scispace - formally typeset
Search or ask a question

Showing papers in "Advanced Materials Research in 2014"


Journal ArticleDOI
TL;DR: In this paper, the authors discussed the advantages of additive manufacturing of titanium alloys and the economic advantages of using additive manufacturing compared to conventional processed material. But, they focused on the work horse, the titanium alloy Ti-6Al-4V.
Abstract: High cost is the major reason that there is not more wide-spread use of titanium alloys. Powder Metallurgy (P/M) represents one cost effective approach to fabrication of titanium components and Additive Manufacturing (AM) is an emerging attractive PM Technique . In this paper AM is discussed with the emphasis on the “work horse” titanium alloy Ti-6Al-4V. The various approaches to AM are presented and discussed, followed by some examples of components produced by AM. The microstructures and mechanical properties of Ti-6Al-4V produced by AM are listed and shown to compare very well with cast and wrought product. Finally, the economic advantages to be gained using the AM technique compared to conventionally processed material are presented. Key words: Additive Manufacturing (AM), 3D Printing, CAD, CAM, Laser, Electron beam, near net shape, remanufacturing, Powder Bed Fusion (PBF), Direct Energy Deposition (DED)

203 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the fatigue behavior of as-built Ti-6Al-4V (Ti64) samples and found that lack-of-fusion (LOF) defects were primarily responsible for fatigue crack initiation.
Abstract: Additive Manufacturing (AM) technologies are considered revolutionary because they could fundamentally change the way products are designed. Selective Laser Melting (SLM) is a metal based AM process with significant and growing potential for the manufacture of aerospace components. Traditionally a material needs to be listed in the Metallic Materials Properties Development and Standardization (MMPDS) handbook if it is to be considered certified. However, this requires a considerable amount of test data to be generated on the materials mechanical properties. Therefore, the MMPDS certification process does not lend itself easily to the certification of AM components as the final component can have similar mechanical properties to wrought alloys combined with the defects associated with traditional casting and welding technologies. These defects can substantially decrease the fatigue life of a fabricated component. The primary purpose of this investigation was to study the fatigue behaviour of as-built Ti-6Al-4V (Ti64) samples. Fatigue tests were performed on the Ti-6Al-4V specimens built using SLM with a variety of layer thicknesses and build (vertical or horizontal) directions. Fractography revealed the presence of a range of manufacturing defects located at or near the surface of the specimens. The experimental results indicated that Lack-of-Fusion (LOF) defects were primarily responsible for fatigue crack initiation. The reduction in fatigue life appeared to be affected by the location, size and shape of the LOF defect.

151 citations


Journal ArticleDOI
TL;DR: An automatic approach is proposed that can determine the number of groups using silhouette coefficient and the sum of the squared error, which can generally find the optimum number of clusters, and can cluster the data patterns effectively.
Abstract: Clustering is an important technology that can divide data patterns into meaningful groups, but the number of groups is difficult to be determined. This paper proposes an automatic approach, which can determine the number of groups using silhouette coefficient and the sum of the squared error.The experiment conducted shows that the proposed approach can generally find the optimum number of clusters, and can cluster the data patterns effectively.

76 citations


Journal ArticleDOI
TL;DR: Wang et al. as mentioned in this paper made a brief review on shale gas formation conditions and the exploration and development projects already have been undertaken, hoping to provide some supports for the development of China's unconventional energy.
Abstract: Because the United States has achieved significant success on shale gas exploration and development, which makes a number of countries in North America, Europe to begin to make a series of exploration work [1]. China also launched China's first shale gas resource exploration project in Qijiang County, Chongqing in October 2009. According to the Shale Gas “Twelfth Five-year” Development Plan, the shale gas production will reach 60 - 100 billion cubic meters in 2020. This paper will make a brief review on shale gas formation conditions and the exploration and development projects already have been undertaken, hoping to provide some supports for the development of China's unconventional energy.

