bluuebunny/crossref_metadata_2025 huggingface dataset:
A Ground Test Method and the Error Analysis of the Heat Exchanger in the Intake of Aircraft
Authors: Cai Yu Fei , Zhu Chun Ling , Shi Su Qing
Published: September 2014

A ground test method of the heat exchanger in intake is proposed using simplified method. A theoretical analysis was carried out to investigate its influences on the performance of heat exchanger. The results show that the performance of heat exchanger keeps invariable with the density of gas if the temperature and mass flow rate remain the same. The error caused by substituting total pressure of free stream for inlet entrance was analyzed and the results show that for subsonic inlet the experimental error is relatively small and the experimental error increasing rapidly as flight Mach number exceed 1.2 and flight altitude has little impact on the experimental error while the error increasing slightly with flight altitude.
3D Ice Accretion Simulation for Complex Configuration Basing on Improved Messinger Model
Authors: Zhu Cheng Xiang , Zhu Chun Ling , Fu Bin
Published: September 2014

Ice accretion on 3D complex configuration is studied by numerical methods. The flow field is obtained by using Fluent 6.0 with a S-A turbulence model. Droplet trajectories and impingement characteristics are obtained by using the Eulerian approach. Ice shape is calculated based on the improved Messinger model with a new runback distribution scheme. By applying the method presented in this paper, ice accretion on NACA0012 is computed and the results are in good agreement with the available experiment data. It preliminarily shows that the improved method in this paper is feasible, Meanwhile, ice accretion on a four-element wing is studied. According to the analysis of the calculated result, the method presented in the paper can correctly simulate the ice accretion on 3D complex configuration.
Automatic Machine for Sorting Colored Objects with Conveyor Belt
Authors: Prewthaisong Kataphon
Published: September 2014

This research is to develop the automatic machine for sorting colored objects with conveyor belt. It was designed to classify colored objects such as red, green, blue and other colors by using fiber optic sensor. The microcontroller is automatically used to move the material objects along with the conveyor belt into the containers on the tray. The microcontroller is automatically used to move the materials along with the conveyor belt, and then fell into the defined containers on the tray. The fiber optic was used for the object detection to read the amount of the intensity of light that hits the object then reflected back to the sensor, after that converted into an electrical signal to the microcontroller to control the stepper motor in order to choose containers and color of objects to match each other. Design and experiments of this research can be used as a basis for practiced mechatronics engineering laboratory. In addition, the machine can be used as a model for related industries of colored sorting. From the result, it can be shown that the sorting machine classified the colored objects as red, green, blue and other color with high accuracy. The average time of the test objects is 9.96, 13.47, 16.58 and 9.04 seconds for objects as red, green, blue and other colors respectively.
Effect of Thermocycling on Shear Bond Strength of the Three No-Mixed Bonding Adhesives
Authors: Dechkunakorn Surachai , Anuwongnukroh Niwat , Arunakol Jirawat , Tua-Ngam Peerapong
Published: September 2014

Objective: To investigate the effect of thermocycling on the shear bond strength of the three no-mixed bonding adhesives.
Evaluating a Test Parameter in Static Bending for Pinus sp. Wood
Authors: Morales Elen Aparecida Martines , Kondo Helder Kenzo , Barbosa Juliana Cortez , de Campos Cristiane Inácio , Rocco Lahr Francisco Antonio , Christoforo André Luis
Published: September 2014

Abstract. The study aimed to analyze the longitudinal modulus of elasticity (Em), based on static bending tests, in different spans and confirm that it’s necessary adopt as 21 the ratio between span and height of the cross section of the specimen to turn no significant the influence of shear stress on vertical deflection. So, simplified equation to determine Em can be employed. Specimens of Pinus elliottii var. elliottii and Pinus elliottii var. elliottii × Pinus cariabeae hondurensis (hybrid), came from Itapeva region, São Paulo State, Brazil, were considered. Bending tests were conducted in Labs of Experimental Campus Itapeva, UNESP, adapting recommendations of Brazilian Code ABNT NBR 7190. Twelve specimens of each species were tested. The trend lines for the plotted graphics showed clearly a nonlinear behavior until the neighborhood of ratio 21 and no expressive variations after this point, confirming that normative recommendations are correct.
The Influence of Different Carbon Type Fillers on the Mechanical and Physical Properties of Co-Extruded PP-Based WPC
Authors: Turku Irina , Kärki Timo
Published: September 2014

In order to improve the properties of a co-extruded wood-plastic composite (WPC), five different carbon-based fillers, namely graphite (G), expandable graphite (EG), carbon nanotubes (CNTs), carbon black (CB) and carbon fibres (CFs) were introduced into the shell layer of polypropylene (PP)-based WPC. The addition of CB, G, EG and CNTs improved the tensile strength by 45%, 25%, 5% and 32%, respectively; the addition of carbon fibres decreased the tensile strength by 22%. However, the tensile modulus of the composites decreased for all filler types. The incorporation of CNTs and CFs increased the impact strength by 11% and 21%, respectively; the impact strength of CB, EG and G-loaded WPCs decreased by 7%. The incorporation of CB, EG, G, CNTs improved the hardness by 25%, 9%, 25% and 59%, respectively; the addition of CFs decreased the hardness slightly. The wettability of the composite decreased with the CB, CNTs and CFs loadings. The presence of EG increased water absorption, whereas thickness swelling decreased compared to the reference.
Design of Pressurized Vaulted Rectangular Conduits Using the Rough Model Method (Part 2)
Authors: Achour Bachir , Khattaoui Mohammed
Published: September 2014

