bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Ag/ZnO Nanocomposite with Excellent Photocatalytic Performance via a Facile Sol-Gel Method
Authors: Sun Lin , Shao Rong , Tang Lan Qin , Chen Zhi Dong
Published: February 2014

Ag/ZnO nanocomposite photocatalysts with high photocatalytic performance were successfully synthesized via a facile sol-gel method. The prepared Ag/ZnO products were characterized by XRD, SEM, EDS, FT-IR, BET surface area, TG and DSC. Photodegradation experiments of the samples were carried out by choosing Methylene Blue (MB) as a model target under UV irradiation with homemade photocatalytic apparatus. Among these products, when the molar ratio of Ag to ZnO was fixed at 0.07 and the calcination temperature was around 450 °C, the obtained samples exhibited the highest photocatalytic activity.
Preparation and Characterization of Micron-Sized Elastic Microspheres as a Novel Profile Control and Flooding Agent
Authors: Yao Chuan Jin , Lei Guang Lun
Published: February 2014

A series of micron-sized elastic microspheres were optimally prepared through inverse suspension polymerization of acrylamide (AM) and N, N’-methylene bisacrylamide (MBA) in oil phase when [Span80 & Tween80] and ammonium persulfate (APS) were used to be dispersion stabilizer and initiator, respectively. Their profile control and flooding performance in mid-high permeability sand pack models were characterized in laboratory. The results show that the conversion rate is high, and the coagulum is low when the mass ratio of Span80 to Tween80 is 3:1. The particle size of the elastic microspheres can be controlled by varying the amount of dispersion stabilizer. The micron-sized elastic microspheres can plug sand pack effectively and selectively. The ultimate plugging rate is more than 90% and the ability of profile improvement is up to 70%. The results indicate that the micron-sized elastic microspheres have better profile control and oil flooding performance in the heterogeneous mid-high permeability reservoirs.
Development of Epoxy Composite Filled with Micro Tungsten Disulphide Particles and its Mechanical Properties
Authors: Sidhu J.S. , Lathkar G.S. , Sharma S.B.
Published: February 2014

The aim of this research article is to discuss the mechanical performance of WS2-Epoxy composite with varying % vol.of WS2. Studies were carried out with epoxy (ARL136+ AH-126) composite system consisting of Tungsten disulphide (WS2) as filler. The samples tested consist of bisphenol-A based epoxy liquid resin and Lapox AH-126 hardener with varying tungsten disulphide (WS2). Appropriately cured samples gave excellent mechanical properties. Results showed that the tensile strength of the composites increased with increase in filler content for the range of filler contents (2.5-4 % vol.) and decreased with increase in the filler contents 5% vol. onwards. The result indicated that at 3% of filler concentration the tensile strength obtained is good with moderate density and hardness.
Preparation of Phosphorus Modified HZSM-5 Zeolite Catalysts and their Catalytic Performances of Methanol to Olefins
Authors: Tian Shu Xun , Ji Sheng Fu , Sun Qi
Published: February 2014

To improve the selectivity of light olefins, Phosphorous modified ZSM-5 zeolites catalysts with different phosphorous content were prepared by impregnation and were used in the conversion of methanol to olefins. The properties of acidity and microporous structure of the phosphorous modified ZSM-5 zeolites were investigated by XRD, N2-adsorption and desorption, and NH3-TPD. The highest propylene yield (50.82%) was observed over the H-ZSM-5 modified with the phosphorus content at 9% (weight percent). The selectivity of propylene depended strongly on the phosphorus content in the zeolites; The enhancement of propylene selectivity with increasing phosphorous content was attributed to reduction of strong acid sites on the H-ZSM-5. Modification of the ZSM-5 zeolites with phosphorous also changes the microporous structure.
Affection of Post-Nitrogen-Doping of TiO2 Nanoparticle Film Photo-Anode on Performance of Dye-Sensitized Solar Cells
Authors: Zhou Hong Quan , Zou Xiao Ping , Yang Gang Qiang , Teng Gong Qing , Huang Zong Bo , Zhang Bao Li
Published: February 2014

A nitrogen-doped titania nanoparticle film on an ITO substrate was successfully obtained by gas phase method. Such a nitrogen-doped titania nanoparticle film on an ITO substrate shows efficient at the responsivity under the visible light exposure. TiO2 photo-anode with N-doped was fabricated using nanocrystalline pastes and their N719-sensitization led to a short-circuit photocurrent density of 3.95 mA/cm2 and a solar energy conversion efficiency of 1.72% under air-mass 1.5 global and illumination with the intensity of 100 mW/cm2 (AM 1.5G, 100 mW/cm2).
Preparation, Characterization and Catalytic Activity of Highly Dispersed Gold Catalyst
Authors: Liu Chun Xiu , Jia Mei Lin , Bao Yu Hong , Wang Jiang , Sagala Sagala , Zhao Ri Ge Tu
Published: February 2014

Highly dispersed supported gold catalysts have been prepared by solution reduction method using L-lysine as protection agents, and their catalytic activity was evaluated by the liquid phase catalytic oxidation reaction of glucose to gluconic acid. The results suggested that the Au/ZrO2 catalyst, exhibited high activity for the selective oxidation of glucose. At the reaction temperature of 323K, reaction time of 1h, with the NaCO3-NaHCO3 as buffer solution, the yield of gluconic acid was 100%.
A New Route for the Synthesis of Pure Bi4(SiO4)3 Crystals by Glass Melt-Cooling Method
Authors: Gao Dang Ni , Li Z.J. , Guo H.W. , Wang X.F.
Published: February 2014

