ALBERT

Description: Nanoindentation experiments were performed to investigate the irradiation effects on the mechanical properties of 6H-SiC irradiated by 4 MeV Kr ions at high fluences from room temperature (RT) to 550°C. The irradiation temperature is the primary factor that affects modifications of the comprehensive mechanical properties, while the effect of the fluence is less significant. Elastic modulus and hardness decrease drastically for RT-irradiated samples, but they almost recover for elevated temperature samples, with hardness slightly higher than its original value. The hardness increases first and then decreases with increasing temperature, and the elastic modulus decreases linearly as the swelling increases. Meyer's index is related to the indentation size effect of hardness and the magnitude of the lattice damage. The ratio of irreversible work is associated with the degree of elastic recovery and the ratio of hardness to elastic modulus of SiC. Compared with the unirradiated value, fracture toughness changes slightly for RT irradiation, while increasing significantly for elevated temperature irradiation and has the same variation tendency of hardness. Results indicate that mechanical properties change with the variations of interatomic bond strength, dislocation mobility, and the behavior of crack propagation, which is strongly affected by the defects induced by heavy-ion irradiation.

Description: In this study, based on self-reactive quenching technique, hollow ceramic microspheres (HCMs) containing barium ferrites were synthesized using Al+Fe 2 O 3 +BaO 2 +sucrose+ epoxy resin as the reactive system and polyethylene glycol (PEG) as the foaming agent. The influence of PEG on the particle size and microwave absorption properties of HCMs is investigated using SEM, XRD, laser particle size analyzer and vector network analyzer. Preliminary results show that the average particle size increases initially from 28 μm to 53 μm after adding PEG, as well as the particle distribution gets narrower and the surface takes on classical hexagonal crystals. BaFe 2 O 4 , the intermediate phase of M-type barium ferrites (BaFe 12 O 19 ), can be seen in XRD. The microwave absorption properties are improved greatly in the frequency range of 8–18 GHz. And the minimum reflection loss can reach −10 dB.

Description: Homogenous liquid precursor for ZrC – SiC was prepared by blending of Zr ( OC 4 H 9 ) 4 and Poly[(methylsilylene)acetylene]. This precursor could be cured at 250°C and converted into binary ZrC – SiC composite ceramics upon heat treatment at 1700°C. The pyrolysis mechanism and optimal molar ratio of the precursor were investigated by XRD. The morphology and elements analyses were conducted by SEM and corresponding energy-dispersive spectrometer. The evolution of carbon during ceramization was studied by Raman spectroscopy. The results showed that the precursor samples heat treated at 900°C consisted of t- ZrO 2 (main phase) and m- ZrO 2 (minor phase). The higher temperature induced phase transformation and t- ZrO 2 converted into m- ZrO 2 . Further heating led to the formation of ZrC and SiC due to the carbothermal reduction, and the ceramic sample changed from compact to porous due to the generation of carbon oxides. With the increasing molar ratios of C / Zr , the residual oxides in 1700°C ceramic samples converted into ZrC and almost pure ZrC – SiC composite ceramics could be obtained in ZS-3 sample. The Zr , Si , and C elements were well distributed in the obtained ceramics powders and particles with a distribution of 100 ~ 300 nm consisted of well-crystallized ZrC and SiC phases.

Description: The implementation of Ceramic Matrix Composites necessitates the understanding of stress-dependent damage evolution. Toward this goal, two liquid silicon infiltrated SiCf reinforced SiC composites were tensile tested with electrical resistance (ER) monitoring as well as acoustic emission to quantify matrix cracking. ER was modeled using a combination of resistors in series and parallel to model transverse matrix cracks and fiber/matrix segments between matrix cracks. It is shown that resistance change is sensitive to transverse matrix crack formation and stress-dependent debonding length. The model appears to be accurate up to the stress for matrix crack saturation.

Description: LaMgAl 11 O 19 -3 mol% yttria partially stabilized zirconia ceramics were successfully prepared by pressureless sintering at 1550°C for 3 h. The ceramic's mechanical properties were measured, and the phase composition and microstructure observed using X-ray diffraction and scanning electron microscopy. The results show that the mechanical properties of the ceramic were initially improved on addition of LaMgAl 11 O 19, but further additions were detrimental. When the amount of LMA added was equal to 2 wt.%, the bending strength and fracture toughness reached 812 ± 37 MPa and 14.0 ± 0.3 MPa·m 1/2 . This equates to an increase of 8.0% and 6.9% compared with untreated 3 mol% yttria partially stabilized zirconia (3YSZ) ceramic, respectively. However, the bending strength and fracture toughness both decreased when the amount of LaMgAl 11 O 19 added was 4 and 6 wt.%. A crack propagation and force analysis of the crack tips in LaMgAl 11 O 19 -platelet-reinforced 3YSZ ceramic were also carried out. The results indicate that phase transformation and crack deflection were the dominant toughening mechanisms in the LaMgAl 11 O 19 -3YSZ ceramic. At the same time, energy dissipation by the LaMgAl 11 O 19 platelets also helps to restrain crack propagation in the matrix, which improves toughness more effectively.

Description: Ce -doped BaTiO 3 -based ceramics were prepared and studied to satisfy ultra-broad temperature stability (from −55°C to 300°C, capacitance variation rate based on C 20°C is within ±15%). The sample with 0.6 mol% CeO 2 succeeds to achieve this performance with a remarkably high ceiling temperature of 300°C. Meanwhile, the sample has good dielectric and electrical properties at room temperature (ε r  = 1667, tanδ = 1.478%, ρ V  = 5.9 × 10 12  Ω·cm). Ce ion can substitute for Ti ion as Ce 4+ or Ba ion as Ce 3+ . The substitution decreases the spontaneous polarization of BaTiO 3 , and then weakens the ferroelectricity of BaTiO 3 . As a result, the temperature stability of samples is improved obviously. Besides, CeO 2 addition promotes the formation of exaggerated grains, which are consisting of Ba 6 Ti 17 O 40 .

Description: This study aims to optimize quantitative X-ray diffraction (XRD) mineralogical analysis of the minority phases in clinker. The proposed method consists of applying Rietveld quantitative refinement to the XRD patterns for both clinker and the insoluble residue remaining after it is attacked with methanol and salicylic acid (Takashima method). The method was tested with industrial clinker and the same material after modifying its mineralogy by refiring at 1500°C followed by slow cooling. The findings showed that the C 4 AF / C 3 A ratios for quickly and gradually cooled clinker were much higher when the clinker diffractograms were refined with the Rietveld procedure than when the proposed method was used. The proportion of C 3 A found with the proposed method was ≈2.8-fold higher than when Rietveld only was applied to the diffractograms for clinkers. Taken together, the refinement data for the two materials (clinker and Takashima residua) revealed that Rietveld quantitative XRD applied to clinker underestimates the low C 3 A content. These findings are supported by postsulfate attack durability studies conducted on cements prepared with the two clinkers.

Description: The effect of increasing poling fields on the properties of (1− x )BZT– x BCT compositions across the morphotropic phase boundary (MPB) is studied using large signal polarization and strain, small signal permittivity and piezoelectric coefficient, and XRD measurements. Successive poling causes charge carrier migration inducing an internal bias field, which becomes large with respect to the coercive field resulting in biased ferroelectric and ferroelastic switching. Improvements in piezoelectric coefficient of 9% are significantly smaller in the tetragonal 60BCT composition compared with the improvement of approximately 50% in the rhombohedral 40BCT and MPB 50BCT compositions. While the properties continue to change with increased poling fields, the remnant ferroelastic domain texture parallel to the field direction, as observed from XRD, stays approximately constant. The improvement in overall domain alignment leading to largely enhanced intrinsic piezoelectricity originates from the alignment of 180° domains and possibly non-180° domains in grains with orientations inclined to the electric field. As a result, poling is most effective in BZT–BCT materials that have low coercive fields, show low distortions and possess more polarization orientations, such as compositions in the rhombohedral phase field or near the MPB.

Description: The defect chemistry-modulated dielectric properties of dense yttria-doped zirconia ceramics prepared by conventional sintering (at 1350°C–1500°C) and electric field-assisted flash sintering (55 V/cm at 900°C) were studied by impedance spectroscopy. While the bulk dielectric properties from both sets of samples showed only small and insignificant changes in conductivity and permittivity, respectively, a huge increase of these properties was measured for the grain boundaries in the flash sintered specimens. A close analysis of these results suggests that flash sintering reduced grain-boundary thickness (by about 30%), while increasing the concentration of oxygen vacancies near these interfaces (by about 49%). The underlying mechanism proposed is electric field-assisted generation and accommodation of defects in the space-charge layers adjacent to the grain surface. The changes in measured permittivity are attributed to the boundary thickness effect on capacitance, while conductivity involved variations in its defect density-dependent intrinsic value, accounting for changes also observed in grain-boundary relaxation frequencies. Therefore, in terms of modifications to the specific dielectric properties of these materials, the overall consequence of flash sintering was to considerably lower the semi-blocking character of the grain boundaries.

Description: This article presents a detailed study on the nanoscaled interface between microelongated gold particles (GP) and biphase leucite/feldspar glass-ceramic matrix. The glass-ceramic composite with a nonuniform GP distribution was processed through hot-pressing under vacuum using a commercial dental ceramic furnace for glass-ceramic dental crown manufacturing. Heat treatments at 900°C, 1100°C, and 1300°C were conducted, and microstructural features along the interface were used to verify the chemical reactions between GP and glass-ceramic matrix. It was observed that the amorphous glass-ceramic matrix had nanoscaled biphase structures, and the distributed nanoscaled amorphous leucite phase was attracted to GP during hot-pressing, and was more reactive with GP than the feldspar phase. The thickness of the interfacial phase formed through chemical reactions between GP and glass-ceramic matrix is around 30 nm. The chemically bonded interface has contributed significantly toward the substantial improvements in both strength and toughness of the GP-reinforced glass-ceramic matrix composite. Characterization techniques, including X-ray diffraction and field-emission scanning electron Microscopy, incorporating X-ray microanalysis using energy dispersive spectrometry, have been employed in this study.

