bluuebunny/crossref_metadata_2025 huggingface dataset:
Load Bearing Behavior of UHPFRC Beams Reinforced with High Grade Steel
Authors: Randl Norbert , Mészöly Tamás
Published: October 2014

In the frame of a research project funded by the Austrian Research Foundation (FFG) a series of 10 UHPC beams with an I-shaped cross-section and a full length of 3.5 m was produced and subjected to four-point bending and shear loading respectively until failure. The amount of longitudinal reinforcement as well as the fiber content was varied. The tensile strength of the longitudinal reinforcement was 800 to 1100 MPa. Several circular shaped openings were foreseen in order to facilitate potential installation crossings. The cross-section was optimized for load bearing capacity and ductility. Special attention was paid on the crack development and SLS criteria as well as the ductility after reaching ultimate load level.
The full constitutive law of the applied UHPFRC mixture was derived from compression tests, uniaxial tension tests and several small scale four-point bending tests. On the basis of the derived constitutive law in tension, the UHPFRC was classified as “type 2 – low strain hardening” fiber reinforced concrete.
Influence of Aspect Ratio of Hooked End Steel Fiber on Flexural Behavior of Fiber Reinforced Concrete
Authors: Ni Kun , Shi Yun Xing , Ding Yi Ning , Zhang Yan Gang , Shi Jing Bin , Liu Wei
Published: October 2014

The aim of present work is to further investigate the flexural behavior of FRC with four types of hooked end steel fibers. The flexural toughness of FRC beams was tested under a three point bending system, and the data of experiments were analyzed according to the standard JGJ/T221-2010 and RILEM recommendation. The results showed equal dosage of different aspect ratio fibers didn’t result in the same flexural toughness. It was found that nominal ultimate flexural strength () and equivalent flexural strength () of beams increased as aspect ratio of the steel fiber was increased. However, the highest equivalent flexural strength () was obtained by the fiber with aspect ratio of 67.
Probabilistic Estimation of Airtightness Performance of Concrete Vacuum Tube Structures
Authors: Park Joo Nam , Cho Jeong Min , Park Hyung Jun
Published: October 2014

A probabilistic analysis is performed where the pressure change inside a concrete tube is probabilistically estimated considering the uncertainties inherent in the material, system discontinuity and outside pressure. A set of uncertain variables that are related to the equivalent system air permeability and the atmospheric pressure are defined as random variables with specific distributions. The pressure change inside a concrete tube is then probabilistically described using both analytical and simulation approaches. The analysis confirms the need of probabilistic approach for evaluation of the airtightness performance of vacuum tube structures.
Research on Strength Inspecting Technique for High Strength Concrete by Rebound Method and Ultrasonic-Rebound Combined Method
Authors: Zhang Rong Cheng
Published: October 2014

This paper in detail introduces basic principles and technical development process of inspecting the material strength of high performance concrete by rebound method and Ultrasonic-rebound combined method. The strength-inspected curves of high performance concrete in Beijing region are given by using above mentioned two methods. Existing problem that 2.207J rebound device could not be used to inspect the strength of concert at grades 50MPa and above, has been solved. This article is one of the research results in “ Technical specification for strength testing of high strength concrete ”JGJ/T 294-2013 during compiling, which can be used in inspecting the material strength of high strength concrete in Beijing region.
Study on the Mechanical Properties of High Performance Hybrid Fiber Reinforced Cementitious Composite (HFRCC) under Impact Loading
Authors: Yang Hui Xian , Li Jing , Huang Yan Sheng
Published: October 2014

The dynamic material properties of high performance hybrid fiber reinforced cementitious composites (HFRCC) with various volumetric fractions of steel and polyvinyl alcohol (PVA) fibers were studied by the Split Hopkinson Press Bar (SHPB) test. The results show that HFRCC with higher volumetric fraction of steel fibers are more sensitive to stain rate and the dynamic compressive strength increase more prominently with the strain rate increasing, but peak strain shows the opposite trend. The PVA fibers increase the ductility of HFRCC more effectively than steel fibers. Compared to PVA fiber reinforced cementitious composites (FRCC), HFRCC present better dynamic material properties under impact loading.
A Brief Review on TiO2 Coating Deposited by Cold Spraying
Authors: Shen Yan Fang , Song Wan , Cui Xin Yu , Xiong Tian Ying
Published: October 2014

TiO2 is a promising photocatalyst with great potential for environment purification and energy conversion. TiO2 coatings have more advantages over powders in practical use. Cold spraying is an ideal technique to fabricate TiO2 coatings because of its low heat input compared with thermal sparing which may induce undesirable phase transformation from anatase to rutile. The paper will give a short introduction on recent development of TiO2 coatings by cold spraying. Then, the factors affecting the quality of coating should be analyzed. And finally, the bonding mechanism of cold sprayed TiO2 coating on metal substrates will also be proposed.
Protective Agent Free Eco-Synthesis of Silver Nanowire via Needle-Shaped Silver Acetate Precursor
Authors: Sugawara Kenta , Hayashi Yamato , Fukushima Jun , Takizawa Hirotsugu
Published: October 2014

We developed new synthetic method of silver nanowire by reducing silver acetate precursor. Silver acetate could be easily synthesized by ultrasound irradiation to the mixture of non-toxic starting materials, only ethanol and silver (I) oxide. All of reaction was performed in relatively low temperature and it does not need any protective agents. The precursors had high aspect ratio needle-shaped morphology. They decomposed easily by heating up to 300 °C and then produce only silver without any residues. This process is expected to be new synthetic method of silver nanowire that doesn’t require any protective agents and emit much waste.
Study on Recycling of Electric Arc Furnace Dust
Authors: Bui Anh Hoa , Vu Thanh Lam , Nguyen Van Thanh
Published: October 2014