Pure eulytite Bi4(SiO4)3 crystals were prepared by high temperature melt cooling method using Bi2O3 and SiO2 as starting materials. In this study, the properties of the samples were characterized by thermo gravimetric (TG),differential scanning calorimeter (DSC), field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results showed that eulytite Bi4(SiO4)3 was crystallized when high temperature glass-melt were cooled to 943°C and obvious exothermal peak is shown on the DSC curve; and pure eulytite Bi4(SiO4)3 crystals were synthesized by keeping the processing temperature for 8 hours. Bi4(SiO4)3 grains grew larger and the amount of vacancy increased along with the extension of holding time, while Bi4(SiO4)3 grains still presented a structure of partial ordering. Eulytite Bi4(SiO4)3 prepared through melt-cooling method is of high purity and good stability, and can be applied as starting materials of preparation of Bi4(SiO4)3 thin film and high quality Bi4(SiO4)3 macrocrystal.
Local Materials for Building Houses: Laterite Valorization in Africa
Authors: Abdou Lawane Gana , Messan Adamah , Pantet Anne , Vinai Raffaele , Thomassin Jean Hugues
Published: February 2014

This paper presents the preliminary results of geological and geomechanical studies on the laterite stone exploited at Dano quarry in Burkina Faso. The field work described the geological structure of quarry sites and their environment to determine the rocks alteration and the links between the bedrock and lateritic material. Physic-mechanical properties have been studied for assessing the potentiality of this material for lightweight housing, to be completed with thermal and environmental considerations. Some social and economic evaluations are in progress in order to foster its utilization under local conditions
Biomimetic Nanofiber Scaffolds for Tendon-to-Bone Insertion Repair
Authors: Xie Jing Wei , Ma Bing , Shuler Franklin D.
Published: February 2014

This paper reports the fabrication of nanofiber scaffolds with dual gradients in both mineral content and fiber orientation, which can be used to mimic the composition and collagen fiber organization at native tendon-to-bone insertion site. Such scaffolds show great potential for rotator cuff injury repair.
Fillers in Electrical Papers for Power Transformers
Authors: Calva Primo Alberto , Díaz Aarón Israel , Martínez Gutierrez Hugo
Published: February 2014

The electric papers have a wide variety of uses like in transformers, cables and power capacitors. Each application involves different requirements related to its mechanical and electric properties. The kraft is the dielectric paper most used due its high mechanical resistance and a dielectric strength of around 5 kV/mm that is increased up to 30 kV/mm when is impregnated with mineral oil and typically has a density of 0.7, nevertheless continuous improvements in the design, for example, of power transformers raise the need to improve its electrical properties particularly those related to its relative permittivity. In this article, structural parameters such as distribution and pore size of kraft paper and theoretical analysis for possible addition of nanofillers to improve their dielectric behavior are reported. A possible and better criterion for designing transformers can be the employment of kraft paper nano-inserted with 5 % of TiO2 or BaTiO3 stew in mineral oil and immersed in natural ester liquid.
Cu-Fe/TiO2 Photocatalyst for Deep Desulfurization Process
Authors: Kait Chong Fai , Mohd Eqram B. Abu Kassim , Hayyiratul Fatimah Bt. Mohd Zaid
Published: February 2014

A series of Cu-Fe/TiO2 photocatalysts were prepared and calcined at 400°C and 500°C for 1 h. The photocatalysts were characterized using diffuse reflectance spectroscopy (DR-UV-Vis), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The performance for sulfur removal was carried out using model oil containing 100 ppm S (from dibenzothiophene). The highly dispersed Cu-Fe/TiO2 photocatalyst displayed mainly spherical shaped particles. The best performing photocatalyst was 0.8wt% Cu-Fe loading and calcined at 400°C (0.8wt400) giving 18% sulfur removal. The band gap for 0.8wt400 was lowered to 2.96 eV compared to 3.21 eV for TiO2.
Composition, Surface Structure and Catalytic Properties of Manganese- and Cobalt-Containing Oxide Layers on Titanium
Authors: Vasilyeva M.S. , Rudnev Vladimir S.
Published: February 2014

Silicon-containing oxide layers deposited on titanium using the plasma electrolytic oxidation (PEO) method were modified with manganese and cobalt compound through impregnation followed by annealing. The obtained manganese composites are catalytically active in the process of oxidation of CO at 100 оС, while cobalt-containing structures demonstrate this type of activity at temperatures above 200оС. The composition and surface structure of the obtained systems were investigated by means of X-ray phase and energy dispersive analyses and by high resolution scanning electron microscopy (SEM). Granule-like particles with diameters of a few dozens of nanometers were observed on the surface of oxide-cobalt layers on titanium, whereas the surface of oxide-manganese layers was coated by nano-whiskers of diameters <50 nm and length <1 μm. The presence of manganese-containing nano-whiskers substantially increases the catalyst specific surface, thus facilitating the attainment of higher degree of transformation of initial gaseous substances.
Solar Selective Coatings with Enhanced Thermal and Corrosion Stability: Electrochemically Deposited Black Chrome on Stainless Steel in the Presence of Graphite Encapsulated FeCo Nanoparticles
Authors: Usmani Belal , Harinipriya S. , Kumar Narendra , Gupta Vatsana
Published: February 2014