Description: The cyclic oxidation of bulk Ti 2 AlC at intermediate temperatures of 600–1000°C in air was studied by thermogravimetric analysis. It was demonstrated that Ti 2 AlC exhibited good cyclic-oxidation resistance at temperatures above 700°C. The cyclic-oxidation kinetics approximately follows a parabolic rate law at 700–1000°C range. The surface scales are dense, resistant to spalling and adhesive to Ti 2 AlC substrate. An abnormal oxidation whose cyclic-oxidation kinetics obeys a linear law is observed at 600°C. As revealed by scanning electron microscope (SEM), oxidation-induced cracks present at 600°C results in poor protectivity and accounts for the abnormal oxidation. The cracks are caused by the stress associated with the volume expansion due the formation of anatase TiO 2 in the scale.

Description: Recent investigations have revealed the great potential of Raman spectroscopy for the characterization of clinker minerals and commercial Portland cements. The usefulness of this technique for the identification of anhydrous, hydrated, and carbonated phases in cement-based materials has been demonstrated. In the present work, the application of micro-Raman spectroscopy for the characterization of the main clinker phases of calcium aluminate cements and calcium sulfoaluminate cement is explored. The main stable hydrated phases as well as several important carbonated phases are investigated. Raman measurements on the following phases are reported: (i) pure, unhydrated phases: CA, C 12 A 7 , CA 2 , C 2 AS, cubic- C 3 A , C 4 AF, and C 4 A 3 ; (ii) hydrated phases: ettringite, monosulfoaluminate, and hydrogarnet ( C 3 AH 6 ); (iii) carboaluminate phases: hemicarboaluminate and monocarboaluminate. The present results, which are discussed in terms of the internal vibrational modes of the aluminate, carbonate, and sulfate molecular groups as well as stretching O–H vibrations, show the ability of Raman spectroscopy to identify the main hydrated and unhydrated phases in the aluminate and sulfoaluminate cements. The Raman spectra obtained in this work provide an extended database to the existing data published in the literature.

Description: Acmite ( NaFeSi 2 O 6 ) films were formed on steel coupons via solvothermal reaction of silica, sodium hydroxide, and 1, 4-butanediol in an autoclave under autogenous pressure. Systematic variation in processing variables led to homogenous coatings comprised of pinacoidal acmite grains with an average grain size of ~33 μm. The coatings were produced on the steel coupons from reactant conditions of 0.635 m SiO 2 , 2.546 m NaOH , and 3.087 m 1,4-butanediol for 72 h at 240°C.

Description: The nanocomposite CeO 2 /Y 2 O 3 partially stabilized zirconia (Ce-PSZ/Y-PSZ)-toughened alumina was prepared by wet chemical simultaneous coprecipitation process. The thermal stability of phases and morphology of powders were characterized by TG-DTA, FTIR, and FESEM. The microstructure, stabilization of phases and compositional analysis with different mol% CeO 2 /Y 2 O 3 -doped zirconia in alumina are characterized by FESEM, XRD, and EDAX spectra. Significant improvement in fracture toughness and flexural strength has been observed in 10 vol% of partially stabilized zirconia (2.5 mol% Y 2 O 3 in ZrO 2 /9 mol% CeO 2 in ZrO 2 )-toughened alumina, which is suitable for high-speed machining applications.

Description: A 50:50 vol% MgO – Y 2 O 3 nanocomposite with ~150 nm grain size was prepared in an attempt to make 3–5 μm infrared-transmitting windows with increased durability and thermal shock resistance. Flexure strength of the composite at 21°C is 679 MPa for 0.88 cm 2 under load. Hardness is consistent with that of the constituents with similar grain size. For 3-mm-thick material at 4.85 μm, the total scatter loss is 1.5%, forward scatter is 0.2%, and absorptance is 1.8%. Optical scatter below 2 μm is 100%. Variable intensity OH absorption (~6% absorptance) is observed near 3 μm. The refractive index is ~0.4% below the volume-fraction-weighted average of those of the constituents. Thermal expansion is equal to the volume-fraction-weighted average of expansion of the constituents. Specific heat capacity is equal to the mass-fraction-weighted average of heat capacities of the constituents. Thermal conductivity lies between those of the constituents up to 1200 K. Elastic constants lie between those of the constituents. The Hasselman mild thermal shock resistance parameter for the composite is twice as great as that of common 3–5 μm window materials, but half as great as that of c -plane sapphire.

Description: In this work, novel Y 2 Si 2 O 7 / ZrO 2 composites were developed for structural and coating applications by taking advantage of their unique properties, such as good damage tolerance, tunable mechanical properties, and superior wear resistance. The γ- Y 2 Si 2 O 7 / ZrO 2 composites showed improved mechanical properties compared to the γ- Y 2 Si 2 O 7 matrix material, that is, the Young's modulus was enhanced from 155 to 188 GPa (121%) and the flexural strength from 135 to 254 MPa (181%); when the amount of ZrO 2 was increased from 0 to 50 vol%, the γ- Y 2 Si 2 O 7 / ZrO 2 composites also presented relatively high facture toughness (〉1.7 MPa·m 1/2 ), but this exhibited an inverse relationship with the ZrO 2 content. The composition–mechanical property–tribology relationships of the Y 2 Si 2 O 7 / ZrO 2 composites were elucidated. The wear resistance of the composites is not only influenced by the applied load, hardness, strength, toughness, and rigidity but also effectively depends on micromechanical stability properties of the microstructures. The easy growth of subcritical microcracks in Y 2 Si 2 O 7 grains and at grain boundaries significantly contributes to the macroscopic fracture toughness, but promotes the pull-out of individual grains, thus resulting in a lack of correlation between the wear rate and the macroscopic fracture toughness of the composites.

Description: The as-prepared BiFeO 3 ceramic shows a piezoelectric d 33 coefficient of −14 pC/N, that is, an obvious ferroelectric self-poling phenomenon. The temperature gradient between the two surfaces of BiFeO 3 ceramic was intentionally enlarged when BiFeO 3 was prepared with a rapid liquid sintering method. This temperature gradient and the corresponding thermal strain can introduce defect dipoles through separating bismuth vacancies from oxygen vacancies. A mass of these dipoles introduce a macroscopic internal electric field ( E in ) which downward poles BiFeO 3 ceramic during its cooling down process. As expected, an E in of 〉10 kV/cm is confirmed by the asymmetrical polarization/strain versus electric field curves.

Description: The effect of Ba content on the stress sensitivity of the antiferroelectric to ferroelectric phase transition in ( Pb 0.94− x La 0.04 Ba x )[( Zr 0.60 Sn 0.40 ) 0.84 Ti 0.16 ] O 3 ceramics is investigated through monitoring electric field-induced polarization and longitudinal strain under compressive prestresses. It is found that incorporation of Ba significantly suppresses the stress sensitivity of the phase transition, as manifested by slight decreases under prestresses up to 100 MPa in the maximum polarization ( P m ) and longitudinal strain ( x m ). The energy storage density is even increased under the mechanical confinement in compositions x  = 0.02 and 0.04. X-ray diffraction, transmission electron microscopy, and dielectric measurements indicate that the suppressed stress sensitivity is associated with the disruption of micrometersized antiferroelectric domains into nanodomains and the transition from antiferroelectric to relaxor behavior.

Description: Powders and nanoceramics composed of composites of CoFe 2 O 4 , CoFe 2 , and a small amount of FeO were prepared by heating CoFe 2 O 4 powder in reducing atmosphere and by sintering the product of reducing reaction at 350°C via spark plasma sintering technology. In the powders, increase in the molar ratios of CoFe 2 : CoFe 2 O 4 and a great change in magnetic parameters were observed with the change in heating temperature from 300°C to 400°C, and the dominance of dipole interaction over exchange coupling in the interparticle interactions was confirmed by the steps in magnetic hysteresis loops and the negative Henkel plots. However, in the nanoceramics, significant enhancement in exchange coupling was found when the sintering temperature was raised to 500°C and 650°C, which was confirmed by both the positivity of Henkel plot and the single-phase style of the magnetic hysteresis loop.

Description: Gas adsorption porosity measurement of geopolymers (GPs) is required for quantitative understanding of such mesoporous structures, but the complex nature of the GP system makes analysis difficult. Previous results in the literature are often ambiguous or contradictory. A systematic investigation of metakaolin GP gas adsorption results was conducted to optimize the use of this measurement technique and verify that results match known theory about GP structure. It was found that GP undergoes structural change upon degassing at 100°C or higher. If and only if this change is prevented by degassing at a lower temperature could it be shown that specific surface area and total gas adsorption increases with both increasing curing temperature and decreased Si : Al ratio. This observation is consistent with previous suggestions of increased zeolitic character under these conditions, where previous gas adsorption investigations had not observed this expected relationship. Hydrogen physisorption is proposed as a substitute technique for micropore isotherms in GPs due to the difficulty of removing trace gasses from GPs and the measurement effect of such gasses at high vacuum. A hydrogen physisorption isotherm qualitatively resembled an equivalent nitrogen micropore isotherm.

Description: The (1- x )(K 0.5 Na 0.5 )NbO 3 - x LaFeO 3 (abbreviated as (1- x )KNN- x LF, x  =   0–0.03) ceramics were synthesized by the conventional solid-state sintering method. X-ray diffraction analysis shows that the phase structure of the (1- x )KNN- x LF ceramics transfers from orthorhombic to pseudocubic with increasing the LF content. The SEM studies reveal that a small amount of LF, as a grain growth inhibitor, has an evident effect on grain size reduction. The (1- x )KNN- x LF ( x  =   0.02) ceramics show high permittivity maximum (near 2000) and low dielectric loss (〈5%) in the temperature range of 100–400°C, and the capacitance variation (ΔC/C 150°C ) is keeping within ±15%, indicating the potential application for the high-temperature capacitors.