The problem of calculating the diameter of a pressurized vaulted rectangular conduit is solved explicitly through two methods which are based on an referential rough model whose geometric and hydraulic characteristics are well defined. The first method provides a highly reliable approximate relation which gives very accurate results for all practical applications. The second method consists in introducing into the calculations a rectangular rough model whose geometric and hydraulic properties were judiciously chosen. The theoretical development leads to an equation of third degree whose resolution has been made possible by the hyperbolic and trigonometric functions. Practical examples are presented to explain the procedure of calculation.
Effect of Ionizing Beta Radiation on the Strength of Bonded Joints of Polycarbonate
Authors: Bednarik Martin , Manas David , Manas Miroslav , Stanek Michal , Navratil Jan , Mizera Ales
Published: September 2014

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polycarbonate. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 50 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.
Temperature Stability of Modified PBT by Radiation Cross-Linking
Authors: Mizera Ales , Manas Miroslav , Manas David , Holik Zdenek , Stanek Michal , Navratil Jan , Bednarik Martin
Published: September 2014

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers. The principle of radiation processing is the ability of high energy radiation to produce reactive cations, anions and free radicals in materials. The industrial applications of the radiation processing of plastics and composites include polymerization, cross-linking, degradation and grafting. Radiation processing mainly involves the use of either electron beams from electron accelerators or gamma radiation from Cobalt-60 sources. The PBT Polybutylene terephthalate tested showed significant changes of temperature stability and mechanical properties after irradiation. From this point view, new applications could also be seen in areas with service temperatures higher than their former melting point. The comparison of the temperature stability and mechanical properties of irradiated and non-irradiated PBT is presented in this paper.
Influence of Recycled Irradiated HDPE on Mechanical Behavior of LDPE/Hdpex Blends
Authors: Navratil Jan , Manas Miroslav , Stanek Michal , Manas David , Bednarik Martin , Mizera Ales
Published: September 2014

This research paper deals with utilization of recycled irradiated high-density polyethylene (HDPEx). Grit prepared of irradiated HDPEx was used as a filler into virgin low-density polyethylene (LDPE). Concentrations from 10 to 60 % were made and their influence on mechanical properties was investigated. Tensile test at ambient and elevated temperature was used to describe mechanical properties of resulting blends. Results show that there is an upward trend of elastic modulus and ultimate tensile strength and downward trend of nominal strain at ambient temperature. Similar findings were observed at elevated temperature, which might suggest possible utilization of such modified thermoplastic materials. However other material properties have to be tested to make final conclusion.
Injection Molding of Rubber Compound Influenced by Injection Mold Surface Roughness
Authors: Stanek Michal , Manas David , Manas Miroslav , Ovsik Martin , Senkerik Vojtech , Skrobak Adam
Published: September 2014

Delivery of polymer melts into the mold cavity is the most important stage of the injection molding process. This paper shows the influence of cavity surface roughness and technological parameters on the flow length of rubber into mold cavity. The fluidity of polymers is affected by many parameters (mold design, melt temperature, injection rate and pressures) and by the flow properties of polymers. Results of the experiments carried out with selected types of rubber compounds proved a minimal influence of surface roughness of the runners on the polymer melt flow. This considers excluding (if the conditions allow it) the very complex and expensive finishing operations from the technological process as the influence of the surface roughness on the flow characteristics does not seem to play as important role as was previously thought. Application of the measurement results may have significant influence on the production of shaping parts of the injection molds especially in changing the so far used processes and substituting them by less costly production processes which might increase the competitiveness of the tool producers and shorten the time between product plan and its implementation.
Effect of Temperature on Deactivation Force of Three Commercial NiTi Orthodontic Archwires
Authors: Anuwongnukroh Niwat , Dechkunakorn Surachai , Tangit Nathaphon , Tongkoom Subongkoch
Published: September 2014