Black chrome coatings were electrodeposited under galvanostatic conditions on SS substrates. To enhance the thermal stability of the coatings for viable usage in parabolic trough receiver tubes in solar thermal applications beyond 250°C, graphite encapsulated FeCo nanoparticles had been introduced in the electrolyte solution at different weight percentages (0.025, 0.05, 0.1). An increase in the thermal stability of the coatings in the range of 400°C to 600°C is noticed from the STA analysis. The corrosion analysis (Tafel) and cyclic voltammetric studies of the coatings in the presence and absence of nanoparticles have been carried out in 3.5% NaCl solution to understand the stability of the coating in saline environment.
Removal of Alkali in the Red Mud Using CO2 at Ambient Conditions
Authors: Wang Xin Ke , Zhang Yi He , Lv Feng Zhu , Lu Rong Rong
Published: February 2014

A laboratory study was carried out to investigate the ability of neutralization of red mud(RM) using carbon dioxide gas at ambient conditions. It was to evaluate the removal of alkali in the red mud using CO2.The neutralized red mud was characterized by X-ray diffraction(XRD) , FP-640 flame photometer and auto titration method. XRD patterns of red mud revealed that the intensity of sodalite was decreased by using CO2. The pH of red mud was decreased from 11 to 8 . The specific advantages of these processes are that, through adding with hydrochloric acid(HCl) and N-Methyldiethanolamine(MDEA), the removal of alkali in the red mud (Na2O) was decreased from 12.5% to 2.3% by adding with HCl.What is more , the removal ratio of sodium oxide in the red mud by adding with HCl can be received at 80%.
Rotating Electromagnetic System for Railway Track Crack Detection
Authors: Buonsanti Michele , Leonardi Giovanni , Megali Giuseppe , Scoppelliti Francesco
Published: February 2014

The aim of this paper is to provide an alternative methodology, high reliability, in order to monitor, exploiting non-invasive techniques, railway track. In this particular case study, the presence of structural defects is assessed through an innovative system. The proposed approach provides the use of rotating magnetic field. Within this framework, the Eddy Current Techniques (ECTs) have greatly increased their importance for their capacity to detect the magnetic field variations caused by the presence of material alterations. Whilst the researches in this field propose various solutions to the detection of flaws (in surface and subsurface), a still open problem concerns the difficult detection of defects due to the geometrical complexity of the structure and the particular orientations of the crack. Particularly, this contribution proposes an approach based on Finite Element (Finite Element Method, FEM) for the modeling of railway tracks, in order to obtain a rapid and precise assessment about their integrity.
An Innovative Low Cost Solution for Bamboo Trusses with High-Ductility Connections
Authors: Sassu Mauro , Andreini Marco , de Falco Anna , Giresini Linda
Published: February 2014

Innovative solutions of bamboo connections and an application on Polonceau trusses to use for simple constructions are presented. Experimental tests show the performances and the high level of ductility of the proposed technique, joined with simplicity, with low-level of technology and low cost of all used materials. Their applications with sustainable maintenance are suitable in developing countries.
Sandstone Colour Change due to the High Temperature Exposure
Authors: Hager Izabela
Published: February 2014

An analysis of colour change in sandstone under the influence of heat is presented in this paper. The colour change observed is primarily a result of transformations occurring within the material. The colour change may be used to reveal the exposure temperature of stone elements subjected to fire, from which the corresponding damage can be estimated. The paper presents the results of tests carried out on sandstone with a clayey-ferruginous binder. The colour change was investigated using Scion Image v.4.0.3, an image analysis software package (Scion Corporation ©, USA). In the proposed method the digital image is split into three RGB colour components: red, green and blue, which are then presented as a histogram using counts of pixel intensity. The histogram results show colour distributions in unheated sandstone material and in material heated to temperatures ranging from 200 to 1000 °C. The significant colour changes in tested stones was observed and attributed to the presence in sandstone structure of minerals with iron compounds.
Analysis of Seismic Vulnerability - Case of Buildings of High Seismic Hazard
Authors: Guettiche Abdelheq , Mimoune Mostefa
Published: February 2014

Seismic vulnerability of an urban environment is characterized by the ability of buildings and structures to support seismic events (physical vulnerability) and by the ability of people to behave in a consistent and rational face a major event (social vulnerability). Constantine is a city with moderate seismicity but the level of risk is high because of urban concentration and topography of the site. The seismic risk reduction therefore requires assessing the physical vulnerability of its buildings. It is proposed in this paper an analysis of a group of buildings for residential use located west of the city, consisting mainly of relatively high buildings. Following a survey of a portion of the housing stock of this city, a seismic survey method was applied based on "observations" post-seismic. Vulnerability indicators are statistically related to damage through a vulnerability index "IV" to establish curves of damage (or vulnerability). These are used to estimate the level of damage that is likely resulting in damage cards. The goal is to develop an initial database of some of the housing stock in the Constantine city (knowledge of earthquake hazards, construction defects ...) to be used in the estimation of seismic risk and verification of seismic safety of existing buildings. Keywords: Earthquake hazard; Seismic vulnerability; Constantine city; damage.
The Effect of Lubricant on Electrical Connector’s Sliding Performance
Authors: Ye Xiao Lan , Lin Xue Yan
Published: February 2014

