Showing papers in "Advanced Materials Research in 2013"

Decontamination of Wastewaters Containing Synthetic Organic Dyes by Electrochemical Methods: A Review

Abstract: Bioelectrochemical systems or electrochemical reduction reactors have great potential for treating wastewater that contains dyes for decolorization. They are reported to enhance decolorization rate and degree with external energy supply and to help microorganisms or noble metal as catalysts. Till now literatures regarding dye decolorization with electron reduction using BESs or electrochemical reactors is deficient. This paper reviews the performance limitations, future prospects, and improvements of the common used dyes decolorization and decolorization with external voltage or current supply in Bioelectrochemical systems.

High Cycle Fatigue (HCF) Performance of Ti-6Al-4V Alloy Processed by Selective Laser Melting

Abstract: Selective laser melting (SLM) is a relatively new additive manufacturing (AM) technology which uses laser energy for manufacturing in a layered pattern. The unique manufacturing process of SLM offers a competitive advantage in case of very complex and highly customized parts having quasi-static mechanical properties comparable to those of wrought materials. However, it is not currently being harnessed in dynamic applications due to the lack of reliable fatigue data. The manufacturing process shows competitive advantages particularly in the aerospace and medical industry in which Ti-6Al-4V is commonly used, especially for high performance and dynamic applications. Therefore, in this exploratory research, high cycle fatigue (HCF) tests were performed for as-built, polished and shot-peened samples to investigate the capability of SLM for these applications. As-built samples showed a drastic decrement of fatigue limit due to poor surface quality (Ra ≈ 13 µm) obtained from the SLM process. Polishing improved the fatigue limit to more than 500 MPa, the typical value for base material. The effect of shot-peening proved to be antithetical to the expected results. In this context, fractographic analysis showed that very small remnant porosity (less than 0.4%) played a critical role in fatigue performance.

High-Value SLM Aerospace Components: From Design to Manufacture

Abstract: Today additive manufacturing is shaping the future of global manufacturing and is influencing the design and manufacturability of tomorrows products. With selective laser melting (SLM), parts can be built directly from computer models or from measurements of existing components to be re-engineered, and therefore bypass traditional manufacturing processes such as cutting, milling and grinding. Benefits include: 1) new designs not possible using conventional subtractive technology, 2) dramatic savings in time, materials, wastage, energy and other costs in producing new components, 3) significant reductions in environmental impact, and 4) faster time to market. SLM builds up finished components from raw material powders layer by layer through laser melting. SLM removes many of the shape restrictions that limit design with traditional manufacturing methods, thereby allowing computationally optimised, high performance structures to be utilised. Functional engineering prototypes and actual components can then be built in their final shape with minimal material wastage. Samples and small product runs can be produced quickly at comparatively low cost to test and build market acceptance without major investment. In this chapter we present and discuss some of the concepts and findings involved in the design, manufacture and examination of high-value aerospace components from Ti-6Al-4V alloy produced at the RMITs Advanced Manufacturing Precinct.

Relationship between Compressive, Splitting Tensile and Flexural Strength of Concrete Containing Granulated Waste Polyethylene Terephthalate (PET) Bottles as Fine Aggregate

Abstract: This paper describes the experimental investigation of relationship between splitting tensile strength and flexural strength with the compressive strength of concrete containing waste PET as fine aggregates replacement Waste PET was reprocesses and used as the artificial fine aggregate at the replacement volume of 25%, 50% and 75%, Cylindrical and prism specimens were tested to obtain the compressive, splitting tensile and flexural strength at the age of 28 days Based on the investigation, a relationship for the prediction of splitting tensile and flexural strength was derived from the compressive strength of concrete containing waste PET as fine agglegate replacement

Friction Welding of Type 304 Stainless Steel to CP Titanium Using Nickel Interlayer

