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This paper has been investigated on the electric field distribution in 3-phase power cables by using individual and multiple nanoparticles inside insulation part based on recent theoretical approaches. It has been studied the effect of multiple nanoparticles arrangement in polymeric material for controlling on electric field distribution inside power cables insulation. Also, this work has been succeeded to obvious the effect of types and concentrations in nanocomposites and multi-nanocomposites for controlling on dielectric strength of power cables insulating materials. A comparative study has been held about the industrial features of using multiple nanoparticles against individual nanoparticles and traditional industrial materials. [ABSTRACT FROM AUTHOR]

The understanding of a material's response to shock loading (or any other loading regime) requires knowledge of microstructural development during the loading process. Given that many engineering materials have complex microstructures consisting of individual grains of different orientations, textural effects and the possibility of multiple phases, the mechanical response can be cumulative in nature, making the individual aspects difficult to isolate. Matters can be simplified for example by examining the response of single crystals, where many, if not all of these additional features can be eliminated. In this paper, we investigate the microstructural response of single crystal tantalum, orientated in the principal ([001], [011] and [111]) orientations. Recovered samples have been shock loaded and released under full one-dimensional strain conditions, using a technique where all three orientations were loaded simultaneously in the same fixture. [ABSTRACT FROM AUTHOR]

The influence of the composition of cementitious materials on the resulting modulus of elasticity has already been investigated in detail. However, the question of which factors influence the value of the modulus of elasticity in the early stage of ageing of cementitious materials has not been completely solved yet. This paper deals with the development of the modulus of elasticity in cement pastes in the early age. The measurements were conducted on pastes with different water/cement ratios and with different amounts of plasticizer. The modulus of elasticity was determined based on continuous measurement using the ultrasonic method in the first 24 hours of ageing with simultaneous measurement of the internal temperature in the specimens. In addition to the measurement of the dynamic modulus of elasticity, the static modulus of elasticity test was also conducted at the age of 24 and 72 hours. [ABSTRACT FROM AUTHOR]

The efficiency of X-ray diffraction (XRD) method for quantitative estimation of elastic modulus in materials with gradient structure have been demonstrated in the paper. This method was used to calculate the elastic modulus for NiTi samples irradiated at a beam energy E= 15 J/cm² and pulse duration τ = 150 µsx. It is determined that the compared values of XRD elastic modulus E(hkl, ψ) and elastic modulus En obtained for the same samples by nanoindentation are close. [ABSTRACT FROM AUTHOR]

The massive use of composite materials in industrial applications involves developing more accurate and rigorous mechanical behavior models. One of the most common process is RTM (Resin Transfer Molding). This process begins to become more and more mastered either in small or large deformation through several works describing elastic, hyperelastic or even viscoelastic models. However, the geometries become more and more complex which can generate cyclic loading (loading + unloading). Furthermore, the existing models do not make possible to characterize and simulate the unloading phase. Indeed, dissipative phenomena of energy through (hyper)elastic models are not considered. Some works in the literature propose an approach to describe the hysteresis behavior under small strain. But, in most cases, the shaping step of the RTM process leads to unavoidable large strain. The study presented here therefore focuses on dry fabrics subjected to cycling loading under large strain. These types of loads require a dissipative approach often described by a hysteretic behavior. The model developed in this paper concerns the in-plane shear mode and use an innovative coupling between the additive decomposition of Green Nahgdi and the multiplicative decomposition of Krner Lee. This allow the use of the intermediate configuration which represents the condition of the woven material once no more loading is applied to it. Hence, the constitutive modelling presented here is formulated in total Lagrangian. This model is finally validated experimentally through a picture frame test. At the end, some finite element simulations of the shaping phase of the RTM process are made. [ABSTRACT FROM AUTHOR]

The 3D chaotic nature of paper makes it a very valuable source of random bits that can be extracted by optical probing and image processing. Moreover the same bit series can be re-extracted with a high probability when re-probing the same object sample. We present here the general approach used for the digital extraction. Some applications of such a True Repeatable Random Number Generator in Morpho-cryptography are described. [ABSTRACT FROM AUTHOR]

