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Since squeeze casting process is considered as a new technology for light alloys like aluminum and magnesium, more basic research is required for a scientific understanding of the practice. In distinct, as a cost-effective and resource-efficient tool, advanced numerical modelling in conjunction with dynamic boundary conditions and capabilities of predicting the formation of casting defects have to be fully developed for the optimization of squeeze casting processes. In squeeze casting, an external pressure is applied to molten metal before, during and after its solidification, which makes the condition at the casting die interface different from other typical casting techniques. In this paper, Finite Difference Method (FDM) is used to investigate the effect of heat transfer during squeeze casting process and the relationship between casting temperature and solidification on Al-Si alloys.

Debinding is one of the most critical and time consuming stage in metal injection moulding (MIM). German and Bose (1997) reported that early debinding practice relied on thermal binder degradation, requiring up to 300 hours for complete binder removal. Today multi-stage debinding techniques are introduced cutting down the debinding time to as little as 2 hours. This work investigates solvent debinding variables prior to thermal debinding. Solvent debinding is carried out in n-heptane. Wax and stearic acid are the target binder components being leached out from the green bodies, with wax as the major constituent in the binder formulation. Debinding is conducted at 50, 55, 60 and 65°C for 1-4 hours at each temperature. Weight loss measurements were done. For porosity and surface appearance, scanning electron microscope (SEM) analysis and visual inspection were done. Samples de-bound at 65°C showed an appreciable amount of mass loss; however, surface cracks and warping were observed. A 60°C temperature and time of 4 hours demonstrated best results i.e. a satisfactory mass loss, absence of surface cracks and no warping. Mass loss is directly proportional to temperature and time. SEM results are discussed in the paper.

An important step of a new process being developed for the beneficiation of the mineral zircon (Zr (Hf)SiO4) to produce nuclear grade zirconium (Zr) metal, is the separation of the Zr from the hafnium (Hf). Zr ores typically contain between 1 and 3% Hf , whereas the use of Zr metal in the nuclear industry requires a Hf content 2•SiO2) with ammonium bifluoride (ABF). The separation involves the selective sublimation of the two tetrafluorides in an inert atmosphere under controlled conditions, and subsequent similarly selective desublimation. An accurate estimation of the sublimation rates the zirconium tetrafluoride (ZrF4) and hafnium tetrafluoride (HfF4) as a function of temperature is required since this forms the basis of the development of a sublimation model to determine whether the concept under consideration is theoretically possible. The sublimation kinetics of ZrF4is reported in this paper.

Lasers have the potential for the micromachining of germanium (Ge). However, the thermal damages associated with the laser machining process need to be properly controlled. To minimize the thermal damages, a hybrid laser-waterjet ablation technology has recently been developed for micromachining. This paper presents an experimental study to assess the machining performances in microgrooving of Ge by using a nanosecond laser and the hybrid laser-waterjet technology. The effects of laser pulse energy, pulse overlap and focal plane position on the groove geometry and heat affected zone (HAZ) size are analyzed and discussed. It is shown that the hybrid laser-waterjet technology can give rise to narrow and deep microgrooves with minimum HAZ.

As in the most developed contexts the ratio between qualitative and quantitative needs tends to increase progressively, also the sector of architectural design is urged to introduce suitable quality goals in its ideation processes. The assessment of the quality of an architectural design is justified by the advisability to check the results of its solutions with reference to the needs expressed by the point of view of the community, general, impartial and binding. The paper proposes an assessment model based on requirements and aimed at verifying the correspondence of the architectural design to a set of performance, based on multicriteria schemes.

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

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

This paper introduces a new approach for the identification of linear state-space models of dynamical systems of arbitrary complexity. The identification procedure is described and applied for modeling aeroelastic response of helicopter main rotors. With the aim of developing a tool that might be conveniently applied for real-time simulations of helicopter flight dynamics, the state-space model considered is a reduced-order description of loads transmitted to the airframe due to hub motion and blade pitch controls. In order to validate the proposed approach, loads from the state-space, reduced-order model are compared with those predicted by the complete full-state, nonlinear rotor model for prescribed helicopter maneuvers.