Description: In this work, the sinterability of forsterite powder synthesized via solid-state reaction was investigated. X-ray diffraction (XRD) analyses indicate that the synthesized powder possessed peaks that correspond to stoichiometric forsterite. Scanning electron micrographs revealed that the powders were formed agglomerates, which were made up of loosely packed fine particles. Subsequently, the forsterite powders were cold isostatically pressed into a disk shape under 200 MPa and sintered in air at temperature ranging from 1200°C to 1500°C (interval of 50°C) with ramp rate of 10°C/min and dwelling time of 2 h. The sinterability of each sintered samples was examined in terms of phase stability, relative density, Vickers hardness, fracture toughness, and microstructural examination. XRD examination on all the sintered samples exhibited pure forsterite, in which the generated peaks were found to be in a good agreement with JCPDS card no. 34-0189. The densification of forsterite progressed to reach a maximum relative density of ~91% at 1500°C. This study also revealed that high-strength forsterite ceramic can be synthesized via solid-state reaction as forsterite attained favorable mechanical properties, having fracture toughness of 4.88 MPam 1/2 and hardness of 7.11 GPa at 1400°C.

Description: In this work, the role of europium doping of glasses formulated in the ternary system ZnO – CdO – TeO 2 is described. The Eu -doped oxide glasses were prepared by the conventional melt-quenching method and by using three different compositions. Structural studies reveal that there exists a good affinity between Cd and some rare earth (RE) ions to form the crystalline phase. The X-ray diffraction (XRD) diagrams display that the structure of these glasses is amorphous and with the increase in CdO content and the compatibility of Eu 3+ , there is a tendency to form nanocrystals of CdTe 2 O 5 . The scanning electron microscopic (SEM) observation of their microstructure confirms the presence of phase separation. Differential thermal analysis (DTA) of these glasses showed small exothermic peaks noted around 450°C for the V2 glass and 480°C for V1 and V3 glasses, which could be attributed to the formation of these crystals. The infrared spectra showed a main absorption band around 800–600 cm −1 corresponding to the Te – O stretching mode in TeO 4 and TeO 3 groups. By optical absorption (OA), the band gap ( E g ) for each glass was determined; these values were 3.27, 3.14, and 3.3 eV for the V1–V3 glasses, respectively. Furthermore, the presence of Eu 3+ was detected in the 370–470 nm short-range wavelengths. The photoluminescence (PL) experiments of the glasses showed light emission due to the following transitions: 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3, and 5D0 → 7F4.

Description: This article presents a novel systematic approach to the fabrication of highly functionalized, silica (SiO 2 ) nanoparticles used for the adsorption of heavy-metal ions (Hg 2+ , Pb 2+ , Cd 2+ , Zn 2+ ). Almost monodispersed silica (SiO 2 ) nanoparticles with narrow particle size distributions of around 85 ± 5 nm were formed using the Stöber process. The prepared SiO 2 nanoparticles were successfully surface-treated during a one-step procedure by the covalent attachment of mercaptopropyl groups onto the surfaces of the SiO 2 nanoparticles. A FTIR spectra analysis confirmed that the binding of the mercaptosilane molecules onto the surface of the silica nanoparticles mediated the Si–O–Si and –SH vibrations. TEM/EDXS micrographs indicated the almost monodispersed and spherical morphology of the prepared product with strong signals of Si and S, thus implying that the coating procedure involving the mercapto groups onto the silica surface had been successfully accomplished. The final results for the heavy-metal (Hg 2+ , Pb 2+ , Cd 2+ , Zn 2+ ) adsorption showed the strongest affinity within the following sequence Hg 2+ (99.9%) 〉 Pb 2+ (55.9%) 〉 Cd 2+ (50.2%) 〉 Zn 2+ (4%). Adsorption equilibrium was achieved after 1 h for all the analyzed samples.

Description: Surfactant-assisted hydrothermal synthesis of magnesium-doped hydroxyapatite (Ca 10− x Mg x (PO 4 ) 6 (OH) 2 ) with 0 ≤  x  ≤ 1) was realized in aqueous solution at 90°C. β-TCP phase was formed in the Mg 0.6 -HA sample after heat treatment at 1000°C. Magnesium was found to degrade the sintering ability of Mg x -HA ceramics. Flexural strength (σ f ) was found to decrease as a function of Mg-doped HA. The using of carbon nanotubes as reinforcing agents mitigated the strength loss of Mg-HA ceramics. The flexural strength of Mg 0.6 -HA was then increased by nearly 20% from approximately 33 to 39 MPa with an optimum addition of 3 wt% of multi-walled nanotubes.

Description: The conductivity of nominal CaWO 4 , CaW 0.99 Ta 0.01 O 4–δ , 0.7( CaWO 4 )–0.3( La 0.99 Ca 0.01 NbO 4–δ ), and Ca 0.9 La 0.1 WO 4+δ has been studied by means of a.c. impedance measurements. Proton conductivity was observed for CaW 0.99 Ta 0.01 O 4–δ , which displayed exothermic hydration with enthalpy and entropy of –82 kJ/mol and –120 J/molK, respectively. The proton mobility in CaW 0.99 Ta 0.01 O 4–δ was low, with enthalpy and preexponential factor of mobility of 82 kJ/mol and 0.7 cm 2 K/Vs. The high enthalpy of mobility is interpreted to reflect association between the acceptor dopant and protonic defects, whereas the low preexponential factor of mobility may reflect a lower proton concentration than assumed. Rietveld refinement indicated low solubilities of La on Ca -site and Ta on W-site. Proton conductivity was also observed in undoped CaWO 4 , however, not in Ca 0.9 La 0.1 WO 4+δ . The conductivity of 0.7( CaWO 4 )–0.3( La 0.99 Ca 0.01 NbO 4–δ ) behaved much like that of undoped LaNbO 4 , likely due to a very low acceptor dopant concentration.

Description: A new lead-free BNT-based piezoelectric ceramics of (1 −  x ) Bi 0.5 Na 0.5 TiO 3 – x Bi ( Al 0.5 Ga 0.5 ) O 3 ( x  = 0, 0.02, 0.03, 0.04, and 0.05) were synthesized using a conventional ceramic fabrication method. Their structures and electrical properties were investigated. All the samples show a typical ferroelectric P ( E ) loops and S ( E ) curves at room temperature. The optimal properties are obtained at the composition of the x  = 0.03. The substitution of Bi ( Al 0.5 Ga 0.5 ) O 3 enhances piezoelectric constant and increases Curie temperature from 58 pC/N and 310°C of pure BNT to 93 pC/N and 325°C of the x  = 0.03. The temperature-dependent P ( E ) loops and S ( E ) curves of 0.97BNT–0.03BAG indicate that phase transition from ferroelectric to antiferroelectric takes place over a very wide temperature region from 80°C to 180°C. The results show that the introduction of BAG improves the electrical properties of BNT.

Description: We studied ancient enamels on gilded copper from a collection of archeological horse harness pendants of the Museo Instituto Valencia de Don Juan (Madrid, Spain) to test the benefits of a new, nondestructive analytical methodology based on chemometric analysis (i.e., Principal Component Analysis, PCA) on micro-ATR-FTIR spectral data and chemical quantification using SEM-EDS. The novelty of this approach was threefold: (i) PCA allowed the discrimination of the different harness pendants of known origin and attributed to the 14th and 15th centuries according to the chemical complex composition, nanostructure, glass weathering, and/or coloring mechanisms of each colored enamel, separately (i.e., red, purple, blue, and white), (ii) it is a cheap, easily available and nondestructive methodology that enables us to (iii) draw archeological conclusions about the quality of the manufacturing process, reassess the chronology of these objects and attempt to attribute them to different workshops according to the different traditional recipes identified. In particular, the enamels were made of alkali and/or alkaline earth lead-glass with a wide range of chemical compounds in the form of pigments or opacifiers. Two types of coloring mechanisms were identified, colloidal particles such as copper-ruby for red enamels, and ionic mechanisms such as Fe (II) and Co (II) to achieve a blue pigments; Mn (III) in the purple pigment; and two kind of white enamels were identified, i.e., tin oxide as an opacifier and uranium oxide. In addition, we established the reason for the poor state of conservation of some of the enamels by means of the identification of depolymerization and ion exchanges, well-known harmful effects of glass weathering, and finally a chronology was assigned for some of these pieces according to the enamel composition.

Description: Novel glass-ceramics with embedded thermoelectric Bi 2 Se 3 crystals were prepared from glass matrices in the Ge 20 Se 100− x Bi x ( x  = 5, 10, 12 mol%) system. Based on DSC results performed at different heating rates, characteristic activation energies ( E c ) and Avrami exponents ( n ) were obtained and analyzed by using Kissinger's relation, Ozawa's method, Augis–Bennett approximation and Matusita–Sakka theory. XRD results showed that pure Bi 2 Se 3 crystalline phase precipitated upon annealing at different temperatures for various time. The crystal size and crystalline fraction in the samples could be tuned by controlling the annealing time.

Description: In the present investigations nano size high alumina cements (HAC) were prepared by very effective co-melt precursor sintering technique from their metal nitrate precursors. The prime cementing phases observed were CA, CA 2 , and C 12 A 7 . The addition of nano structured cements in refractory castables has improved the thermo-chemical-mechanical properties to a significant extent. Each batch of low cement castables (LCC) was prepared from calcined Chinese bauxite, HAC, and superfine additives. The effect of HAC in bauxite castable with the additives similar to Silicon Carbide, reactive alumina, and micro-fine silica on the sinterability and properties of these castables was investigated. Physical properties such as apparent porosity and bulk density, mechanical properties such as hot modulus of rupture (HMOR), cold and hot modulus of rupture (CMOR), and cold crushing strength (CCS) of hydrated and sintered castables were studied. The sintered castables were also characterized for their solid phase compositions and microstructure using X-ray diffraction (XRD) and FE-SEM, respectively. In the castables new phases such as mullite, α-alumina were formed at the expense of bauxite and silica. Solid solution of mullite formed at high temperature acts as a bonding phase and is accounted for high HMOR, CMOR, and CCS values. These excellent properties of such castables may enable their uses in various applications such as refractory lining for fabrication of steel, aluminium, copper, glass, cement, chemicals, and ceramics.

