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The wettability of the carbon composite electrode on paper substrate was studied using contact angle measurement. Y-Shield HSF54 carbon composite material were coated on paper substrates with a mask using squeegee coating technique. Contact angles of the ten polar probe liquids with the HSF54 electrodes were measured using a customed-built image acquisition system. With the contact angles obtained for each probe liquid placed on the electrodes, the surface tension of the electrodes was determined using Fox-Zisman theory. The result showed that the critical surface tension of HSF54 carbon composite electrodes was 37.2 mN/m which is considered to be moderately hydrophobic.

In this paper, soy protein papermaking process conditions as dry strength agents were studied. The results show that a part of the three parts of soy protein and a mixed system with a cationic starch alone, or cationic starch, soy protein, as compared to dry strength additives will significantly increase the strength. The optimum conditions were: pulp types E, defatted soy protein, dry vacuum drying method is 105°C, adding ways to add the pulp, the best reaction time was 10min, the optimum dosage of 2%. Soy protein sources are widely readily available, and environmentally friendly and easily biodegradable, paper dry strength agents as a good material.

Based on the requirements of sustainable development and innovative design concept, Al films deposited by DC magnetron sputtering solves the paper based Al film forming technology of aluminum plated corrugated cardboard material so as to obtain new environmental protection. To explore the combination design, aluminum plated corrugated cardboard furniture design idea and concept of aluminum plated corrugated cardboard and other materials of the modular design, promotes the application and practical popularization value. The production of functional strong, stylish new aluminum plated corrugated cardboard furniture, can meet the needs of a growing social material production and life.

This document demonstrates how to affect the brightness of liquid package recycled pulp by hydrogen peroxide bleaching and FAS beaching. The optimum H2O2 bleaching process conditions: 8% H2O2, 4% NaOH, bleaching temperature 80 °C, bleaching time 1.5h. The best FAS bleaching conditions was FAS dosage of 0.5%, NaOH dosage of 0.25%, bleaching temperature at 80 °C, time for 30min. And bleaching had no adverse effect on the performance of bleached pulp fiber.

This paper made the detailed discourse for the study on using cellulase, hemicellulase hydrolysis of poplar fiber raw material to make glucose. The raw material used in this experiment is poplar, cellulase and hemicellulase enzymes are used. Hemicellulase is a complex system, xylose is regarded as the main chain for a lot of hemicellulose. The experiment used dry poplar as raw material, through the ball mill, ground poplar into wood powder. In the experiment, the optimal condition of enzyme hydrolysis of wood powder has been discussed based on reaction temperature, reaction time, enzyme concentration, and the pH value of reaction. Finally, under the optimal condition, use enzyme to hydrolyse wood powder, measure reducing sugar content by the DNS method, and calculate the rate of hydrolysis.

Delignification of banana peel, agricultural waste, is considered in the pulp production because lignin is a major obstacle to the gain of cellulose. The soda process as a conventional method and micro-morphology observed by scanning electron microscopy were fulfilled to investigate an optimal condition in this study. The results pointed the potent sequence of operating factors was delignification temperature > solid-liquid ratio > soda concentration > time. The removal of lignin could achieve 92% under the optimal condition using 12%w soda concentration with 1:8 solid-liquid ratio at 100°C for 40 min. This shows that the alkaline delignification is productively sufficient for the pulp production.

The application of photodegradable polyethylene is increasingly important for agricultural uses due to its ability to degrade after suggested shelf life and to counter measure pollution issue caused by conventional polyethylene films. The photodegradable polyethylene (PE) mixtures were formulated with added polypropylene (PP) and photodegradant (RM master batch) and tested in oil palm seedlings cultivation. PP is known to have photodegradable ability and RM master batch is proven to induce photo degradation of polyethylene. Thus, the mixture of these three components according to different ratios was processed into agricultural plastic films. There are four formulations that are tested in this study, namely T1 (80% PE:20% PP:5% RM master batch), T2 (70% PE:30% PP:5% RM master batch), T3 (80% PE:20% PP:3% RM master batch) and T4 (70% PE:30% PP:3% RM master batch). All formulations except control sample were added with photodegradant to impart degradation reaction and compatibiliser was also affixed to allow coalesce between polyethylene and polypropylene. Carbon black was added 0.5% into the formulation as for poly bags application, dark environment of soil is crucial for root development and growth. Penetration of sun light into the planting soil could commence development of shoot instead of root growth. All four formulations showed observable morphological changes on microscopic images on the surfaces after being used in oil palm nursery. From the study, it is shown that T1 and T3, with 20% of additional polypropylene had demonstrated clear surface disintegration when viewed microscopically. The addition of 3% and 5% of photodegradant into the formulations did not show any expressive difference thus suggesting that 3% of photodegradant is the optimum amount to induce photo degradation.

