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Functionally Graded Materials (FGM) are said to be smart materials that are fabricated by forming a compound of two components whose volume fraction has been changed across a certain direction. FGM can be used in many applications such as high temperature, aerospace and nuclear. The aim of this research work is about an investigation of wear behavior of functionally graded material (Al-Si alloy) produced by the Cast-Decant-Cast (CDC) method. In the CDC method, the Al-Si alloys were produced with three different regions. The Si composition has varied in each region. The outer, inner and transition regions consist of 7 wt% Si, 4wt% Si and 4 to 7 wt% Si respectively. out. Taguchi L9 orthogonal array (OA) had been conducted to find out the most significant factor which influence wear rate. Microstructure examination was done using an optical microscope and scanning electron microscope (SEM) helps to understand the distribution of silicon particles in the aluminum matrix. Hardness and wear resistance of the sample was carried. [ABSTRACT FROM AUTHOR]

Foreign substances and organic tissue interaction placed into the jaw in order to eliminate tooth loss involves a highly complex process. Many biological reactions take place as well as the biomechanical forces that influence this formation. Osseointegration denotes to the direct structural and functional association between the living bone and the load-bearing artificial implant's surface. Taking into consideration of the requirements in the manufacturing processes of the implants, surface characterizations with high precise measurement techniques are investigated and thus long-term success of dental implant is emphasized on the importance of these processes in this study. In this research, the detailed surface characterization was performed to identify the dependence of the manufacturing techniques on the surface properties by using the image processing methods and using the scanning electron microscope (SEM) for morphological properties in 3D and Taylor Hobson stylus profilometer for roughness properties in 2D. Three implant surfaces fabricated by different manufacturing techniques were inspected, and a machined surface was included into the study as a reference specimen. The results indicated that different surface treatments were strongly influenced surface morphology. Thus 2D and 3D precise inspection techniques were highlighted on the importance for surface characterization. Different image analyses techniques such as Dark-light technique were used to verify the surface measurement results. The computational phase was performed using image processing toolbox in Matlab with precise evaluation of the roughness for the implant surfaces. The relationship between the number of black and white pixels and surface roughness is presented. FFT image processing and analyses results explicitly imply that the technique is useful in the determination of surface roughness. The results showed that the number of black pixels in the image increases with increase in surface roughness. [ABSTRACT FROM AUTHOR]

Fish scale has the potential to be a rapid biomarker due to its structure and high possibility to come into contact with any pollutant in the aquatic environment. The scale structure consists of osteoblastic cells and other bone materials such as collagen where it is possible to form a molecular complex with heavy metals such as aluminum and iron. Hence, aluminum and iron in water could possibly destroy the scale material and marked as a scale deformation that quantitatively could be analyzed by comparing it to the normal scale structure. Water sampling and fish cage experiment were performed between June and July 2011 in Porong river which represented the water body that has high aluminum and iron contamination. The filtered water samples were preserved and extracted using the acid-mixture procedure prior to measurement of the aluminum and iron concentrations using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), while samples for total suspended solid (TSS) analysis were kept at 4 °C in cool-boxes. The scales were cleaned with sterile water, then dehydrated in 30, 50, 70, and 90% ethanol and dried on filter papers. They were then mounted on an aluminum stub and coated with gold in a sputter coater prior to Scanning Electron Microscope (SEM) observation. According to the SEM analysis, it was found that there were several deformations on the scale samples taken from sites that have high concentrations of aluminum and iron i.e. the increasing number of pits, deformation and decreasing number of spherules and ridges while the control scale exhibited the normal features. However, the site with higher TSS and pH indicated lower aluminum effect. A moderate correlation was found between the number of pits with aluminum (r=0.43) and iron (r=0.41) concentrations. Fish scale deformation using SEM analysis can potentially be a rapid biomarker in aquatic monitoring of aluminum and iron contamination. However, the measurement must be accompanied by pH and TSS observations. [ABSTRACT FROM AUTHOR]