Keywords: electrical contact lubricant contact resistance sliding wear Abstract. The contacts must be reliable in the required life time under practical application. Reliability means that the contact resistance can maintain low and stable. Au-plated contact pairs have been used widely for weak current connectors due to its well electrical and anti-corrosion performance. The high price of gold forces manufacturers to reduce the thickness of Au-plated while maintaining well performance. Increasing thin of Au plating causes the microporosity to increase rapidly, which has harmful effect on the performance of connectors. Appropriate lubricant coated on contact pair is a solution to improve the contact property. This paper focuses on sliding contact performance of gold plated contact pairs coupon with 0.25 m thickness and lubricated with water based lubricant named lub-E under damp heat and corrosion environment respectively. The contact pairs are also exposed in damp heat, corrosion environment respectively to evaluate the anti contamination property. The sliding experiment is conducted at frequency of 1Hz, amplitude of 1cm, and load of 0.5N, 1.0N and 1.5N. Contact resistance data is gotten in every sliding cycle at the condition of DC current 100mA and limited voltage 1.0V. Scanning electron microscopy (SEM) is used to observe the sliding track morphology and X-ray energy dispersive spectroscopy (EDS) is used to analyze the element.
Research on Fretting Performance of Silver Conducting Adhesive
Authors: Long Hui Juan , Lin Xue Yan
Published: February 2014

Fretting is one of the main reasons for electric contact failure. Metal contact pairs have long been used, generally with the structure of copper alloy base, Ni interlayer and surface noble metal (such as gold) plating. The influences of plating material and plating thickness on fretting property have been researched deeply, meanwhile, new materials have been tried. In this paper, a new conductive material, silver conducting adhesive is used as the surface coating of contact pair, and a series of tests have been done to study the performance of fretting wear by compare with the coupons without silver conducting adhesive. The results show that the use of silver conductive adhesive improves the fretting property of electrical contacts, especially with small normal force.
Preparation and Application of Polyacrylamide-Grafted Starch Flocculant
Authors: Gao Ming , Xu Zhi Qiang
Published: February 2014

A polyacrylamide-grafted starch (St-g-PAM) flocculant for the coal slurry wastewater, was prepared by using corn starch and acrylamide (AM) as monomers through solution polymerization. The structure of the synthesized St-g-PAM was characterized by FT-IR and TG. The effects of initiator concentration, reaction temperature, and monomer concentration on percentage of grafting and the grafting efficiency were investigated. The results show that the optimal conditions of the polymerization are as follows: the monomer to substrate ratio of 2.5, potassium persulfate of 0.08 g/mL, reaction time of 3h, the reaction temperature of 65°C. The additional dosage of St-g-PAM is varying between 35 and 45 mg/L to obtain good flocculation capability, better flocculation capability with the addition of 30mg/L of FeCl3.
The Corrosion Status of Reinforced Concrete Structure Monitoring by Impact-Echo Method
Authors: Šamárková Kristýna , Chobola Zdeněk , Štefková Daniela
Published: February 2014

The paper deals with the study of dominant frequencies of an Impact-Echo method response signal obtained from a reinforced concrete beam with a steel rod diameter of 8 mm. Tension pulse was produced in axis of the rod at one end and detected in axis at opposite end of rod. Dominant frequencies of the response signal will be the main criterions for the reinforced concrete rebar corrosion progress. The article presents the results of measurements obtained after 12 months controlled degradation in aqueous NaCl solution. The results were compared with measurements of electrical resistance of reinforcing steel by using the Thomson double bridge.
Analysis of Flexible Roller Parameters Influences on Roll Forming of Three-Dimensional Parts
Authors: Zhen Jiao Jiao , Hu Zhi Qing , Feng Zeng Ming , Cao Jun Hui
Published: February 2014

Roll forming is a well known bending process and sheet metals can only be machined into two-dimensional surfaces in traditional roll forming. While with more and more personalized demands, three-dimensional surfaces are widely required. Thus, flexible rollers are used to achieve three-dimensional surfaces. And in order to optimize experimental parameters and to predict experimental results, finite element method (FEM) is developed. In this paper the set-up of flexible roll-forming is described and the process of roll forming is simulated. Then the influences of forming parameters, such as the thickness and the roll velocity, on forming quality of the sheet metal in roll forming process are discussed. The results show that the analysis of flexible roller parameters is practical for the continuous and efficient forming of three-dimensional surfaces.
Multi-Function Device for Creep Testing at Elevated Temperature
Authors: Majcher Andrzej , Węglowski Bohdan , Ocłoń Paweł
Published: February 2014

Searching for quick methods to assess the material usefulness for constructing machine components working at elevated temperatures and variable stresses is accompanied with development of devices facilitating such testing. The paper presents construction of a device, that enables carrying out the standard creep tests (PN-EN ISO 204) and the dedicated tests with the programmed low-cycle loads and the different profiles for temperature and stress changes. The basic parameters of the device are described and the examples of the programmed strength testings are given.
Effect of Hemp Fibre Morphology on the Mechanical Properties of Vegetal Fibre Composite Material
Authors: Ilczyszyn Florent , Cherouat Abel , Montay Guillaume
Published: February 2014