PBO (p-phenylene benzobisoxazole) short fibers, attached fine fibrils that are called PBO pulp, may precipitate directly from stirred PBO/methanesulfonic acid (MSA) solution by the use of water coagulant in fibrous pulp form. Scanning electron micrographs show that the precipitated PBO pulps have a ribbon-like structure similar to Kevlar pulps. The thermalgravimetric analysis (TGA) show there were no appreciable mass changes until 550 °C in the air. The process yields PBO pulps with different specific surface areas (SSA) depending on the stirring speed, stirring time and the concentration of the PBO/MSA solution. High SSA PBO pulps can be produced by increasing the stirring speed, prolonging the stirring time and reducing the concentration of the PBO/MSA solution.

Green composites of Glucose-reduced graphene oxide (GrGO) and manganese (IV) oxide (MnO2) were prepared in a typical chemical synthesis route assisted with ultrasonic irradiation. Conductivity studies conducted via 2-point probe method shows GrGO/MnO2(4:1) possessed electrical conductivity of 30.29 S cm-1with energy band gap of 8.47×10-1eV. The increase of D/G intensity ratio of GrGO with increase MnO2loading indicates more disorder carbon or defects are introduced from the reaction of carbon with MnO4-.

This article is devoted to investigation of the synthesis process of exfoliated graphite. Exfoliated graphite was obtained from graphite oxide using thermal exfoliation. Graphite oxide samples were synthesized using modified Hummers method. The influence of the synthesis process parameters such as heating rate, temperature, exposure time on the properties of graphite oxide were investigated. The as-received exfoliated graphite were tested as electrode for supercapacitors. The capacitance of the supercapacitors based on exfoliated graphite varied in a range of 17-129 F/g.

We introduced a facile method to construct new ternary hierarchical nanocomposites by combining MnO2coated one dimensional (1D) conducting polyaniline (PANI) nanowires with 2D graphene oxide sheets (GOs). The hierarchical nanocomposite structures of PANI@MnO2/Graphene oxide were further proved by XRD, SEM and TEM measurements. The ternary composites possessed higher electrochemical capacitance than each individual component as supercapacitor electrode materials.Such intriguing electrochemical performance is mainly attributed to the synergistic effects of MnO2, PANI and GOs. The hierarchical ternary nanocomposites show excellent electrochemical properties for energy storage applications, which evidence their potential application as supercapacitors.

For the principle of green sizing, the key research on sizing technology which reduce the degree of COD in wastewater of sizing was carried out. PVA and modified starch slurry was gradually replaced by hemp pole cellulose ether and modified starch slurry, and the original formula was optimized. After valuing viscosity and COD of the slurry, several suitable formulas were chosen. Then experiments on the same batch of hemp/cotton blended yarn sizing were carried out, and the sizing enhancement rate, stretching rate and the increasing grinding rate were tested. Through the comparative analysis, the COD of hemp pole cellulose ether slurry with modified starch is lower than that of PVA slurry with modified starch. Meanwhile, with the certain compound rate, the former sizing performance is better than the later.

Fe3O4microspheres and its composities with graphene are prepared by the controlled thermal decomposition of an iron alkoxide precursor, which are obtained via an ethylene glycol (EG) mediated solvothermal reaction of ferric chloride hexahydrate (FeCl3·6H2O) and sodium acetate (NaAc) with graphene dopings. The resulting Fe3O4microspheres are uniform with a diameter of 0.2-0.5μm. Electrochemical properties of both Fe3O4microspheres and Fe3O4/graphene composites are discussed. SEM analysis shows that a large number of Fe3O4particles with spherical morphologies are homogeneously anchored to the rGO sheets surface. Electrochemical results showed that charge and discharge capacities for Fe3O4/graphene composites are larger than those for Fe3O4microspheres electrodes after the 30th cycles which due to the synergistic effect of Fe3O4and graphene. Graphene improves the electronic conductivity of Fe3O4microspheres and increases the interfacial contact area between the Fe3O4microspheres and electrolyte which is benefitable for lithium ion battery. So Fe3O4/graphene composites are better anode materials than Fe3O4microspheres.

We utilized pressure-, vacuum-, and evaporation-assisted self-assembly techniques through which graphene oxide (GO) was deposited on modified polyacrylonitrile (mPAN). The fabricated composite GO/mPAN membranes were applied to dehydrate 1-butanol mixtures by pervaporation. Varying driving forces in the self-assembly techniques induced different GO assembly layer microstructures. XRD results indicated that the GO layer d-spacing varied from 8.3 Å to 11.5 Å. The self-assembly technique with evaporation resulted in a heterogeneous GO layer with loop structures; this layer was shown to be hydrophobic, in contrast to the hydrophilic layer formed from the other two techniques. From the pressure-assisted technique, the composite membrane exhibited exceptional pervaporation performance at 30 °C: concentration of water at the permeate side = 99.6 wt% and permeation flux = 2.54 kg m-2 h-1. This excellent separation performance stemmed from the dense, highly ordered laminate structure of GO.