Electric arc furnace steelmakers are finding that dealing with the dust is increasingly difficult. Stockpiling this dust on site, recycling or sending offsite for disposal all entail considerable difficulties and costs. Succesful recycle of the valuable metals (iron, zinc) present in electric arc furnace dust will result in resource conservation while simultanuously reducing the disposal problem. In this research, carbothermic reduction of electric arc furnace dust using coke has been performed to observe the reduction ability and volatilization rate of zinc. Several properties of the dust were determined using chemical analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), etc. It was found that the dust contained 24 %mass of iron, 14 %mass of zinc which stayed in oxide form. Experimental results shown that rates of the volatilization zinc in the dust were high, e.g. 96.45% at 1100°C. The activation energy of the reduction was calculated to be 210.63 kJ/mol in temperature range of 900 to 1100°C. Futher study on effective collection of iron and volatile zinc oxide must be carried out to obtain a suitble procedure of recycle of the electric arc furnace dust.
Preparation of Drug Loaded Polyurethane Thin Layer on the Silicone Tube by Electrospinning Technique for Stent Application
Authors: Shin Dong Geun , Lee Y.J. , Kim Y. , Kwon W.T. , Kim S.R. , Riu Doh Hyung
Published: October 2014

Drug loaded polyurethane (PU) thin layer was prepared on the silicone tube by electrospinning technique. Microstructure of the PU layer was varied from nanoporous web to dense coating depending on the polymer solution concentration and the amount of drug loaded. It can be easily adjusted the coating thickness and porosity accurately and controlled the drug loading and releasing properties. However, adhesive strength between PU layer and silicone tube was very weak and easily broken away and white turbidity also another important problem. So, surface of silicone tube was atmospheric-pressure plasma (APP) treated for improving the adhesive and removing white turbidity phenomenon.
Self-Cleaning TiO2/SiO2 Thin Film Prepared by a Simple Sol-Gel Method
Authors: Liu Wen Xiu , Xu Jun Na , Zhang Jun , Liu Xue Mei , Cao Wen Bin
Published: October 2014

TiO2 thin films were prepared on SiO2-coated glass substrates using sols deriving from high concentration titanyl sulfate solution by the spin-coating technique. The calcined films were characterized by X-ray diffraction, UV-Vis spectroscopy, scanning electron microscopy. The film exhibited high transmittance in the visible light region and high absorption in the ultraviolet region. The contact angle of SiO2/TiO2 decreased to below 5° under 30 min of UV light irradiation and can sustain for 1 weeks.
Development of a Carbon Nanotube Paste for the High-Performance Field Emitters by Using the Simple Ball-Milling Method
Authors: Ahn Seung Joon , Kim Jae Woo , Ahn Seong Joon , Han Dong Hwan , Kim Ho Seob , Song Yoon Ho
Published: October 2014

The carbon nanotube (CNT) paste was fabricated by a very simple method where the paste composition could be controlled precisely. We have fabricated several types of field emitters from the CNT paste mixture consisting of the thin multi-walled CNT, the nanosized inorganic fillers, the ethyl cellulose binder and the terpineol solvent. The field emission current density was found to be more than 100 mA/cm2 at a field of 2.5 V/μm for the planar-type CNT emitter and ~5 A/cm2 for the tip-type emitter, respectively. We also optimized the filler material in the paste to make the emitter reliable under the high-temperature conditions. The developed CNT paste had good reproducibility and the field emitters made of the paste showed excellent characteristics as the electron sources for the various applications.
Application of Low Voltage in Quantitative Analysis by Energy Dispersive Spectrum (EDS)
Authors: Wu Wei , Liu Zi Wei , Lin Chu Cheng , Hua Jia Jie , Zeng Yi
Published: October 2014

By scanning electron microscope equipped (SEM) with energy dispersive spectroscopy (EDS) accessory, analysis can be performed simultaneously in the samples’ micromorphology observation and micro composition test. At present, EDS analysis is generally used high acceleration voltage, and the diffusion range of the incident electrons in sample is 3-5 μm. Therefore, the minimum area for the component analysis is several micrometers. The diffusion range of incident electrons can be reduced by reducing the acceleration voltage, and as a result, the nanometer-scale composition analysis in SEM can be achieved. Based on Monte Carlo simulation method, the incident electrons practical effect range can be estimated. While the acceleration voltage is reduced, X-ray yield rates of the B, C, N, O and other light elements will be increased. Thereby the measuring precision of EDS quantitative analysis of light elements can be improved.
Surface Modification of CaCO3 Micro/Nanofillers by Pimelic Acid: Consequences on Crystallization Behaviors of Polypropylene Composites
Authors: Qi Fang Wei , Luo Xue Gang , Lin Xiao Yan
Published: October 2014

In present study, two kinds of CaCO3 with micro-sized and nanometer-sized particles were treated by pimelic acid (PA) with different proportion. Then the treated particles (the total content of micro-sized and nanometer-sized CaCO3 particles was 10 wt%) were mixed with polypropylene (PP) to prepare CaCO3/PP composites by melting blending. The crystallization behavior and morphology of composites were studied by wide-angle-X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized microscope (PLM), respectively. Compared with PP and other samples, the content of β-crystal in the composite NCP2 where the ratio of nanoand micro particles was 2:8 (NCP2), reached the highest values. The growth speed of crystals in PP matrix was much quicker, leading to the larger spherulites than the NCP2 and NCP8. The time of complete nucleation for NCP8 was lower than PP, but higher than NCP2.
Crack-Healing Function of Nano-Ni/(ZrO2+Al2O3) Hybrid Materials
Authors: Pham Hai Vu , Nanko Makoto
Published: October 2014