The hemp fibres present specific fibre morphology and a complex non homogeneous cross section which changes in function of the location along the fibre length. Thus the mechanical properties of hemp fibres request a specific characterization method. In this study, firstly, a digital treatment method was developed allowing to consider different geometrical modelling methods: homogeneous or non-homogenous cross section, average global cross section, and cross section measured at the rupture location, including a 3D CAD model reconstruction of the fibre.
Characterization of Nanocrystalline Titania Thin Film Deposited by Spray Pyrolysis Technique
Authors: Luu Thi Lan Anh , Nguyen Duc Hieu , Neto Mateus Manuel , Nguyen Ngoc Trung , Vo Thach Son
Published: February 2014

Nanocrystalline titania (TiO2) thin ﬁlms prepared by spray pyrolysis deposition on to the heated glass in a temperature range of TS = 350 ÷ 450oC. Analysis of optical transmission spectral of films reveals an optical band gap of about 3.2÷3.4 eV and the transmittance above 80% for TiO2 films with thickness of 0.8÷1.6 µm. X-ray diffraction (XRD) analysis demonstrates that the ﬁlms are found of anatase phase in crystal structure. The AFM photographs show the nano-size of the constituents. The crystallize size and crystalline of the samples is discussed with respect to the film thickness and deposition temperature.
The Determination of Multi-Axial Fatigue in Magnetorheological Elastomers Using Bubble Inflation
Authors: Zhou Yan Fen , Jerrams Stephen , Chen Lin , Johnson Mark
Published: February 2014

Fatigue life is one of the most important physical characteristic that is investigated by materials engineers and scientists. The high dynamic loading experienced by machine parts necessitates understanding fatigue properties in critical components. Despite this requirement, elastomer fatigue criteria are imperfectly understood and even less is known about fatigue resistance in the emerging range of smart elastomers. In this paper, initial research into the equi-biaxial fatigue behaviour of magnetorheological elastomers (MREs) is described. Physical testing was carried out using a bubble inflation testing system. Silicone rubber based test samples were fatigued at different stress amplitudes ranging between 0.75MPa and 1.4MPa using engineering stress as the control mode. S-N (Wöhler) curves showing the plots of stress amplitude (σa) versus cycles to failure (N) are presented. Stress-strain behaviour throughout fatigue process is also described. For a fatigue test at a stress amplitude of 0.75MPa and no pre-stressing, it was found that stress softening occurred for the entire duration of the test, but was particularly pronounced in the first 100 cycles of testing.
Sonic Wave Band Gaps in Two-Dimensional Phononic Crystals Consisting of Hollow Mercury Columns Immersed in a Water Host, and Arranged in Simple Lattices
Authors: Xie Yong Gang , Chen Jian Bing , Huangfu Gai Jing , Yang Hai
Published: February 2014

In this paper, band gaps for two-dimensional phononic crystals consisting of hollow square water columns immersed in a mercury host are investigated by plane-wave-expansion (PWE) method, in which cross sections of the scattering objects are hollow-square and hollow water columns are arranged in simple lattices (square, and triangular lattices). In order to regulate band gaps, we alter inner side lengths of hollow-square column, and change the filling ratio at the same time. From the results, It can be found that the band gap width and the number of the bad gaps can be changed by lattice shapes and corresponding filling fraction. This could be very useful in the design of phononic crystals band gaps and frequency filtering.
Identification Scheme to Assess the Role of Interfacial Damage in a Hemp-Starch Biocomposite
Authors: Guessasma Sofiane , Hbib Mohameden , Bassir David
Published: February 2014

This paper aims at studying the effect of interfacial damage on the mechanical behavior of starch - hemp composite. The procedure encompasses an experimental investigation towards the determination of microstructural features and mechanical testing of the material. A finite element model is developed to account for a particular damage kinetics that triggers failure properties. Our results show that the experimental evidence of interfacial damage driven failure is achieved. Finite element model is able to capture this feature using an abrupt damage criterion. But in order to identify the observed behavior, the experimental response is matched with the numerical one. This process tunes the mechanical parameters to fit the experimental response. The optimization process conducted in this way leads to a precise determination of the mechanical parameters that quantifies the observed ultimate properties.
Experimental Analysis of Petroleum Wax Characteristics for Lubricant Oil Production in Solvent Dewaxing Unit
Authors: Mokhlif Nassir D. , Al-Kayiem Hussain Hamoud , Baharoom Masri Ben
Published: February 2014

Measurements of wax-in-feedstock parameters are vital tools for successful simulation of the wax crystallization phenomena in the solvent dewaxing process. In this paper, comparisons are implemented between different methods to investigate the wax characteristics of SN500 feedstock before and after dewaxing. The measurements involved were the wax content, wax appearance temperature, wax disappearence temperature, solid mass yield of the wax removal. The measurement methods adopted in the analysis are the modified Universal Oil Production method 46-64, Differential Scanning Calorimetry thermal analyzer, Cross Polar Microscopy technique, and Gas Chromatography analysis. Results have demonstrated that the modified Universal Oil Production method is slightly under estimating the wax content in the feedstock compared to the DSC results. This under estimation becomes larger for the wax content in the base stock.
Roughness Evolution and Indentation Size Effect in Superficial Layers under Plane Fatigue Loading
Authors: Mereuta Valentin , Rîpă Minodora , Palaghian Liviu
Published: February 2014