In the present study, cotton fabric has been dyed with natural indigo (Indigofera tentoria) in absence and present ferrous sulfate mordant by using post-mordanting and pad-batch processes. It was observed that with an increase in the dye concentration, the ultraviolet (UV) protection factor (UPF) values good for the cotton fabric. Cotton fabrics dyed with natural indigo showed greenish-blue shade. The fastness properties ranged from good to very good, level. The results confirmed that natural dyes from natural indigo with ferrous sulfate have potential applications in fabric dyeing and in producing UV-protective cotton fabrics.

In the present study, natural dye from cob of purple corn and various metallic salts have been used to identify the proper dyeing condition for attaining high quality natural dyeing along with imparting UV protection property to the dyed silk fabric. Silk fabrics dyed with cob of purple corn extract showed a violetish-pink shade, while those dyed with alum light violetish-pink shade colour. Silk substrates dyed with CuSO4 and FeSO4 gave a yellowish grey and violetish-gray colour, respectively. The fastness properties ranged from fair to good. The ultraviolet protection factor (UPF) values of silk fabric dyed with and without metal mordants ranged between very good and excellent.

The nanocrystalline (NC) and ultrafine-grained (UFG) structures of metallic materials can lead to their extraordinary high strength. However, most of the papers on this topic consider deformation parameters of NC and UFG materials only for the case of quasi-static tensile tests. Characteristics of dynamic strength and fracture of such materials remain unexplored. This paper presents a study of the mechanical behavior of pure titanium Grade 4 with a coarse-grained (CG) and UFG structure under uniaxial compression with different strain rates. The UFG structure was provided using the method of equal-channel angular pressing. The dynamic compression was carried out on a setup with the Split-Hopkinson pressure bar. It is found that in the observed range of strain rates 10–3-3×103 s–1, the yield stress of the CG titanium increases by 20%, and does not exceed the yield stress of the UFG titanium. However, the yield stress of the UFG titanium remains close to a quasi-static value. It is shown that these strain-rate dependencies of the yield strength can be predicted by the incubation time approach. The calculated curves show that at strain rates above 104 s–1 the yield stress of the CG titanium becomes higher than the yield strength of the UFG titanium.

The paper presents some aspects regarding the wetting conditions in aluminium – graphite composite. The wettability depends on several factors like the presence of the oxide skin at the melt surface, formation Al4C3 at the interface between Al and particles, temperature, pressure etc. In this paper, the conditions of perfect wettability of carbon by molten Al achieved under MCl–K2TiF6 molten salts (fluxes), alloying of the melt with surface active elements, heat treatment of reinforcement material and coating of the particles with a metallic thin layer.

Silicon nitride ceramic balls are successfully applied in advanced bearings. In order to improve the performance and precision for ball bearings, the research about the material properties of Si3N4 ball is shown in this paper. For the Si3N4 ball, the material properties can be described by the following factors: density, hardness, apparent porosity, crushing load and fracture toughness. In this paper, Si3N4 balls from three different manufacturers are tested to reveal the inherent correlations of the material properties, and the correlation coefficients are calculated. The results indicate that with the increasing of ball diameter, its crushing load increases correspondingly. The higher hardness contributes to the lower crushing load of the Si3N4 ball. Apparent porosity has a greater influence on the crushing load than hardness and the density. Hardness has the closest relevance with fracture toughness among the material characteristics, with the increasing of the hardness, the fracture toughness of Si3N4 ball becomes lower.

The polymer concretes characterize with very high chemical resistance, achieved through the use of high-quality polymers and aggregates. The paper discusses the possibility of using the waste perlite powder, the very fine by-product of manufacturing and use of expanded perlite, as the component of polyester concrete (PC), in terms of the durability of concrete under chemical attack. Partial substitution of original microfiller (usually the quartz or calcium carbonate powders) of polymer concretes by the perlite powder is one of the potential ways of disposing this waste. In the paper the polyester concretes of various quantitative compositions, thus various waste perlite powder content, were exposed to the chemically aggressive environment. The compositions were designed on the basis of statistical design. The tested composites contained the unsaturated polyester used as the binder, the standard sand and crushed granite gravel of fraction 2-4 mm used as the basic aggregates and mix of quartz and perlite powders used as the microfiller. The specimens of concretes were exposed to the solution of potassium hydroxide of concentration of 5% for 60 days. The measure of polyester concrete resistance to potassium base were changes in mass and changes in the mechanical strength (flexural and compressive strength) of specimens subjected to chemical attack in comparison to specimens chemically unloaded. Additionally the visual inspection of the specimens outer surface and fracture surface after the flexural strength test were conducted.