Ni/(ZrO2+Al2O3) nanocomposites have excellent mechanical properties, as well as self-healing function. The powder preparation was conducted by drying slurry consisting of distilled water, Al2O3, 3 mol % Y2O3 doped ZrO2 and nickel nitrate. After reduction at 600°C in a stream of Ar-1% H2, the powder mixture was consolidated by pulsed electric current sintering (PECS) at 1300°C for 5 min under 50 MPa. Surface cracks were generated by Vickers indentation on the polished surface of the test samples. Ni/(YZ+Al2O3) shows 1200 MPa in bending strength and 6.1 MPa m1/2 in facture toughness. Crack-healing and oxidation tests were conducted at temperature ranging from 1100 to 1300°C in air. As a result, crack-disappearance occurred slightly faster than that of Ni/Al2O3.
Estimation of UV Dose for the Effective Degradation of Pharmaceuticals in Secondary Treated Wastewater
Authors: Kim Il Ho , Kim Ji Sung , Tanaka Hiroaki
Published: October 2014

In the study, UV alone and UV/H2O2 treatment experiments were performed using secondary treated wastewater spiked with 30 pharmaceuticals. UV intensity of 0.384 mW/cm2 was used for calculating UV dose introduced to tested water during each treatment. UV doses of 38 mJ/cm2 to 5,644 mJ/cm2 were needed for 90% degradation of the 30 pharmaceuticals in secondary effluent. These UV doses are much higher than those required for typical disinfection (40 mJ/cm2 ~ 140 mJ/cm2). It can be known that considerable UV dose will be required for the effective removal of pharmaceuticals in secondary effluent. All the pharmaceuticals except 7 pharmaceuticals including cyclophosphamide and 2-QCA (727 mJ/cm2 ~ 1,695 mJ/cm2) were degraded by more than 90% under UV dose of 691 mJ/cm2 (contact time : 30 min) during UV/H2O2 treatment. As a consequence, it is considered that UV/H2O2 treatment can contribute to the reduction of energy consumption for the effective pharmaceuticals removal as well as the improvement of the photodegradation rates for the investigated pharmaceuticals.
Preparation of Fe/N Co-Doped TiO2 Powders by Mild Hydrothermal Method
Authors: Xu Jun Na , Liu Wen Xiu , Sun Peng , Guan Ming , Cao Wen Bin
Published: October 2014

Yellow colored anatase Fe/N co-doped TiO2 powders have been successfully synthesized by one step hydrothermal method at a lower temperature. The grain size was about 10 nm and the specific surface area of the powders ranged from 160 to 166 m2/g. The light absorption of Fe/N co-doped TiO2 powders was enhanced in the visible light region of 400~500 nm and a new absorption peak at about 470 nm appeared when the Fe/Ti ratio exceeded 0.5%. The visible light photoactivity of Fe/N co-doped TiO2 powders has been greatly improved than that of un-doped TiO2 powders under visible light irradiation.
Catalytic Activities of α, β, γ - Bismuth Molybdates for Selective Oxidation of Propylene to Arcrolein
Authors: Thang Le Minh , van Driessche Isabel
Published: October 2014

Since the order of activity of α, β, γ - bismuth molybdates has been debated in the literature, this article aims to clarify this by testing catalytic activity of three phases prepared by different methods, calcined at different temperatures. The impurity by other phases is one reason differentiate catalytic activity of these catalysts. It can be said that the order of three pure phases is: β slightly > α > γ.Keywords: bismuth molybdates, propylene, catalysts, selective oxidation
Synthesis of Diglycerol Ester as Insulating Oil for Offshore Wind Turbine Transformer
Authors: Gwon Mi Seong , Kwak Bo Rae , Park Dae Won , Lee Man Sig
Published: October 2014

Recently the wind power was customized to offshore due to more abundant wind than onshore. Transformer is a multi-terminal electrical device that transforms electrical energy and is filled with insulating oil. This study presents the feasibility of diglycerol ester as insulating oil for offshore wind turbine transformers. The sulfated zirconia (SZ) was prepared by the sol-gel method for use on synthesize of diglycerol ester. The diglycerol ester was synthesized with diglycerol and fatty acids over SZ for use on insulating oil of offshore wind turbine transformer. The SZ600 has the highest conversion of fatty acids. The insulation properties of synthesized diglycerol ester over SZ600 shows that the pour point is-50°C and the flash point is 316°C. Therefore, it is suitable for diglycerol ester over SZ600 to be used in offshore wind turbine transformer.
Antibacterial Properties Evaluation of a Novel Polyurethane-Based Root Canal Sealer
Authors: Wang Jian , Zhao Ming Hui , Li Yu Bao , Zuo Yi , Sun Bin , Jiang Jia Xing , Zou Qin , Li Ji Dong
Published: October 2014

