface Layer of Road Pavement
Authors: Chairuddin Firdaus , Tjaronge M.W. , Ramli Muhammad , Patanduk Johannes
Published: May 2014

This research intended to study the suitability of domato stone (quartzite dolomite) as coarse aggregate and the potential use of liquid Asbuton (BNA liquid) as bituminous binder to produce the porous asphalt. A part of the present study provided the information concerning the rheological properties of BNA liquid. The other part reported the porosity, stability, flow, indirect tensile stress and material loss of porous asphalt.
The Application of BIM in Green Building Energy Saving: Take Helsinki Music Center as an Example
Authors: Jiang Shen , Lei Wang
Published: May 2014

In recent years, Green BIM (building information modeling) is paid much attention and gets widespread concern in construction field, the majority of the projects using green building BIM technology also gained good results to effectively balance between sustainability and economic. This study is based on the innovation practice using BIM technology do energy simulation design in The Helsinki Music Center project. This project Build Green Building Environment through the followings: three-dimensional building information model, Energy Simulation at the Schematic Design Stage, Energy Simulation for Comparison of Design Alternatives, Lifecycle Assessment Analysis. This paper will give you a detail analysis.
The Impact of Different Green Roofs Strategies on the Indoor Thermal Comfort with Special Reference to Cairo-Egypt
Authors: Sheweka Samar Mohamed , Magdy Nourhan
Published: May 2014

In present time, the environmental impact of green buildings on inner and outer climate has becomes more apparent. Green buildings are designed to reduce the overall impact of the built environment on human health and the natural environment. Recently, the popularity of green roof is growing in the context of urban landscaping because of its smaller footprint, aesthetic value, insulation benefits and heat island mitigation impact. Greenery roofs are considered to be a part of new technology that allows the use of alternative vegetation. This paper will explore the potentials of using green roofs as an integral part of the building process to save energy. This paper will introduce the energy crisis and will focus on the current crisis in Egypt and the global UHI effect. It will also identify the impact of vegetation as a sustainable approach for UHI mitigation and energy savings. After addressing green roof types, and their functional, and environmental aspects in general. The paper distills these different types to enhance thermal performance in terms of indoor thermal comfort and energy savings with the integration of PV cells within green roof design. This will be empirically examined by DesignBuilder and EnergyPlus Simulation, to explore the possibilities of improving indoor thermal comfort within the studied types. Then the paper will be concluded by a set of recommendations for buildings within Egypt’s climatic settings.
Effects of Exterior Sun Shades on Heat Transfer by Solar Radiation
Authors: Huang Chih Hong , Tsai Shin Yu
Published: May 2014

Heat transfer in walls, as affected by climatic conditions such as fluctuations in outside air temperature, solar radiation intensity and wind speed as well as wall structures and heat transfer coefficients of materials, becomes a complex and non-steady state. The aim of this paper is to examine the relationship between total whole-day solar radiation and heat absorbed by and released from materials. An reduced scale of experiment was conducted using reduced scale precast concrete slabs and focusing on the effect of heat transfer involving solar radiation, building materials and shading rate. The results show that even though the sun shadings would stem partly the solar radiation into the wall, yet they obstruct in the mean time the release of the heat, which absorbed hours ago. That leads to a temperature raise and uncomfort to the interiors.
Green Attributes Affecting Investment Returns for Green Office Buildings
Authors: Isa Mona , Sipan Ibrahim , Ghazali Megat Mohamed , Hwa Ting Kien , Jibril Jibril D.
Published: May 2014

Green real estate investment paradigm brings a new investment option to property investors. The green office buildings are gradually replacing the conventional buildings due to the fact that green office building provides better return such as high market value and rental value, high occupancy rate and cost savings. Energy and water efficiency, indoor environmental quality, sustainable site planning and management, materials and resources and innovation are prerequisite green criteria that determine the level of greenness which distinguish it from a non-green office building. This paper discusses the green attributes in office building and its enhancement to return on investment.
The Effects of Different Depth of Floor towards Internal Daylighting and Rules of Thumb for Office Room
Authors: Sadin Muhamad Fadle Mohamad Abu , Ibrahim Nik Lukman Nik , Sopian Kamaruzzaman , Salleh Elias Ilias
Published: May 2014