Abstract: Dissimilar metal joints of stainless steel to titanium find extensive industrial applications especially in the nuclear industry. However, it is well known that fusion welding of stainless steel to titanium is difficult because of the formation of brittle intermetallic compounds and the associated problems. To avoid this, welding processes or techniques with high reliability and productivity for these dissimilar materials are demanded. In the present work, joints comprising of 304 stainless steel and commercially pure titanium were produced by friction welding using nickel as interlayer. Investigation on the mechanical properties of the joints shows the occurrence of highest hardness value at the interface of titanium and nickel interlayer. X-ray diffraction studies confirmed the presence of various types of intermetallic compounds at the interface of the welded joint. The tensile strength of the joint varies with the thickness of nickel interlayer used. Joints having maximum strength equals to 72% of that of titanium base metal could be produced. In all the joints, tensile failure occurred at Ti-Ni interface due to the presence of the intermetallic compounds at this interface. Fracture surface analysis reveals that the tensile fracture path is along the intermixing zone of titanium and nickel interlayer.

The Cultural and Environmental Resources for Sustainable Development of Rural Areas in Economically Disadvantaged Contexts - Economic-Appraisals Issues of a Model of Management for the Valorisation of Public Assets

Abstract: Available resources to public policies are always limited: those intended for culture, too often considered non-essential to the development of the community, they are often essential in particular way. Ignoring the economic value of cultural resources, their conservation, costs and total benefits of cultural policies and investment projects with a strong cultural component, can lead to non-optimal allocation of resources, to degradation of cultural capital and to failure to exploit opportunities for development.Another important aspect is the use of resources for the physical recovery and reuse of assets, without adequate attention to the phase of management: too often you find yourself with assets recovered but unused due to the lack of resources for management. A method tested recently is the involvement of private companies in these activities: in economically stronger and more advanced realities, the size of the most significant tourist flows allows to reach levels of return on investment and so makes this a feasible solution.Cultural resources in the rural settings of the most economically disadvantaged areas are characterized by a not elevated number of visitors not spread in the same way throughout the whole year: in these conditions, because of their different costs structures, a company may not have sufficient profit margins, but a private non-profit organizations can achieve a balanced budget that allows the usability of assets of fundamental importance into development strategies based on cultural tourism.This paper focuses on the main economic appraisal aspects and illustrates a management model, economically sustainable, for the tourist value of cultural and environmental resources, particularly suitable to be applied in rural contexts and in economically disadvantaged realities; the analyzed case study is indeed located in Gerace, ionic inland town of Calabria, region of southern Italy.

Recent Progress in High-Entropy Alloys

Abstract: Since the 1990s the novel materials named HEAs concepts come into being, it was concerned by researchers because of its superior performance. This paper describes the concept and formation criteria of the HEAs, at the same time, summaries detail the methods of preparation and new achievements.

Improvement of Working Efficiency of Cutting Tools by Modifying its Surface Properties by Application of Wear-Resistant Complexes

Abstract: The paper presents the results of the methodology for improving of cutting tools performance based on modifying the surface properties of the tool material in the formation of wear-resistant complexes, substantially modifying its properties. Argued and offers a three-component (for carbide tools) and four-component (for HSS tools) system for modifying the surface properties, improves the tool material. This paper describes a method and results of research to note the substantial increase of efficiency of HSS drills and milling and turning tools made of carbide in the processing of structural steel and hard-to-cut superalloy.

Strength and Permeation Properties of Slag Blended Fly Ash Based Geopolymer Concrete

Abstract: Geopolymer is a binder that can act as an alternative of Portland cement. Geopolymers use by-product substances such as fly ash, and can help reduce carbon dioxide emission of concrete production. This paper presents the results of a study on the fly ash based geopolymer concrete suitable for curing at ambient temperature. To activate the fly ash, a combination of sodium hydroxide and sodium silicate solutions was used. The setting and hardening of geopolymer concrete were obtained by blending blast furnace slag with fly ash instead of using heat curing. Ground granulated blast furnace slag (GGBFS) was used at the rate of 10% or 20 % of the total binder. The tests conducted include compressive strength, tensile strength, flexure strength, sorptivity and volume of permeable voids (VPV) test. The geopolymer concrete compressive strength at 28 days varied from 27 to 47 MPa. Results indicated that the strength increased and water absorption decreased with the increase of the slag content in the geopolymer concrete. In general, blending of slag with fly ash in geopolymer concrete improved strength and permeation properties when cured in ambient temperature.