Elimination of microorganisms from the root canal system and the prevention of subsequent reinfection are of importance for long-term endodontic treatment. The application of a sealer with antibacterial properties may reduce the reinfection and improve the success rate of the root filling treatment. The aim of this paper is to evaluate the antibacterial properties of a novel root canal sealer based on injectable self-curing polyurethane with silver phosphate (PU/Ag3PO4). The antibacterial abilities were assessed by direct contact test, anti-bacterial adhesion assay and bacteriostatic rate test. The results show that the fabricated PU/Ag3PO4 sealer can completely inhibit the bacterial growth and prevent bacterial adhension effectively. The bacteriostatic rate is 93.6% and 98.1% when the bacteria incubated with PU/Ag3PO4 sealer for 7 and 24h respectively. The strong antibacterial abilities suggest that PU/Ag3PO4 sealer has great application potential in the field of root canal filling.Key words: Root canal sealer, polyurethane, silver phosphate, antibacterial properties, direct contact test
Fluoridation and Mechanical Properties of Hydroxyapatite with Addition of TiF3, Al2O3 and Fe2O3 by Sintering
Authors: Asif Muhammad , Fu Zheng Yi , Khan Shahzad Ahmad , Wang Wei Min , Wang Hao , Wang Yu Cheng , Rehman Sahibzada Shakir , Ma Rui Fang
Published: October 2014

Fluoridated composite Hydroxyapatite biomaterial was prepared by sintering the hydroxyapatite Ca10 (PO4)6. (OH)2[HA] powder with addition of titanium fluoride 30 wt. % -TiF3 and mixture of iron oxide and aluminum oxide [5 wt. %-Al2O3/Fe2O3 ; (5/1)]. The pellets were prepared by conventional sol-gel technique. The as-prepared samples were sintered at various temperatures and the effect of different temperature on grain size and mechanical properties has been investigated. The samples were sintered at various temperatures of 1100-1400 °C. After sintering, the sample’s mechanical properties such as compressive strength, bending strength, Vickers hardness were improved to be 49±0.26-103±0.26 MPa, 19.6±0.20-36.2±0.20 MPa, and 7.97±0.16-12.50±0.16 GPa with their grains size 4.76±0.10-17.63±0.10 μm and bulk densities 1.8944-2.2426 g/cm3.
Eating Speed Controls the Metabolic Syndrome
Authors: Kim Jee Hee , Roh Sang Gyun , Lee Jae Gook
Published: October 2014

Behavioral and nutritional strategies that can help control appetite and energy intake should be developed and tested for their efficacy in body-weight management [1]. Eating slowly is often advised for weight management because slower eating has been hypothesized to allow satiation to register before too much food is consumed. Peripheral biomarkers associated with meal termination include physicochemical measures related to stomach distension and responses of several hormones, including cholecystokinin and glucagon-like peptide 1. It has been proposed that slower rates of ingestion allow more time for these processes to take place, lengthen satiety’s time course, and reduce total energy intake. Speed of eating has long been of interest as a factor potentially contributing to the development of obesity.
Fractal Research of Pore-Structure in Porous Titanium Fibers
Authors: Liu Shi Feng , Tang Huiping , Yang Xin , Zhang Zhao Hui
Published: October 2014

This paper adopted the vacuum sintering technology to prepare titanium fiber porous material with a three-dimensional spatial network fiber backbone and connectivity pore structure. With the help of fractal geometry theory and scanning and digitizing the image, the fractal research of pore-structure in porous titanium fibers is executed and we studied the influence of adopting the box-counting dimension method to calculate the fractal dimension. Additionally, we determined the quantitative relationship between fractal dimension and the porosity of the porous in titanium fiber, while described the physical meaning of the fractal dimension.
Structure and Mechanical Properties of Lotus-Type Porous Copper with a Ti Coating on the Pore Wall by Arc Ion Plating
Authors: Du Hao , Lu Dong Zhu , Nakajima Hideo , Wang Yuan , Yin Li Song , Xiong Tian Ying
Published: October 2014

A Ti coating was deposited on not only surface but also inner surface (pore wall) of a lotus-type porous copper with porosity of 43.3% and pore size of 603.5μm by arc air plating for modification. The structure, microhardness and compressive properties of the porous copper were investigated, and compared to those after annealing under 600°C and 800°C for 6 hours. It is indicated that Ti coating with thickness from 4.6μm to 12.5μm has been deposited on the pore wall for the porous copper successfully. It is found that the HV0.01 increases from 89.32 to 348.19 for the porous copper after the deposition, which is attributed to the higher hardness of the Ti coating. In case of 0.2% yield stress, it keeps almost the same for the porous copper with the deposition of the Ti coating, while increases from 21.22 to 23.79MPa after annealing, which may stem from the improved adhesion of the coating with pore wall by diffusion. It is believed and much possible for metal coating to improve the mechanical properties of lotus-type porous metal.
Thermal Stability of Amorphous Al-Fe-Y Prepared by Mechanical Alloying
Authors: Nguyen Hoang Viet , Oanh Nguyen Thi Hoang , Quynh Pham Ngoc Dieu , Lap Tran Quoc , Kim Ji Soon
Published: October 2014

Al-Fe-Y amorphous alloys of Al84Fe16, Al82Fe18 and Al82Fe16Y2 composition were prepared by mechanical alloying in a planetary ball mill P100. A nearly complete amorphization could be achieved for the Al84Fe16, Al82Fe18 and Al82Fe16Y2 powder alloys after 100h of milling at a rotational speed of 350 rpm in hexane medium. Differential scanning calorimetry (DSC) analyses revealed three-stage crystallization processes for Al82Fe18 and Al82Fe16Y2 alloys and four-stage crystallization processes for Al84Fe16 alloy, respectively. Taking into account the DSC data, the thermal stability increased in the order of Al84Fe16, Al82Fe18, and Al82Fe16Y2 composition. The Al82Fe16Y2 alloy exhibited a relatively better thermal stability than the other two alloys.
Study on Microstructure and Fracture Morphology of 2205 Duplex Stainless Steel Resistance Spot Welds
Authors: Chang Xu , Liu Jie , Fan Guang Wei , Tao Ren Long
Published: October 2014