Objective: The purpose of this study was to investigate the transition temperature range (TTR) and the effect of temperatures at 10, 20, 30, 40, 50 and 60 °C on the deactivation force of three commercially available NiTi archwires. Materials and methods: Three different brands of NiTi archwires, NiTi OR (Ormco), NiTi GH (G&H) and NiTi H (Highland), with a cross sectional area of 0.016 x 0.022 inch2 were analysed for transformation temperature range (TTR) by using differential scanning calorimeter and load-deflection characteristics using a three-point bending test at temperatures of 10, 20, 30, 37, 40, 50 and 60 °C. Statistical Analysis: Descriptive analysis was used to calculate each variable and Kruskal Wallis test was performed to assess the difference in measurements among the three NiTi wires. P<0.05 was considered as statistical significant. Results: TTR showed austenitic temperature finish (Af) at 24.45 °C for NiTi OR, 27.55 °C for NiTi GH and 51.5 °C for NiTi H. The highest deactivation force was found in NiTi H followed by NiTi OR and NiTi GH at the temperatures below and higher than 37°C. There were siginificant differences (p<0.05) in the deactivation force of NiTi OR - NiTi H and NiTi GH - NiTi H at 10 °C and 20 oC, and NiTi GH – NiTi H and NiTi GH – NiTi OR at 30 °C and 37 °C. However, no significant difference was found among all NiTi wires at 40, 50 and 60 oC, except NiTi GH – NiTi H at 60 oC. A close relationship was found between temperature and unloading curves (deactivaton force); increase in the temperature led to an increase in the plateau of delivery deactivation force and decrease in temperature led to a decrease in the plateau of delivery deactivation force. Conclusion: The TTRs of commercial NiTi archwires are variable, expecially the austenitic finish temperature. The deactivation force increases in higher temperature and decreases in lower temperature.
Self-Tapping Screws without Pre-Drilling for Brazilian Reflorestation Species
Authors: Calil Neto Carlito , Christoforo André Luis , da Silva Bertolini Marília , Rocco Lahr Francisco Antonio , Calil Junior Carlito
Published: September 2014

Wood is a renewable source of structural material with high relative strength/weight, low energy production, which kidnaps and stores carbon in its production. The large use of wood is due to its special qualities as raw material for other products manufactured in residential construction or major works such as bridges, has been widely used in roofing for industrial and commercial buildings. Commercially there are limitations on the length of the wood, resulting from the extraction of tree trunks, thus requiring the adoption of binding elements is the use of self-tapping screws efforts required by side and which can be axial, shear, tensile or compression. Whereas in Brazil does not yet exist and the promising future of the product, this research aims to study the behavior of self-tapping screws together with Brazilian reforestation species of Pinus oocarpa and Lyptus (softwood and hardwood). Rothoblaas self-tapping screws had a good penetration in both woods without requiring pre-drilling, the species of Lyptus wood showed the highest values of strength and the inclination of the screws, at 45 degrees showed the best results on either species of wood.
The Dynamics Model Analysis of Drying Process in Gelcasting Method
Authors: Zhang Xiao Long , Li Bo , Ye Jun Xian , Zhou Ji
Published: September 2014

Gelcasting is a widely
used method for manufacturing ceramic components. Currently the research on drying process is limited to qualitative analysis for drying process. In order to reveal the mechanism of the gelcast bisque’s drying process, the one-dimensional dynamics model for drying process has been formulated, based on the microscopic quantitative description of the evaporation process and mass transferring process through the gelcast bisque. Then the model has been modified with the consideration of the capillarity effect and the bisque’s drying shrinkage influence. By comparing with the experimental results the one-dimensional dynamic model of drying process can be proved to accurately describe the bisque’s drying process.
The Influence of the Production Process on Mechanical Properties of Rubber Testing Samples
Authors: Skrobak Adam , Stanek Michal , Manas David , Ovsik Martin , Senkerik Vojtech , Reznicek Martin
Published: September 2014

The article deals with the influence of production technology on mechanical properties of rubber testing samples. In practice, rubber testing samples are cut out from a compression molded sheet, also in case of testing of rubber compounds appointed for injection molding. However, the different way of the preparation of testing samples and the production itself may have a negative effect on the mechanical properties of the final product. Thus the article judges, to what extent the mechanical properties (tensile strength, extension, tear strength and microhardness) of testing samples from selected rubber materials are influenced by injection molding, and evaluates the possible divergence.
Comparison of the Initial Repeated Bond Strength among Three Orthodontic Bonding Systems
Authors: Anuwongnukroh Niwat , Dechkunakorn Surachai , Arunakol Jirawat , Wichai Wassana
Published: September 2014

One of the problems that often occurred during orthodontic treatment is bracket failure. This is usually the result either of the patient’s accidentally, applying inappropriate forces to the bracket or of a poor bonding technique. Thus, a significant number of teeth have to be rebonded in an orthodontic practice. Objective: The aim of this study was to evaluate the in vitro initial repeated shear bond strength of the three adhesive systems at two and five minutes after placement of a bracket. Materials and Methods: The three bonding agent adhesives are System1+, Rely-a-bond, Unite. Two hundred and forty human premolar teeth were divided into two groups, a control and an experimental group. Each group was further divided into three subgroups for bonding brackets with the three different adhesives. Only the teeth in the experimental group were sequentially bonded and debonded two times with the same adhesive. The teeth in control and experimental groups were tested for shear bond strength (at two and five minutes after the bracket was bonded) with an Instron testing machine. Results: The studies were found that : (1) there were differences between the shear bond strength of each adhesive in the control and experimental group. Unite had the highest shear bond strength followed by Rely-a-bond and System1+ at two minutes and five minutes, (2) the experiment group ( rebonded brackets) had higher shear bond strength than control group and Unite had in significant difference (p<0.05) of initial repeated bond strength with System1+ and Rely-a-bond at two minutes and five minutes and (3) there were mostly significant difference (p<0.05) between repeated shear bond strength at two minutes and repeated shear bond strength at five minutes. Conclusion: There were significant difference of the initial repeated shear bond strength of each adhesive. The orthodontists should be aware of applying force for tooth movement into the repeated bonding brackets.
Effects of Al Additions and Reheat Treatments on Microstructures of Modified Nickel-Based Superalloy, Grade Inconel 738, by Vacuum Arc Melting Process
Authors: Wangyao Panyawat , Jariyasakuntham Peerada , Polsilapa Sureerat , Promboobpa Aimamon , Pongsugitwat Suvanchai
Published: September 2014