Multi-criteria optimization problems are known to give rise to a set of Pareto optimal solutions where one solution cannot be regarded as being superior to another. It is often stated that the selection of a particular solution from this set should be based on additional criteria. In this paper a methodology has been proposed that allows a robust design to be selected from the Pareto optimal set. This methodology has been used to determine a robust geometry for a welded joint. It has been shown that the robust geometry is dependent on the variability of the geometric parameters.

In this paper we investigated the influence of vibratory stress relieving technique, which is widely used for stress relaxation of weld and casting components/structure, on machining residual stresses in a ring-component of 12%Cr-steel. It was shown that the employed vibratory treatment, without significantly altering the microstructure, turned the surface layer from tension into compression but retained the compressive residual stresses in the subsurface. In comparison, a stress relieving heat treatment, included as a reference in the study, removed completely the surface tensile residual stresses and reduced the subsurface compressive residual stresses to a low level. Significant microstructural changes in the form of recrystallization also occurred in a thin surface layer of the machining affected zone after the heat treatment.

The incremental hole-drilling method is a widely used technique to determine residual stress depth profiles in technical components. Its application is limited in respect to the components geometry, for instance the components thickness. In this paper, a direct correction of the measured strain relaxations is proposed to consider the impact of deviant geometries, here the component thickness, on the residual stress evaluation that moreover, allows the application of commercially available evaluation software. The herein proposed approach is based on finite element simulation of the incremental hole drilling. The simulated strain relaxations for thin metal sheets are evaluated with an algorithm as used in commercially available evaluation software (i) for uncorrected data as well as (ii) for strain data corrected by the proposed correction procedure. It is shown that the correction approach leads to a significant improvement of the measurement accuracy. Further, by means of the approach residual stress depth profiles in thin metal sheets can be as usual determined using commercial evaluation software for the incremental hole-drilling method regardless of the algorithm used, i.e. differential or integral.

A two-level homogenization approach is adopted in order to predict the stress state of deformed polycrystals in correlation with the microstructure. This study is devoted to complex loading paths behaviour of cubic material. A mechanical description of the grain is developed through a micro-meso transition based on elastoplastic Kroner's model. The meso-macro transition using a self-consistent approach is applied to deduce the global behaviour. Mechanical tests and neutron diffraction measurements are used to validate and assess the model. Classic one transition level models were developed to predict the influence of the local mechanical behavior to the global one. The grain is considered as an uniform region neglecting the formation of the dislocation microstructure. These approaches permit to predict correctly the yield surface, the crystallographic texture linked to the plastic deformation, the intergranular stresses due to initial and induced anisotropy during monotonic loadings. Nevertheless, this kind of description fails to reproduce the mechanical behaviour during changing strain paths. These methods do not, or weakly, take account of the formation, the evolution and the stability of induced dislocation microstructures which are strongly path dependent. In this work, a two-level homogenization approach is developed for the micromechanical modelling of the elastoplastic material behavior (1). This study is particulary devoted to complex loading paths. At the microscopic scale, the mechanical behavior is described by the Kroner model. The grain is considered as two-phase material: dislocations walls (with high density dislocation) and cells (with low density dislocation). The intragarnular heterogeneities are highlighted by a non- local work-hardening, which is linked to the two-phase description. At the global scale, the mechanical behavior is deduced from the mesoscopic one by an elastoplastic self-consistent model. To validate our numerical approach and explain the Bauschinger mechanisms, we conclude this paper by a confrontation between the simulation results with those from neutron diffraction (ND). This will allow to get a complete analysis at different levels: diffraction volume scale and macroscopic one.

For X-Ray Diffraction Measurement of Depth Profiles of Residual Stress, Step-Wise Removal of Materials has to be Done to Expose the Underneath Layers to the X-Rays. this Paper Investigates the Influence of Layer Removal Methods, Including Electro-Polishing in Two Different Electrolytes and Chemical Etching, on the Accuracy of Residual Stress Measurement. Measurements on Two Shot-Peened Steels Revealed Large Discrepancy in Subsurface Distributions of Residual Stress Obtained with the Respective Methods. Especially, the Chemical Etching Yielded much Lower Subsurface Compressive Stresses than the Electro-Polishing Using a so Called AII Electrolyte. the Difference was Explained by the Influence of the Different Layer Removal Methods on the Microscopic Roughness.