In this paper there are presented results of research carried out for establishing the most favourable scenario of curing of the Polymer-Cement Concrete (PCC). The general recommendations for PCC point to the need of alternating conditions of curing of PCC. Polymer-cement concrete should be first cured in the wet conditions for effective hydration of Portland cement and then in air-dry conditions for polymer setting. According to the literature, the often accepted curing regime of PCC covers 5 days of wet curing and then the air-dry curing until the time of testing. According to the European Standards, the wet period should last 3 days. However, the authors` experiences show that the aforementioned scenarios is not the optimum one. The studies presented in this paper are the part of the larger research program, which – according to the authors` intention – should lead to the establishing of the optimum curing regime for PCC. The tests were carried out using two types of polymer modifiers: two-component epoxy resin and water dispersion of polyacrylates, introduced into the cement concrete mix. The following properties were accepted as the criteria of evaluation of PCC curing effectiveness: compressive strength, tensile splitting strength, surface tensile strength (by pull-off method), wear resistance, water penetration under pressure. These properties were evaluated after 28 days of curing according to the various regimes. The tests showed that the extension of the wet curing period beyond 5 days was favourable for the technical properties of PCC. The establishing of the optimum time of wet curing, however, needs further research. Also, some conclusions were formulated about the usefulness of the various properties as the criteria of PCC curing efficiency evaluation.

Surface protection by hydrophobic impregnation and surface coating are widely used for concrete bridges located at coastal area in Japan. This paper deals with the improvement of adhesion between surface coating and hydrophobic impregnated concrete by different types of silanes and by invastigating surface treatment methods. As a result, adhesion between hydrophobic impregnated concrete and epoxy-based surface coating were improved by applying abrasive paper, portable electric grinder, solvent or diluted hydrochloric acid treatment. Especially, using portable electric grinder gave a remarkable improvement to the adhesive property. Also, hybrid-surface protection system consisting of surface coating and hydrophobic impregnation was discussed to prevent blistering.

We investigated the mechanical and antiburning properties of composites of organic and inorganic domestic wastes. A lot variations of composition: organic content, paper content, plastic content, and textile content as well as binding material, polyvinyl acetate (PVAc) we conducted to obtain the optimum set of synthesis parameters. The process was made using a simple mixing and hot pressing steps. We obtained a maximum mechanical strength of 67.64 MPa for composite processed at the following parameters (expressed in weight fraction): PVAc: organic: paper: plastic: textile = 18.18: 54.55: 15.15: 6.06: 6.06. The produced composites were then simple mixed with an antiburning material and then hot pressed to obtain fire retardant boards.

Rapid developments in telecommunications and digital processing of information are facing the problem of electromagnetic wave pollution and interference. The aim of this article is the characterization at microwave frequencies of composite materials based on silicone rubber. These materials contain 80% siloxane rubber and only 20% powdery feeling like nanocarbon and pyrite cinder. To achieve these objectives were reviewed and selected raw materials and characteristics were determined in a structural material, the electromagnetic attenuation as well as electrically, by making measurements of electrical conductivity of thin layers of polymer matrix composites produced by the doctor blade technique. Starting from sample siloxane rubber, i.e. without additives or filler reinforcement in compression analysis we find that reinforcing agents leads to increased values of the modulus of elasticity in especially for pyrite ashes. For materials analyzed in this paper, measurements were made in the frequency range between (1-18) GHz and have found high attenuation over 45 dB in the case of composite materials with pyrite ash filler. So we can say that this materials can used for shielding against electromagnetic waves in order to protect the human factor. The novelty of the paper consists in the compositions of the specimens and their mechanical and electromagnetic characteristics.

Nanotechnology has become a driving power in most of the branches of industry recently and construction industry is not an exception. Therefore, this paper deals with the topical problem of using nanoparticles in concrete. Carbon nanotubes (CNTs) with exceptional physico-mechanical properties were used in the experimental part of the paper. Their potential for enhancing characteristics of common concrete is promising. A frequent problem of application of carbon nanotubes is their agglomeration, which is caused by high surface tension, Van der Waals force and high ratio of sides. This fact limits possibilities of application of CNTs and it is the main reason of rare use of the promising potential of CNTs. Formed agglomerations can be dispersed by adding energy from outside and if suitable surface active agent in the solution of CNTs and water is added, their re-agglomeration can be prevented. Experimental part of the paper focuses on possibilities of dispersing CNTs by means of ultrasonic homogenizer Bandelin Sonopulse HD 3200 and suitable surface-active substance. Tests specimens were prepared from a suspension of water and CNTs with two different proportions and development of physico-mechanical properties in time was observed. Results confirmed the trends described in foreign literature sources and gave valuable impulses for further attempts to use nanotechnology in concrete technology.