This research has an aim to modify and improve the microstructures and hardness property of cast nickel-based superalloy, IN-738 by modified chemical composition of various Al additions as well as different reheat treatment conditions. IN-738 was modified by adding aluminium in 1, 2 and 3% by weight and casting with vacuum arc melting process. Then all casted alloys were performed with 5 different solutioning temperatures of 1125°C, 1145°C, 1165°C, 1185°C and 1205°C for 6 hours and all following with the same precipitation aging temperature of 845°C for 24 hours. The various obtained microstructures of the casting and reheat treatments were observed and investigated by SEM to evaluate the average area fraction and size of γ’ precipitated particles. The mechanical property was evaluated by Vickers hardness. From the obtained results, it was found that fine microstructure, which would be the most appropriate for using at elevated temperature, was obtained by the Al addition with 1%wt. following with solutioning temperature range between 1125°C – 1145°C/6 hours and precipitation aging at 845°C/24 hours. The microstructures received consist of high area fraction of γ’ particles in cubic shape with the proper size. However, the maximum hardness value of 683 HV was obtained from the alloy with 3%wt. Al addition following with solutioning temperature of 1205°C.
Effect of Beta Low Irradiation Doses on the Micromechanical Properties of Surface Layer of LDPE
Authors: Manas David , Ovsik Martin , Manas Miroslav , Stanek Michal , Kocman Karel , Bednarik Martin , Spanhelova Marcela
Published: September 2014

The experimental study deals with the effect of modification of the surface layer by irradiation cross-linking on the micromechanical properties of the low-density polyethylene (LDPE) tested using the instrumented nanohardness test. The surface layer of LDPE specimen made by injection technology was modified by irradiation cross-linking using beta irradiation, which significantly influences micromechanical properties of the surface layer. Compared to the heat and chemical-heat treatment of metal materials (e.g. hardening, nitridation, case hardening), cross-linking in polymers affects the surfaces in micro layers. These micromechanical changes of the surface layer are observed in the instrumented microhardness test. Our research confirms the comparable properties of surface layer of irradiated LDPE with highly efficient polymers. The subject of this research is the influence of irradiation dosage on the changes of micromechanical properties of surface layer of LDPE.
Evaluation of Bamboo Particleboards Produced with Urea-Formaldheyde Resin
Authors: Valarelli Ivaldo D. , Batistelle Rosane A.G. , Branco Luiz A. Melgaço N. , Chahud Eduardo , Christoforo André Luis , Rocco Lahr Francisco Antonio , Bezerra Barbara Stolte
Published: September 2014

The bamboo waste can be an alternative material to sustain the crescent demand for particleboards, also bringing ecological benefits as reduction of the pressure for raw materials and landfill space demands. In this context, this research aimed to manufacture and determine some physical and mechanical properties of particleboards with bamboo waste particles (Dendrocalamus giganteus), obtained from different sources, bonded with four different percentages of urea–formaldehyde (UF) based resin (6%, 8%, 10% and 12% related to dry material of particles). Response variables investigated were: density; moisture content; thickness swelling in 2 and 24 hours; water absorption in 2 and 24 hours; internal adhesion (STpe); strength in tension parallel to faces (STpa); modulus of elasticity (MOE) and modulus of rupture (MOR). Results permitted to conclude that particleboards as mentioned showed good performance only in the physical properties requirements imposed by Brazilian Standard NBR 14810, but this was not observed to mechanical properties considered. New researches are needed in order to optimize the producing process parameters.
Influence of Reactive Organic Flame Retardants on Properties of Resol Phenoplast Foams
Authors: Bruyako Mihail Gerasimovich , Grigorieva Larisa , Sokoreva Evgeniya Viktorovna
Published: September 2014

Found that Organophosphorus Compounds Reduce the Flammability of Resol Phenoplast Foams. Quality Improves Thermal Insulation Materials, the Use of such Phenolicfoam. Analysis of Using the Heat-Insulating Materialsindicates that Heat Insulation Made with Filling Phenol Foam Plastics Havinglow Heat-Conductivity and Relatively Low Cost of Raw Materials is Superior Bytheir Technical and Economic Performance to Mineral and other Polymericheat-Insulating Materials. Meanwhile, Relatively Low Strength and Smolderingpropensity of Resole Foam Phenol Plastics, as well as Excessive Fumes Duringthe Production Process of Heat-Insulating Materials on their Base, Containwider Usage of Phenol Foam Plastics in Building.
A Simple and Efficient Route for Preparing 4-Chloro-3,5-Dinitropyrazole
Authors: Rui Qiao , Wang Yan Hong , Li Yong Xiang
Published: September 2014