Laboratory X-ray diffraction is commonly used for surface residual stresses determination. Nevertheless, the in-depth residual stress gradient also needs to be known. Chemical or electro-polishing method is generally used for material removal. However, material removal may seek a new equilibrium and stress field may change in such a way that experimental residual stress values must be corrected. Different methods exist to account for the residual stress relaxation associated with the material removal operation and will be discussed in this paper.

Selectively induced compressive residual stress depth profiles are gaining increasing importance as design tool for internally pressurized components. Hydraulic Autofrettage (AF) is a well-known manufacturing process to induce pronounced compressive residual stresses. However, AF does not stand alone in the technical process chain. In this paper, results from neutron diffraction experiments performed on thick-walled cylinders are presented and compared to finite-element simulations with Abaqus/CAE. The impact on the final residual stress depth profile after pre-machining, Autofrettage and post-machining is discussed.

Titanium aluminide (TiAl) is a lightweight intermetallic compound with a range of exceptional mid-to-high temperature mechanical properties. These characteristics have the potential to deliver significant weight savings in aero engine components. However, the relatively low ductility of TiAl requires improved understanding of the relationship between manufacturing processes and residual stresses in order to expand the use of such components in service. Previous studies have suggested that stress determination at high spatial resolution is necessary to achieve better insight. The present paper reports progress beyond the current state-of-the-art towards the identification of the near-surface intragranular residual stress state in cast and ground TiAl at a resolution better than 5 μm. The semi-destructive ring-core drilling method using Focused Ion Beam (FIB) and Digital Image Correlation (DIC) was used for in-plane residual stress estimation in ten grains at the sample surface. The nature of the locally observed strain reliefs suggests that tensile residual stresses may have been induced in some grains by the unidirectional grinding process applied to the surface. © (2014) Trans Tech Publications, Switzerland.

The use of short process chains for the realization of complex and high performance components is a reasonable approach to achieve sustainable products and to reduce energy consumption. In the Collaborative Research Center SFB/TR TRR30 which is supported by the German Research Foundation DFG this approach is investigated applying thermo-mechanically forming processes. In this way, combining hot metal forming and heat treatment steps in a single process, tailored materials properties together with appropriate geometries are achieved [1, 2] . However, still additional machining operations, e. g. turning operations in case of shafts, are needed to achieve proper workpiece finish. Due to locally varying mechanical properties, undesired changings of the process conditions occur, leading to varying surface and subsurface properties, e.g. the residual stress state. It is well known that residual stresses have a major impact on the components properties during service [3]. In this paper, a survey is given about near surface residual stress states after exterior dry turning of differently heat treated cylindrical workpieces made of steel AISI 6150.

Strain is routinely used in state-of-the-art semiconductor devices in order to improve their electrical performance. Here we present experimental strain measurements obtained by different transmission electron microscopy (TEM) based techniques. Dark field electron holography, nanobeam electron diffraction (NBED) and high angle annular dark field scanning electron microscopy (HAADF STEM) are demonstrated. In this paper we demonstrate the spatial resolution and sensitivity of these different techniques on a simple calibration specimen where the accuracry of the measurement can easily be assessed. Introduction. Although the effects of introducing strain in semiconductor devices is well known from an electrical point of view, little is known about the distribution of strain. Indeed, it is only in the last few years that methods that can measure the strain with the required level of spatial resolution have been developed. Dark field electron holography (1), NBED (2) and HAADF STEM (3) are different TEM based techniques that have been developed in order to solve this problem. A calibration specimen was designed so that the different strain mapping techniques could be tested and compared to accurate simulations that would account for the relaxation of the thin TEM specimen. The calibration specimen that was examined was grown by reduced pressure chemical vapour deposition and comprised from top to bottom, a 150-nm-thick capping layer, then four 10- nm-thick SiGe layers with Ge concentrations of 45%, 38%, 31% and 20%, each separated by 30nm of silicon on a silicon substrate. As the growth is epitaxial, the lattice spacing in the in-plane (x- direction) does not change. However, in the growth (z-direction) the lattice parameter is expanded relative to the unstrained substrate due to the presence of Ge and it is this relative expansion which is measured. The dark holography experiments were performed using a probe corrected FEI Titan operated at 200 kV, the precession NBED (PED) and the HAADF STEM experiments were performed using a double corrected FEI Titan operated at 200 kV. All of the data was processed using software written at CEA.