76 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the thematic of public-private economic negotiation in the realization of urban regeneration programs and present the economic negotiation between public and private that the Municipality of Reggio Calabria (Italy), with the technical and scientific support of the university laboratory of economic and appraisal evaluation (LaborEst), has promoted in recent years through two PUCs.
Abstract: This paper discuss the thematic of public-private economic negotiation in the realization of urban regeneration programs. The Complex Urban Programs (PUC) represent a generation of planning instruments generally in variation to ordinary instruments of general planning (PRG). These instruments found its legitimacy on new forms of concerted planning, in which the objectives are the effectiveness and efficiency of the public administration and the most important point of view are the quality and transparency of the negotiation between public and private. In these circumstances for the purposes of the feasibility, the arguments of urban planning must necessarily be supported by economic-financial considerations resulting from appraisals of the benefits financial and the new real estate values generated by the decision to promote the program in PRG variant. Particular attention must be paid on the modality for consultation between the public government, the owners and the developers when they comparing on mutual convenience as part of the PUC: the negotiation activities is the time during which the public body can capture a portion of land value generated by the choices of modify the PRG. The aim of this paper is the presentation of the economic negotiation between public and private that the Municipality of Reggio Calabria (Italy), with the technical and scientific support of the university laboratory of economic and appraisal evaluation (LaborEst) has promoted in recent years through two PUC. The two Complex Urban Programs are both located in the south of cities of Reggio Calabria (Italy). The paper describes in particular the model for appraisal of extrastandard charged by private entities participating in the two programs. The model developed by both authors is the result of their common research.

64 citations


Journal ArticleDOI
TL;DR: The successful formation of magnesium oxide nanoparticles was confirmed employing XRD, SEM-EDX and PSA analysis in this article, where the size of the particles was found to be 60-70 nm as deduced from XRD and SEM analysis.
Abstract: Nephelium lappaceum L. peels was effectively used for the synthesis of magnesium oxide nanoparticles as a natural ligation agent. The XRD and SEM revealed the crystallinity and spherical morphology of the biosynthesized nanoparticles. The size of the particles was found to be 60-70 nm as deduced from XRD and SEM analysis. The particle size of as-synthesized magnesium oxide powders measured by PSA was approximately 100 nm. The successful formation of magnesium oxide nanoparticles was confirmed employing XRD, SEM-EDX and PSA analysis.

61 citations


Journal ArticleDOI
TL;DR: In this article, a 2.2 µm titanium nitride coating was deposited by reactive sputtering on a silicon substrate, and the radius of curvature was measured, before and after coating by optical profilometer, considering the whole surface of the sample.
Abstract: Thin films’ residual stress is often determined by the Stoney formula, using the measurements of the substrate curvature, even if the required hypotheses are not completely respected. In this study, a 2.2 µm titanium nitride coating was deposited by reactive sputtering on a silicon substrate. The Stoney formula was used in order to calculate the residual stress of the film. The radius of curvature was measured, before and after coating by optical profilometer, considering the whole surface of the sample. The effect of the substrate shape (square and rectangular) with various dimensions was investigated. We showed that the shape of the substrate influence strongly the deformation. Moreover, it was highlighted that the choice of the radius (maximum value, minimum value, mean value, with or without initial curvature correction) is critical to the determination of the stress.

61 citations


Journal ArticleDOI
TL;DR: In this article, a spinel magnetite Fe3O4 nanoparticles were synthesized using rambutan peel waste extract as a green ligation and chelating agent.
Abstract: Spinel magnetite Fe3O4 nanoparticles were synthesized using rambutan peel waste extract as a green ligation and chelating agent. The green synthesized nanoparticles were characterized employing X-ray diffraction (XRD), Raman spectroscopy, FTIR spectroscopy and transmission electron microscopy (TEM) studies. The XRD study revealed spinel phase hda a magnetite structure. The formation of iron oxide nanoparticles using rambutan extract was confirmed employing IR studies. XRD, FTIR and Raman spectrum analyses all supports the synthesis of Fe3O4 nanoparticles. The TEM revealed the spinel morphology of the biosynthesized nanoparticles with 200 nm.

59 citations


Journal ArticleDOI
TL;DR: The analysis of results of power inspections and search of possible solutions of energy saving and increase of power efficiency of budgetary organizations (kindergartens) taking into account feature of these objects and justification of their economic efficiency is given in this paper.
Abstract: The analysis of results of power inspections and search of possible solutions of energy saving and increase of power efficiency of budgetary organizations (kindergartens) taking into account feature of these objects and justification of their economic efficiency is given in article.