Fracture morphologies, microstructures and mechanical properties of the spot welded joints on 2205 duplex stainless steel (2205DSS) were studied by using three-phase inverter resistance welding machine with the welding currents of 6.4kA, 7.4kA, 9.5kA and 11.6kA, the welding pressures of 0.5MPa, 0.6MPa and 0.7MPa, and the welding time of 200ms. The results show that the macroscopic fracture fashion of 2205DSS spot welding joints are mainly button fracture and joint fracture, and the microstructures and mechanical properties of 2205DSS spot welding joints have the best performance with the welding current of 9.5kA, the welding time of 200ms and the welding pressure of 0.6MPa.
Effect of C Content on the Microstructure and Physical Properties of Fe-36Ni Invar Alloy
Authors: Ha Tae Kwon , Min Seok Hong
Published: October 2014

Thermodynamic equilibrium of Fe-36Ni-base Invar alloy containing C contents from 0.25 to 0.38 weight per cent during solidification has been investigated in this study. From the thermodynamic simulation using ThermoCalc®, it has been revealed that equilibrium phases which can be formed are two kinds of MC-type precipitates, i.e. (Nb, Mo, V)C and MoC, and M2C carbides. The MoC carbide was expected to be formed at relatively lower temperature below 770oC. Microstructure observation revealed the coarse precipitates in the as-cast ingots, which was Mo-rich non-equilibrium phase and could be resolved by the successive heat treatment. With increasing C contents from 0.25 to 0.38 wt.%, tensile strength of Invar alloy increased from 950 to 1100MPa after hot rolling and thermal expansion coefficient showed a trivial increase. Hot-rolled Invar alloy was successfully drawn at room temperature from 6 to 4 mm in diameter, which dramatically decreased thermal expansion coefficient.
Effects of Chromium Content and Impact Load on Microstructures and Properties of High Manganese Steel
Authors: Khanh Pham Mai , Nam Nguyen Duong , Chieu Le Thi , Quyen Hoang Thi Ngoc
Published: October 2014

In this paper, the effects of Cr content and impact load on the microstructure and properties of High Manganese Steel (HMS) were investigated. The results show that the hardness of HMS was increasing when the Cr content increased, but the hardness was not much changing when the Cr contents changed from 2% to 2,5% of weight. Under the impact load, the microstructure and the hardness were changed also. The Cr content effected on the depth of transition layer on surface under the impact load and the twinning occurred during impacting load.
Characterization of Cast Iron Scrap Chips toward β-FeSi2 Thermoelectric Materials
Authors: Laila Assayidatul , Nanko Makoto
Published: October 2014

The upgrade recycling process of cast-iron scrap chips toward β-FeSi2 is regarded as an eco-friendly and cost-effective production process. It is useful for reducing the material cost in fabricating β-FeSi2 by utilizing the waste that is obtained from the manufacturing process of cast-iron components. In this research, β-FeSi2 was successfully obtained from cast iron bscrap chips and showed good thermoelectric performance in Seebeck coefficient and electrical conductivity which is around 70% to almost 100% compared to β-FeSi2 that was prepared from pure Fe and other publications. The thermoelectric power factor was achieved 90% performance compared to other literatures and β-FeSi2 prepared from pure Fe.
Effect of CaO Content on Yb: YAG Disk Laser Weldability of AZ31 Mg Alloy
Authors: Kang Min Jung , Kim Cheol Hee
Published: October 2014

Magnesium alloys have recently attracted increased attention as structural materials owing to their low specific gravity. However, they must typically be casted, formed, melted, and even heated under a protective shielding gas to prevent them from oxidizing and igniting. So-called “ECO-Mg” alloys have recently been developed by adding CaO to conventional Mg alloys. ECO-Mg alloys exhibit higher oxidation resistance during melting and superior castability, even when beryllium is not added or toxic protective gasses such as SF6 are not used. We laser-welded AZ31 Mg alloys with various CaO contents and examined the mechanical properties of the welds. Increasing the CaO content in the AZ31 increased the burning resistance of the ECO-Mg alloys, thereby suppressing plume generation during laser welding; thus the ECO-Mg alloy welds could be fully penetrated faster than conventional Mg alloy welds. The weld strength also increased with increasing CaO content in the AZ31 because the CaO refined the grains.
Graphene Oxide Based Selective VOCs Sensor for Indoor Air Quality Monitoring
Authors: Ahn Ho Sang , Jung Byung Kwon , Park Jae Ro , Joo Jin Chul
Published: October 2014