Dye-sensitized solar cell (DSSC) is part of the thin film family that consists of a TiO2 electrode coating which acts as a photo electrode, sensitizer from dye molecules soaked in the TiO2 film, electrolyte layer and a counter electrode. This paper focuses on the usage of a sensitizer from the rose flower and will review some of the research conducted on dye sensitizers from other researcher. Rose flower also known as woody perennial of the genus Rosa, within the family Rosaceae is extracted and were used as sensitizer to fabricate dye sensitized solar cell (DSSC). The photoelectrochemical performance of Rose sensitized solar cell shows parameter of open circuit voltage, VOC,short circuit current, (ISC), fill factor (FF), solar cell efficiency (η), and peak absorbance rate as much as 0.13 V, 57.58 µA, 0.58, 0.85% and 3.5 at 550nm respectively. The photoelectrochemical performance of DSSC and the usage of natural sensitizer from Rose flower dye demonstrate good potential to be applied as a sensitizer yet detail investigations are essential in terms of its applicability for long term application.

This paper investigates experimentally and numerically the degree to which the stress relaxation in shot-peened simple geometric features of steel turbine materials can be modelled by using an understanding of simple eigenstrain distributions. The residual stress is determined as the elastic response of whole component when the plastic strains caused by shot peening is incorporated as an eigenstrain in an appropriate finite element (FE) model. The application of a subsequent live load is then modelled as an additional load step in the FE model which will superpose the effect of this loading on the residual stress field. The results show that the eigenstrain approach is particularly useful in predicting residual stress relaxation in shot-peened components.

Layer removal method is an experiment method which is used to calculate the average stress indirectly by deformation of the specimen. However, in the experiment, some certain predeformation can be caused after each clamping, which can affect the accuracy of the test data, and make the deformation data larger. Based on the comparison of the simulation calculation, this paper builds an amended function by fitting the deformation error, which solves the deviation caused by larger deformation on stress calculation while the specimen is milled by layer, that is to say, the stress calculation model can be compensated by this function. This method can make the experimental calculation model more accurate.

Ultrasonic impact treatment (UIT) is a remarkable post-weld treatment, which reduce not only in external stress concentration, but also in residual stress in a welded joints. Internal and surface stresses were investigated on UIT treated welded joints by neutron and X-ray diffraction method. This paper discuses the effect of internal and surface residual stress and surface stress concentration after UIT on fatigue resistance by the comparison of fatigue experiments to predictions calculated with the results of the experimental investigations.

Residual stress measurement techniques can be categorized as either relaxation or diffraction methods. Practitioners often advocate a particular category and sometimes a specific technique (hole drilling, contour, XRD, neutron, etc) based on their experience or capability rather than using the best technique for the particular application. This paper considers some of the implications from applying this “drunkard’s search” or “streetlight” approach by examining examples where the critical stress could be hidden from both relaxation and diffraction measurements. A better approach to planning residual stress measurements would begin with a detailed consideration of why the stresses should be measured and how the results will be used. Only then can the most appropriate measurement plan be developed. Since a single measurement technique cannot reveal the full state of stress, especially in challenging parts, the use of multiple measurement types often provides the most useful information to customers.

9th European Conference on Residual Stresses, ECRS-9, Troyes, France, july 7-10, 2014, session 3.5 - Acoustics and Electromagnetics, paper 194; International audience; For amorphous materials such as glass, the fragility of the material can be limited using surface reinforcement by chemical tempering. The principle of chemical tempering consists in forming a superficial compression layer on the surface by immersing the glass in a solution of molten potassium nitrate. In this study, dispersion of surface ultrasonic waves caused by the presence of residual surface stresses was studied. The thickness and the level of the stressed cortical zones were estimated using an inverse method.