57 citations


Journal ArticleDOI
TL;DR: In this paper, an economic analysis of investments in energy saving actions is analyzed and the model allowing to carry out the specified analysis is offered, and recommendations about reduction of payback periods are provided.
Abstract: Calculation of payback periods of the energy saving actions directed on increase of level of thermal protection of external enclosure structures of buildings is given. Economic efficiency of investments in energy saving actions is analyzed and the model allowing to carry out the specified analysis is offered. Recommendations about reduction of payback periods are provided.Article also is devoted definition of optimum, economically well-founded thickness of a insulant in systems of rear ventilated facades. Are resulted thermotechnical and economic calculations. The optimum thickness of the insulant in the given systems is offered.A number of the energy saving actions is necessary for economy of thermal energy, allowing to eliminate defects of protecting designs or to reduce their influence on building heatconsumption. Construction of hinged ventilated facades at simultaneous introduction of automated individual thermal points with automatic equipment dependent on weather [1] can become an example of the engineering decision on increase of heat-shielding properties of protecting walls.

55 citations


Journal ArticleDOI
TL;DR: In this article, each layer of an additively manufactured wall was rolled with the aim of reducing the residual stress, and the results showed that the residual stresses were reduced particularly at the boundary with the substrate.
Abstract: Wire + Arc Additively Manufactured components contain significant residual stresses that manifest in distortion. Each layer of an additively manufactured wall was rolled with the aim of reducing the residual stress. Neutron diffraction and contour method measurements show that the residual stresses were reduced particularly at the boundary with the substrate. The process also reduced distortion, and refined the microstructure which may facilitate implementation on aerospace components.

Journal ArticleDOI
TL;DR: The stages in the development of the theory of optimal problem in modern enterprise, which develops, including technical and economic issues tasking and optimal allocation of costs between projects, are described.
Abstract: Management Science develops naturally through the development of any science - from simple to complex, from simple to complex controls production control systems, spacecraft, etc. Now science has approached the management is perhaps the most difficult task – to control the person, team, organization, society. The fact that a man unlike any most complex technical system has the properties of activity, ie, its own goals, the foresight to achieve their goals is able to distort the information transmitted by the management body (able to deceive), and is also able to deliberately fail to perform prescribed tasks (plans). The task of managing such active objects and is the essence of the theory of active systems. This article briefly describes the stages in the development of the theory of optimal problem in modern enterprise, which develops, including technical and economic issues tasking and optimal allocation of costs between projects.

Journal ArticleDOI
TL;DR: In this article, the structural analysis of power consumption of the building of kindergarten is carried out, on the basis of the analysis of actual data of heatconsumption and the carried-out tool energy audit the data, allowing to estimate a condition of systems of heating, power supply, water supply.
Abstract: In article the structural analysis of power consumption of the building of kindergarten is carried out, on the basis of the analysis of actual data of heatconsumption and the carried-out tool energy audit the data, allowing to estimate a condition of systems of heating, power supply, water supply are obtained. Actions for energy efficiency increase are offered. It is shown need and economic feasibility of performance of the organizational and technical actions offered to realization on economy of thermal and electric energy.

Journal ArticleDOI
TL;DR: In this paper, a Zwick Z010 tensile testing machine is used to determine the tensile properties of polylactic acid (PLA) thermoplastic material in different build orientation.
Abstract: Fused Deposition Modelling (FDM) of thermoplastic materials is generally a well-known technology among all additive manufacturing (AM) technologies and therefore, it is essential to investigate the mechanical properties of such FDM processed materials. Several open-source and low cost AM machines, known as 3D Printers, have recently been developed using thermoplastic extrusion process based on the original FDM technology. Many of these 3D Printers use Polylactic Acid (PLA) plastic for building parts. The main objective of this paper is to investigate the tensile properties of the PLA thermoplastic material processed by the Cube-2 3D Printer. In this study, the dog-bone sized PLA specimens are printed in different build orientations and a Zwick Z010 tensile testing machine is used to determine the tensile properties of PLA in different build orientation.