We suggest new approach to monitor indoor air quality by using selective VOCs sensor specialized to detect formaldehyde, benzene, toluene with distinct sensitivity. One of the major drawbacks in semiconductor type gas sensors is poor selectivity despite of high sensitivity in detection of trace level of gases. Graphene oxide was deposited as a sensing layer on silicon dioxide sensor with platinum bottom electrodes. Thermal treatments under varying temperature, time, and gas, were performed to reduce graphene oxide at a certain amount as desired. Depending on the degree of reduced graphene oxide, obvious difference in functional groups in terms of type and number was observed. Following sensing behavior measurements confirmed that partial reduction of graphene oxide determined the selective gas adsorption to influence the sensing behavior to improve the selective VOCs detection for better indoor air quality.
Low-Temperature Thermocatalytic Degradation of Polyethene Films by Nano-Titanium Dioxide in Water
Authors: Li Ke , Luo Xue Gang , Wang Mian , Qi Fang Wei , Wu Pei , Meng Qiu Feng
Published: October 2014

nanoTiO2 powders were utilized as thermocatalyst for catalytic degradation of polyethylene in water. LDPE/TiO2 composite films were prepared by the method of melt blending. The aging experiments were conducted in ovens under temperatures of 30 °C, 40 °C and 50 °C, respectively. The thermocatalytic degradation behavior towards the composite films was characterized by fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). Results show that both pure LDPE films and LDPE /TiO2 composite films can be degraded even under low temperatures in water. After thermal degradation for 90 days at 50 °C, the composite film with 2wt% nanoTiO2 was oxidized the most acutely: the quantity of branched chains decreased to some extent and lots of small molecules were detected, the decomposition temperature was also reduced by 28.2 °C. Besides, the surface of the films became rougher than that of the film before degradation.
Effect of Lignin and RLDPE Soil Amendments on Water Holding Capacities of Desert
Authors: Meng Qiu Feng , Luo Xue Gang , Lin Xiao Yan , Zhang Si Zhao , Li Ke
Published: October 2014

The influence of recycled low density polyethylene (RLDPE) with different sizes and lignin soil amendments on dry bulk density (BD), water holding capacities (WHC) including saturated soil moisture content (SSMC), and moisture content at wilting point (MCWP) of desert was investigated. Results obtained show that BD decreased with the lignin and RLDPE added in desert. Lignin could significantly improve SSMC of desert soil. SSMC increased with the addition of RLDPE when the weight of RLDPE was less than 20 wt%, while its content was more than 20%, SSMC appeared a sharp decline. As for MCWP (5, 10, 15 and 20 wt%), it showed that the lignin presented dramatically positive effect, while RLDPE with different sizes presented slightly negative effect. Smaller particle sizes of RLDPE showed apparently the impact on soil properties in comparison with larger ones. It is hopeful that both lignin and RLDPE may be potential soil amendments for improving WHC of desert.
Biosorption of Strontium Ions by Low-Cost Sunflower Stem and Leaf
Authors: Ai Lian , Luo Xue Gang , Lin Xiao Yan
Published: October 2014

Low cost agricultural by-products are potential materials for water pollution treatment such as removal of radionuclide. This paper deals with removal of strontium ions from aqueous solution using sunflower stem (SFS) and leaf (SFL). Batch sorption experiments were performed as a function of initial solution pH, adsorbent dosage and initial strontium (II) concentration. The removal efficiency of strontium (II) increased with initial pH and achieved maximum values at a pH range of 4.0-7.0 both for SFS and SFL. The isotherm adsorption data was modeled best by the nonlinear Langmuir-Freundlich equation. The maximum sorption capacity of SFS and SFL were observed to be 17.87 and 22.31 mg/g under optimal conditions, respectively.
Effect of Calcium Compounds on Mechanical Properties of Eco-Friendly Non-Cement Mortar
Authors: Kim Yoo Tack , Park Jun Young
Published: October 2014

Improvement in the mechanical properties of non-cement mortars using ASTM Class C fly ash (FA) containing high amounts of CaO produced from a fluidized bed-type boiler and blast furnace slag (BS) was studied. This type of FA has been used to carbonate non-cement mortar under supercritical conditions for CO2 fixation, because such mortars cannot be recycled and easily reclaimed owing to the presence of high amounts of CaO that may adversely affect their eco-friendliness because of the high volume expansibility of CaO. Because a substantial increase in the compressive strength was observed for the specimen containing 20% FA, two types of Ca compounds—CaO and Ca (OH)2—were added to the BS specimens to investigate the effects of Ca compounds on the mechanical properties of non-cement mortar specimens. Three types of curing methods—room temperature, room temperature with hermetic sealing, and high temperature with hermetic sealing—were used and the specimens were aged for 3, 7, and 28 days. Because both CaO and Ca (OH)2 enhance the compressive strength at the concentration corresponding to that in the FA, it is speculated that the amorphous materials in the BS is destroyed without adding any acid or reagents because of the increase in pH by the Ca compound present in the specimen. An increase in the specimen pH may affect the strength improvement because of ion elution and curing reaction. It is concluded that enhancement in the mechanical property by the addition of 20% FA to BS can be explained from the results obtained by adding Ca compounds.
Enhancement of PEM Fuel Cell Performance by Flow Control
Authors: Duy Vinh Nguyen , Lee Jung Koo , Park Ki Won , Kim Hyung Man
Published: October 2014

Flow-field design affects directly to the PEM fuel cell performance. This study aims to stimulate the under-rib convection by adding sub-channels and by-passes to the conventional-advanced serpentine flow-field to improve the PEM fuel cell performance. The experimental results show that if reacting gases flow in the same direction as the neighboring main channels, the under-rib convection shows a flow from the main channels to the sub-channels makes progress in reducing pressure drop and enhancing uniform gas supply and water diffusion. Alternatively, if in the direction opposite to that of the neighboring main channels, the under-rib convection shows a flow from the inlet side towards the outlet side across the sub-channel as in the conventional serpentine channels. Analyses of the local transport phenomena in the cell suggest that the inlet by-pass supplies the reacting gases uniformly from the entrance into the sub-channels and the outlet by-pass enhances water removal. Novel serpentine flow-field pattern employing sub-channels and by-passes shows uniform current density and temperature distribution by uniformly supplying the reacting gas. Furthermore, performance improvement of around 20% is observed from the experimental performance evaluation. As a result, longer battery life is expected by reducing the mechanical stress of membrane electrode assembly.
Dust Removal Using Electrode-Plates Coated with Activated Carbon
Authors: Jun Taeh Wan , Park Hyun Chul , Ahn Kwang Ho , Sajjad Muhammad , Kim Kwang Soo
Published: October 2014