Description: The applications of robotics in recent years has emerged beyond the field of manufacturing or industrial robots itself. Robotics applications are now widely used in medical, transport, underwater, entertainment and military sector. In medical field, these applications should be emphasized in view of the increasing challenges due to the variety of findings in the field of medicine which requires new inventions to ease work process. The objective of this review paper is to study and presents the past and on-going research in medical robotics with emphasis on rehabilitation (assistive care) and surgery robotics which are certainly the two main practical fields where robots application are commonly used presently. The study found that, rehabilitation and surgery robotics applications grow extensively with the finding of new invention, as well as research that is being undertaken and to be undertaken. The importance of medical robot in medical industry is intended to offer positive o...

Description: The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1–5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30–60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

Description: This study aims to create a simplified model of a reinforced square hollow section (SHS) T-joint found in bus superstructures. The approach is to use a combination of one- and two-dimensional finite element models to represent a reference three-dimensional finite element (solid) model of the joint and determine stress concentration factors (SCFs) as functions of the geometrical variables of the joint. This approach requires the stiffness of the simplified model to be equivalent to the stiffness of the reference solid model. Trial models, therefore, must be proposed and their stiffnesses must be evaluated against the stiffness of the reference solid model. The best trial model is then selected based on the stiffness error function defined to represent the deviation of the simplified model's stiffness from the reference model's stiffness. After a trial model with minimum stiffness error is selected, its SCFs, relating the maximum stress in the simplified model to the maximum stres...

Description: Tunnelling magnetoresistance (TMR) in polycrystalline Sr 2 FeMoO 6 has been a matter of intense interest for more than a decade now, where the nature of the insulating tunnel barrier turned out to be the core issue of debate. Other than the nonmagnetic grain boundaries as conventional tunnel barriers, intragrain magnetic anti-phase boundaries (APB) as well as magnetically frustrated grain surfaces have also been proposed to act as tunnel barriers and influence the TMR response of Sr 2 FeMoO 6 in different ways. In this paper, it is shown that depending upon the physical state of the sample, at least three different types of tunnelling mechanism may persist in polycrystalline Sr 2 FeMoO 6 and a purely conventional TMR response, seldom reported in this important magnetoresistive material, is also possible.

Description: This paper presents an efficient method to prepare ZnO nano-porous structure via immersion of Si substrate with catalyst assistance (gold) in the mixture of zinc nitrate hexahydrate (Zn(NO 3 ) 2 .6H 2 O) and urea (CH 4 N 2 O). Photoluminescence (PL) spectra of nano-porous ZnO revealed it had strong UV emission with low oxygen defect. Optical properties are found to be significantly affected by varying the Zn 2+ : urea ratio but from surface morphology observation, the porous structure was stabile and seemingly unchanged.

Description: The paper addresses the problem scheduling a batch processing machine with multiple incompatible job families, non-identical job dimensions, non-identical job sizes and non-agreeable release dates to minimize makespan. The research problem is solved by proposing a mixed integer programming model that appropriately takes into account the parameters considered in the problem. The proposed is validated using a numerical example. The experiment conducted show that the model can pose significant difficulties in solving the large scale instances. The paper concludes by giving the scope for future work and some alternative approaches one can use for solving these class of problems.

Description: Nano-magnesium oxide (Nano-MgO) had successfully deposited on glass substrate using sol-gel spin coating technique at different drying temperature (100, 200 and 300°C). The dielectric layer properties of deposited nano-MgO films were investigated in terms of its resistivity, leakage current density, relative permittivity, topology and morphology respectively. Changing in drying temperature resulted in variation of nano-MgO films properties and film dried at 200°C has compact, uniform, less porous and in nano size that lead to the enhancement in relative permittivity value.

Description: Aggregate Production Planning (APP) is a medium-term planning which is concerned with the lowest-cost method of production planning to meet customers' requirements and to satisfy fluctuating demand over a planning time horizon. APP problem has been studied widely since it was introduced and formulated in 1950s. However, in several conducted studies in the APP area, most of the researchers have concentrated on some common objectives such as minimization of cost, fluctuation in the number of workers, and inventory level. Specifically, maintaining quality at the desirable level as an objective while minimizing cost has not been considered in previous studies. In this study, an attempt has been made to develop a multi-objective mixed integer linear programming model that serves those companies aiming to incur the minimum level of operational cost while maintaining quality at an acceptable level. In order to obtain the solution to the multi-objective model, the Fuzzy Goal Programming...

Description: The growing use of internet and online purchasing among young consumers in Malaysia provides a huge prospect in e-commerce market, specifically for B2C segment. In this market, if E-marketers know the web-based factors affecting online buyers' behaviour, and the effect of these factors on behaviour of online consumers, then they can develop their marketing strategies to convert potential customers into active one, while retaining existing online customers. Review of previous studies related to the online purchasing behaviour in B2C market has point out that the conceptualization and empirical validation of the online purchasing behaviour of Information and Communication Technology (ICT) literate users, or ICT professional, in Malaysia has not been clearly addressed. This paper focuses on (i) web-based factors which online buyers (ICT professional) keep in mind while shopping online; and (ii) the effect of web-based factors on online purchasing behaviour. Based on the extensive l...

Description: Value stream mapping is a tool which is needed to let the business leader of XYZ Hospital to see what is actually happening in its business process that have caused longer lead time for self-produced medicines in its pharmacy unit. This problem has triggered many complaints filed by patients. After deploying this tool, the team has come up with the fact that in processing the medicine, pharmacy unit does not have any storage and capsule packing tool and this condition has caused many wasting times in its process. Therefore, the team has proposed to the business leader to procure the required tools in order to shorten its process. This research has resulted in shortened lead time from 45 minutes to 30 minutes as required by the government through Indonesian health ministry with increased %VA (valued added activity) or Process Cycle Efficiency (PCE) from 66% to 68% (considered lean because it is upper than required 30%). This result has proved that the process effectiveness has be...

Description: This work presents a self-tuning feedwater heater model. This work continues the work on first-principle gray-box methodology applied to diagnostics and condition assessment of power plant components. The objective of this work is to review and benchmark the optimization algorithms regarding the time required to achieve the best model fit to operational power plant data. The paper recommends the most effective algorithm to be used in the model adjustment process.

Description: P-type silicon was used as a substrate of deposition of nanostructured ZnO by sol-gel spin coating technique, while zinc acetate, diethanolamine, and isopropyl were used as starting material, stabilizer and solvent respectively. Surface morphology was studied by Field Emission Scanning Electron Microscopy (FESEM). It was found that nanostructured ZnO was distributed uniformly over the P-type Silicon substrate. This was supported by atomic force microscopy (AFM) image which shows the all the surfaces are covered by nanoparticle of ZnO. X-ray diffraction (XRD) was employed to analyse the structural and crystalline of nanostructured ZnO. Three peak (100), (002), and (101) correspond to nanostructed ZnO are appear. Temperature dependence I-V characteristic was investigated in range of 25 K to 300 K by using Close Cycle Cryostat and using Helium as cooler agent. It is found that the resistance were decrease toward the higher temperature. The result shows that resistivity gradually de...

Description: In this paper, several advanced manufacturing systems in food processing and packaging industry are reviewed, including: biodegradable smart packaging and Nano composites, advanced automation control system consists of fieldbus technology, distributed control system and food safety inspection features. The main purpose of current technology in food processing and packaging industry is discussed due to major concern on efficiency of the plant process, productivity, quality, as well as safety. These application were chosen because they are robust, flexible, reconfigurable, preserve the quality of the food, and efficient.

Description: The data available on the Internet is in various models and formats. One form of data representation is a table. Tables extraction is used in process more than one table on the Internet from different sources. Currently the effort is done by using copy-paste that is not automatic process. This article presents an approach to prepare the area, so tables in HTML format can be extracted and converted into a database that make easier to combine the data from many resources. This article was tested on the algorithm 1 used to determine the actual number of columns and rows of the table, as well as algorithm 2 are used to determine the boundary line of the property. Tests conducted at 100 tabular HTML format, and the test results provide the accuracy of the algorithm 1 is 99.9% and the accuracy of the algorithm 2 is 84%.

Description: The polymer nanocomposite is a new choice to conventionally filled polymers. The lack of proper binding between the filler and the polymer can lead the decrease of the thermal and other properties of the nanocomposites. In this study, the nanocomposited PMMA/TiO 2 nanocomposites were prepared using sonication and solution casting method at different weight percent TiO 2 . The aims of adding TiO 2 in the PMMA is to study the effects of TiO 2 nanofiller on the thermal properties nanocomposites. FESEM results show the higher amounts of TiO 2 in PMMA increase the rough surface morphology of the samples. Further, the Raman results reveal that the TiO 2 nanofiller were successfully intercalated into the PMMA matrix. In addition, the thermal properties of nanocomposited PMMA/TiO 2 nanocomposites were increased with the addition of TiO 2 in the PMMA.

Description: ZnO nanorod, SnO 2 nanoparticle and ZnO/SnO 2 cubic structure were prepared using sol-gel immersion method. These three structures had been growth on top sputtered ZnO thin film. The surface morphology of all thin film were characterized using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). The prepared thin films were fabricated for humidity sensor application. The composite sensor ZnO/SnO 2 cubic structure gave excellent sensitivity compare to ZnO nanorod and SnO 2 nanoparticle. The improvement sensitivities of ZnO/SnO 2 cubic structure were 22.5 times from ratio of R 40RH% to R 90RH% at 25°C. ZnO/SnO 2 cubic structure had a great potential for humidity sensor application with good in repeatability and stability.