4-Chloro-3,5-dinitropyrazole(ClDNP) as an insensitive energetic compound has been prepared with 4-Chloropyrazole(4-ClP)via nitrated by mixture of nitric acid and sulfuric acid. The reactionconditions were investigated, such as the molar ratio of 4-chloropyrazole and HNO3, reaction temperature, reaction time. Through the single factor experiment, the optimum reaction condition was determined that the molar ratio of 4-chloropyrazole and HNO3 was 1:4, the reaction time was 4h, the reaction temperature was 100-105°C. The yield of the ClDNP was up to 73.8% under the above conditions．The ClDNP was re-crystallization by methylbenzene.The target product was characterized by IR, 1H NMR, 13C NMR and Gauss Photography．
Analysis of Structural Transformations of Fe80Ni10Si5B5 Amorphous Alloy Based on Temperature Changes of Electrical Resistivity
Authors: Kotvitckii Aleksandr , Kraynova Galina S. , Frolov A.M. , Ivanov Vitaly , Plotnikov Vladimir S.
Published: September 2014

In this paper the change of electrical resistivity of the amorphous alloy Fe80Ni10Si5B5 during heat treatment is investigated. Parallel studies by magnetometry technique, X-ray diffraction and calorimetric analysis were used to interpret the nature of the changes in the structure and properties of the alloy during annealing. These features are related with magnetic nature of the alloy and crystallization at a higher temperature.
Modelling of Fretting Wear under Partial Slip Conditions Using Combined Isotropic-Kinematic Hardening Plasticity Model
Authors: Mohd Tobi Abdul Latif , Ali M.Y. , Zainulabidin M.H. , Saad A.A.
Published: September 2014

This paper presents finite element modelling of fretting wear under partial slip conditions using combined isotropic-kinematic hardening plasticity model with the emphasized to investigate the cyclic-plasticity behaviour predicted under fretting condition. The model is based on two-dimensional (2D) cylinder-on-flat contact configuration of titanium alloy, Ti-6Al-4V. A number of wear profiles at specific number of wear cycle (6000th, 60000th, 150000th and 300000th) are simulated. Contact pressure, tangential stress, shear stress, equivalent plastic strain, tangential plastic strain and also shear plastic strain are gathered and analysed. It is found that the plastic strain response of the combined isotropic-kinematic hardening plasticity model is slightly higher compare to linear kinematic hardening plasticity model [1].
Comparison Study of Oxidation Behavior of Low Carbon Steel at Elevated Temperatures
Authors: Ha Sang An , Kim Dong Kyun , Lee Woo Jin , Kang Chang Yong , Kim Kwon Hoo , Wang Jei Pil
Published: September 2014

Comparison study of oxidation behavior of low carbon steel was conducted at the temperature range of 500°C to 700°C under a 0.2 atm oxygen pressure by continuous and discontinuous oxidation methods. Oxidation rate of both cases was found to be increased with increasing temperature from 500°C to 700°C and obeyed parabolic rate law. In addition, activation energy for the continuous oxidation of steel was found to be a 164.8 kJ/mole, which means that oxidation rate is proportionally dependant on temperature. In case of cyclic oxidation, the oxidation rate was shown to faster than continuous oxidation at all temperatures due to direction oxidation through spallation of the oxide layer.
Synthesis of Vanadium Powder by Magnesiothermic Reduction
Authors: Lee Dong Won , Lee Hak Sung , Yun Jung Yeul , Kim Young Ho , Wang Jei Pil
Published: September 2014

Vanadium metal powder was successfully synthesized by combination reduction process with hydrogen gas and liquid magnesium. V2O5 as a raw material was first reduced by hydrogen gas to produce V2O3 at 873K for 3 hours and then it was reduced by liquid magnesium at 1,073K for 48 hours to become final vanadium powder. The microstructure and chemical composition of pure vanadium powder fabricated were examined by SEM(Scanning Electron Microscopy) and EDX(energy dispersive spectroscopy), respectively. The oxygen content of vanadium powder was finally found to be 0.5 wt.% showing the structure loosely agglomerated with fine particles of about 1~2μm.
Hydrothermal Synthesis of Porous Materials Using Calcined Kaolin with Small Molecular Amine Templates
Authors: Li Jin Tang , Qiu Shi , Chen Rong Yi , Gan Chuan Hai , Zeng Xue , Luo Xue Tao
Published: September 2014

Three kinds of porous materials were synthesized using calcined kaolin with small molecular amine templates by hydrothermal methods. Sodium silicate was chose as silicon sources and three different amines namely acetamide, ethylenediamine and hexamethylenetetramine were chose as the organic templates. The physicochemical properties of obtained samples were characterized by X-ray diffraction, infrared spectrum and scanning electron microscopy.Crystallinity and morphology of samples were investigated. The influence of small molecular amines templates was discussed.
Nickel Recycling by Magnesium Reaction of Fe-Ni Alloy Scrap
Authors: Lee Dong Won , Lee Hak Sung , Shin Shun Myung , Wang Jei Pil
Published: September 2014