Adaptive negative stiffness: A new structural modification approach for seismic protection

Abstract: Yielding can be emulated in a structural system by adding an adaptive “negative stiffness device” (NSD) and shifting the “yielding” away from the main structural system-leading to the new idea of “apparent weakening” that occurs ensuring structural stability at all displacement amplitudes. This is achieved through an adaptive negative stiffness system (ANSS), a combination of NSD and a viscous damper. By engaging the NSD at an appropriate displacement (apparent yield displacement that is well below the actual yield displacement of the structural system) the composite structure-device assembly behaves like a yielding structure. The combined NSD-structure system presented in this study has a re-centering mechanism thereby avoids permanent deformation in the composite structure-device assembly unless, the main structure itself yields. Essentially, a yielding-structure is “mimicked” without any, or with minimal permanent deformation or yielding in the main structure. As a result, the main structural system suffers less accelerations, less displacements and less base shear, while the ANSS “absorbs” them. This paper presents comprehensive details on development and study of the ANSS/NSD. Through numerical simulations, the effectiveness and the superior performance of the ANSS/NSD as compared to a structural system with supplemental passive dampers is presented. A companion paper presents the NSD and its mechanics in detail.

Synthesis and Characterization of Reduced Graphene Oxide

Abstract: Reduced graphene oxide is an excellent candidate for various electronic devices such as high performance gas sensors. In this work Graphene oxide was prepared by oxidizing graphite to form graphite oxide. From XRD analysis the peak around 11.5o confirmed that the oxygen was intercalated into graphite. By using hydrazine hydrate, the epoxy group in graphite oxide was reduced then the solution of reduced graphite oxide (rGO) is exfoliated. Raman spectrum of rGO contains both G band (1580 cm-1), D band (1350 cm-1). The remarkable structural changes reveals that reduction of graphene oxide from the values of ID/IG ratio that increase from 0.727 (GO) to 1.414 (rGO). The exfoliated reduced graphite oxide solution is spin coated on to the SiO2/Si substrates.

The mechanical properties of PET fiber reinforced concrete from recycled bottle wastes

Abstract: This research is carried out to investigate the performance of concrete containing Polyethylene Terephthalate (PET) bottle waste as fiber. PET bottle waste was chosen because it is being thrown after single use and cause environmental problem. One way to recycle wasted PET bottles is grinded into irregular fiber. Then, it was incorporate with the concrete and test the performance of the concrete. The study was conducted using cylindrical mold of concrete to investigate the performance of the concrete in term of mechanical properties. A total of four batches of concrete were produced namely, normal concrete and concrete containing PET fiber of 0.5%, 1.0% and 1.5% fraction volume. In this research, the mechanical properties that were measured are compressive strength, splitting tensile strength and modulus of elasticity (MOE) following British Standard method. The results revealed that the presence of PET fiber in concrete will increase the concrete performance. Nevertheless, the content of PET fiber was specified in a specific limit to avoid effect of concrete strength.

Improving the Efficiency of the Cutting Tools Made of Mixed Ceramics by Applying Modifying Nanoscale Multilayered Coatings

Abstract: The paper studies the influence of properties of a tool made of mixed ceramic by applying modifying with nanoscale multi-layered coatings on machinability of hardened tool steel XVG. The paper also examines the influence of cutting speed on wear resistance of mixed ceramic with nanoscale multilayered coatings. The mathematical models that found out the dependence of tool life of a ceramic tool with coating from cutting speed were developed.

Machining and Tool Wear Mechanisms during Machining Titanium Alloys

Abstract: This paper investigates the machining mechanism of titanium alloys and analyses those understandings systematically to give a solid understanding with latest developments on machining of titanium alloys. The chip formation mechanism and wear of different cutting tools have been analyzed thoroughly based on the available literature. It is found that the deformation mechanism during machining of titanium alloys is complex and it takes place through several processes. Abrasion, attrition, diffusion–dissolution, thermal crack and plastic deformation are main tool wear mechanisms.