The paper presents some results about changes in integrity state of metal surface processed at different roughness levels subjected to fatigue plane bending tests. Experimental tests show that during fatigue process there are micro-geometrical changes related to local plastic deformations which can be evidenced by micro-hardness modifications and indentation size effect, ISE. ISE can be a quantitatively and qualitatively factor for characterize fatigue behavior of a metallic surface.
Hierarchical ZnO Nanostructure on Steel Substrate by Electrochemical Deposition
Authors: Zhang Bao Li , Zou X.P. , Lv X.M. , Yang G.Q. , Wei C.L. , Sun Z. , Huang Z.B. , Zhou H.Q.
Published: February 2014

In this paper we use electrochemical deposition to grow a layer of gray compact film on the steel, characterized the product by X-ray diffraction (XRD) we find the ZnO cone-like rods and hierarchical rod-like nanostructure are all preferentially growing along the C-axis, which is confirmed by the direction of crystal growth in the transmission electron microscope (TEM) image. In the TEM image we find the hierarchical ZnO nanorods have an in situ growth in the high-energy electron beam irradiation, which makes the specific surface area increase and to some extent enhance the absorption of light energy.
Influence of Precursor Solution Concentration on Zinc Oxide Nanostructures by Hydrothermal Growth
Authors: Huang Zong Bo , Zou X.P. , Yang G.Q. , Lv X.M. , Wei C.L. , Sun Z. , Zhou H.Q. , Zhang B.L.
Published: February 2014

In this paper, various ZnO nanostructures, such as rods, flowers were grown on indium-tin-oxide (ITO) substrates by hydrothermal growth at low temperature, using the different concentrations of equimolar (1:1) zinc nitrate (Zn (NO3)26H2O) and methenamine (C6H12N4) mixed as precursors solution, and adding ammonia solution to control the pH levels. SEM, XRD were utilized to characterize morphologies and crystal structures of ZnO. It was indicated that the concentration of precursor solution leads to the significantly changes in the nanostructured ZnO. The possible growth mechanism is discussed in this work.
The Application of Laser-EMAT Technique Used to Testing Defect in Rail
Authors: Zhao Yang , Jia Zhong Qing , Rui Guo , Ma Jian , Song Jiang Feng , Sun Ji Hua , Liu Shuai
Published: February 2014

Nondestructive test systems are increasingly applied in the industrial context for their strong potentialities in improving and standardizing quality control. Especially in the service stage of rail, early detection of nucleus defects in the rail can avoid the broken rail accident. The aim of present work is to propose a kind of non-contact nondestructive testing method based on the laser and electro-magnetic acoustic transducer techniques, which is suitable to inspect the nucleus defects. This paper describes the testing system, principle and signal processing. The result shows the relative error of testing nucleus defects is about 3.24 %.
Rheology, Deformational Properties and Fatigue of the Asphalt Mixtures
Authors: Schlosser Frantisek , Sramekova Erika , Šrámek Juraj
Published: February 2014

The deformational properties and fatigue of asphalt layers are important for the design and assessment of semi-rigid and flexible pavements. The Two-point Bending Test was used for determination of deformational characteristics of asphalt mixtures on Department of Construction Management in Zilina. The results are evaluated with the KATEMS assessment software. The long-term research lead to estimation of deformational characteristics and fatigue of different types of asphalt mixtures. The tests have shown a positive impact of additives (ground rubber, hydrate lime component) on the results of these mixtures. This article is focused on assessment of deformational properties and fatigue of selected types of asphalt mixtures.
Measurement of the Speed of Sound in 2,3,3,3-Tetrafluoropropylene (R-1234yf) Liquid Phase with an Ultrasonic Sensor
Authors: Gao Lei , Shibasaki Takuro , Honda Tomohiro , Asou Hiroyuki
Published: February 2014

The speeds of sound in near saturated and subcooled liquid phases of R-1234yf have been measured using a ultrasonic sensor. The measurements were conducted at the temperature range from 0 to 80 °C, and the pressure range from 0.316 to 2.52 MPa. In order to validate the ultrasonic sensor, the measurement in pure water at the temperature range from 0 to 80 °C was also performed. The measurement result of water was compared with those calculated from REFPROP (based on IAPWS-95) and PROPATH (based on IAPWS-IF97). The result of water agrees well with that calculated from REFPROP within a maximum deviation of 0.28%, except for that at temperature of 80 °C. And it agrees well also with that calculated from PROPATH within a maximum deviation of ±0.2%. The measurement results for near saturated and subcooled liquid phases of R-1234yf were compared with those calculated from REFPROP and JSRAE thermodynamic table.
Chracterizition of Dynamic Properties of Roof Bolts and their Applications
Authors: Chen Gang S. , Chen Gang , Chen Liang Biao
Published: February 2014

The dynamic properties of rock bolts are characterized by measurement. The acceleration and strain of a rock bolt specimen were recorded using axial impact testing in laboratory environment. The systems dynamic properties such as natural frequencies and damping are characterized by using spectral analysis and Wavelet method. The characterized dynamic properties are used to update and calibrate a system simulation model, which is a multiple-degree-of-freedom system involving roof mass, the roof bolt, grout interface and head connections. The proposed approach enables accurately and effectively quantifying system dynamic parameters and establishing the analytical model for the design, development and performance monitoring of roof bolting systems.
Observation of Tamarind Gum Solubility in Aqueous Solution from Turbidity Measurement Technique
Authors: Sittikijyothin Wancheng , Paunyakamonkid Kannika , Klamtrakul Niphon
Published: February 2014