Ni recycling from Fe-Ni alloy scrap was successfully performed by Mg reaction and distilling process. Ni component in Fe-Ni alloy scraps dissolve selectively in molten magnesium metal and then vacuum distilling was applied to remove Mg from Mg-Ni liquid. Above 1,073K in dissolving stage, more than 99% Ni from scraps was recovered and under the distilling process at 1,273K, 10-5 torr, the high quality Ni with 99.5% could be obtained. This study suggests the recycling process of Ni in Fe-Ni scrap with the combination of Mg reaction and distilling process.
Exhaust Dyeing Poly(Lactic Acid) Fabrics with Indigo Dye Obtained from Indigofera Tinctoria
Authors: Sidarkote Rakchanok , Suwanruji Potjanart , Suesat Jantip
Published: September 2014

Natural indigo dye, Indigofera tinctoria, was applied on poly (lactic acid) (PLA) fabrics by exhaust dyeing in the presence of 5 g/L sodium dithionite and 0.2 g/L NaOH. Three dyeing parameters e.g. dyeing temperature, dyeing time and dye concentration were studied. When 5%owf indigo dye was applied on PLA, the maximum color strength was obtained at 80°C and 60 minutes. The color strength also increased as the dye concentration increased in the range of 4–20%owf. Applying natural indigo dye to PLA fabrics is more attractive than the commercial one due to better energy savings and the process being environmentally friendly.
Medium Density Particleboard with Addition of Impregnated Paper
Authors: Barbosa Juliana Cortez , da Silva Michelon Anderson Luiz , Morales Elen Aparecida Martines , de Campos Cristiane Inácio , Christoforo André Luis , Rocco Lahr Francisco Antonio
Published: September 2014

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.
Utilization of Terahertz Spectroscopy for Optical Behavior Determination of Recycled Modified HDPE
Authors: Navratil Jan , Manas Miroslav , Stanek Michal , Manas David , Bednarik Martin , Mizera Ales , Gavenda Tomas
Published: September 2014

Little research was done to investigate possible utilization of irradiated materials after the end of their lifetime. This research paper deals with the possible utilization of irradiated high-density polyethylene (HDPEx) after its service life. Irradiated HDPE was used as filler into the virgin low-density polyethylene (LDPE). Three material combinations were investigated (powder/powder, granules/powder and granules/grit) and influence of the filler on optical behavior was measured. Terahertz spectroscopy at wide range of frequencies was used for refractive index determination. According to measured data there is significant influence by the amount of the filler. Moreover influence of particle size was also observed. All three combinations have similar curve courses; however the most consistent results were achieved at the powder/powder combination. Behavior of virgin LDPE and virgin HDPE is in correlation with previous findings.
Creep of Radiation Cross Linked HDPE at Elevated Temperature
Authors: Reznicek Martin , Manas David , Stanek Michal , Ovsik Martin , Bednarik Martin , Skrobak Adam , Mizera Ales
Published: September 2014

This article studies creep of a radiation cross linked HDPE polymer material. It describes a process of production of test samples, which are then radiation cross linked in six doses of radiation. These samples are tested for creep resistance at elevated temperatures on a machine of custom design that will provide sufficient information about a suitable use for the material and to find an optimal dose to achieve minimal stretching. [1-3]
Modeling Errors in Coordinate Measuring Machines and Machine Tools Using Homogeneous Transformation Matrices (HTM)
Authors: di Giacomo Benedito , de Morais César Augusto Galvão , de Souza Vagner Augusto , Neves Luiz Carlos
Published: September 2014

Coordinate Measuring Machines (CMM's) have attributes to provide results with accuracy and repeatability in measurements, so they are considered equipment with potential for application in industrial environments, specifically in inspection processes. However, as in a machine tools the knowledge of the errors in CMM is needed and allows applying techniques of error compensation. This study aimed to develop a mathematical model of the kinematic errors of a bridge type CMM in "X", "Y" and "Z" directions. Modeling of the errors was accomplished using coordinate transformations applied to the rigid body kinematics; the method of the homogeneous transformation was used for the development of the model. The position and angular errors for the three axes of CMM, in addition to errors related to the absence of orthogonality between them were equated. This study allowed to conclude that modeling of errors applied to CMM allied to calibration is able to evaluate the metrological performance of equipment with displacement on guides, thus is possible to use this technique as error budget analysis in machines.
Hydrolyzed Fish Collagen Inhibits Inflammatory Cytokines Secretion in Lipopolysaccharide-Induced HUVECs
Authors: Liu Chao , Xue Yang , Sun Jiao
Published: September 2014