Inconel 718 is a nickel based superalloy that is widely used as a turbine disc material in gas turbine industries. This study details the effect of thermal exposure on the residual stresses produced when broaching Inconel 718. The chosen parameters for broaching in this study are similar to those used when manufacturing turbine discs. The broaching operation produced a high level of tensile residual stresses at the broached surface. A layer with tensile residual stresses was formed in the sub-surface region, followed by a layer several times thicker with compressive residual stresses. Thermal exposure was conducted at 550 °C. The depth distributions of residual stresses after thermal exposure are presented and discussed in this paper. Complete relaxation of the surface tensile residual stresses was observed after 30 h thermal exposure, whereas the 3000 h thermal exposure influenced both the surface and sub-surface residual stress states.

This paper investigates residual stress due to fillet rolling on bolts made of ATI 718Plus® superalloy. Incremental hole drilling, neutron diffraction and neutron transmission have been used to assess residual stress near the bolt head fillet. A compressive residual stress field was identified in the first 0.5 mm from the surface. Post fillet rolling solution anneal can relieve the residual stress at the fillet.

During the revision of the individual parts of a hydroelectric power plant the cracks in the pins of quick operating and revision flap valves of Francis turbine were found. Our department has been approached with a request to investigate the causes of these cracks. This paper deals with the complex analysis of influential factors, especially the measurements of residual stresses by hole-drilling method, in order to reveal the factors causing the cracks in the pins.

Retracted paper: In order to realize the fast and accurate communication between AB SLC500 PLC and Profibus network, this thesis studies the Profibus protocol and develops the Profibus application program in the Flex I/O module. Thus the communication between SLC500 PLC and Profibus network is realized. Compared with the applying of SLC500 to control the other equipments and network, the applying of the Flex I/O module promotes the controlling efficiency and responding rate and realizes the complete control of the controlling system. The result of this research shows that this plan can ensure the accuracy, reliability and efficiency of the data transported.

Tribological surface textures are considered in this paper as a non-traditional friction control solution for microforming. Textured pads fabrication techniques are first evaluated and load-controlled micro-embossing is chosen as the optimal method to produce repeatable textured patterns on metallic pads. Using tribometer experiments and finite element simulations of dry contact between untextured and textured surfaces for pressure levels representative of microforming conditions, it is shown that there are competing mechanisms creating a sinusoidal-like friction reduction behavior when surface textures are present. Ultimately, it is concluded that a proper design of surface textures and loading conditions can be used for friction reduction in microforming. Accepted version

This paper presents a study on the effect of alkali treatment of Oil Palm Kernel Shell (OPKS) on the mechanical properties ofpolyester composite. The dosage of NaOH in this study is limited to 5wt% concentration.The experiments on mechanical properties investigate the tensile strength, the flexural strength and theflextural modulus of untreated, cold alkali treated and hot alkali treated OPKS reinforced polyester composite. It is found that the alkali treatment improves the mechanical properties of the composite. However, the improvement due tothe hot alkali treatment is significant compared to the cold alkali treatment. The morphology of OPKS and the fracture surface of OPKS composites were investigated using scanning electron microscopy (SEM), showing a rough surface and good interfacial adhesion between OPKS as filler and polyester as a matrix.

Integrated Product Development Process (IPDP) oriented for Assistive Technology (AT) usually engages multidisciplinary areas for design development. The involvement of professionals from different areas contributes to strengthening the IPDP phases, but a major barrier is the correct interpretation and understanding of the information shared by them, which allows the addressing of the product’s requirements and the feeding of the design structure. This paper aims to outline the first steps of the IPDP oriented for TA using the Integrated Definition Methods (IDEF) tool applied to a device design to assist in the training of athletes with visual disabilities. This step of the process focused on Object-Oriented Design Method (IDEF4) and Ontology Capture Method (IDEF5) from IDEF family. The result shows that through the use of the IDEF method oriented for the design of an AT product, the information sharing and the design global aspect to all team members was favored, promoting better communication.