Description: Thin films of lanthanum phosphate (LaPO 4 ) nanostructures were fabricated on quartz substrate using sol-gel spin coating method subsequent with drying and annealing process. Increase of annealing temperature will increase the intensity of diffraction peaks; reveal that the particle size and crystallinity increase with temperature. A monoclinic structure was shown to be present in LaPO 4 thin films after first anneal at 200°C. The LaPO 4 nanostructures of average size 30 – 50 nm were observed with field emission scanning electron microscopy. While the crystallize size were measured with x-ray diffraction (XRD). The images of LaPO 4 nanostructure films show uniformity of samples with homogenously close-packed morphology.

Description: Cancer is one of the contagious diseases that become a public health issue, both in the world and in Indonesia. In the world, 12% of all deaths caused by cancer and is the second killer after cardiovascular disease. Early detection using the IVA is a practical and inexpensive (only requiring acetic acid). However, the accuracy of the method is quite low, as it can not detect the stage of the cancer. While other methods have a better sensitivity than the IVA method, is a method of PAP smear. However, this method is relatively expensive, and requires an experienced pathologist-cytologist. According to the case above, Considered important to make the cancer cervics detector that is used to detect the abnormality and cervical cancer stage and consists of a digital microscope, as well as a computer application based on artificial neural network. The use of cervical cancer detector software and hardware are integrated each other. After the specifications met, the steps to design the c...

Description: The manufacturing environment rapidly changes in turbulence fashion. Digital manufacturing (DM) plays a significant role and one of the key strategies in setting up vision and strategic planning toward the knowledge based manufacturing. An approach of combining 3D machine vision (3D-MV) and an Additive Manufacturing (AM) may finally be finding its niche in manufacturing. This paper briefly overviews the integration of the 3D machine vision and AM in concurrent product and process development, the challenges and opportunities, the implementation of the 3D-MV and AM at POLMAN Bandung in accelerating product design and process development, and discusses a direct deployment of this approach on a real case from our industrial partners that have placed this as one of the very important and strategic approach in research as well as product/prototype development. The strategic aspects and needs of this combination approach in research, design and development are main concerns of the pre...

Description: The effect of strain rate on the mechanical behavior of Al-Zn magnesium alloys was examined in room temperature from low to high strain rates by using a Universal Testing Machine. Quasi static tensile test was performed in four different strain rates to obtained their effect on tensile properties and work hardening rate using a round shape tensile sample. Two types of Al-Zn magnesium alloys were used in this research study i.e. AZ31 and AZ61 magnesium alloys. The yield stress and tensile strength of AZ31 were found to be strain rate dependent but not for AZ61. The elongation of AZ31 were approximately about 15% for all strain rate levels but for AZ61 the elongations were slightly decreased with increasing strain rates. For all strain rate levels, the work hardening rate of AZ61 were found higher compared to that of AZ31. The change in fracture mode as observed from the fracture surface implies that the fracture mechanisms in AZ31 change as the strain rate increases.

Description: Meta-analysis has been conducted based on 20 previous works from 4,040 firms at 16 countries from Asia, Europe and America. Throughout this paper a meta-analysis, this paper reviews the relationships between TQM and business performance amongst the regions. Meta-analysis result concludes that the average of rc is 0.47; Asia (rc=0.54), America (rc=0.43) and Europe (rc=0.38). The analysis also shows that Asia developed countries have greatest impact of TQM (rc=0.56). However, the analysis of ANOVA and t-test show that there is no significant difference amongst type of country (developed and developing countries) and regions at p=0.05. In addition, the average result of rc 2 is 0.24; Asia (rc 2 =0.33), America (rc 2 =0.22) and Europe (rc 2 =0.15). Meanwhile, rc 2 in developing countries (rc 2 =0.28) are higher than developed countries (rc 2 =0.21).

Description: All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Description: In this article an approach will be presented which supports transparency regarding the effectiveness of manufacturing equipment by combining the fuzzy set theory with the method of the overall equipment effectiveness analysis. One of the key principles of lean production and also a fundamental task in production optimization projects is the prior analysis of the current state of a production system by the use of key performance indicators to derive possible future states. The current state of the art in overall equipment effectiveness analysis is usually performed by cumulating different machine states by means of decentralized data collection without the consideration of uncertainty. In manual data collection or semi-automated plant data collection systems the quality of derived data often diverges and leads optimization teams to distorted conclusions about the real optimization potential of manufacturing equipment. The method discussed in this paper is to help practitioners t...

Description: ##IMG## [http://ej.iop.org/images/1757-899X/46/1/011001/banner.jpg] {Banner} The 2013 International Conference on Manufacturing, Optimization, Industrial and Material Engineering (MOIME 2013), was held at the Grand Royal Panghegar Hotel, Bandung, Indonesia, from 9–10 March 2013. The MOIME 2013 conference brought together researchers, engineers and scientists in the field from around the world. MOIME 2013 aimed to promote interaction between the theoretical, experimental, and applied communities, so that a high level exchange was achieved in new and emerging areas within Material Engineering, Industrial Engineering and all areas that related to Optimization. We would like to express our sincere gratitude to all in the Technical Program Committee who reviewed the papers and developed a very interesting Conference Program as well as the invited and plenary speakers. This year, we received 103 papers and after rigorous review, 45 papers wer...

Description: In this work, the hybrid treated layer on austenitic AISI 316L stainless steels were characterized to investigate the improvement on its surface properties. Characterization of this resulting layer was performed by FESEM (Field Emission Scanning Electron Microscope), USPM (Universal Scanning Probe Microscope) and nanoindentation. By using these methods, changes in the mechanical properties due to the diffusion of carbon and nitrogen at low temperature treatments have been traced. This hybrid treated sample has confirmed a considerable increase in hardness and a small rise in the elastic modulus compared to the untreated sample. It is found that all treated samples have enhance E/H ratio which exhibited the decreasing tendency to plastic deformation and reduced the mismatch of properties, while keeping deformation within the elastic range.

Description: The Production and Supply Optimization in PT. Goodyear Indonesia Tbk and its study in this paper provide the purposes to create a model of the Master Production Schedule (MPS). The mentioned MPS complies with company policy, production capacity and supply received. From view point of Industrial Engineering, there are needs for forecasting method effectiveness toward the company production capacity. Furthermore, from view point of Information Systems, there are needs to provide the MPS as compare to prior systems that was done manually resulting in the frequent error at the time of making MPS deductible. Several Methods are used and considered, such as: The method of time series, Mean Square Error (MSE), Mean Absolute Percentage Error (MAPE), the calculation of production capacity, MPS, and designing information systems. By having the combination of views from Industrial Engineering and Information Systems perspective the improvement can be conducted from both theoretical develop...

Description: Zinc sulphide thin films were deposited on Corning glass substrates by the chemical bath deposition technique at different temperatures. The influence of the bath temperature and deposition time on the morphological and optical properties of the ZnS films are herein investigated. ZnS films were deposited by changing the bath-temperature from 50 °C to 90 °C, and deposition times from 60 to 160 min. Thin and transparent films were obtained with thicknesses from 10 to 90 nm with the increment of the bath temperature, meanwhile the band gap energy E g values diminishes from 4.15 to 3.4 eV. The quality of the ZnS film surfaces was also influenced by increasing the bath temperature, as showed by the reduced grain size and the increase of roughness, obtained from atomic force microscopy images. ZnS films of good optical quality were obtained at 90 °C with a mean value of E g = 3.56 ± 0.03 eV.

Description: In this work, we proposed a low cost material to be used as an excellent absorber for solar collectors, to increase its thermal efficiency by the high capacity to absorb solar radiation. The material, known as "smoke black" (soot) can be obtained by the incomplete combustion of organic materials, such as the oxygen-acetylene, paraffin, or candles. A comparative analysis between the optical properties (reflectance, absorbance, and emissivity) measured on three covered copper surfaces (without paint, with a commercial matte black paint, and with smoke black) shows amazing optical results for the smoke black. Reflectance values of the smoke black applied over copper surfaces improves 56 times the values obtained from commercial black paints. High values of emissivity (E=0.9988) were measured on the surface covered with smoke black by spectrophotometry in the UV-VIS range, which represents about 7% of increment as compared with the value obtained for commercial black paints (E=0.938...

Description: Polymer Concrete was reinforced with recycled-tire fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6, 0.9 and 1.2 vol%). The results show increment of 50% in average of the compressive and flexural strength as well as on the deformation when adding 1.2 vol% of recycled-fibers.

Description: This paper presents the adsorption results of acid, basic, direct, vat, and reactive-type dyes on carbonaceous adsorbent materials prepared starting off vegetable residue such as Opuntia ficus indica and Casimiroa edulis fruit wastes. The adsorbents prepared from Opuntia ficus indica waste were designated: TunaAsh, CarTunaT, and CarTunaQ. The materials obtained from Casimiroa edulis waste were named: CenZAP, CarZAPT, and CarZAPQ. TunaAsh and CenZAP consist of ashes obtained at 550 °C; CarTunaT and CarZAPT consist of the materials carbonized at 400 °C; lastly, CarTunaQ and CarZAPQ consist of chemically activated carbons using H 3 PO 4 at 400 °C. Only the chemically activated materials were washed with distilled water until a neutral pH was obtained after their carbonization. All materials were ground and sieved to obtain a particle size ranging from 0.25 to 0.84 mm. The static adsorption results showed that both ashes and chemically ...

Description: Polymers have had a significant increase in the industrial field, and polycarbonates (PCs) are an example. PCs have important properties such as high impact resistance, high heat capability, hardness, toughness, optical clarity, heat resistance, abrasion resistance and high refractive index. PCs with these properties have a variety of applications, for example, astronaut helmets, CDs/ DVDs, automobile parts, bulletproof windows, ophthalmic lenses and welding masks. In the present work we report the synthesis and characterization of network polycarbonates, based (1,1'-biphenyl)-4,4'-diyldiallylcarbonate (I) and hexa(4-allylcarbonatephenoxy) cyclotriphosphazene (III). The polycarbonates were obtained by bulk polymerization technique. The polymers obtained with thermal initiators showed degrees of cross-linking greater than 80%. The PCs obtained have thermal stability to 250 °C. The polycarbonate obtained from the monomer III showed a limiting oxygen index of 46.3%, therefore this ...