The main purpose of this research work was to evaluate dust removal efficiencies using electrode plates coated with activated carbon in dust removal chamber. The experiments were performed with electrode-plates coated with activated carbon with black carbon and poly vinyl acetate (PVA) as binding agent. Methanol was added into the coating mixture for lowering the viscosity and at the same time helped the activated carbon (AC) pores not to be blocked by PVA. After coating the electrode surface, it was tested to collect dust in cylindrical chamber with and without power supply. In both case, AC coated electrode showed higher dust removal efficiencies compared to conventional aluminum electrode. Continuous test for PM10 dust control revealed that removal efficiency gradually increased with time passage, and as increasing the distance from inlet, the removal efficiency becomes stable. However, where the interval between electrodes was as short as 1cm, and also at the back of the chamber, “back discharge” effect was observed, and resolved easily by the elevation of humidity level. Volatile organic compounds (VOCs) were controlled successfully with the AC coating material so that it proved both particular and gaseous contaminants can be treated with this AC-coated electrostatic precipitator.*Corresponding author (Kwang Soo Kim): Daehwa-Dong 283, Goyangdae-Ro, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 411-712, Korea / kskim@kict.re.kr / Tel. + 82 31 9100 299 / Fax. +82 31 910 0291
Characteristics of MSWI Ash and its Application to Zeolite Synthesis
Authors: Yoo Yeong Seok , Jo Jun Ho
Published: October 2014

In this study, composition for bottom ash and fly ash of MSWI was analyzed and zeolite was synthesized in order to expand its recycling on high quality and mass consumption. Analysis of ash its characteristics was performed by XRF, XRD, SEM, EDX, TG/DTA. Bottom/fly ash was fired for elimination of unburned carbon at 750°C/12 hr, crushed and synthesized to zeolite in 1, 2, 3, 4, 5 M NaOH solutions under 105°C/24hr by hydrothermal method. Calcite and calcium-silicate compound was mainly contained in bottom ash and CaCl2∙4H2O, Ca (OH)2, NaCl, and calcite and KCl in fly ash. Especially amount of Cl was much contained in fly ash due to Korean food waste characteristics. Bottom ash could synthesize Zeolites in form of sodalite under 3~4 M NaOH and fly ash could synthesize Zeolite A under 1~2 M NaOH. In addition, zeolite synthesized with bottom ash had higher specific surface area and zeolite from fly ash had higher CEC value. Accordingly, ash from MSWI could be recycled for further valuable uses such as non-point pollutant control and/or soil amendment.
Permian rocks of the Cache Creek Group in the Marble Range, Clinton area, British Columbia
Authors: Trettin H P
Published: October 2014

A major outcrop area of Carboniferous to Middle(?) Triassic strata between the f1aser and Thompson Rivers is divisible into three belts. The eastern belt includes the type area of the original lower Cache Creek Group and the' central belt that of upper Cache
Creek Group or Marble Canyon Formation. Strata of the western belt previously assigned by the writer to Division I of the Pavilion Group are restored to the Cache Creek Group as mapped by G.M. Dawson.The study area provides more insight into the stratigraphy and structure of the central belt than
the type area of the Marble Canyon Formation. Five successive lithological units are distinguished. Map-unit I comprises incompletely metamorphosed basalt, underlain by thin units of limestone and chert. Map-unit 2 consists of well-bedded limestone (mostly wackestone) with some marble and dolostone,
ail containing stringers of chert. The poorly exposed map-unit 3 includes ithic arenite, pelite, chert, and thin units of volcanic and carbonate rocks. Map-unit 4 is characterized by massive limestone (mostly wackestone). Map-unit 5 is similar to map-unit 3. Map-units 2 and 4 both contain
fusulinacean faunas of probable early Guadalupian (Wordian) age. Lithology, fossils and structure suggest that map-units 4 and 5 constitute a major thrust sheet that repeats and overrides map??units 2 and 3. If so, the Marble Canyon Formation consists of a single limestone body divisible into two
facies (map-units 2 and 4). The presumed early thrust faulting was followed by the formation of fairly extensive folds in map-units 2 and 4 that are upright or overturned to the northeast. The folds are offset by faults with both vertical and horizontal displacements. A poorly exposed, broad,
northwestward-plunging anticlinorium could be younger than the other folds.
Beach morphology and coastal changes at selected sites, mainland Nova Scotia
Authors: Taylor R B , Wittmann S L , Milne M J , Kober S M
Published: October 2014