The palm industry in Malaysia is a growing industry as from a mere 400 hectares planted in 1920, the hectarage increased to 5 million hectares in 2011 [1]. A by-product known as palm oil fuel ash (POFA) was a waste from the palm industry. Uncontrolled dumping of POFA give a serious impacts to environmental which creates pollution and health hazard. In this paper, the material characterization of POFA as an additive material to granite residual soil in terms of physical, mineralogical, chemical and mechanical properties has been investigated for the potential usage of the material. Results showed a general improvement of soil sample when mixed with POFA in all physical properties. The domain mineral present in natural soil is kaolinite. The mechanical behaviour also showed an improvement especially when compared to the landfill hydraulic barrier requirements.

RETRACTED PAPER: The synthesis of graphite nanoparticles at ambient temperature by high energy mechanical milling is modelled using ANN (Artificial Neural Network). The effect of milling time on the evolution of particle size, inclusion, microstructure and morphology were examined using XRD (X-Ray Diffraction), EDS (Energy Dispersive X-Ray Spectroscopy), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). ANN was effectively used to predict the influence of milling time on particle size and to forecast the milling time for the formation of nanoparticles. XRD results of investigation revealed change in strain behaviour of graphite particles of different sizes when heat treated.

This paper presents the results of three different fibers, Kenaf(hibiscus cannabinus), oil palm (Elaeis guineensis) and abaca (Musa textilis) which were treated using 5 different types of surface treatments namely sodium hydroxide for 24 hours, glycidoxypropyltrimethoxy-silane for 24 hours, NaOH followed by Silane (each 24 hours), NaOH followed by Silane (each 12 hours) and NaOH followed by Silane (each 6 hours). The mechanical strength of the fibers were then studied and compared to the untreated fibers. The highest strength was given by the fibers treated with NaOH followed by the combined treatments and the lowest were the fibers treated with silane. Also the bonding strength between the fibers and unsaturated polyester resin were then evaluated using micro droplet pull out tests. It was proven that all the treatments improved on the bonding strength. The highest was silane followed by NaOH. For the combined treatments it was found that the highest IFSS was given by the lowest treatment duration at 6 hours, due to the alkali nature of NaOH corroding the fibers which were then filled with silane, thus losing the ability to properly bond with the resin. The samples were also then characterized using a SEM to check the surface morphology which revealed that the NaOH reduced the diameter by removing impurities and lignin, thus increasing the aspect ratio. While silane coats the surface, increases the diameter and reduces the aspect ratio. Keywords. Kenaf, Abaca, OPF, Chemical Treatment, Bonding Strength, Droplet Test, SEM

This paper presents static fatigue laboratory experiments conducted in three different configurations. The experiments are designed so as to cause delayed tensile failure in dry Gabbro specimens after the sustained application of a static subcritical load. Results from the static fatigue experiments give a time to failure of the specimen related to the applied static load. In the presented experiments, results spanning up to six orders of magnitude of time to failure were collected for three-point bending, four-point bending, and indirect tensile (Brazilian) specimens. The data supports an exponential relationship between tensile stress and time to failure, noting that a power law relationship is also supported by the data. The salient difference among the configurations is hypothesized to be the size of the region of the specimen that is subjected to a close approximation of the maximum tensile stress. The time to failure at a given nominal tensile stress, the decrease in time to failure associated with a given increase in stress (i.e. the slope in a semi logarithmic plot), and the magnitude of the scatter of the data about the best-fit curve are all observed to correlate inversely with the nominal size of the region subjected to the maximum tensile stress.

Palm oil industry produces huge amount of oil palm decanter cake (OPDC). Currently it is not yet commercialized however due to its characteristics, it can be used to produce oil palm decanter cake natural polymer composite (OPDC-NPC). NPC is a type of material made by combining natural fiber with polymer. Therefore the objective of this paper is to produce NPC from OPDC and then determine its mechanical and physical properties such as elasticity, stiffness, tensile strength and water absorption rate. The OPDC samples were collected from Felda Trolak Palm Oil Mill. Prior to NPC development, the oil was removed from OPDC using hexane soxhlet extraction method. OPDC-NPC was fabricated using molding method where the mixture of 95% polypropylene (PP) and 5% OPDC were mixed using twin-screw extruder. The results showed that OPDC-NPC has an elasticity of 2231 MPa, stiffness of 30 MPa, tensile strength of 32 MPa and water absorption rate of 0.16 % which was slightly better with the other types of fibers.