The paper presents the results of studies the deformation behavior of aluminium alloy D16 by acoustic emission (AE) method. The purpose of this study was to establish the deformation stages and deformation mechanisms at each stage. Studies were carried out on the samples of aluminum alloy D16 (analog 7075). This paper contains a method for the separation of AE signals. The method of AE sources identification based on the the two-parameter distribution analysis (frequency parameter Kfvs energy of AE signals). The frequency parameter Kf is based on wavelet transform of AE signals. Two-parameter distribution allows one to separate the AE signals emitted by dislocations from the signals of micro cracks. The investigation results allowed the various deformation stages to establish by the different types of AE signals. By the AE analysis shows the dislocation mechanism of hardening the aluminum alloyD16. The paper presents the results that characterize the influences of heat treatment and structural condition of aluminum alloy on the AE parameters.

The paper presents the results of experimental research on the wear mechanism of the tool-electrode as a result of machining metal materials by applying electric discharges in pulse. It examines several phenomena noticed on the tool - electrode surface, exactly, the oxide layer formation and the modification of the micro geometry of the tungsten tool electrode surface. The paper presents the experimental results on the behavior of the tool electrode made of stainless steel after the metal parts have been machined. It also presents the phases of mass transfer in the gap between electrodes.

Nitrile butadiene rubber (NBR) comes into widespread applications due to the excellent performances, but it is susceptible to aging during its storage and usage periods. This paper surveys the external factors that act on the aging process of NBR. The aging of NBR in liquid environment, and non-liquid environment such as thermo-oxidative aging, ozone aging, stress aging and radiation aging, are considered. The emphasis of present works is test of physical and mechanical properties of NBR, and the micro analysis should gain special attention. One direction of future research on NBR aging is the coupling effects of various factors included in this paper.

The microwave differential thermal analysis (MW-DTA) is a new procedure to evaluate the materials, barium ferrite type M in this paper, according to the phenomena appeared during the material heating. The paper presents a new evaluation technique which is faster and with low energy consumption. The microwaves are used to heat the material, two infrared pyrometers for monitoring the temperatures on the material surface and a temperature regulator where the data are recorded for evaluation. The material, a homogeneous mixture of Fe2O3+BaCO3, is a ceramic material with good absorbance properties, so the heating will be pure microwave heating. The results and the DTA graphic is automatically generated by the temperature recording device based on the data sensed by the infrared pyrometers. The paper presents technical aspect regarding to the microwave heating and temperature measurement in microwave field and how to make differential thermal analysis in microwave field.

The effects of grain sizes and oxygen impurities on thermal conductivity in aluminum nitride (AlN) ceramics has been calculated by density functional perturbation theory (DFPT) and quasi-harmonic approximation (QHA) combined with Debye theory in the paper. From 300K up to 1000K, the predicted thermal properties are compared with experimental data. The agreements with experiment suggest that the theoretical method used in the paper is an effective approach. From our theoretical study, the reduction of thermal conductivity is greater between grain sizes of 1μm and 5μm, while it’s smaller between 8μm and 10μm. Oxygen defects bring about greater influence on thermal conductivity at low temperature than at high temperature. The influence of the oxygen defect is not as significant as the grain sizes when the oxygen concentrations are less than 0.70 at. %, so it’s more important to increase the grain sizes than reduce the oxygen contents in the preparation process to achieve high thermal conductivity AlN ceramics.

Composite materials are the most advanced class of materials invented and produced by humans in modern times as well as a challenge for the future in the field of scientific and technological performance. They are made up of at least two phases of different nature which are so combined to form a new material with a superior combination of properties. They are generally materials with unusual performances on the relationship between properties and specific gravity. Composites are multiphase materials with distinct and well-defined interface between the constituent phases ensuring a transfer of property but can lead to obtaining a product with exceptional performance from the starting material. In this paper we have focused research on Al-Mg alloys with magnesium and silicon carbide (SiC). Stabilized Aluminium Foams (SAF) are new class of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They offer potential for lightweight structures, for energy absorption, and for thermal management; and some of them, at least, are cheap. Metal foams offer significant performance gains in light, stiff structures, for the efficient absorption of energy, for thermal management and perhaps for acoustic control and other, more specialized, applications. They are recyclable and nontoxic. They hold particular promise for market penetration in applications in which several of these features are exploited simultaneously. The paper presents some results related to the research of metallic foams based on AlMg10 metallic alloy obtained by melt bubbled C4H10 addition of SiC particles. Microsrtucture of these foams is analyzed by using (SEM) Scanning Electron Microscope, laying out the network of pores imbued into each others developed around SiC particles and other issues microstructural characteristics.