Ophthalmology is entering a very interesting period with new diffractive multifocals, improved refractive multifocals, and accommodative lenses, all coming out at the same time. A new diffractive-refractive design for providing intermediated vision is apodization. In an apodized pattern, physical diffractive step heights are reduced in height, in an almost continuously varying manner. This study is aimed to investigate the use of ultrashort laser pulses to ablate the surface of intraocular lenses, and thus provide an alternative to conventional techniques. Ablation experiments were performed on hydrophilic and hydrophobic intraocular lenses (IOLs). The samples were irradiated with a Ti:Sapphire laser at λ=0.785 μm, pulse duration 150 fs, repetition rate 1 kHz and with a Nd:YAG 4ω laser at λ= 0.266 μm, pulse duration 155 ps, repetition rate 10 Hz. We investigated the ablation efficiency and the surface modification with a Scanning Electron Microscope (SEM). The experimental results and the theoretical assumptions on the relevant ablation mechanism are discussed. [ABSTRACT FROM AUTHOR]

Ophthalmology is entering a very interesting period with new diffractive multifocals, improved refractive multifocals, and accommodative lenses, all coming out at the same time. A new diffractive refractive design for providing intermediated vision is apodization. In an apodized pattern, physical diffractive step heights are reduced in height, in an almost continuously varying manner. This study is aimed to investigate the use of ultrashort laser pulses to ablate the surface of intraocular lenses, and thus provide an alternative to conventional techniques. Ablation experiments were performed on hydrophilic and hydrophobic intraocular lenses (IOLs). The samples were irradiated with a Ti:Sapphire laser at λ=0.785µm, pulse duration 150 fs, repetition rate 1 kHz and with a Nd:YAG 4w laser at λ=0.266µm, pulse duration 155 ps, repetition rate 10 Hz. We investigated the ablation efficiency and the surface modification with a Scanning Electron Microscope (SEM). The experimental results and the theoretical assumptions on the relevant ablation mechanism are discussed. [ABSTRACT FROM AUTHOR]

LiNi0.5Mn1.5O4 is a potential cathode material for 5 V batteries. This material was prepared by the solid-state redox method using nitrate and acetate based reactants. The precursor material was obtained when the mixture reactants was heated at 500° C for 10 hours and calcined at different temperatures in the range between 650 and 950° C for 12 hours. The structures of the synthesized materials were verified with X- ray diffraction (XRD) measurement and Scanning Electron Microscope (SEM). The charge-discharge technique was determined using Solartron 1470. As calcination temperature increases, the well-ordered crystal growth oriented to [1 1 1] direction shows a clear octahedral morphology, which is the characteristic of the typical cubic spinel. The Li/LiNi0.5Mn1.5O4 prepared from acetate based reactants calcined at 750° C for 12 h delivered the discharge capacity of 140 mAh/g. [ABSTRACT FROM AUTHOR]

Surface morphology study of Zinc Oxide (ZnO) thin films by using Thermal Chemical Vapor Deposition (Thermal-CVD) was investigated. The ZnO compound was synthesized from zinc acetate dehydrate which act as a starting material to form the ZnO thin films. It was deposited on as-prepared Nanonstructured Silicon (NSi) with deposition temperature ranging from 400–600° C without catalyst-assisted. The surface morphology of the samples before and after the deposition process was examined by using Analytical Scanning Electron Microscope (SEM). The result shows that the obtained ZnO thin films possess good crystalline structure at deposition temperature of 600° C and the surface morphologies of the ZnO thin films improved greatly with an increase in deposition temperature. XRD was employed to study the evolution of the crystalline orientation using X-Ray Diffractrometer (XRD). [ABSTRACT FROM AUTHOR]