In this paper, we propose the information entropy of acoustic emission (AE) signatures as an index for assessment of degradation in materials. This is a new method for health monitoring of materials and structures that relies on the estimation of the information entropy from the AE signals detected, for example from cyclic fatigue loading of the materials. Different ways of calculation of the information entropy from AE signals are explored and discussed in this paper. As an example of the materials degradation, this study investigates the behavior of maximum entropy (Smax) at the time of the materials' failure using a series of fatigue cracking tests on titanium alloy, a material commonly used in certain aircraft structures. This paper describes the fatigue tests in which AE waves and features were measured and discusses the various approaches to estimate the information entropy corresponding to the detected AE. The results show that fatigue failure occurs at the same maximum entropy value regardless of the trajectory of the fatigue crack growth and loading conditions that caused the fatigue. [ABSTRACT FROM AUTHOR]

The flat, two dimensional materials play important role in the research and industrial applications in the last 15 years. The new materials with flat atomic structures are discovered almost every month. The focus of the paper is on the discrete modeling of the single layer molybdenum disulphide based material (SLMoS2). Two methods, based on the molecular statics and molecular dynamics of estimation of material properties and numerical simulations at the nanolevel are described and discussed. [ABSTRACT FROM AUTHOR]

A design of an experimental setup is presented in this paper. The experiment is aimed at determination of the electrical properties of building materials exposed to low temperatures. The primary objective of this research was to investigate the possibilities of electrical properties measurement and to identify weak points in the presented technique. Within this research, some initial data were obtained and presented and critical aspects of the measurement were identified. Based on that identification, objectives of further research were drawn. [ABSTRACT FROM AUTHOR]

Composite materials continually displace traditional materials in engineering. A composite material is a combination of two or more phases that are chemically distinct and insoluble; its properties and structural performance are superior to those of the constituents acting separately. The extensive use of composites will contribute to significant material and energy savings and, in several cases, it minimizesenvironmental pollution. Aluminium and its alloys occupy a third largest place among the commercially used engineering materials. New materials used in recent times are the aluminium metal matrix and hybrid composites (AMMHCs), which have the capacity to meet the demand for advancement in processing applications. Composites of aluminium matrix offer improved mechanical and tribological properties over conventional metals and are currently considered as potential lightweight material and well suited in the automotive, space, aircraft, defense, and other engineering sectors. Because of its high strength to weight ratio, high tensile strength, durability, high wear resistance it pursued composites of the metal matrix. In the preparation of metal matrix composites, several factors need to be considered, including the difficulty of achieving a uniform distribution of matrix reinforcement, high processing costs with methods other than casting, availability of low-cost reinforcement and, if required, composite machining after fabricating of product. The most widely used reinforcement materials in recent times are SiC, Al2O3, TiB2, B4C along with some fewer research reported on organic powders such as fly ash, rice husk, coconut husk, lignite ash to achieve a better combination of properties. The present paper reviews the recent development for the manufacturing of AMMCs, various processing methods, processing parameters, and mechanical propertiesto the synthesis of AMMCs composites. [ABSTRACT FROM AUTHOR]

The X-ray fluorescence (XRF) analysis with using synchrotron radiation (SR) is a powerful technique for resolving elemental composition of the different samples with high sensitivity. This technique is suitable for nondestructive multi-elemental analyses of heavy elements such as rare-earth elements. In this paper, the choice of optimal excitation energies for the determination of the trace amounts of the different rare-earth elements (REEs) from La to Lu by the SRXRF method was discussed. The SRXRF spectra have received at the synchrotron radiation (SR) station using radiation from the 9-pole wiggler on VEPP-4M at the Siberian Synchrotron and Terahertz Radiation Center (SSTRC). As samples the Russian and international standards of magmatic rocks (AGV-1, BCR-1, DNC-1, BIR-1, SGD-1A, and G-2) were used. This powerful technique should be useful for nondestructive analyses of rare-earth and heavy elements in geological, geochemical and archaeological samples as well as industrial materials. [ABSTRACT FROM AUTHOR]