Cutting technology is one of the important methods to fabricate small-sized precision components in the semiconductor, electro-mechanics, and automobile industries. This paper focuses on high efficiency machining of small hole drilling for PPS (Polyphenylene Sulfide). In this paper, drilling experiments were designed to investigate the influence of the depth of cut on the burr formation. The experimental results obtained are as follows, (1) The thrust force and radial force increase with the increase in feed per revolution and depth-of-cut. (2) On the prevention of burr formation, the step feed is better than the non-step feed. Also, the burr formation decreases with the increase in the feed per revolution. (3) The hole straightness increases with the increase in depth-of-cut.

The composite extrusion process, which is investigated at the Institute of Forming Technology and Lightweight Construction (IUL), allows the combination of different materials within an aluminum profile. In contrast to the useage of reinforcing elements, this paper focuses on the embedding of functional elements, such as isolated electric conductors. Results of the experimental and numerical investigations are presented within this paper.

The paper presents the theoretical bases of gas flow, as drowned jets, the device used for viewing the pure gas cone (argon) using a smoke screen infused on the edge of the argon jet and then the results of researches carried out on four sizes of nozzles often used in TIG welding. On each type of nozzle the argon flow parameter was varied and the height of the cone of pure argon was photographed and measured. The paper ends with the mathematical correlations that allow us to maximize the height of pure cone argon in relation to its flow. Keywords: TIG welding, Pure argon cone

Microchannel heat sink plays a vital role in removing a considerable amount of heat flux from a small surface area from different electronic devices. In recent times, the rapid development of electronic devices requires the improvement of these heat sinks to a greater extent. In this aspect, the selection of appropriate substrate materials of the heat sinks is of vital importance. In this paper, three boron-based ultra-high temperature ceramic materials (ZrB2, TiB2, and HfB2) are compared as a substrate material for the microchannel heat sink using a numerical approach. The fluid flow and heat transfer are analyzed using the finite volume method. The results showed that the maximum temperature of the heat source didn’t exceed 355K at 3.6MWm-2 for any material. The results also indicated HfB2 and TiB2 to be more useful as a substrate material than ZrB2. By applying 3.6 MWm-2 heat flux at the source, the maximum obtained surface heat transfer coefficient was 175.2 KWm-2K-1 in a heat sink having substrate material HfB2.

The aim of this paper is to perform a study on how the elevated temperature and gradient of temperature affect the natural frequencies of aluminum honeycomb plate. This study is carried out for temperature range between 200K and 800K, and gradient temperature (ΔT) across the thickness direction of the plate between [0-500K]. Different honeycomb plate geometries have been selected for the analysis, by changing the core thickness, skins thickness and cell size. The obtained results show that the effect of the temperature is noticeable. At temperature 800K, the natural frequencies decrease by 16.1% in comparison to their values at ambient temperature (300K). That means, high temperature makes the material suffers from weak rigidity, which furthermore contribute to high decrease of all the frequencies. In addition, investigations carried out in this work relate to the modal analysis of the honeycomb plate, under various gradients of temperature across the core of the plate. The obtained results show that the gradient of temperature has an effect on the modes of vibration of the honeycomb plate. This effect becomes significant when the gradient of temperature is very high. At ΔT equal 500K, the natural vibration modes decrease by 9.5% in comparison to the case where no gradient of temperature (ΔT = 0K) is applied between the two faces of the plate. Keywords: honeycomb panel; aluminum; natural frequency; finite element method; temperature.

Zirconium alloys are solid solutions of zirconium or other metals. Zirconium has very low absorption cross-section of thermal neutrons. Zirconium has high corrosion resistance, ductility and hardness. Zirconium is mainly used as a good refractory metal. Zirconium can be manufactured by using standard fabrication techniques. In the present scenario zirconium alloys are used in water reactors for the cladding of fuel rods in nuclear reactors in nuclear technology. We use the composition of zirconium alloys as more than 94.5 weight percentage of zirconium and less than 2.45 weight percentage of copper which are added to improve mechanical, thermal properties and corrosion resistance. This paper first focuses on the study of thermal properties of Zirconium. And this particularly concentrated on variation of Coefficient of Thermal Expansion by varying temperatures by using Dilatometer and as well as ANSYS

Friction Stir Welding, abbreviated FSW is an innovative joining process. The FSW is a solid-state welding process with a lot of advantages comparing to the traditional arc welding, such as the following: it uses a non-consumable tool, it results of good mechanical properties, it can use dissimilar materials and it have a low environmental impact. First of all, the FSW process was developed to join similar aluminum plates, and now, the technology was developed and the FSW process is used to weld large types of materials, similar or dissimilar. In this paper it is presented an experimental study and the results of it, which includes the welding of three dissimilar aluminum alloy, with different chemical and mechanical properties. This three materials are: AA2024, AA6061 and AA7075. The welding joints and the welding process were analyzed considering: process temperature, micro-hardness, macrostructure and microstructure.