Description: A sorbent material based on silica particles modified with poly(N-vinylimidazole) (SiO 2 -PVI) has been evaluated for the treatment of samples by matrix solid-phase dispersion (MSPD). The extraction of four organophosphorus pesticides was done from a spiked tomato and the extracts were analyzed by gas chromatography coupled to mass spectrometry. Six elution solvents were evaluated and acetone was selected due to better recovery of the four pesticides and low background signal in the chromatograms. A factorial design 2 4 was used for selection of extraction conditions. The factors were contact time, acetone volume, treatment (with or without freeze-drying) and adsorbent (SiO 2 or SiO 2 -PVI). The best recoveries were obtained using 15 minutes of contact, 2 mL of solvent and sorbent without freeze-drying. The recoveries were between 60 and 83% for SiO 2 -PVI in spiked tomato with 0.2 and 0.8μg/g.

Description: The present work shows the analysis of a sandblasting process using alumina abrasive particles on Ti-6Al-4V surfaces. The metallic samples were first characterized by optical microscopy (OM), revealing an α+β microstructure with a Widmanstätten morphology. Topography of the samples was assessed by scanning electron microscopy (SEM), before and after sandblasting. The Al 2 O 3 particles used had a granulometric distribution between 420 and 850 μm, with a median particle size (d50) of 670 μm, which decreased to 420 μm after sandblasting for 10 seconds. This change in the size of the particles generated a loss on particle kinetic energy by a factor of 3.5. Such variation on processing conditions induced a progressive increase on average roughness (Ra) of the Ti - 6Al-4V surfaces, until the first 7 seconds were reached. From that point on, a reverse process was observed, exerting a polishing effect on the surface of the Ti-6Al-4V alloy.

Description: Using ZnO pellets and molecular hydrogen as solid source and reactant gas respectively, Zn-ZnO microspheres were grown by hot filament chemical vapor deposition in low temperature growth regime. The presence of Zn-ZnO microspheres was confirmed by scanning electron microscopy (SEM) technique. It is suggested that microspheres formed in the gas phase by nucleation of Zn atoms. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) measurements suggest that microspheres were only superficially oxidized by water vapor species.

Description: Zn 2 GeO 4 ceramic materials were synthesized by the solid-state method. Zn 2 GeO 4 powders were investigated with X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Oxygen defects in the Zn 2 GeO 4 ceramics were investigated by photoluminescence, Raman, and EDS spectra. Conductivity of Zn 2 GeO 4 was 0.18 S/cm at low temperature of 773 K, and its activation energy was 0.49 eV. The results showed that Zn 2 GeO 4 was a promising low-temperature electrolyte with high conductivity.

Description: Using a high-speed and high-resolution-camera system of droplets in glaze sprays and their impact on the surface of a green ceramic body based on silicate tiles have been characterized. The influence of the surface tension of the glaze slips on the droplet size distribution and their wetting behavior on contact with the green silicate body surface have been investigated. The unfired glaze layers have been studied by means of scanning electron microscopy and computer tomography. The impact angle of the droplets as well as the size of the droplets is of great importance for a high glaze surface quality.

Description: Dense (97.3%) zirconium diboride (ZrB 2 ) ceramics were obtained via gelcasting and pressureless sintering. Four wt% B 4 C was used as sintering aid. ZrB 2 , SiC, and B 4 C can codisperse well in the alkaline region, using a polyacrylate dispersant. Compared with monolithic ZrB 2 (Z), the mechanical properties of ZrB 2 -SiC (ZS) were enhanced. The Vickers hardness and fracture toughness of ZS were (13.1 ± 0.6) GPa and (2.5 ± 0.4) MPa m 1/2 , respectively.

Description: This article details the influence of zirconium doping on the piezoelectric properties and relaxor characteristics of 94( Bi 1/2 Na 1/2 ) TiO 3 –6 Ba ( Zr x Ti 1− x ) O 3 (BNT–6BZT) bulk ceramics. Neutron diffraction measurements of BNT–6BZT doped with 0%–15% Zr revealed an electric-field-induced transition of the average crystal structure from pseudo-cubic to rhombohedral/tetragonal symmetries across the entire compositional range. The addition of Zr up to 10% stabilizes this transition, resulting in saturated polarization hysteresis loops with a maximum polarization of 40 μC/cm 2 at 5.5 kV/mm, while corresponding strain hysteresis measurements yield a maximum strain of 0.3%. With further Zr addition, the ferroelectric order is progressively destabilized and typical relaxor characteristics such as double peaks in the current density loops are observed. In the strain hysteresis, this destabilization leads to an increase of the maximum strain by 0.05%. These changes to the physical behavior caused by Zr addition are consistent with a reduction of the transition temperature T F-R , above which the field-induced transformation from the relaxor to ferroelectric state becomes reversible.

Description: Precursor glasses for the ferroelectric barium bismuth titanate ( BaBi 4 Ti 4 O 15 ) (BBiT) have been prepared by the melt-quench technique in the SiO 2 – K 2 O – BaO – Bi 2 O 3 – TiO 2 (SKBBT) glass system with and without Eu 2 O 3 doping. BBiT glass–ceramic (GC) nanocomposites have been derived from these glasses by controlled heat treatment. The structural properties of the GCs have been investigated using X-ray diffraction (XRD), electron microscopy (FE-SEM, TEM), and FT-IR reflectance spectroscopy. FE-SEM images show the formation of randomly oriented hexagonal rod-shaped crystals of 200–400 nm and TEM images show 10–20 nm crystallites. FT-IR spectra exhibit the characteristic bands of BBiT at 480, 585, and 680 cm −1 . The activation energy of crystallization ( E c ) varies from 295 to 307 kJ/mol. The dielectric constants (ε r ) of glass and GC nanocomposites increase with an increase in frequency up to 3.0 MHz and then decrease up to 5.0 MHz. Heat-treated GCs show higher ε r values, in the range 25–55, compared to the precursor glasses (20–37). Dielectric losses (tan δ) for all the samples increase from 0.005 to 1.0 with an increase in frequency from 100 Hz to 5.0 MHz. Excitation spectra were recorded by monitoring emission at 613 nm corresponding to the 5 D 0 → 7 F 2 transition. An intense 466 nm excitation band corresponding to the 7 F 0 → 5 D 2 transition was observed. Emission spectra were then recorded by exciting the glass samples at 466 nm. Longer heat-treatment times led to a 15-fold increase in the intensity of the red emission at 612 nm, attributed to the segregation of Eu 3+ ions into the low phonon energy BBiT crystallites. The hardness (3.8–5.1 GPa) and fracture toughness (1.8–3.5 MPam 0.5 ) values obtained in the GCs are high and suitable for structural applications.

Description: Carbon doping is known to be very effective for enhancing the high-field properties of magnesium diboride, MgB 2 , but not for the low-field properties. Here, we report that both the high- and the low-field properties can be improved simultaneously without doping by increasing the initial magnesium partial pressure, by simply reducing the size of the magnesium particles. It is shown that in situ processed bulk MgB 2 sintered with fine magnesium powders has superior superconducting properties compared with a bulk sample fabricated using coarse magnesium lumps. The change in the lattice parameters was almost negligible; however, a clear increase in lattice strain can be observed for the sample sintered with fine magnesium powders. The increase in the lattice strain results in an enhancement of the high-field properties. Furthermore, it has also been found that the low-field critical current density is not reduced, but rather slightly increased for the fine magnesium powder sample. This is due to a closer linkage among the grains that drastically improves grain connectivity. These findings demonstrate that the initial growth mechanism of MgB 2 is very crucial for its superior superconducting properties, and it especially indicates the importance of magnesium vapor pressure.

Description: Revisiting classic phase diagrams and chemical phase relations in the solid state of a very well-studied oxide system, such as the lithium aluminosilicate (LAS) system, can open a new window for the design of new advanced materials with improved properties. Crystal chemistry and phase equilibria are used to demonstrate the ability to design materials with particular desired properties in the alumina-rich corner of the LAS phase diagram. The experimental results demonstrate the alumina and β-eucryptite solid-state compatibility.

Description: This work reports the crystallization, microstructure, and surface composition of Cu In 0.7 Ga 0.3 Se 2 (CIGS) thin films grown by femtosecond pulsed laser deposition at different annealing temperatures. The structural and optical properties of the CIGS films were characterized by X-ray diffraction, Raman scattering, UV-visible spectroscopy, and Hall effect measurement. The results indicate that binary crystals of CuS e initially formed on the as-deposited film, but then completely turned into a quaternary chalcopyrite structure after annealing at 400°C. Phase transformation significantly affects the surface morphology, Hall properties, and band gap. Transmission electron microscopy further revealed that an interface between the Mo substrate and CIGS crystallites contains an amorphous layer even at the high temperature of 500°C. For the application of photovoltaic devices, we also report on the photoresponse of both as-deposited and annealed films as demonstrated by preliminary tests.

Description: Reactive sintering of 3 Ti : Sn :2 C and 3Ti:Sn:2C:0.6Fe powder mixtures is studied in the temperature range 510°C–1200°C under argon. It is demonstrated that the recently discovered Ti 3 SnC 2 phase is formed, provided that Fe is added to a 3 Ti : Sn :2 C reactant mixture within the synthesis conditions used. Using dilatometric and X-Ray diffraction analyses, the formation mechanism of Ti 3 SnC 2 is discussed. Results show that at low temperature (about 510°C), tin is consumed to form Fe x Sn y intermetallics. At high temperature (about 1060°C), tin is newly available to form Ti 3 SnC 2 due to the melting of Fe x Sn y . Then, the intermediate phases, TiC and Ti 2 SnC , and/or Ti 5 Sn 3 , TiC , C , and Ti are dissolved in the ( Fe  +  Sn ) liquid phase and Ti 3 SnC 2 very likely precipitate from the melt. The second part of the study deals with the optimization of the Fe content in the initial 3Ti:Sn:2C reactant powder mixture to synthesize samples with larger Ti 3 SnC 2 content by hot isostatic pressing.