Rules of thumb in daylighting have been expressed in a variety of modes in architectural. It can be divided into categories based on the parameters which constitute them. One of the categories is floor depth. This paper presents the impact of different floor depth on daylighting performance of the simulated office room using 1 meter shading device. Several parameters such as shading device, ceiling height, and material reflectance have been appointed. Overcast sky was chosen as tropical-compatible sky types. Models then were simulated and analyzed using an application of IES_VE software called RADIANCE. Existing daylighting rules of thumb has been modified and thus create new formula for Kuala Lumpur sky based on the smallest academic office room in public university.
Analysis of the Grain Refinement Mechanism for Commercial Pure Titanium by ECAP and SMAT
Authors: He Xiao Mei , Zhu Shan Shan , Zhang Cong Hui
Published: May 2014

Equal Channel Angular Pressing (ECAP) and Surface Mechanical Attrition (SMAT) are the two Severe Plastic Deformation (SPD) processes that have been used to process ultrafine grained (UFG) materials. These two kinds of processes have been used to refine the grain size of coarse-grained commercial pure titanium (CP-Ti). The development of microstructure during equal channel angular pressing (ECAP) and surface mechanical attrition (SMAT) of commercial pure titanium (CP-Ti) is investigated to establish the mechanisms of grain refinement. Based on the various experimental results and analysis, it has been found that the high-strain-rate and many direction loading is conducive to the formation of nanograins and also the grains with less than 100 nm cannot be obtained by the single equal channel angular pressing (ECAP).
Corrosion Behavior of 13Cr Steel in Different Temperature
Authors: Qiu Zhi Chao , Liu Xiang , Zhang Na
Published: May 2014

Corrosion experiments were applied for 13Cr steel. Through the experiments, the corrosion rate of 13Cr steel in different temperature was tested. The corrosion rate of 13Cr steel was increased with the increase of temperature. Moreover X-ray diffraction analysis and scanning electron microscope analysis were applied to understand the corrosion behavior of 13Cr in micro-scale.
Microstructure and Properties of AZ31B Magnesium-LY12 Aluminum Alloys Diffusion-Bonded Joint
Authors: Du Shuang Ming , Qin Qian
Published: May 2014

In this paper, AZ31B magnesium alloy/LY12 aluminum alloy were bonded together with copper foil as interlayer by vaeuum diffusion bonding technology at different temperature for holding time 60 min and pressure 2.5MPa. Analysis the microstructure of the joint under the condition of 450°C,and the effects of heating temperature on the shear thrength , microhardness and the width of the interface zone were studied. The results showed that under the condition of 450°C in holding time 60 min and pressure 2.5MPa, the microstructure at interface zone of diffusion brazing joint includes α-Mg solid solution, Mg2Cu, Cu2Mg, γ-Cu solid solution, CuAl, CuAl2 and β-Al solid solution. The width of the interface increases with brazing temperature increasing, and the microhardness gradient of interface zone in the side of aluminum alloy is much higher than that in magnesium alloy side. As the welding temperature increases, the shear strength shows an increasing trend at first and then decreases. When the welding process is 460°C keeping for 60 min, welding pressure is 2.5Mpa, the highest shearing strength of the joint can reach 35 MPa.
Study on the Effect of Streambed Substrate on Invertebrate Diversity
Authors: Luo Zhi Wen , Wu Wen Yan , Le Kun
Published: May 2014

Invertebrates are important components of stream ecosystems. A field experiment was conducted to study the effects of substrate particle size, shape and roughness on the composition and biodiversity of invertebrates. The results show that the particle sizes, porosity,and interstial dimensions of the substrate affect the invertebrate community,while the shape and surface roughness of the substrate do not strongly affect the benthos composition and density. The invertebrate composition in the gravel is stable. The density and species richness in the gravels, leaf humus and are much higher than those in the black silt and sands.
Assessment and Characteristics of Heavy Metal Contaminated Soil in the Vicinity of a Zinc Mine Dump Heaps
Authors: Wang Hong , Li Hai Bo , Lv Xue Dong , Wang Peng Fei , Ma Ji Fu
Published: May 2014