A Parametric Study of a Gravitation Vortex Power Plant

Abstract: This study is the analysis and design of a basin structure which has the ability to form a gravitational vortex stream. Such a high velocity water vortex stream can possibly be used as an alternative energy resource. In this study we are interested in the formation of a water vortex stream by gravitation, which is a new technique used in the field of hydro power engineering. The advantage of this method for electrical generation is the capability of producing energy using low heads of 0.7 to 3 meters. It can be applied in a low head micro hydro power plant. The governing equations are the Navier-Stokes equations. The SIMPLE method was adopted to solve the discretized equation. The flow fields in the flume, under different incoming flow conditions and basin configurations, were numerically simulated using the software ANSYS Fluent. The studies investigated parameters which affect the velocity vector flow field, which include 1) Outlet diameter at the bottom center of basin 2) Gravitational vortex head and 3) Flow rate. Computational fluid dynamics is used to simulate the vector flow field. The tangential and radial velocity distribution is used to determine the suitable turbine blade for testing. A gravitational vortex power plant model is created to investigate electrical power output.

Feasible build orientations for self-supporting fused deposition manufacture: A novel approach to space-filling tesselated geometries

Abstract: Support material is often utilised in additive manufacture to enable geometries that are not otherwise self-supporting. Despite the associated opportunities for innovation, the use of support material also introduces a series of limitations: additional material cost, cost of removal of support material, potential contamination of biocompatible materials, and entrapment of support material within cellular structures. This work presents a strategy for minimising the use of support material by comparing the geometric limits of an additive manufacture process to the build angles that exist within a proposed geometry. This method generates a feasibility map of the feasible build orientations for a proposed geometry with a given process. The method is applied to polyhedra that are suitable for close packing to identify space-filling tessellated structures that can be self-supporting. The integrity of an FDM process is quantified, and using the associated feasibility map, self-supporting polyhedra are manufactured. These polyhedra are integrated with non-trivial geometries to achieve a reduction in consumed material of approximately 50%. Nomenclature

Methods of Manufacturing Data Acquisition for Production Management - A Review

Abstract: Knowledge about the state of the production system is necessary for proper management of a company. A modern company typically uses an ERP (Enterprise Resources Planning) system for management support, but still there is usually a gap between business and manufacturing layers of a company. There is a need to provide solutions allowing data acquisition directly from the production system, analyse this data and display it in a convenient form. Each type of production systems require a different approach to collect data because of variety of objects and conditions. The ability of production data acquisition mostly depends on the level of automation. This paper presents a comparison of methods of data acquisition from different types of manufacturing systems. Methods of data acquisition, from both automated and non-automated manufacturing systems, are described. Automation equipment resources (sensors, actuators, PLC, DCS, CNC, HMI, SCADA) and automatic identification systems (barcodes, RFID, vision systems etc.), as well as communication solutions (fieldbus, wired and wireless networks) and information exchange standards (OPC, MTConnect) are discussed.

Foundation Slab in Interaction with Subsoil

Abstract: In the paper the experiment results of deformation in foundation slab segment in interaction with subsoil are presented. Pilot measurement is carried out on original subsoil with characteristics which were tested in cooperation with geotechnics specialists. Concrete precast slab with square dimensions 500 mm and with thickness 48 mm made of plain concrete is exposed to vertical load. The tests results are compared with bending moments and deformations analysed according to subsoil models given in Eurocodes using FEM analysis.

Application of ARIMA Model in Short-Term Prediction of International Crude Oil Price

Abstract: International crude oil price is the referential scale of spot crude oil price and refined oil price. This paper made an analysis and prediction of Brent crude oil price by ARIMA model based on its price data from November 2012 to April 2013. It indicated that model ARIMA (1,1,1) possessed good prediction effect and can be used as short-term prediction of International crude oil price.