This paper designed and completed the different polymer dosage of recycled concrete, was prepared by adding amount was 7%, 14%, 21%, 14% styrene butadiene latex recycled concrete, recycled rubber powder recycled concrete and ordinary concrete block, the cube compressive strength and damping performance test. The cube compressive strength of concrete test according to the ordinary concrete mechanics performance test methods, specimen is 150×150×150 mm cube specimens, pressure testing machine loading speed is 0.5 MPa per second. The concrete damping performance test is carried out according to the free attenuation method, with the hammer vibration test device, the test piece is T type. Based on the damage form of specimens, the compressive strength and damping performance analysis, and compared with ordinary concrete as the benchmark analysis test results show that the polymer recycled concrete cube compressive strength failure process and failure pattern basic consistent with common concrete. In the water/cement ratio, sand ratio, and amount of material per unit volume is the same, under the condition of polymer recycled concrete cube compressive strength is lower than normal concrete, damping performance is higher than that of ordinary concrete, the compressive strength is inversely proportional to the damping sexual relations.

Ground granulated blast furnace slag, red mud, wheat straw ash are secondary material which after alkaline activation can be used in the construction materials’ domain. Their disposal poses a threat to the environment, whereas by reusing them we would be able to reduce this negative impact. This paper describes the research carried out in order to synthesise some geopolymer recipes, which are based on ground granulated blast furnace slag, red mud and wheat straw ash, alkaline activated with sodium hydroxide or a solution made with sodium hydroxide and sodium silicate. Factors that influence the compression strength have been studied such as: the nature of the alkaline activator, the chemical composition of solid materials in the recipes and the curing time. The geopolymer samples have been dried at room temperature for 7 and 28 days, respectively, and after the compressive strength tests has been made. Following this research it has been found out that NaOH/Na2SiO3 activated geopolymer samples have shown a higher resistance in the compressive strength. From the SEM analysis it has been found out that the samples with a higher amount of ground granulated blast furnace slag in their composition had a more homogeneous and less porous design than those with a smaller amount of ground granulated blast furnace slag.

Magnetorheological elastomers (MREs) are a kind of smart materials, which change the mechanical properties (viscoelastic characteristics) under the magnetic field action. In the paper the determination of damping properties (reactive force) of specimens made out of magnetorheological elastomers is presented. The specimens made out of MREs have been fabricated as a composite with matrix made out of silicone rubber with certain contents of magnetisable particles (carbonyl iron powder). The cylindrical specimens have been tested in compression loading, controlled by an electro-mechanic system. The MRE characteristics of the specimens have been determined in the presence of a magnetic field produced with an electromagnet (coil device). The reactive force occurring in the MRE specimen has been determined on the basis of the measured data during loading. The variation curves of the reactive force versus magnetic field induction are drawn. As a conclusion, the rigidity of the MRE specimen is increasing since the magnitude of the magnetic field induction is increasing.

Carbon fiber reinforced silicon carbide composite (Cf/SiC) is the new high temperature ceramic composite developed in recent years, widely used in the aviation, aerospace and other high-tech fields. In this paper, a variety of joining methods of Cf/SiC composite to metallic materials, including active filler brazing, solid phase diffusion welding, liquid infiltration joining, as well as chemical vapor deposition of niobium transition joining technology were introduced. At the same time, the features and disadvantages of each technique were evaluated. This review is intended to provide a comprehensive guide to the design and application of Cf/SiC composite joining to metals.

This paper studies how the addition of Carbon nanotubes (CNT) influencing the properties, especially the mechanical properties and colorimetry of ethylene propylene diene rubber (EPDM)/SiO2 composites. The results show that the increased content of CNT can turn EPDM/SiO2 composites from lighter, redder, and yellower to darker, greener and bluer, respectively. The total color change (ΔE) of EPDM/SiO2 composites would be acceptable when the CNT content is below 3%. When the CNTs content reaches 4%, the tensile strength of EPDM is the maximum.

The mechanical properties, including the compressive strength, flexural strength and adhesion strength of the rapid setting conventional and polymer-modified waterproof mortars are systematically compared in this paper. The polymer modification is demonstrated to increase the flexural strength and adhesion strength of the rapid setting waterproof mortar whereas it reduces its compressive strength.

In this paper, molecular dynamics (MD) model is explored to study single-crystal nickel micro-nanomachining mechanism. Accordingly, LAMMPS would implement the simulation of nanometric cutting process, and snapshots at different steps are obtained by VMD and OVITO. On this basis, a reasonable explanation is given to the forming mechanism of chip and surface machined in the machining process of single-crystal nickel. The result of work-piece temperature distribution shows that there is a temperature gradient around the machining zone, where chip part achieved the highest temperature. Moreover, a large number of dislocations are observed. Part of dislocation atoms move forward and generate the chips, taking a lot of heat. Another part of dislocation atoms combine with the work-piece surface atoms with elastic recovery, and form the machined surface.