Tamarind gum obtains from the endosperm of tamarind seed. Polysaccharide is the main component as about 78.85%. It consists of three types of monosaccharide as glucose, xylose and galactose. Since it is a hydrocolloid that give viscous solution in aqueous. The objective of this work is to observe the solubility of tamarind gum at room temperature by simple turbidity measurement of the solutions. The tamarind gum concentrations from 0.07 to 0.97wt% and two particle sized as <75 and 75-355 μm were interested variables. The relationship between the viscosity and solubility of the solution was investigated. We found that both turbidity and viscosity reached constant values at the same time. At this time, it could be noted that represented the saturated time of dissolution. For higher tamarind gum concentrations and with less particle size (<75 μm), the results showed that the saturated time of solubility appeared faster due to more specific area for dissolving and also the solubility rate increasing.
DSSC-Integrated Glassblocks for the Construction of Sustainable Building Envelopes
Authors: Corrao Rossella , D'Anna Dario , Morini Marco , Pastore Luisa
Published: February 2014

The paper shows the first results of the optical performance analysis carried out on the DSSC integrated glassblock, an innovative building product developed at the Department of Architecture of the University of Palermo. In the field of a research that is being conducted in order to define innovative solutions for the construction of photovoltaic and energy efficient translucent building envelopes, different hypotheses of integration of DSSC into the glassblock have been foreseen. The integration of glassblock with third generation PV systems allows to define a novel building-PV product that meets the current requirements of the BIPV (Building Integrated Photovoltaics) market. By means of OptiCAD® software, several numerical simulations were conducted to analyse the solar factor, the light transmittance and the shading coefficient of the device.
Experimental Studies of Creep Characters of Tunnel Lining Concrete
Authors: Gao Jian Ren , Zhang Gang , Wang An Li , Zhang Sheng , Jin Xiao Guang
Published: February 2014

Adopting MTS815 hydraulic servo system, through triaxial compressive deformation and triaxial creep experiment result of tunnel supports, research the stress-strain and creep properties of tunnel supports. Test results show that deformation process of support concrete displays obvious strain softening, instantaneous elastic strain increments with stress level and strain of creep curve appears increased trend with time. Creep curve of concrete drive to a fixed value when stress level is lower and strain rate of concrete more and more small. The generalized Kelvin model of three element and LUBBY2 model are feasible as creep model of concrete support. Based on the relation of creep characteristic curves for rock salt, the creep parameters of generalized Kelvin model and LUBBY2 model are advanced.
Analysis and Simulation of Temperature and I-V Characteristics for SiC Schottky Barrier Diodes
Authors: Yuan Bo , Chen Shi Bin , Jia Xiao
Published: February 2014

In this paper, semiconductor simulation software ISE TCAD 10.0 was used to simulate W/SiC SBD forward voltage characteristics and reverse voltage characteristics at different temperatures on the basis of theoretical analysis, and the valuable results were achieved. Under the temperature range from 73 K to 773 K, the simulation results of W/SiC Schottky barrier diode forward voltage characteristics showed that forward characteristics were significant influenced by the temperature. At room temperature (303K), if bias voltage was low, the current will be exponential growing with voltage, and the turn-on voltage of W/SiC Schottky barrier diode was about 0.2V. If bias voltage was high, the current increased will be high, and the series resistance effect will become obvious. Under lower bias (2V), a different temperature from 73K to 573K had small impact on reverse current-voltage characteristics. The results showed that the device had the good rectifier characteristics, small reverse current, high breakdown voltage, and the device can steadily and long-term work in high temperature and other complex environment.
The Technology in Sample Preparation for Transmission Electron Microscopy and Ultrastructure Observation of Lung Tissue in Rats with Experimental Silicosis
Authors: Li Qian , Zhang Li Juan , Yang Fang , Zhang Wen Li , Xu Hong
Published: February 2014

ts hard to get ideal ultrathin sections because of the adamant SiO2 dust in silicosis, after perfusion fixation methods and strict control of the cutting speed, improving the success rate of the Silicosis tissue TEM sample preparation of ultrathin sections,so we can more clearly and accurately observed ultrastructural changes of silicosis,and it also can offer morphological basis for research the silicosis organizations function histological changes.
Eco-Toxicological Evaluation of Fire-Fighting Foams in Small-Sized Aquatic and Semi-Aquatic Biotopes
Authors: Kawano Tomonori , Otsuka Kohei , Kadono Takashi , Inokuchi Reina , Ishizaki Yuki , Dewancker Bart , Uezu Kazuya
Published: February 2014

A variety of chemicals including foaming agents are used to aid in the protection of forest resources from the wild land fires. The fire-fighting foams (FFFs) are formulations composed principally of surfactants. As a part of Japanese national project, environmentally inert FFFs have been developed. There is an emerging need for testing the impacts of these FFFs on the living organisms composing the typical landscapes or eco-systems in Japan. In the present report, we aimed to describe our latest attempt for assessing both the short-tem and long-term impacts of FFFs in aquatic (fresh water) and semi-aquatic (wetland) eco-systems, by employing the laboratory-sized model assays (preliminary studies) and the biotope-based observation, respectively. In the biotope assays which was based on the observation in compact biotopes mimicking the fresh water environments and wetland, both the acute and long-term eco-toxic impacts of two FFFs (soap-based and synthetic detergent-based) were assessed. Spraying of synthetic detergent-based foam formula was shown to be more toxic compared to soap-based formula and mock water treatment.
Study on High Temperature Air Combustion of Hot Blast Stove
Authors: Zhang Fu Ming , Hu Zu Rui , Cheng Shu Sen
Published: February 2014