The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to enhance the bonding between the implant and bone in human body. The coating process was implemented at different spraying power for each spraying condition. The coatings formed from a rapid solidification of molten and partly molten particles that impact on the surface of substrate at high velocity and high temperature. The study was concentrated on different spraying power that is between 23 to 31 kW. The effect of different power on the coatings microstructure was investigated using scanning electron microscope (SEM) and phase composition was evaluated using X-ray diffraction (XRD) analysis. The coatings surface morphology showed distribution of molten, partially melted particles and some micro-cracks. The produced coatings were found to be porous as observed from the cross-sectional morphology. The coatings XRD results indicated the presence of crystalline phase of HA and each of the patterns was similar to the initial powder. Regardless of different spraying power, all the coatings were having similar XRD patterns. [ABSTRACT FROM AUTHOR]

Zinc Oxide (ZnO) nanorods were grown on porous silicon substrate by sol-gel immersion method, which is containing of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and hexamethylenetetramine (C6H12N4).ZnO Nanorods prepared under the different deposition temperature. The surface morphology and photoluminescence spectrum of the samples were characterized using scanning electron microscope (SEM), and photoluminescence spectroscope (PL). The result indicated that the ZnO nanorods start to form at 85° C. From the photoluminescence spectrum, it shows that a strong ultra-violet (UV) emission peak and several weak emission peaks related to the deep level excitation de-excitation were detected. [ABSTRACT FROM AUTHOR]

In this study, ZnO thin films were deposited on the silicon substrate by using dip-coating method. To prepare zinc solution, zinc acetate dehydrate was used as starting material and dissolved in 2-methoexyethanol. Monoethanolamine was used in this solution as stabilizer. Then, the solution was stirred at 60° C for one hour and stayed at room temperature for one night. Thin film was obtained by dip coating the solution on silicon substrates at different withdrawal speeds. The effect of different withdrawal speed on the surface morphology of the ZnO thin film was investigated scanning electron microscope (SEM).The SEM image showed that the grain size has decreased as speed increased. [ABSTRACT FROM AUTHOR]

Mechanism of doping of Mg in GaN thin film grown on c-plane sapphire substrate by plasma assisted-metalorganic chemical vapor deposition (PA-MOCVD) method have been investigated. The growth was carried out at temperature of 680 °C, which flow rate of Cp2Mg as dopant source was varied of 0.003; 0.006; 0.009 and 0.012 sccm. The Van der Pauw technique, X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize their electric, crystallographic and morphology properties. Hole concentrations of up to 1019 cm-3 have been observed for Mg-doped GaN films without any post-growth annealing. The XRD analysis showed change of the FWHMs for the (0002) orientation plane from Mg-doped GaN films. The difference of the atomic radius between Ga and Mg atoms causes lattice distortion in crystal. This lattice distortion generates dislocation and causes growth of the layer to be three-dimensional as showed on SEM images. [ABSTRACT FROM AUTHOR]

Pressure-shear plate impact experiments and soft recovery experiments were performed for 92.93 wt% aluminas with 75-mm-diameter compressed-gas gun. The in-material longitudinal and transverse particle velocities were traced by the embedded electromagnetic velocity gauges. The decoupled transverse particle velocities show an attenuation of shear waves with decreasing of material shear rigidity. SEM analysis of the intact samples shows heterogeneous meso-structures, and that of recovered samples shows the transit of intergranular microcracks to transgranular microcracks with increasing shock loading. The transverse shear promotes the microcracks nuclearing and expanding, and these microcracks result in remarkable dilation of alumina samples after unloading. [ABSTRACT FROM AUTHOR]

Plasmonic nanoparticle grating (PNG) structure of different periods has been fabricated by electron beam lithography using silver halide based transmission electron microscope film as a substrate. Conventional scanning electron microscope is used as a fabrication tool for electron beam lithography. Optical microscope and energy dispersive spectroscopy (EDS) have been used for its morphological and elemental characterization. Optical characterization is performed by UV-Vis absorption spectroscopic technique. [ABSTRACT FROM AUTHOR]