Journal ArticleDOI
TL;DR: A detailed review of the current situation of exploration and development for shale gas in China is offered in this article, where the authors make suggestions concerning future exploration and exploration for this resource.
Abstract: Shale gas, which has been demonstrated as a rediscovered resource that might largely alleviate the increasing pressure for fuel demand, has been under extensive exploration and development in China. However, there are too few commercial shale gas plays discovered up to now due to several reasons, including the complex geologic setting, lack of mature pipeline infrastructure, etc. A detailed review of the current situation of exploration and development for shale gas in China is offered and suggestions concerning future exploration and development are made.

Journal ArticleDOI
TL;DR: In this paper, the strength and thermophysical test results made on the basis of the masonry samples of cellular autoclave curing concrete (aerated concrete blocks) with the use of polyurethane adhesive are presented.
Abstract: This article deals with the strength and thermophysical test results made on the basis of the masonry samples of cellular autoclave curing concrete (aerated concrete blocks) with the use of polyurethane adhesive. Aerated concrete masonry walling with the use of polyurethane adhesive is indicated herein to be technologically feasible and economically viable. The major advantage of the masonry option under consideration lies in the following aspect: thermal conductivity of polyurethane adhesive used to fasten aerated concrete blocks in masonry walls is significantly less than thermal conductivity of concrete adhesives and mortars. For this reason, thermal insulation properties of the masonry with polyurethane adhesive appear to be better comparatively to the block masonry made with the usage of concrete adhesives of any other type. On the ground of the tests conducted the following was resumed: it is acceptable to carry out masonry works with the use of aerated concrete blocks and polyurethane adhesive in construction of exterior and interior nonbearing walls provided appropriate justifying calculations are made.

Journal ArticleDOI
TL;DR: In this article, the authors describe a method of increasing the efficiency of heat energy based on installation of heat metering system and automatic controlled domestic heating plant in residential building, which is used for comparative calculation of the heat input and estimation for heat energy in a typical residential building.
Abstract: The article describes a method of increasing the efficiency of heat energy. The method is based on installation of heat metering system and automatic controlled domestic heating plant in residential building. An example of comparative calculation of the heat input and estimation for heat energy in a typical residential building, according to different methods which are used for the calculation of extra charge by the energy supplier, in the presence of the heat metering system and automatic controlled domestic heating plant and without. Calculated payback period of the proposed activities.

Journal ArticleDOI
TL;DR: Vatin et al. as mentioned in this paper investigated the compression resistance of thin-walled cross-sections and shear strength of stud-to-rack joints in the Russian building industry and found that the profiles have a negative effect on the strength of the profiles.
Abstract: This summary report is based on the experimental and numerical research of thin-walled cross-section’s compression resistance and shear strength of their joints carried out in St. Petersburg State Polytechnical University and HAMK University of Applied Sciences, Sheet Metal Centre. Current situation on Russian market concerning the usage of cold-formed thin-walled cross-sections is aimed to find out a base foundation to start up a stipulation of the elements under discussion in the building industry (Kolesov et al. 2007; Peleshko, Urchenko 2009; Zhmarin 2012). Some questions about the compression resistance of such cross-sections were raised on different conferences (Vatin, Sinelnikov 2013; Winter 1952; Yu Wei-Wen et al. 1996) by scientific community and by companies such as Rautaruukki Oyj (Finland). Steel galvanized C-and U-profiles and thermo-profiles are types of thin-walled cross-sections that are normally used in small houses construction (Shatov 2011; Smaznov 2011). Thermo-profiles have slots in web that decrease the thermal flow through the web, but have a negative effect on strength of the profiles (Schafer, Pekoz 1998; Vatin, Popova 2006). These profiles were an object of the research. Investigations carried out included tests to prove the compression resistance of the thin-walled cross-sections and shear strength of stud-to-rack joints. Numerical modelling of thin-walled cross-sections (Cheng, Schafer 2007) was done with contemporary analysis software (SCAD Office, Lira) (Kriksunov et al. 2010; Perel'muter et al. 2009) using the finite element method (FEM) (Bayan et al. 2011; Gordeeva, Vatin 2011; Rasmussen 2009).