This paper investigates the effect of process parameters such as Blank Holder Force (BHF) and Feed Rate, on the spring back behavior of a polymer metal laminate (PML) system comprised of aluminum and polypropylene. Specimens were formed over a hemispherical punch in stamp forming process. A novel real time strain measuring system, ARAMIS, was employed to capture the strain evolution during forming. The results of this work indicate that both BHF and feed-rate exert influence in PML spring back behavior. Fundamental correlation between strain evolution during spring back and the shape of the finished part will be presented. A major finding from this work is that aluminum dominates the spring back behavior of PML in stamp forming.

This paper presents modelling techniques for Lithium Iron Phosphate (LiFePO4) battery in an electric vehicle. Artificial intelligence techniques namely multi-layered perceptron neural network (MLPNN) and Elman recurrent neural network are devised to estimate the energy remained in the battery bank which referred to state of charge (SOC). The New European Driving Cycle (NEDC) test data is used to excite the cells in driving cycle-based conditions under varied temperature range [0-55]°C. Accurate SOC prediction is a key function for satisfactory implementation of Battery Supervisory System (BSS). It is demonstrated that artificial intelligence methods can be effectively used with highly accurate results. The accuracy of the modeling results is demonstrated through validation and correlation tests.

This paper presents the preliminary results of geological and geomechanical studies on the laterite stone exploited at Dano quarry in Burkina Faso. The field work described the geological structure of quarry sites and their environment to determine the rocks alteration and the links between the bedrock and lateritic material. Physic-mechanical properties have been studied for assessing the potentiality of this material for lightweight housing, to be completed with thermal and environmental considerations. Some social and economic evaluations are in progress in order to foster its utilization under local conditions

Strip profile control during rolling is required to assure the dimensional quality of rolled thin strip is acceptable for customers. Throughout rolling, the strip profile is controlled by using the advanced shape control rolling mill, such as the combination of work roll crossing and shifting during asymmetrical rolling, the one of the valuable methods to control the strip profile quality in rolling process. In this paper, the influences of cold rolling parameters such as the crossing angle and axial shifting value of work rolls on the strip profile are analysed. The strip shape control is discussed under both symmetrical and asymmetrical rolling conditions. The obtained results are appropriate to control the rolled thin strip profile in practice.

This paper presents the results on dielectric properties of pulverized material based on agricultural waste namely oil palm frond and pineapple leaf fiber for microwave absorber application in the X-band frequency range. The investigation is started by identifying the pulverized materials permittivities and loss tangents using coaxial probe technique, followed by density measurement comprising the determination of bulk and solid densities. Then, by using dielectric mixture model, the solid particle dielectric properties were determined. It is observed that the air properties give quite an effect on the permittivity and loss tangent of the pulverized materials. It is also found that the lower the material density the higher material dielectric constant will be. Furthermore, the results show that, both oil palm frond and pineapple leaf fiber are potential to be X-band absorber with average dielectric constant of 4.40 and 3.38 respectively. The loss tangents for both materials were observed to be more than 0.1 which mark them as lossy materials.

Titanium and its alloys have excellent properties and are promising biomaterial in medical engineering field. A bioactive surface on a Ti substrate is a prerequisite for great performance and long service life of implants. Based on the mechanism for inducing cell/tissue responses, three kinds of methods, namely morphological, physicochemical and biochemical methods, are reviewed in this paper. Hybrid methods that integrate individual methods or have additional functions are also discussed.

The aim of this paper is to investigate the effect of cutting speed and uncut chip thickness on cutting performance. A Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material mode and Coulombs friction law was used to simulate of High Speed Machining (HSM) of AISI 1045 steel. In this simulation work, feed rate ranging from 0.05 mm/rev to 0.13 mm/rev and cutting speed ranging from 200 m/min to 600 m/min at three different cutting speeds were investigated. From the simulation results it was observed that increasing feed rate and cutting speed lead to increase temperature and stress distribution at tool/chip interface. The results obtained from this study are highly essential to predict machining induced residual stresses and thermo-mechanical deformation related properties on the machined surface.