Description: The effects of non-stoichiometry on the microstructure, oxygen vacancies, and piezoelectric properties of ( Na 0.5 K 0.5 ) x NbO 3 (NK x N, where x  =   0.98, 1.00, 1.01, and 1.02) ceramics doped with sintering aid CuTa 2 O 6 (CT) doping were investigated. X-ray diffraction (XRD) patterns indicated that a secondary phase formed in CT-doped NK x N (NK x NCT) ceramics with x  〈   1.00 and that a pure phase was obtained with x  ≥   1.00. The grain size of NK x NCT ceramics increased with increasing x value due to the formation of a liquid phase. The internal bias field, activation energy, and Raman analysis for NK x NCT ceramics showed that the number of induced oxygen vacancies increased with decreasing x value. The high mechanical quality factor ( Q m ) value obtained for NK x NCT ceramics did not correspond to a higher concentration of oxygen vacancies, illustrating that the suitable compensation (excess Na and K ) is more important than the concentration of oxygen vacancies to obtain the ceramics with high Q m values. The NK x NCT ceramics with x  =   1.01 exhibited excellent piezoelectric properties, with k p and Q m values of 39.9% and 2,070, respectively.

Description: Low-temperature sintering of β-spodumene ceramics with low coefficient of thermal expansion (CTE) was attained using Li 2 O – GeO 2 sintering additive. Single-phase β-spodumene ceramics could be synthesized by heat treatment at 1000°C using highly pure and fine amorphous silica, α-alumina, and lithium carbonate powders mixture via the solid-state reaction route. The mixture was calcined at 950°C, finely pulverized, compacted, and finally sintered with or without the sintering additive at 800°C–1400°C for 2 h. The relative density reached 98% for the sample sintered with 3 mass% Li 2 O – GeO 2 additive at 1000°C. Its Young's modulus was 167 GPa and flexural strength was 115 MPa. Its CTE (from R.T. to 800°C) was 0.7 × 10 −6  K −1 and dielectric constant was 6.8 with loss tangent of 0.9% at 5 MHz. These properties were excellent or comparative compared with those previously reported for the samples sintered at around 1300°C–1400°C via melt-quenching routes. As a result, β-spodumene ceramics with single phase and sufficient properties were obtained at about 300°C lower sintering temperature by adding Li 2 O – GeO 2 sintering additive via the conventional solid-state reaction route. These results suggest that β-spodumene ceramics sintered with Li 2 O – GeO 2 sintering additive has a potential use as LTCC for multichip modules.

Description: Pyrochlore-structured lanthanide stannate ceramic ( Ln 2 Sn 2 O 7 ) has been synthesized via a new complex precipitation method. A suite of characterization techniques, including FTIR, Raman, X-ray, and electron diffraction as well as nitrogen sorption were employed to investigate the structural evolution of the synthesized and calcined powder. Raman, XRD, and selected area electron diffraction results confirm the presence of the pyrochlore structure after calcination of the powder above 1200°C. TEM imaging shows fine crystallites gradually increased in size from approximately 100 nm to about 500 nm with higher calcination temperatures. Grain growth and powder densification upon increasing the calcination temperature was confirmed by nitrogen sorption results. This aqueous synthetic method provides a simple pathway for the preparation of homogeneous lanthanide stannate ceramics.

Description: Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray ...

Description: A thin film composite (TFC) membrane has been developed by coating polydimethylsiloxane (PDMS) and glutaraldehyde (GH) on a surface porous polyvinylideneflouride (PVDF) membrane for membrane gas absorption (MGA) application. The optimum conditions for dip coating method were determined using response surface methodology (RSM). A central composite design (CCD) was used to investigate the effects of two independent factors, which PDMS concentrations (wt%) and dipping time (s) of GH on the four specific responses which are CO 2 and N 2 permeances, selectivity and contact angle (CA) value. The optimum conditions for PDMS concentration and GH dipping time are 10 wt% and 19 s, respectively where 354 GPU for CO 2 permeance, 66 GPU for N 2 permeance, 5.4 of selectivity and 132° of CA value were obtained. Through atomic force microscopy (AFM) analysis, the result shown the root mean square roughness (R ms ) of the TFC membrane was 381 nm a...

Description: Cadmium Selenide (CdSe) quantum dots (QDs) is inorganic material by using spray-atomization method which is the novelty to find out the optical properties for the CdSe QDs. The Selenium (Se) precursor and Cadmium (Cd) precursor were prepared first. Se precursor by using sodium sulfite aqueous was mixed with selenium (Se) powder. For Cd precursor was used cadmium chloride (CdCI) as the Cd precursor. From previous research, CdSe QDs was obtained by using capping agent such as tri-n-octylphosphine oxide ( TOPO) and trioctylphosphine (TOP). These capping agent are hazardous to environment and human. By using spray-atomization method it is more safe and economically. The photoluminescence (PL) was used to investigate the optical properties and to investigate the energy band gap from PL result. The field emission scanning electron microscopy (FESEM) was used to know the surface morphology of CdSe QDs. By PL result, the energy band gap was calculate and the comparison was investi...

Description: Multiwalled Carbon Nanotubes (MWCNs) were synthesized using double-furnace thermal chemical vapor deposition technique at 700 – 900 °C on porous silicon nanostructure (PSiNs). Palm oil used as a carbon natural source, ferrocene as a catalyst and nitrogen gas as a carrier gas. The precursor were vaporized at 475 °C carried by nitrogen gas which flow at constant rate 150 sccm/min. Carbon nanotubes characterized by using Raman Spectroscopy and field emission scanning electron microscopy (FESEM) to check its structure and crystallites before tested with I-V probe. Au contact used as a metal contact deposited on CNTs layer. Carbon nanotubes (CNTs) with uniform diameter were found grown on porous silicon for each temperature used. Based on micro-Raman spectroscopy result, the peak of carbon nanotubes (around 1 300 to 1 600 nm) was detected. The I-V characteristic of CNTs deposited had different profile when deposited at different temperature.

Description: Indonesia has a lot of potential flood disaster places with clean water problems faced. Various solution programs always initiated by Government, companies CSR, and people sporadical actions to provide clean water; with their advantages and disadvantages respectively. One solution is easy to operate for instance, but didn't provide adequate capacity, whereas the other had ideal performance but more costly. This situation inspired to develop a water treatment machine that could be an alternative favor. There are many methods could be choosed; whether in simple, middle or high technology, depends on water source input and output result quality. MSWT, Mobile Surface Water Treatment, is an idea for raw water in flood area, basically made for 1m 3 per hour. This water treatment design adopted from combined existing technologies and related literatures. Using common ideas, the highlight is how to make such modular process put in compact design elegantly, and would be equippe...

Description: A method is proposed to forecast how micrometric powders are converted on intermetallic nanocrystals by high-energy milling. Mixtures of MO-N or M-N as precursors were processed to obtain PbTe or PbSe. This transformation takes place by oxidizing highly reactive chalcogens such as Se or Te and reoxidation of PbO to form Pb complex chalcoxides. In the latter phases Te or Se share electrons to act as Te IV or Se IV , PbTeO 3 or PbSeO 3 . Once that state is completed, the reduction state manifests itself as an amorphous precipitation of phases. The final stage is traced as high purity nanocrystals.

Description: Using the transfer matrix method and the Ben Daniel-Duke equation for variable mass electrons propagation, we calculate the transmittance for symmetric finite superlattices where the width and the height of the potential barriers follow a linear dependence. The width and height of the barriers decreases from the center to the ends of the superlattice. The transmittance presents intervals of stopbands and quite flat passbands.

Description: ZnO films were deposited by single source chemical vapor deposition (SSCVD) at low temperatures on glass substrates using zinc acetate as a source of Zn and oxygen gas as the oxidizing agent. The zinc acetate was sublimated on a resistance heated to 210°C. The substrate temperature was varied from 200 to 300°C every 50°C with a deposition time of 5 min. X-ray diffraction results show that all deposited films are polycrystalline with an average grain size below 8 nm in all directions. The ZnO films showed a transmittance higher than 75% in the visible region.

Description: Ceramics have played a crucial role in the development of fission based nuclear power, in glass & glass composite high level wasteforms, in composite cements to encapsulate intermediate level wastes (ILW) and also for oxide nuclear fuels based on UO 2 and PuO 2 /UO 2 mixed oxides. They are also used as porous filters with the ability to absorb radionuclides (RN) from air and liquids and are playing a key role in the cleanup at Fukushima. Non-oxides also find current fission applications including in graphite moderators and B 4 C control rods. Ceramics will continue to be significant in the near-term expansion of nuclear power via next-step developments of fuels with inert matrices or based on thoria and in wasteforms using alternative composite cements or single or multiphase ceramics that can host Pu & other difficult RN. Longer term advances for Generation IV reactors, which will operate at higher temperatures & with higher fuel burn-up require innovative fuel developments potentially via carbides & nitrides or composite fuel systems. Novel non-thermal (cement-like) and thermal techniques are currently being developed to treat some of the difficult legacy wastes. Non-thermally derived wasteforms developed from geopolymers, composite cements, hydroceramics, and phosphate-bonded ceramics and thermally derived wasteforms made by Hot Isostatic Pressing and fluidized bed steam reforming (FBSR) as well as vitrification techniques based on cold crucible melting (CCM), Joule-heater in-container melting and plasma melting (PM) are described. Future developments in waste treatment will be based on separation technologies for partitioning individual RN along with design & construction of RN-containing ceramic targets for inducing transmutation reactions. Near demonstration actinide-hosting ceramic wasteforms including multiphase Synroc systems are described. Opportunities also exist for ceramics in structural applications in Generation IV reactors such as composite SiC / SiC and C / C for fuel cladding and control rods and MAX phases and ultrahigh-temperature ceramics (UHTCs) may find near core fuel coating and cladding applications. Uses of ceramics in fusion reactor systems will be both functional (ceramic superconductors in magnet systems for plasma control and in Li silicate breeder blankets in tokamaks) and structural including as sapphire diagnostic windows, graphite diverters, and plasma facing C and UHTCs. In all these cases, performance is limited by poorly understood radiation damage and interface controlled processes, which demands a combined modeling/experimental approach.