Journal ArticleDOI
TL;DR: In this paper, the authors presented the results of experimental and model research of powertrain system built with torsional vibration damper and found that the main factor affecting the right development of the structure should be dynamic criterion, since only use of static criteria leads to big errors.
Abstract: The paper presents the results of experimental and model research of powertrain system built with torsional vibration damper. The behaviour of powertrain system with and without vibration damper was shown in the conditions of acceleration and deceleration with different increases of rotational speed. Next, authors describe the process of building a mathematical model of such a system and its identification on the basis of experimental results. When examining the results obtained with empirical and model research, it has been shown that in the structural and parametric identification of model of such system, the main factor affecting the right development of the structure should be dynamic criterion, since the only use of static criteria leads to big errors. On the basis of such model we can make some structural solutions to the system to minimize torsional vibrations.

Journal ArticleDOI
TL;DR: In this article, a scenario-based development of disassembly systems is presented with varying possible design aspects as well as different amounts of end-of-life battery systems in short, medium and long term.
Abstract: The rising number of lithium ion batteries from electric vehicles makes an economically advantageous and technically mature disassembly system for the end-of-life batteries inevitable. The disassembly system needs to cope with the size, the design and the remaining state of charge of the respective battery system. The complex design resulting from the number and type of connection elements challenges an automated disassembly. The realisation of an automated disassembly presupposes the consideration of elements from Design for Disassembly throughout the battery system development. In this paper a scenario-based development of disassembly systems is presented with varying possible design aspects as well as different amounts of end of life battery systems. These scenarios point out the resulting implications on battery disassembly systems in short, medium and long term. Using a morphological box the best option for each disassembly scenario is identified and framed in a disassembly system design. The disassembly systems are explained and the core elements are introduced. Newly developed and innovative disassembly tools, such as a robot that allows a hybrid human-robot-working-space and an advanced battery cell gripper are introduced. The gripper system for the battery cells enables with an integrated sensor an instant monitoring of the battery cell condition. The proposed disassembly element is verified in an experimental test series with automotive pouch cell batteries.

Journal ArticleDOI
TL;DR: In this article, a method for the voltammetric determination of dopamine (DA) and uric acid (UA) based on poly (Phthalo blue) modified carbon paste electrode (PTBMCPE) is reported.
Abstract: A convenient and useful method for the voltammetric determination of dopamine (DA) and uric acid (UA) based on poly (Phthalo blue) modified carbon paste electrode (PTBMCPE) is reported in this paper. The PTBMCPE exhibits excellent electro-catalytic activities for the oxidationreduction of DA and UA, as well as eliminating the interference. Factors influencing the detection processes are optimized and the kinetic parameters are calculated. The effects of pH, scan rate and concentration of dopamine on the peak current were investigated, and the results indicated that the peak current of dopamine is the highest in 0.2 M pH 7.0 Phosphate buffer solution (PBS) and the electrode reaction corresponds to a rate-controlled process. The proposed method possesses the distinct advantages of simple, appropriate for operation, good reproducibility and highly selective and sensitive.

Journal ArticleDOI
TL;DR: In this article, the authors carried out theoretical and experimental investigations on global buckling and bearing capacity of steel members of C-shaped notched profiles of different cross-sections area.
Abstract: Nowadays cold bent steel thermal сold-bent С-profile is widely used in building construction but we still have some little studied questions in the fields of thermal conductivity, air permeability, resistibility and corrosion behavior of the profile. Cold-bent notched С-profile is used for interior exterior panel members. Lengthwise notches made chequerwise in the profile walls increase the distance of heat flow and decrease heat conductivity and eliminate cold bridges that is why the profile is called “thermal profile”. Cold-bent profile made by cold bending requires alternate approach when engineering structures are designed and maintained. The approach means thin walls’ and the profile special form’ impact on the bearing capacity and stability of the structures should be taken into account. In spite of the wide use of cold-bent notched C-profile in building frameworks, we see lack of information on how the notches influence the bearing capacity and stability of structures. There are no official normative documents on calculation and designing of cold-bent notched profile structures. We carry out theoretical and experimental investigations on global buckling and bearing capacity of steel members of C-shaped notched profiles of different cross-sections area. We carry out theoretical and experimental investigations on heat current passing through the thermal profile structure is held with the use of testing bed.