The typical problem in design of experiments methodology is to avoid risk of obtaining predictions outside of ranges with technological or physical sense. Such situation occurs very often if a simple linear regression or other unbounded is involved as a predictive model. The possible solution is to provide mappings of the outcome from the range of interest into the full range from negative to plus infinity before the linear regression is applied. The intermediate values obtained from unbounded predictive model is re-transformed into the physical domain by the inverse transformation. The key issue is to decide if the mapping is required and subsequently what mapping is necessary. Author proposed a simple heuristic supporting this decision and tested such solution in some examples described in this paper.

To know the physical and mechanical properties of wood to be employed as structural elements in is an important factor for its use in a rational way. The connections between members of timber structures are also relevant topic once local stress concentrations can occur and safety must be seriously taken in account. Brazilian Code ABNT NBR 7190: 1997 "Design of Timber Structures" provides guidelines for connections calculation based on two alternative limit states: wood strength to embedment or bending of the bolt. The purpose of this paper is estimate the strength to embedment of Pinus sp. to bolts in three directions with respect to the grain: parallel, perpendicular and inclined at 45o. Specimens obeying requirements of Brazilian Code related to bolts diameter (10mm) were prepared and tested. The embedment strength in parallel direction to the fiber was the highest and the failure modes were more frequent crushing and cleavage.

Shear failure is often found for masonry structure when subjected to complex loading. This paper presents the numerical analysis of shear strength test on triplet masonry specimens under different normal compressive stresses. Two different models were produced using a commercially available finite element analysis package ANSYS. The first model is a continuum model with the brick unit modeled as linear elastic material, while the mortar joints are modeled using a Drucker-Prager (DP) material or a concrete material. In the second model, the mortar joints as well as the brick/mortar interfaces were represented by a series of contact elements, and the Mohr-Coulomb failure surface was employed by these contact elements. Comparisons with the experimental results show that both models give satisfactory predictions for the maximum failure load, while the finite element model with interfaces has a better performance in terms of the load displacement response.

In Italy, during the last few years (2008-2013), the processes of land development have stalled due to the economic and political situation of the Country. The lack of public resources available to enable the above mentioned processes, as well as a complex and incomplete legislative and regulatory framework are the main causes of the crisis affecting the construction industry. This industry, which has always assured a turnover of 20% of Gross Domestic Product (GDP), should be revived through the development of public-private partnerships (PPP). This paper shows a working model of participatory management, based on PPP, which meets the purpose of supporting public administrations (PA) in a more efficient management of their lands development processes. The proposed model, inspired by the urban management experience developed in the city of Ladispoli (a best practise example), is based on European and International procedural and evaluation models. The models aim is to achieve public-interest objectives, within an articulated development initiative, based on a complex planning vision that involves a plurality of purposes, interventions, actors.

This paper proposes a new iterative method to achieve an optimally fitting plate for pre-operative planning purposes. The proposed method involves integration of four commercially available software tools, Matlab, Rapidform2006, SolidWorks and ANSYS, each performing specific tasks to obtain a plate shape that fits optimally for an individual tibia and is mechanically safe. A typical challenge when crossing multiple platforms is to ensure correct data transfer. We present an example of the implementation of the proposed method to demonstrate successful data transfer between the four platforms and the feasibility of the method.

This paper presents the investigation of minimum recast layer of zirconium oxide (ZrO2) due to micro-EDM using EDM-3 synthetic oil as dielectric fluid and tungsten as the tool electrode with control parameters of rotational speed and gap voltage. The investigation was performed using multi-process micro machine tools DT 110. The recast layer thickness was observed using scanning electron microscope and its hardness was measured using micro-Vickers hardness tester. The hardness data were analyzed and an empirical model was developed. The optimum value for minimum recast layer hardness was 873.46 Hv with rotational speed of 395 rpm and gap voltage of 110 V.

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.