NOx is the major technical barrier to increase hot blast temperature and prolong campaign life of hot blast stove (HBS) at present. In order to restrain the amount of NOx formation during combustion process in the HBS, the paper studies and analyses the generation mechanism of NOx production, and calculates NOx generation rate and amount in HBS by means of thermodynamic generation model. A new dome combustion stove is developed based on high temperature air combustion (HTAC) technology. A comparison on the combustion process and characteristic of conventional HBS and HTAC HBS is performed by application of CFD numerical simulation model. Temperature and concentration field distribution, flame shape and NOx concentration distribution of two kinds of stove are calculated. The result shows quite symmetrical HTAC stove temperature field distribution. Under the same dome temperature, NOx generation is 80ppm only, reduced by approximate 76% in comparison with conventional stove. HTAC HBS can obtain higher temperature, energy-saving, emission-reducing, and decrease NOx emission efficiently, as well as realize long campaign life of HBS.
Experimental Analysis of the Welded Joint Temperature Field
Authors: Kraváriková Helena
Published: February 2014

The aim of experimental solution was to measure the thermal characteristics at predetermined locations in the experimental samples in HAZ during the welding process. To measure the thermal cycles were used thermocouples of suitable type. Location of thermocouple was settled in the welding process at the bottom of the experimental samples. Measured values were recorded directly into the computer by using a special program of universal measuring system QUANTUM X.
NMOS Low Boron Activation in Pre-Amorphise Silicon
Authors: Mohd Said Muzalifah , Fauzan Zul Atfyi , Azmi Nur Fatihah
Published: February 2014

The high demand of smaller and compact size of MOSFETs has leads to desirable for ultra shallow junction formation with low sheet resistance and good electrical performances. These two characteristics are required to suppress short channel effects and to increase the efficiency of device. In this paper, Pre-amorphise implantation (PAI) PMOS with different doses of Boron and the basic PMOS structure are done by using ATHENA and the performance of devices is compared by using ATLAS software package from Silvaco TCAD. Comparison done in electrical characteristic, I-V curve Ion and Ioff has showed PMOS with PAI technology with low boron doses resulted in increasing electrical performance characteristic.
Buckling Analysis of Advanced Grid Stiffened Composite Cylinders
Authors: Lim Kang Hee , Wei He , Guan Zhi Dong
Published: February 2014

Advanced Grid Stiffened(AGS) composite cylindrical shells are widely used in aerospace industry. This study analyzes the buckling loads for various types of grid structures of AGS composite cylindrical shells. The grid structures are classified as Angle-grid, Iso-grid, Kagome-grid, Ortho-grid, Orthotropic-grid and the characteristics had been analyzed for each grid type. In this study, the various types of grid structure were designed that weight of the whole structure keeps a constant. Under the condition of constant-weight, design variables such as grid angle, number of the grid, h/t ratio of the grid were controlled, and buckling loads of the grid structures were analyzed. The results were analyzed for each type of grid and each design variable of the structures. This study was performed through finite element method and the accuracy of the analysis was verified by previous studies. Finally, buckling modes were analyzed with the thickness of the skin. The selection for the most appropriate design variables had been verified for each grid type and the result can be applied to the optimization of grid structure design, and is also very helpful for reducing the computational cost and obtaining optimization values more accurately.
Performance of TiO2 Nanoparticles Synthesized at pH 2 as Photoelectrode in Dye Solar Cell
Authors: Ramli Anita , Ahmad Ita Athirah
Published: February 2014

Nanocrystalline TiO2 was prepared using sol-gel hydrothermal method to be used as photoelectrode material for dye solar cells (DSC) employing continuous stirring of titanium tetrachloride (TiCl4) with hydrochloric acid (HCl) and deionized water at 70 oC for 6 hours. TiO2 nanopowder was obtained after calcinations in air at 400 oC. The samples were characterized using FESEM, TEM, XRD, BET and UV-Vis optical absorption. This paper discusses the effect of surfactant on the physicochemical properties and the efficiency of the synthesized TiO2 photoelectrode to convert light into electricity.
Estimation of a Nusselt Correlations for Numerical Prediction of Frost Thickness Growth over a Cold Cylinder
Authors: da Cunha Ribeiro da Silva Raquel , Salinas Carlos T. , Ismail Kamal A.R.
Published: February 2014

This paper evaluates numerically some of the parameters involved in modeling the process of frost formation over a cold cylinder surface subject to the flow of humid air. Was utilized for numerical predictions the empirical Nusselt correlation from the literature, obtained in experimental studies on frost formation phenomena of frost grow over a cold cylinder surface. To predict frosting process a numerical solution was utilized, and a new correlation for Nusselt number based on the experimental correlation of Kim was estimated. For the new Nusselt correlation an optimization method that adjusts the numerical solution of modeling the frost formation process with experimental results of the frost layer thickness was used. The calculation procedure allows the estimation of the parameter K of equation. The modeling process was validated by comparison with available experimental data.