Determination of thermal conductivity of porous building materials at high temperatures is of a great importance of today's materials engineering as it offers wide opportunities for practical applications. There are several methods to perform this measurement. An inverse analysis of an experimentally obtained temperature field in a one-sided heated sample seems to be the most promising technique as it enables to express the thermal conductivity as a function of temperature. The experimental monitoring of the temperature field is usually conducted by means of inbuilt thermocouples that are composed of various metal wires, depending on the temperature range applied. Anyway, metals in general have several times higher thermal conductivity than porous materials which leads to deformation of temperature field measured. Such a deformation may be then reflected in the following data processing and thus may load the results by systematic errors. This paper quantifies the influence of the thermocouple presence on the temperature field deformation as the first step towards the systematic errors elimination. It was revealed, that depending on the time of heating and thermocouple position, the temperature field deformation may reach up to 55 °C. These results were obtained using a three-dimensional computational modelling of heat transfer, in which the temperature fields of a simple specimen and a specimen with an inbuilt thermocouple were compared. [ABSTRACT FROM AUTHOR]

Material selection is a critical decision and one of the most important factors is to consider the design. Selection of the right material, which is a most important problem that mechanical and material engineers frequently encounter. In the literature, the problem which one or more decision maker take the best decision by considering more than one criterion from among more than one alternative. That is called the multi-criteria decision-making problem. So in this paper an effort is taken to priortize the best dental implant material by Fuzzy Ahp method on the basis of characteritstics of dental implant. [ABSTRACT FROM AUTHOR]

Dislocation is the most important defect of modern engineering materials involving structural and electronic application. Proper operation and understanding of dislocation also serve the basis for other characterization work. This paper deals with both underlying principles and practical aspects of dislocation characterization. Thin foil of electronic grade Cu is loaded into a double tilt specimen holder of Analytical TEM, JEOL JEM 1200EX. [001] Low Index Zone Axis was located with the aid of Kikuchi Lines. Two-Beam Condition was achieved for [2̄00] [2̄20] g vector. Bright Field and Dark Field Image of the Dislocation and their related Diffraction Patterns were taken at the Sample Edge. Dark field weak beam imaging has advantages in the accurate characterization of dislocations since the images produced by this technique meet all basic requirements for dislocation study. [ABSTRACT FROM AUTHOR]

An experimental study on superplastic forming behaviors and microstructure characters of commercial magnesium alloy sheet AZ31B is presented in this paper. The main experimental results show that the commercial magnesoium alloy AZ31B sheet has superplastic capability. For the received sheet without any pre-processing, the maximum elongation is 295%. The dynamic recrystallization and grain refinement can be found, In the case of temperature <350°C, and the grain growth appears if temperature >= 350°C. The superplastic behaviors can be improved by controlling the dynamic recrystallization and grain refinement. Some experimental results of free superplastic bulging are presented in this paper. The results show that influence of temperature on forming capability is much less than the influences of temperature on elongation. In addition, the maximum principle strain. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper presents experimental observation and modeling of time dependent energy localization occurring when a shock propagates along and through a grain boundary. This work is part of a larger program of investigation of the effect of grain boundaries on shock propagation in materials. The project is initially focused on the simplest of materials: a bicrystal. Our study covers the effects of grain orientation, the grain boundary angle, the boundary region, shock properties and the interplay between these in determining the characteristics of shock propagation. Ultimately, we will use this information as a basis for incorporation into models of polycrystalline materials. Some of the physics found in polycrystals is absent, but the use of simple, well-defined samples allows thorough measurements to be made. Laser-based experiments and diagnostics are used throughout, permitting us to perform the many experiments required in an economical way. NiAl was chosen as a suitable anisotropic material; single crystal and bicrystal samples were prepared. The EOS and single-crystal elasticity were estimated with ab fere initio quantum mechanics. Laser flyer impact and direct drive experiments, coupled with line-imaging VISAR, were used to test and refine the EOS, and to measure crystal plasticity. Initial models of bicrystals under shock loading have been developed, shock experiments have been conducted on bicrystals and recovered samples have been analyzed. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Measurement conditions and material properties have a significant impact on the dimensions of a part, especially for polymers parts. Temperature variation causes part deformations that increase the uncertainty of the measurement process. Current industrial tolerances of a few micrometres demand high accurate measurements in non-controlled ambient. Most of polymer parts are manufactured by injection moulding and their inspection is carried out after stabilization, around 200 hours. The overall goal of this work is to reach±5μm in uncertainty measurements a polymer products which is a challenge in today's production and metrology environments. The residual deformations in polymer products at room temperature after injection molding are important when micrometer accuracy needs to be achieved. Numerical modelling can give a valuable insight to what is happening in the polymer during cooling down after injection molding. In order to obtain accurate simulations, accurate inputs to the model are crucial. In reality however, the material and physical properties will have some variations. Although these variations may be small, they can act as a source of uncertainty for the measurement. In this paper, we investigated how big the variation in material and physical properties are allowed in order to reach the 5 μm target on the uncertainty. [ABSTRACT FROM AUTHOR]