Heavy metal contamination of soils is a widespread and serious enviroment problem in the process of exploitation and utilization of lead-zinc mine. In this study, the distribution, pollution index of lead, cadmium, zinc and copper of the soils near an abandoned zinc mine dump heaps were investigated. The results showed concentrations of Pb, Cd, Zn and Cu in smelting slags averaged at 11950mg/kg, 92mg/kg, 8878mg/kg, and 2129mg/kg respectively, whereas concentrations of heavy metal in adjacent soils exceed the maximum of soil environment. Pb and Cd are main pollutant. All the samples were heavy pollution by the assessment of single-factor pollution index and integrative pollution index. Hheavy metals next to the smelting slags mainly existed in the surface soil (0-20cm). Heavy metasl had lower ability of transforing downwards. The distribution characteristics of heavy metals in farmland was probably relateded to plowing processing, mixing fresh soil and the change of soil pH.
Erosion Experiment of Self-Excited Oscillation Pulsed Jet
Authors: Tang Chuan Lin , Pei Jie , Hu Dong , He Xiao Ting
Published: May 2014

In order to improve the erosion effect of jet under submergence condition, experimental studies of erosion generated from the self-excited pulsed jet was carried out by using developed self-excited oscillation nozzle. The erosion volume and depth of pulsed jet were measured and taking mortar block as an erosion part. The results were that the standoff has significant influence on erosion effect. The erosion volume firstly decreases with increases in cavity length and then increases to a peak value. Erosion volume of pulsed jet is significantly higher than that of continuous jet, the erosion depth of two jet has slight difference.
Analysis of Relaxation and Relaxation Training on Sprint Performance Impact
Authors: Wang Pin
Published: May 2014

The sprint is an extreme speedy sport of high strength lack of oxygen metabolism. While athletes are improving sprint speed, they often ignore the importance of relaxing, which is one of the factors to enhance their performance. This article, from the perspective of exercise physiology, the principle of energy metabolism and muscle area, describes the influence of relaxation and relaxation training on sprint performance. At the same time, it expresses individual opinion on how athletes achieve relaxation in the state and the training methods and so on, for reference.
Stiffness Improvement of Stamping Die by Means of Topology Optimization
Authors: Hamasaki Hiroshi , Nakazono Masayoshi , Hino Ryutaro , Yoshida Fusahito , Manabe Hideki , Kondo Hiroki , Toropov Vassili V.
Published: May 2014

Stiffness improvement of stamping die without weight increase 780MPa grade high strength steel sheet was achieved by using Finite Element (FE) simulation combined with topology optimization. In the first step of the procedure, FE simulation of a stamping process was conducted in order to evaluate the contact force on a die surface at the end of stamping. Subsequently, topology optimization was carried out subject to the prescribed weight constraint, in which the stiffest die structure for the given force and displacement boundary conditions was obtained. Maximum displacements during stamping between thus optimized die and the one designed by the experienced engineer were compared. It was found that the optimized die showed less deformation than the other even if the total weights of both dies were almost the same.
Influence of Dendritic Morphology on the Calculation of Macrosegregation in Steel Ingot
Authors: Li Jun , Wu Meng Huai , Ludwig Andreas , Kharicha Abdellah , Schumacher Peter
Published: May 2014

The simulation of macrosegregation in a 2.45-ton steel ingot with the three-phase mixed columnar-equiaxed model was presented previously. The results showed an overestimation of the intensity of bottom negative segregation. The reason is due to the assumed globular morphology for the equiaxed crystal. Therefore, in this paper a simple approach is suggested to treat the dendritic morphology of equiaxed crystals. Three aspects are improved: the drag force between the moving equiaxed crystals and the surrounding melt, the mechanism of the columnar-to-equiaxed transition, the packing limit of the equiaxed crystals. The modified model is used to calculate the macrosegregation of the same ingot. It is found that the modified model predicts less severe negative segregation in the bottom equiaxed zone than the previous globular equiaxed model does, i.e. it agrees better to the experiment. The model considering simplified-dendritic morphology improves the calculation accuracy.