The present study was designed to investigate the effects of hydrolyzed fish collagen (HFC) on the cytokine production of lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVECs). The in vitro inflammation model was established using LPS-induced HUVECs.The cell viability of HUVECs and the secretion level of inflammatory cytokines,IL-6, IL-8, and TNF-α from LPS-treated HUVECs exposed to HFC were determined respectively using MTT and ELISA assays. Our results indicate that HFC promoted HUVECs proliferation, and significantly reduced IL-6, IL-8, and TNF-α production in LPS-stimulated HUVECs. It suggested that HFC had a prominent anti-inflammatory property, HFC could be considered as a promising candidate for anti-inflammatory wound dressing.
Alloying of Molybdenum Disilicide with Aluminum by SHS
Authors: Zhou Ying , Xiao Jin , Ye Guo Tian , Liu Chen Yong
Published: September 2014

In this work, a series of samples of Mo (Si1-xAlx)2 (X =0, 0.10,0.20,0.30,0.40) were prepared by self-propagating high-temperature synthesis (SHS). The influence of the addition of Al on the structures and the micrographs of the final compounds were investigated. X-ray diffraction pattern characterization (XRD) and scanning electron microscopy (SEM) were used to characterize the obtained products. It was found that, the reactions between Mo and Si could be promoted with introducing Al during the SHS process. The high temperature β-MoSi2 phase with hexagonal structure (C40) was obtained and the peaks of the C40 phase shifted towards a higher d value with increasing aluminum substitution. The substitution of Al could reach to 40%. The morphology of the final products was similar with that of the raw Mo powders, which was independent of Al contents.
Compatibilization of Thermoplastic Polyurethane and Polypropylene with a SEBS Compatibilizer
Authors: Vesna Ocelić Bulatović , Emi Govorčin Bajsić , Veljko Filipan
Published: September 2014

The effect of styrene-ethylene/buthylene-styrene triblock copolymer (SEBS) on the thermal and rheological properties of thermoplastic polyurethane/polypropylene (TPU/PP) blends was investigated. For the selection of polymer materials and polymer blends for various fields of applications the stability of materials under constant deformation are very important. The blends were therefore characterized by measuring secondary viscoelastic functions creep, recovery and creep modulus using dynamic mechanical analysis (DMA) in the creep fatigue regime. The master curves at the reference temperature of 25°C were created by time-temperature correspondence (TTC) principle. The correlation of the creep modulus with time, temperature and addition of compatibilizer was discussed. The differential scanning calorimetry (DSC) results indicated that the addition of SEBS as a compatibilizer in TPU/PP blends increases glass transition temperature (Tg) and decreases crystallinity (χc). SEBS block copolymer acts as an efficient compatibilizer for TPU/PP blends.
Strength of Bonded Joints of Linear Low – Density Polyethylene after Radiation Cross – Linking
Authors: Bednarik Martin , Manas David , Manas Miroslav , Stanek Michal , Navratil Jan , Mizera Ales
Published: September 2014

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of linear low – density polyethylene (LLDPE). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of linear low – density polyethylene. Bonded surfaces with ionizing beta radiation doses of 0, 66, 132 and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 132 kGy by which the highest surface energy and the highest strength of bonded joints of LLDPE were achieved. The strength of bonded joints after irradiation was increased up to 60 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.
Three-Dimensional Periodic Hematite Photocatalysts Fabricating by Direct Writing Method
Authors: Peng Qin Mei , Li Bo , Wang Jin , Li Ji Jiao , Zhou Ji
Published: September 2014

Three-dimensional (3-D) periodic hematite scaffold was successfully fabricated by direct writing method as a catalyst for degradation of organic contaminants. Photo-catalytically active α-Fe2O3 nanoparticles have been synthesized by sol-gel technique. Aqueous slurries of iron oxides were freeform fabricated to produce hematite scaffolds with a 3-D periodic architecture and multiscale porosity. The catalytic activity of the hematite scaffolds was evaluated in the degradation of Methylene Blue (MB). It was found that the degradation rate of MB dye was over 83%. The result strongly indicates that the hematite scaffolds exhibits a high catalytic activity. Moreover, this work provides an important step forward in the creation of suitable structures for photocatalyst.
Influence of Mould Release Agent on Surface Properties of Concrete with Special Matrix
Authors: Pernicová Radka , Kostelecká Michaela
Published: September 2014

Influence of mould release agent for surface properties of concrete with special matrix are presented in this paper. Porosity, roughness and sorption capacity was tested depending on the selected separators. These properties are very important for architectural concrete or further non-treated concrete mainly due to efflorescence. From the results obtained follows that the different kind of separators as well as type of cements have impact on the concrete surface properties.
Analysis of Formation and Testing of Efflorescence on Concrete Elements
Authors: Pernicová Radka
Published: September 2014

Complex of measurements methods for indicate white efflorescence are presented in this paper. This article is focus on primary efflorescence, specifically lime based, which cannot be completely avoided. Tests involve not only qualitative and quantitative methods but also recommended additional measurement. Because there are not any standard for determination this kind of efflorescence, this set of tests should help for design concrete elements and limited risks of its creation.
Polarization Behavior of Steel Corrosion in Laterite, Yellow Soil and Kaolin
Authors: Sundari Rita , Sa'adan Amy Wahida Mohamad
Published: September 2014