Journal ArticleDOI
TL;DR: In this paper, the recovery mechanism of the enhanced oil recovery was determined by measuring oil-nanofluid interfacial tension and the viscosity of the nanofluide.
Abstract: Application of nanotechnology in enhanced oil recovery (EOR) has been increasing in the recent years. After secondary flooding, more than 60% of the original oil in place (OOIP) remains in the reservoir due to trapping of oil in the reservoir rock pores. One of the promising EOR methods is surfactant flooding, where substantial reduction in interfacial tension between oil and water could sufficiently displace oil from reservoir. The emulsion that is created between the two interfaces has a higher viscosity than its original components, providing more force to push the trapped oil. In this paper, the recovery mechanism of the enhanced oil recovery was determined by measuring oil-nanofluid interfacial tension and the viscosity of the nanofluid. Series of core flooding experiments were conducted using packed silica beads whichreplicate core rocks to evaluate the oil recovery efficiency of the nanofluid in comparison to that using an aqueous commercial surfactant, 0.3wt% sodium dodecyl sulfate (SDS). 117 % increase in the recovery of the residual oil in place (ROIP) was observed by the 2 pore volume (PV) injection of aluminium oxide nanofluid in comparison with 0.3wt% SDS. In comparison to the type of material, 5.12% more oil has been recovered by aluminium oxide compared to zinc oxide nanofluid in the presence of EM wave. The effect of the EM wave on the recoverywas also studied by and it was proven that electric field component of the EM waves has been stimulating the nanofluid to be more viscous by the increment of 54.2% in the oil recovery when aluminium oxide nanofluid was subjected to 50MHz EM waves irradiation.

Journal ArticleDOI
TL;DR: The state-of-the-art of textile wastes recycling has been presented in this article, where various recycling technologies have been developed so as to maximize the use of the fibrous waste collected.
Abstract: A higher amount of post industrial and post consumer fiber waste has been accumulated, due to the growth in world population, overall improvement of living standards and global fiber consumption. General descriptions of fibrous waste, statistics, material characteristics (compositions) and sources in the world were provided. The state-of-the-art of textile wastes recycling has been presented. Varied recycling technologies have been developed so as to maximize the use of the fibrous waste collected. Prevailing recycling technologies, including reusing, recycling, incineration, and landfill, are reviewed. Some promising recycling techniques, such as dissolution and deploymerization, which are applicable to valuable PET or nylon, were focused upon in this paper. The summary on some selected recycling technologies and products from the recycling processes was also offered. Different combinations of incineration, materials recycling, and biological treatment of biodegradable waste, or landfilling could be an expectable choice, a system analysis should be done for diverse waste textile treatment options. Observations on future trends and needs for further development are discussed in the end. Intensive research and development that make lower added-value recycled products from waste textiles should be encouraged, which can consume the largest volume low value waste textiles.

Journal ArticleDOI
TL;DR: In this article, external surface qualities, micro hardness, composition and microstructures of five ER4043 aluminium wires were investigated, and the results indicate that the internal and external properties of the wires exert great influence on the performance of the WAAM parts.
Abstract: Wire+arc additive manufacture (WAAM) is a high build rate process for production of near-net shape components layer by layer. The performance and quality of the deposited metal are heavily affected by the properties of wires, which are the raw materials for WAAM. Therefore there may be higher requirements for the qualities and properties of wires for WAAM than for welding. External surface qualities, micro hardness, composition and microstructures of five ER4043 aluminium wires were investigated in the present research. The results indicate that the internal and external properties of the wires exert great influence on the performance of the WAAM parts.

Journal ArticleDOI
TL;DR: In this article, the role of rambutan extrac on the formation of zinc oxide nanoparticles was confirmed employing HPLC and GC-MS studies, which revealed the crystallinity and spherical morphology of the biosynthesized nanoparticles.
Abstract: Nephelium lappaceum L. peels was effectively used for the synthesis of zinc oxide nanoparticles as a natural ligation agent. The role of rambutan extrac on the formation of zinc oxide nanoparticles was confirmed employing HPLC and GC-MS studies. The XRD and TEM revealed the crystallinity and spherical morphology of the biosynthesized nanoparticles. The size of the particles was found to be 20 nm as deduced from XRD and TEM analysis.