Study on fly ash based geopolymer for coating applications

Abstract: Geopolymer is cementitious binders that do not require the presence of ordinary Portland cement (OPC). Fly ash with geopolymer formulations prepared with mixing alumino-silicate with the alkaline activator solution has been applied as protective coating material that suitable for high temperature applications such as fire resistant panel. Geopolymer coating samples were cured at 70 °C for 24 hours before sintered using temperatures range from 600 °C to 1500 °C in order to increase strength and improve thermal properties. Curing conditions also have a significant effect on the development of mechanical strength in most cementitious systems. The chemical compositions, microstructure and FTIR were studied. Geopolymer coating samples cures to a glassy texture and effectively used to create a resistant surface. Fly ash geopolymer coating was improved the compressive strength of the coatings materials as high as 40 MPa. This technology develop a geopolymeric mix design that superior use as cementitious coatings with high thermal application.

Molecular Docking Studies Involving Transitional Metal Complexes (Zn(II), Co(II), Cu(II), Fe(II), Ni(II) with Cholic Acid (AC) as Ligand against Aurora A Kinase

Abstract: Colorectal cancer is a malignant tumor, one of the main types of cancer which produces a large number of deaths each year in many countries around the world. The main objective of this work is to employ various bioinformatics tools to perform docking of the transitional metal complexes (Zn (II), Co (II), Cu (II), Fe (II), Ni (II)) with cholic acid (AC) as ligand against Aurora A Kinase (RCSB Protein Data Bank code: 2X6E). Molegro Virtual Docker (MVD) was used for the docking process. The molecular docking score and the values of the statistic parameter Root Mean Square Deviation (RMSD) are presented in Table 1. The results obtained in this study serve to design new complex combinations with potential action against Aurora A Kinase inhibitor.

Multi-Attributes and Neural Network-Based Fault Detection in 3D Seismic Interpretation

Abstract: Seismic attributes have been widely used in seismic object detection. While no unique attribute is expected to perfectly identify the targeted object, various attributes contributing to the same purpose should be utilized simultaneously when performing detection. Artificial neural network has been successfully applied in seismic object detection by combining multiple attributes into a single object-sensitive attribute. An optimized neural network fault detection approach was introduced by a case study from Stratton field, south Texas, United States. Results indicate that the new produced fault probability attribute could suppress the surrounding noises and highlight the faults. Application of ant-tracking to the fault-cube shows more convincible results than to individual attributes. In addition, several potential cross-strike fractures increase the structural complexity. The neural network-based fault detection contributes to better structural interpretation and is of great significance to hydrocarbon exploration, especially in area with complex fault system.

Welding of Ultra High Strength Steels

Abstract: The ongoing need to reduce the weight of products while increasing strength has resulted in new generation steel manufacturing using special heat treatments to produce High Strength Steels (HSS) and Ultra High Strength Steels (UHSS) with up to 1700 MPa tensile strength. The high strength level of these steels makes it possible to produce structures with a considerable weight and cost reduction, and such steels have been adopted in the automotive industry and for mobile heavy equipment. Welding of UHSS is, however, not without its complications and welding processes for these steels need careful attention. For instance, their high susceptibility to cracking and Heat Affected Zone (HAZ) softening are risks that need to be borne in mind when choosing welding parameters. This research work discusses the difficulties and challenges of successful welding of UHSS. Common welding methods used in welding of UHSS are briefly reviewed to gain a better understanding of the effects of different welding parameters and methods. The paper finds that UHSS can be satisfactorily welded with laser welding, electron beam welding, resistance welding, and conventional arc welding methods, but the quality of the weld is dependent on appropriate control of several parameters and variables of the welding processes.

Design of Bilateral Switched Reluctance Linear Generator to Convert Wave Energy: Case Study in Sicily

Abstract: The aim of this work is a case study of the adaptation bilateral switched reluctance linear generator to the exploitation of energy of the sea. This type of generator can be used to convert wave energy in electrical energy. In this paper we present an analytical sizing and FEM simulation. As for the results, analysis of the data extracted through the simulations it was possible to calculate the emf. The emf was calculated in two cases of motion of the slider: first hypothesis has set the constant speed while the second is a variable speed according to the law of an oscillatory motion of the sea.