Corrosion of buried pipelines caused by aging process has taken serious problems. Pitting corrosion in underground pipelines may yield material damage causing great loss of economic value and therefore, this study has emphasized on carbon steel corrosion in three types of soil (laterite, yellow soil and kaolin). Yellow soil solution performed remarkable polarization behavior compared to laterite and kaolin solutions on the basis of Tafel plot. Corrosion potentials of – 0.36V, – 0.47V and – 0.35V were showed by carbon steel corrosion in laterite, yellow soil and kaolin solutions. Yellow soil solution also performed the most corrosive effect on carbon steel due to temperature effect (30o – 90oC). In addition, the corrosion of carbon steel in yellow soil solution posed the lowest enthalpy with regard to thermodynamic effect. This study also showed that the carbon steel corrosion in laterite solution referred to pitting corrosion based on linear adsorption isotherm. This investigation gives valuable information with respect to underground pipelines corrosion.
Acid Value Reduction Process in Mixed Crude Palm Oil by Using Low-Grade Ethanol
Authors: Intarat Naruemon , Somnuk Krit , Theppaya Thanansak , Prateepchaikul Gumpon
Published: September 2014

In Thailand, the ethanol production was produced from factory fermentation of many food crops such as sugar cane, molasses, and cassava. Thus, this alcohol is not required to be imported from abroad. Moreover, the advantages of ethanol over methanol are less toxic, and the fatty acid ethyl ester (FAEE) has higher heat content, cetane number and lower cloud point, pour point than the fatty acid methyl esters (FAME). In this study, the 95% commercial ethanol (as a low-grade ethanol) was used to reduce the acid value in the mixed crude palm oil (MCPO). The Response surface methodology (RSM), a 5-level 2-factor central composite design (CCD), was employed to optimize the ethanol, and sulfuric acid. The results showed that the 95% ethanol can reduced the acid value from 34.5 mgKOH/g to less than 2 mgKOH/g. Therefore, the esterified oil can be used to produce biodiesel by base-catalyzed transesterification when the optimal condition: 81.3 vol.% ethanol, 10 vol.% sulfuric acid, and 75°C reaction temperature are used. Moreover, the acid value in MCPO was sharply reduced to less than 7.477 mgKOH/g at 5 min, and to less than 1.621 mgKOH/g after 30 min of reaction time when the model of optimal condition was verified.
The Cracking Mechanism and Anti-Cracking Measures for Hydraulic Mass Concrete
Authors: Peng Zhang
Published: September 2014

The article describes and analyzes the process of mass concrete casting and crack problems during the period of construction. The article illustrates the necessity of crack control for mass concrete structures and introduces the present application situation of commercial software used to analyse the temperature field and stress field. Combining the engineering practice, the article sums up the measures to deal with hydraulic mass concrete structure cracks and the application situation of various methods. Then the article puts forward the future research direction to solve the problem of hydraulic mass concrete crack.
Finite Difference Kinetics Modeling for Galvanized Steels with Post Heat Treatments
Authors: Kanapa Luckchai , Boonyongmaneerat Yuttanant , Supradist Mawin
Published: September 2014

Galvanized steels are widely used in construction, electronic, and automotive applications. By applying heat treatment after the hot-dip galvanizing process, zinc and iron in the galvanized coatings are interacted and series of zinc-iron intermetallic phases are developed. Correspondingly, the properties of galvanized steels may be enhanced. In the recent past, attempts have been made to develop kinetics models to help predict the interdiffusion of zinc and iron in the hot-dip and annealing steps, yet they are generally complicated and sometimes do not agree well with the actual data. In this work, we extend the prior works to develop a mathematical model for predicting the interdiffusion of zinc and iron and the growth of intermetallic phases during annealing that is less complicated, yet provides reasonably accurate results, by using an explicit finite difference method (FDM) along with a special treatment at the boundaries of each phase. The data from literatures are compared and discussed to justify the accuracy of the model.
Effect of Cr Plating and Plasma Nitriding on Hardness and Corrosion Resistance of H13 Steel
Authors: Tanakorn Lertjirakul , Boonyongmaneerat Yuttanant , Patama Visuttipitukul
Published: September 2014

H13 steel has been widely used in several metal working industries. Plasma nitriding is employed for improving surface hardness, but it significantly decreases corrosion resistance of H13 steel. To improve corrosion resistance, Cr plating before and after plasma nitriding is studied in the research. Surface characterization, phase analysis, hardness and corrosion test were done to evaluate the appropriate method to improve corrosion resistance. It was found that Cr plating after plasma nitriding can improve the corrosion resistance close to as-heat treated sample. The formation of Cr can increase the corrosion potential to-310.66 mV(Ag-AgCl) comparing to-349.54 mV(Ag-AgCl) of as-heat treated sample. For the corrosion resistance at constant applied voltage tested by potentiostatic technique, the sample with plasma nitriding prior to Cr plating shows the lowest corrosion current which implies the lowest corrosion rate. For the process in which Cr plating is applied before plasma nitriding, CrN layer can be formed on the surface, but this layer is very thin (about 100 nm thick). This thin layer retards nitrogen diffusion; hence, nitrided layer beneath CrN layer cannot be formed. With only thin layer of CrN, both corrosion resistance and micro-scale surface hardness cannot be improved.