Journal ArticleDOI
TL;DR: In this article, a highly porous polythiophene (PTh) nanofibers were synthesized by surfactant assisted dilute polymerization method using FeCl3 as oxidant.
Abstract: A highly porous polythiophene (PTh) nanofibers were synthesized by surfactant assisted dilute polymerization method using FeCl3 as oxidant. They were confirmed by XRD and FTIR analysis. The surface morphology of PTh was done by scanning electron microscopy (SEM). The prepared polythiophene nanofibers were subjected to calcination under inert gas atmosphere at 1400oC for 2 hrs to get carbonaceous PTh nanofibers. The asymmetric supercapacitor was assembled using PTh nanofibers as the cathode and carbonaceous PTh nanofibers as the anode in 6M KOH electrolyte. The electrochemical supercapacitor performances were carried out to find out the specific capacitance, energy density and power density of the cell. The above results confirmed that the prepared PTh nanofibers and carbonaceous PTh nanofibers could be used as electrode materials for asymmetric supercapacitor applications. Keywords: Polythiophene, Dilute polymerization method, Carbonaceous material, Asymmetric supercapacitor, Specific capacitances

Journal ArticleDOI
TL;DR: In this paper, the effect of molybdenum on the structure, microstructure, and selected mechanical properties of Ti-15Zr-xMo (x = 5, 10, 15, and 20 wt%) alloys were analyzed.
Abstract: New titanium alloys for biomedical applications have been developed primarily with the addition of Nb, Ta, Mo, and Zr, because those elements stabilize the β phase and they don’t cause cytotoxicity in the organism. The objective of this paper is to analyze the effect of molybdenum on the structure, microstructure, and selected mechanical properties of Ti-15Zr-xMo (x = 5, 10, 15, and 20 wt%) alloys. The samples were produced in an arc-melting furnace with inert argon atmosphere, and they were hot-rolled and homogenized. The samples were characterized using chemical, structural, and microstructural analysis. The mechanical analysis was made using Vickers microhardness and Young’s modulus measurements. The compositions of the alloys were sensitive to the molybdenum concentration, indicating the presence of α’+α”+β phases in the Ti-15Zr-5Mo alloy, α”+β in the Ti-15Zr-10Mo alloy, and β phase in the Ti-15Zr-15Mo and Ti-15Zr-20Mo alloys. The mechanical properties showed favorable values for biomedical application in the alloys presenting high hardness and low Young’s modulus compared with CP-Ti.

Journal ArticleDOI
TL;DR: In this article, the physical nature and process of oscillation cutting and shaping have been studied and the results of these studies have been recommended to be applied in engineering methods to calculate manufacturing of reinforcement units.
Abstract: New technologies of reinforcement works have been developed. The results of studies have been recommended to be applied in engineering methods to calculate manufacturing of reinforcement units. Oscillation cutting has been theoretically grounded, the physical nature and process of oscillation cutting and shaping have been studied.

Journal ArticleDOI
TL;DR: In this paper, a hybrid welding system at the WKK of the University of Kaiserslautern was developed called Ultrasound Supported Friction Stir Welding (US-FSW) with the aim to shatter the brittle interlayer lines and to scatter fragments in the welding area during the FSW process.
Abstract: Fusion welding of dissimilar metals is in the most cases difficult or even impossible as a result of different melting points and the development of undesirable brittle intermetallic phases. This often leads to joint strengths considerable below the tensile strength of the base materials. By using Friction Stir Welding (FSW) it is possible to reduce the development of the intermetallic phases of Al/Mg-joints significantly but not to avoid them completely. Hence a hybrid welding system at the WKK of the University of Kaiserslautern was developed called “Ultrasound Supported Friction Stir Welding (US-FSW)” with the aim to shatter the brittle interlayer lines and to scatter fragments in the welding area during the FSW process. Pre-investigations have shown that for Al/Mg-US-FSW-joints the strength can be increased up to 30% in comparison to conventional FSW. Moreover for the reliable detection of nonconformities in the weld during a post-process inspection by suitable non-destructive testing (NDT) methods is necessary. Also there is a strong need for better process monitoring and control by in-process NDT methods. Furthermore the corrosion behavior of the basic materials and hybrid-joints was investigated by electrochemical methods indicating an increased corrosion of the Mg alloy in the area of the Al/Mg-butt weld.