Description: This paper presents the sound absorption properties of a natural waste of date palm fiber perforated panel. A single layer of the date palm fibers was tested in this study for its sound absorption properties. The experimental measurements were carried out using impedance tube at the acoustic lab, Faculty of Engineering, Universiti Kebangsaan Malaysia. The experiment was conducted for the panel without air gap, with air gap and with perforated plate facing. Three air gap thicknesses of 10 mm, 20 mm and 30 mm were used between the date palm fiber sample and the rigid backing of the impedance tube. The results showed that when facing the palm date fiber sample with perforated plate the sound absorption coefficient improved at the higher and lower frequency ranges. This increase in sound absorption coincided with reduction in medium frequency absorption. However, this could be improved by using different densities or perforated plate with the date palm fiber panel.

Description: Catalysts which are typically a transition metal is mandatory and plays an important role in the production of CNT. In this work, the effect of iron (Fe) and cobalt (Co) nitrate catalyst on the growth of carbon nanotubes (CNT) were systematically studied. Green bio-hydrocarbon precursor namely palm oil was used as a precursor. The synthesis was done using thermal chemical vapour deposition method at temperature of 750°C for 15 min synthesis time. The Fe and Co solution were spin-coated separately on silicon substrate at speed of 3000 rev.min-1. The CNT characteristics were analyzed using field emission scanning electron microscopy and micro-Raman spectroscopy. The experimental results revealed that CNT properties were strongly affected by the catalyst type. CNT catalyzed by Co yields large diameter, crooked tube and lower quality, whereas CNT produced by Fe catalyst results in the smallest diameter and reasonably good graphitization. As a conclusion, Fe was considered as the opt...

Description: Productivity is one aspect that determines the success of a company in the competitive world of business. There are seven main types of activities that do not have value-added in manufacturing processes such as overproduction, waiting time, transportation, excess inventory, unnecessary motion and defects. The whole activity is a waste (waste) that can cause harm to the Company. Therefore, in production activities is important to pay attention so that the objectives of production productivity can be achieved. Problems experienced by CV Piranti Works is a production target is not achieved resulting in a lost sale raises the cost of which can cause harm to the Company. From the analysis conducted major known cause of the problem is the length of time required for changeover. This is supported by the high non-value added activity in the changeover activities. Lean Manufacturing is an approach to make system more efficient by reducing waste. This study refers to the book compiled by ...

Description: Carbon nanotubes (CNTs) have been successfully synthesized on nanoporous silicon template (NPSiT) using botanical source, camphor oil. Diameter of CNTs synthesized was controlled by pore size of NPSiT prepared by photo-electrochemical anodization method. The diameter of CNTs grown on different NPSiT corresponded to the pore diameter of NPSiT. FESEM images showed self-organized bundles of fiber-like structures of CNTs with diameter of around 20nm which were successfully grown directly on nanoporous silicon while raman spectra obtained ratio of I D /I G at 0.67.

Description: Augmented Reality (AR) is a potential area of research for education, covering issues such as tracking and calibration, and realistic rendering of virtual objects. The ability to augment real world with virtual information has opened the possibility of using AR technology in areas such as education and training as well. In the domain of Computer Aided Learning (CAL), researchers have long been looking into enhancing the effectiveness of the teaching and learning process by providing cues that could assist learners to better comprehend the materials presented. Although a number of works were done looking into the effectiveness of learning-aided cues, but none has really addressed this issue for AR-based learning solutions. This paper discusses the design and model of an AR based software that uses visual cues to enhance the learning process and the outcome perception results of the cues.

Description: The aim of this paper is to determine acceptance of internet banking system among potential young users, specifically future young managers. The relationships and the effects of computer self-efficacy (CSE) and extended technology acceptance model (TAM) on the behavioural intention (BI) to use internet banking system were examined. Measurement of CSE, TAM and BI were adapted from previous studies. However construct for TAM has been extended by adding a new variable which is perceived credibility (PC). A survey through questionnaire was conducted to determine the acceptance level of CSE, TAM and BI. Data were obtained from 275 Technology Management students, who are pursuing their undergraduate studies in a Malaysia's public university. The confirmatory factor analysis performed has identified four variables as determinant factors of internet banking acceptance. The first variable is computer self-efficacy (CSE), and another three variables from TAM constructs which are perceived...

Description: The light guide rod (LGR) has been popularly used for the vehicles, and the automobile lamp industries need mass production to match this trend. This paper aims to develop a systemic way to find the best parameters' combination for the LGR, and the parameters are usually restricted to some levels and random values. In this paper, the LGR example with two optical performances of illuminance flux and uniformity is to be optimized by use of the real-coded genetic algorithm (RGA) and grey relational analysis (GRA). The illuminance flux and uniformity of the best parameters' combination are obtained and compared with the initial set. Comparisons with Taguchi-Grey can improve 5% of gain and comparisons with Pareto genetic algorithm (PaGA) can improve 1.7% of gain. The combined multi-objective optimization can saving 7% time and it is found that the new proposed method has positive gains in performances.

Description: This paper proposes an analytical tool that supports the design process of a disc spring valve system used in hydraulic dampers. The proposed analytical tool obtains a key design characteristic of a valve, which is the flow rate and the corresponding maximum stress level in the stack of plates. The tool is prepared based on the cases produced by a first-principle model using a finite element approach. The finite element model was calibrated based on experimental results to provide accurate results in the entire range of input parameters.

Description: This research focused on the effects of S45C carbon steel using different pH values of electroless Ni-P plating. The experimental results show that the specimens using acid and alkaline baths of pH5 and pH8 of Ni-P deposition can acquire a higher hardness; the hardness values were the HV 0.05 701 and HV 0.05 803, respectively. Moreover, for pH5 and pH8 of Ni-P deposition with heat treatment of 350°C and 300°C and soaking for 1 hr, the highest level of hardness appeared in HV 0.05 1027 and HV 0.05 1066, respectively. The specimens underwent the main precipitate phase of Ni 3 P after heat treatment. Due to precipitation, strengthening of the Ni 3 P phase increased the surface hardness of specimens after heat treatment; thus, the wear depth was decreased and wear resistance was enhanced. The optimal process appeared in Ni-P deposition by pH5 and pH8 after 350°C and 300°C heat treatment and for 1 hr of soaking, respectively.

Description: The iodine doped copper (I) iodide (I 2 : CuI) at different weight of iodine dopant have been prepared to investigate its thin films properties and photovoltaic performance. A novel method of mist atomization technique has been used for the deposition of CuI materials. The structural and electrical properties of CuI thin films deposited on the glass substrates were studied. The thin films morphology examined by FESEM shows a variation of crystal size and structure. Brick-like structure with smooth faces and sharp edges were seen for the doped thin films. The CuI thin films at 30 mg of iodine doping shows the highest resistivity of 4.56 × 101 Ω cm which caused by the surface traps create by iodine doping. The photovoltaic performance of ss-DSSC on the effect of variation iodine doping was investigated. The ss-DSSC fabricated with undoped CuI materials shows the highest efficiency of 1.05% while the 40 mg I 2 content shows the lowest conversion efficiency of 0.4...

Description: Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al 2 O 3 ·2SiO 2 (mullite) (Al 2 O 3 = 60%, SiO 2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared...

Description: Chromatography has been established as the method of choice for the separation and purification of optically pure drugs which has a market size of about 250 billion USD. Single column chromatography (SCC) is commonly used in the development and testing phase of drug development while multi-column Simulated Moving Bed (SMB) chromatography is more suitable for large scale production due to its continuous nature. In this study, optimal performance of SCC and SMB processes for the separation of optical isomers under linear and overloaded separation conditions has been investigated. The performance indicators, namely productivity and desorbent requirement have been compared under geometric similarity for the separation of a mixture of guaifenesin, and Tröger's base enantiomers. SCC process has been analyzed under equilibrium assumption i.e., assuming infinite column efficiency, and zero dispersion, and its optimal performance parameters are compared with the optimal prediction of an ...

Description: Recently, there has been a considerable growing interest in utilizing nanozeolites due to their advantages over conventional micron sized materials. Zeolite particle may be reduced by mechanical treatment such as ball milling or grinding in order to get smaller particles. In this paper, effect of milling time on particle size and surface morphology of Zeolite were investigated by a few designed of experiments in aqueous environment. Zeta-sizer Nano series of particle sizer and Field Emission Scanning Electron Microscopy (FESEM) have been used to characterize this nanozeolite. Results shown that, there were changes of particle size and also the surface morphology of Zeolite.

Description: Titanium dioxide, TiO 2 is one of the semiconductor materials. The aim of this paper is to determine the production of TiO 2 by sol-gel method. The sol-gel method used because this method is quite simple compare to other methods such as dip-coated and refractive sputtering. The parameter will be used in this paper is the concentration. The sol-gel TiO 2 solution then spin coated on the glass substrate to form homogenous and transparent thin film. The thin film was coated at 8 layers to adjust the refractive index characteristics and to get the clear images during characterize by spin coating technique. Other than that, this work also to get the band gap energy similar to the standard bandgap for TiO 2 . The optical properties such as absorption and transmittance of TiO 2 can be done by Ultraviolet-visible Spectroscopy (UV-Vis). The changes on the surface morphology were observed using Atomic Force Microscopy (AFM), Field Emission ...

Description: In this paper, a relatively new algorithm inspired by the viral replication system called Viral Systems is used to solve the Single-Machine Total Weighted Tardiness (SMTWTP). SMTWTP is a job scheduling problem which is one of classical combinatorial problems known as np-hard problems. This algorithm makes the process of finding solutions through neighborhood and mutation mechanism. The experiment was conducted to evaluate its performance. There are seven parameters which are required to tune in to find best solution. The experiment was implemented on data sets of 40 jobs, 50 jobs, and 100 jobs. The results show that the algorithm can solve 235 optimally out of 275 problems.