Fragmentation, texturing and plastic flow in the subsurface of friction-processed copper single crystal

Abstract: Copper single crystals grown according to the Bridgman method and having their axes [] or [11 aligned with the normal load axis were processed by dry sliding. As shown, sliding-induced severe plastic deformation occurred in the subsurface of single crystals and caused formation of a lip by mechanism of texture formation. The SEM structure of this lip was found to be composed of fragments with their shapes dependent on the single crystal orientation with respect to normal load and friction force.

Chatter Control in Turning Process with a Nonlinear Energy Sink

Abstract: This paper presents the interest of an original absorber of vibration in order to reduce chatter vibration in turning process. The device is composed of a linear oscillator corresponding to a flexible cutting tool subject to chatter strongly coupled to a Nonlinear Energy Sink (NES), with purely cubic stiffness. The novelty of this work is the use of a nonlinear cutting law, more accurate for modeling the cutting process. The delayed equations of motion are analyzed using a combination of the method of multiple scales and harmonic balance. Different types of responses regimes are revealed such as periodic response and also Strongly Modulated Response (SMR). Analytic results are then compared with numerical simulations. Finally, the potential of the NES is demonstrated to control chatter in turning process.

A Procedure to Evaluate the Indoor Global Quality by a Sub Objective-Objective Procedure

Abstract: This paper proposes two complementary procedures for assessing the indoor global comfort: the first one, prevalently objective, is based on the acquisition of microclimate measured data and computed subjective values; the second one, that is purely subjective, uses a questionnaire drawn from the ISO/DP 10551 Recommendation. An application to some lecture-halls is here showed

Application of Automated Complex Gas Reaction Controller for Hydrogen Storage Materials Investigation

Abstract: Automated complex Gas Reaction Controller and its application for hydrogen storage materials investigation are described in this article. Pressure-composition isotherms (PCI) and kinetics measurements of LaNi5 have been obtained for validation of the apparatus. Measurements of both absorption and desorption PCI curves and kinetics measurements at different conditions have been obtained for carbon nanotubes to estimate its hydrogen storage properties.

Dynamic Evolution of the Microbial Community in BIOX Leaching Tanks

Abstract: Laboratory scale (7 L) reactors, inoculated with the L. ferriphilum dominated BIOX inoculum, were used to test the stability of the community under controlled conditions. Further, the effect of increased temperature, solids loading and pH fluctuations on the bioleaching performance and community structure were studied. Both performance and community structure remained stable under controlled conditions (41.5°C, 20% solids loading, 7 day residence time). Increasing the solids loading to 31% did not significantly affect performance or community structure. An increase in temperature (2°C every 10 days) did not have a significant effect up to 48°C, but the increase from 48°C to 50°C resulted in the loss of L. ferriphilum and a decrease in leaching performance. A more gradual increase (1°C increments) from 48°C to 50°C resulted in a stable community, dominated by Ac. cupricumulans and Acidithiobacillus caldus. A similar shift in community structure was observed when the pH fell below pH 0.8, but this was transient and L. ferriphilum recovered dominance upon adjustment to a pH > 1.0. A further increase in temperature to 52°C resulted in the loss of At. caldus and the emergence of Sulfobacilli. However, leaching performance under these conditions was poor, despite the presence of over 10 g/L ferric iron. In addition, yeast extract was required to maintain high cell numbers at 52°C. This work has identified a selection of conditions under which the community in BIOX reactors could evolve dynamically towards those communities currently observed in commercial operations.

Plant Diseases Detection Using Nanowire as Biosensor Transducer

Abstract: The plant disease such as Cucumber Mosaic Virus (CMV) and Papaya Ring Spot Virus (PRSV) is a most dangerous disease that can decrease productivity and quality of the vegetable and fruit. Besides that, its also can destroy and kill those plant in long term when infected and to tackle this problem at early stages, the nanowire based biosensor application is a most reliable sensor nowadays because of advantages towards detecting biological molecule especially plant diseases.In order to dealing with tiny form of molecules such as virus is very difficult and due to the nanostructure uniqueness such as nanowire, it can be done by undergo formation of nanowire process.Result will be elaborated about how nanowire working environment in order to detecting those virus.