Non-destructive inspection of carbon-fiber-reinforced (CFR) composites applied in aerospace industry attracts a wide attention. In the paper, high frequency focused ultrasound (50-100 MHz) has been applied to study the bulk microstructure of the CFR material and mechanisms of its destruction under the mechanical loading. It has been shown impulse acoustic microscopy provides detecting the areas of adhesion loss at millimeter and micron level. Behavior of the CFR laminate structure fabricated by prepreg or infusion technology has been investigated under the tensile and impact loading. [ABSTRACT FROM AUTHOR]

After the major severe accident in nuclear reactor, there has been lot of concerns regarding long term core melt stabilization following a severe accident in nuclear reactors. Numerous strategies have been though for quenching and stabilization of core melt like top flooding, bottom flooding, indirect cooling, etc. However, the effectiveness of these schemes is yet to be determined properly, for which, lot of experiments are needed. Several experiments have been performed for coolability of melt pool under bottom flooding as well as for indirect cooling. Besides these tests are very scattered because they involve different simulants material initial temperatures and masses of melt, which makes it very complex to judge the effectiveness of a particular technique and advantage over the other. In this review paper, a study has been carried on different cooling techniques of simulant materials with same mass. Three techniques have been compared here and the results are discussed. Under top flooding technique it took several hours to cool the melt under without decay heat condition. In bottom flooding technique was found to be the best technique among in indirect cooling technique, top flooded technique, and bottom flooded technique. [ABSTRACT FROM AUTHOR]

The transient response for the solar cell when switched off from steady-state can provide useful information about the quality of the material used for fabrication of the device. In this paper we shall discuss the photovoltaic transients of amorphous silicon solar cells when switched off from open circuit configuration and illuminated by electrical pulse. The open-circuit voltage (Voc) decay can be performed by two methods, by optical excitation and by electrical pulse. When one of carriers has a concentration much higher than the other the photoconductivity is dominated by majority carriers; in that case the Voc decay which depends on the np product can be used as complementary method for obtaining information about the minority carriers. Also the series resistance drop in an electrical Voc decay method can be used to obtain a μτ product as an additional information regarding the material of the device. [ABSTRACT FROM AUTHOR]

Electrical Discharge machining (EDM) is a nonconventional machining technique, which has been commonly used to create dies and mold. Harder Materials can be machined into complex shapes as long as they conduct electricity. Recent advances in the technologies brought the development of new engineering materials, which are hard to machine with traditional machining processes. EDM is capable of machining these materials; given these materials have an adequately high electrical conductivity. In EDM, Material removal rate (MRR) Tool Wear rate and surface roughness (Ra) are important performance measures. Numbers of ways are explored by researchers to improve and optimize MRR along with a reduction in tool wear rate (TWR) and surface roughness (Ra). This paper discusses researches on EDM, involving the enhancement of MRR in conjunction with a little insight into material removal mechanism. [ABSTRACT FROM AUTHOR]

Slag and fly ash are the most commonly used industrial materials as a replacement for mortar which helped to reduce CO2 emissions. The activation of fly ash and slag with lime mortars have been studies in this paper. The parameters of the processes studies are: two kind of fly ash (Drax and Didcot), curing water pure and humidity room at 65%, and fly ash to-slag ratio (0/100, 10/90, 20/80, 30/70, 40/60, 50/50, 60/40, 70/30, 80/20, 90/10 and 100/0). The main tests are flexural strength and compressive strength. Six samples were prepared for each percentage for both kinds of fly ash, and then curried for 56 days to be ready for test. The results showed that the influence of water pure curing on the development of strength is higher than the influence of humidity room. The samples cured in water showed higher strength than those cured in the humidity room. At 56 days, the highest compressive strength and flexural strength were obtained for samples having 30% of Didcot. [ABSTRACT FROM AUTHOR]