In 1981, under the auspices of the federal government Summer Canada Student Employment Program, a network of shoreline survey stations was established at sixteen shore bluff sites and seventeen beaches along the mainland coast of Nova Scotia. ln addition, the
physical characteristics and recent evolution for eight of the beaches were documented and a complete bibliography of previous coastal research along mainland Nova Scotia was compiled. Ali of the shores examined, with the exception of Waterside Beach on Northumberland Strait, exhibit signs of
landward retreat. Rates of shore bluff (till) recession average 1.1 m·a-1 and 0.4 m·a-1 respectively for the Eastern Shore and South Shore of Atlantic Nova Scotia and maximum retreat is 3.3 m·a-1 at exposed headlands. Those beaches where aggregate extraction took place in the 1950s
and 1960s exhibit the greatest signs of retreat and new inlets and large washover channels developed across several of these beaches. Sand beaches along Atlantic Nova Scotia are characterized by mean foreshore slopes of 1.2° to 1 .8° and are backed by a primary dune ridge that reaches 3 .6
to 4. 7 m above mean sea level. In contrast, the pebble-cobble beaches are steeper and characterized by well developed storm swash ridges.
Surficial geology of the Glenlyon map area, Yukon Territory
Authors: Ward B C , Jackson L E
Published: October 2014

Regional Quaternary mapping and stratigraphic and sedimentological studies were undertaken in the Glenlyon map area (NTS 105 L), with stratigraphic studies extending westward into the Carmacks map area (NTS 115-I). Surficial sediments were divided into 23 units,
which range from Early Pleistocene to Holocene.
Evidence exists for at least three glaciations: pre-Reid (Early Pleistocene), Reid (Middle Pleistocene), and McConnell (Late Wisconsinan). Deposits of the Pre-Reid glaciation(s) have a very subdued surface morphology. The Reid Glaciation was less extensive and has better preserved landforms.
Organic beds of Middle Wisconsinan age were identified, and insect macrofossils and pollen indicate forested conditions at 36 000-37 000 BP. Landforms and sediments of the McConnell Glaciation are well preserved, allowing for better reconstruction of conditions than the previous glaciations. The
stratigraphic record suggests that rivers aggraded and an oscillation in the location of the ice front occurred during glacial advance. At glacial maximum, the Selwyn and Cassiar lobes of the Cordilleran Ice Sheet affected the area, with topography strongly controlling ice flow. Because of aridity,
local cirques in the Glenlyon Range supported only small glaciers that did not contribute to the Selwyn Lobe.
At the end of the McConnell Glaciation, the retreat of glaciers was very rapid, with the ice sheet downwasting and stagnating in place. Many small lake basins developed in the Pelly River valley and large thicknesses of sediment were deposited on top of stagnant ice. Sediments were derived from the
active ice margin, stagnant ice, marginal streams, and recently deglaciated valley sides.
A New Method for Motif Mining in Biological Networks
Authors: Xu Yuan , Zhang Qiang , Zhou Changjun
Published: October 2014

Network motifs are overly represented as topological patterns that occur more often in a given network than in random networks, and take on some certain functions in practical biological applications. Existing methods of detecting network motifs have focused on computational efficiency. However, detecting network motifs also presents huge challenges in computational and spatial complexity. In this paper, we provide a new approach for mining network motifs. First, all sub-graphs can be enumerated by adding edges and nodes progressively, using the backtracking method based on the associated matrix. Then, the associated matrix is standardized and the isomorphism sub-graphs are marked uniquely in combination with symmetric ternary, which can simulate the elements (-1,0,1) in the associated matrix. Taking advantage of the combination of the associated matrix and the backtracking method, our method reduces the complexity of enumerating sub-graphs, providing a more efficient solution for motif mining. From the results obtained, our method has shown higher speed and more extensive applicability than other similar methods.
The Marginal Damage Costs of Different Greenhouse Gases: An Application of FUND
Authors: Waldhoff Stephanie , Anthoff David , Rose Steven , Tol Richard S. J.
Published: October 2014

The authors use FUND 3.9 to estimate the social cost of four greenhouse gases—carbon dioxide, methane, nitrous oxide, and sulphur hexafluoride—with sensitivity tests for carbon dioxide fertilization, terrestrial feedbacks, climate sensitivity, discounting, equity weighting, and socioeconomic and emissions assumptions. They also estimate the global damage potential for each gas—the ratio of the social cost of the non-carbon dioxide greenhouse gas to the social cost of carbon dioxide. For all gases, they find the social costs and damage potentials sensitive to alternative assumptions. The global damage potentials are compared to global warming potentials (GWPs), a key metric used to compare gases. The authors find that global damage potentials are higher than GWPs in nearly all sensitivities. This finding suggests that previous papers using GWPs may be underestimating the relative importance of reducing noncarbon dioxide greenhouse gas emissions from a climate damage perspective. Of particular interest is the sensitivity of results to carbon dioxide fertilization, which notably reduces the social cost of carbon dioxide, but only has a small effect on the other gases. As a result, the global damage potentials for methane and nitrous oxide are much higher with carbon dioxide fertilization included, and higher than many previous estimates.
Individual Learning in Construction Projects: Professions and their Approaches
Authors: Wasif Ingeborg , Josephson Per-Erik , Styhre Alexander
Published: October 2014

New materials, use of sophisticated technologies and increased customer demands, in combination with growing competition among construction companies, have led to a high organizational boundaries. The results indicate that personal networks are the most common source of learning for all professions. While clients, architects, and designers also engage in reading and attending courses, site managers and workers are less engaged in these activities. Experimenting and organizing for learning appear to be underutilized strategies by all professions. This leads to the conclusion that attempts to increase learning have to address the differences in learning behaviours of the various groups. Further, focus on experimenting and organizing for learning is a possibility to change the learning behaviour from learning as a consequence of problems to learning for future improvement.degree of specialization. For successful integration of the different professional specialists, there is a need for shared learning between project co-workers. Based on twenty eight interviews in six different Swedish construction projects, this paper illustrates strategies for individual and shared learning, among different actors and across various