Multilayer coating onto orthopedic implants has been studied extensively due to their excellence mechanical and biological properties. A multilayer coating was coated onto metal implants to prevent the leaching of metallic ions into human body. This paper aims to study the hardness of multilayer coatings of Chromium (Cr), Chromium Nitride (CrN), Chromium Carbonitride (CrCN) and Zirconium Nitride (ZrN) by Physical Vapour Deposition (PVD). The deposited multilayer coating was characterised by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Energy Dispersive X-ray (EDX). Cr, CrN, CrCN and ZrN have been successfully deposited onto stainless steel substrates by PVD. XRD analysis detected major peak in preferred orientation of (200) and other peaks with (111), (220), (311) for CrN cubic phase. For CrCN, XRD analysis detected only low intensity peaks of Cr7C3 and ZrN peaks with preferred orientation of (111), (200) with other peak (220), (311) and (222). Microvickers Hardness results showed an increment in hardness value from substrates with 160HV to 174HV for Cr, 236HV for CrN, 362HV for CrCN, 364HV for ZrN and 370HV for multilayer coatings.

Lithium tantalate (LiTaO3) has piezoelectric, electro-optical and nonlinear optical characteristics, and a wide transparency range going from ultraviolet to infrared. It is desirable that LiTaO3 wafer was a smooth surface in order to function with good quality. Chemical mechanical polishing (CMP) has been used to planarize integrated circuits (ICs) or obtain a high surface quality of the substrates. This paper investigates the effect of citric acid as an additive in the slurry for LiTaO3 CMP. The roughness of the wafers was measured by an atomic force microscopy (AFM, XE-100) after polishing. The slurry, which contains citric acid as an additive, has a higher material removal rate and friction force than a slurry without an additive. After polishing, the surface roughness of the LiTaO3 wafer can be reduced down to 1.7Å of Ra.

Fly ash is a pozzolanic material which is produced during coal combustion in thermal power plants. This paper investigates the suitability of Malaysian fly ash for geopolymer synthesis. Chemical composition analysis, particle size analysis, amorphous and crystalline phases present, bonding nature, and microstructural behavior are used to determine the suitability of fly ash for geopolymer synthesis. The results showed that fly ash contains silica, alumina, ferrous oxide, and calcium oxide in major proportions which are the main ingredients required for geopolymer synthesis. Higher portion of particles having size in the range of 1-15 µm. Fly ash contains quartz, mullite, and ferrite as the crystalline compounds while the major portion of fly ash is in amorphous form. The band due to asymmetric stretching vibration mode of Si-O-T appears at 1095 cm-1 which is the main band used to follow geopolymer formation. Microstructure of fly ash shows that the higher portion of fly ash is in amorphous form while it contains cenospheres, magnetic spheres, carbon, and a large number of small particles. Malaysian fly ash is a suitable material for geopolymer and it can be used for geopolymer synthesis.

The aim of this paper was to investigate the effects of cross-linked reaction on physicochemical properties of chitosan film by using genipin as cross-linker agent. Series of chitosan film samples with different amount concentration of genipin loaded (0-3 wt %) were prepared and characterized. The physicochemical properties of films were evaluated by Fourier Transform Infra-red (FTIR), UV-vis spectroscopy, Oxygen Transmission Rate (OTR), Scanning Electron Microscopy (SEM), water vapour and tensile test. The cross-linking reaction had affected on colour changing of chitosan film samples from light yellow to dark blue in line with the increasing of genipin concentration. Thus, UV-vis spectroscopy on the cross-linked samples showed the absorbance value at 600 nm wavelength due to genipin content. FTIR observation on cross-linked film samples showed no characteristic of –OCH3 peak from genipin at 1444 cm-1 which resulted by new covalent bonding occurred between chitosan and genipin. Cross-linking also had increased the oxygen barrier and reduced the water vapor rate through the film. Chitosan film sample with addition of 1 wt% genipin achieved the highest tensile stress average at 49.46 MPa compared to other samples while percent of elongation at break reduced with the increasing of genipin concentration loaded

The development of optical fibre temperature indicator using epoxy glue as a detection membrane is presented. This study, investigates the effects of epoxy glue from the reaction of epoxy resin, bisphenol A (BPA) (80-05-7) and adhesive epichlorohydrine (ECH) (106-89-8) as a temperature indicator membrane. In this work the response of epoxy glue to excitation source 395 nm is tested and analyzed under cryogenic conditions. A fiber optic temperature sensor for detecting ambient temperature ranging from 15 °C to 80 °C has been examined. The epoxy glue fluoresce when excited with UV-blue light source. The intensity of the fluorescence of the material decreases when the epoxy glue is exposed to an environment of higher temperature. These decrease level of fluorescence signal has been used to indicate temperature. In this paper, the basic principle of operation, development process and emission response characteristics of this sensor are discussed.