In this paper, the results of studies on cobalt-molybdenum catalysts based on modified carbon-mineral materials derived from sapropel are presented. The influence of the modified raw materials method on the textural and acid-basic characteristics of the support and properties of the obtained catalysts in the hydroconversion of 1-methylnaphthalene and dibenzothiophene is shown. It has been found that an acid treatment has the maximum effect on the activity of cobalt-molybdenum catalysts based on carbon-mineral materials from sapropel, allowing a conversion of methylnaphthalene to be increased by 28 times and for dibenzothiophene – by 37 times, compared with the initial untreated sample. [ABSTRACT FROM AUTHOR]

Realistic lifetime prediction and testing procedures for solar mirrors have been demanded by investors, plant developers and material manufacturers during the last years. It has been proven that most of the commonly used accelerated aging tests, which were adopted from other industries, cannot be correlated to outdoor exposure. This work studies different accelerated aging test sequences and analyzes the produced degradation. The results made it possible to discover the most demanding environmental conditions for the three tested mirror types. The degradation of the mirrors was strongly affected by the share of the Copper Accelerated Salt Spray (CASS, ISO9227) testing time in the cycle. The CASS test was combined with several other aging tests and it was concluded that especially the combination with the UV/humidity test according to ISO16474-3 was harmful for the protective coatings of the tested silvered-glass mirrors. The conclusions from the testing campaign presented in this paper are helpful to design suited comparative accelerated aging testing procedures. [ABSTRACT FROM AUTHOR]

With the acceleration of urbanization in China, people put forward higher requirements for civil engineering building materials. This has also become an important part of the current research of relevant scholars. The development and application of new materials have gradually become an important part of the development of construction engineering. Civil engineering projects require a high degree of construction coordination, and are vulnerable to external factors, so the construction is comprehensive. Therefore, more and more attention has been paid to the construction materials used in civil engineering in various fields of the country and society. In this paper, combined with the characteristics of civil engineering construction, new civil engineering materials are studied and analyzed in depth, hoping to provide reference for relevant personnel. [ABSTRACT FROM AUTHOR]

In this paper, a finite element analysis based study of the effect of characteristic element length on the damaged response of a composite is performed taking into consideration the damage evolution concept and how it is implemented in the FEA tool ABAQUS. Various options available to define the damaged response of a material such as fracture energy and characteristic element length are studied using benchmark problems. In the study, only shell elements are considered which can also be extended to other element types with different degrees of freedom. [ABSTRACT FROM AUTHOR]

In this paper Treated Kenaf fiber/PLA based hybrid biocomposites are prepared by dispersing the different MMT (montmorillonite clay) contents by Screw extruder, Compression molding process. The PLA based bio-composites are fabricated with 30% of Treated (with 6%NaOH) Kenaf fiber and 1%, 2%, 3% nanoclay filler. The fabricated 70PLA-30TK, 30TKF- 1MMT-69PLA, 30TKF-2MMT-68PLA and 30TKF-3MMT-67PLA biocomposite are used to characterize the tensile, flexural properties of hybrid biocomposite. The 1 % MMT clay included PLA/treated kenaf fiber demonstrates superior mechanical properties than other biocomposite. SEM analysis discloses that MMT clay improves both micro-structure (morphology) and load transfer capacity. [ABSTRACT FROM AUTHOR]

This paper presents the multiple correlations between yield and tensile strength and content of silicon, manganese and magnesium of the 6082 aluminum alloy used to manufacture rims for road vehicles. The key of an alloy rims is the quality of the alloy and manufacturing technologies, in the case of cast rims manufacturing, their quality depends on the casting technology. Gradually, production of cast alloy wheels is replaced by plastic deformation, leading to a lower weight, improved physical and mechanical characteristics and better performances. [ABSTRACT FROM AUTHOR]

The paper introduces the multiple 2nd degree correlations between the hardness of the brake shoes used by the rolling stock and the content of carbon, phosphorus and sulphur of the phosphorous cast iron they are made of. The graphic correlations allow the determination of the variation limits for the independent parameters so as to range the values of the dependent parameters within a given domain. [ABSTRACT FROM AUTHOR]