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Degradation behavior of acceptor (Y)-doped (Ba,Ca)(Ti,Zr)O 3 ceramics sintered in moist reducing atmosphere and subsequently re-oxidized in dry or wet atmospheres was contrasted. The degradation behavior critically depends on the water vapor incorporation, the time to degradation systematically decreased with the incorporation of hydroxyl defects ( O H ) O • . The electrical conductivity was investigated by means of impedance spectroscopy (IS) to determine properties, such as grain and grain boundary conductivity, grain boundary potential barrier height, and space charge layer thickness. Furthermore, transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) were applied to consider microstructure, microchemistry, and oxygen stoichiometry changes. [ABSTRACT FROM AUTHOR]

In this study, a numerical simulation is performed to explore oscillatory natural convection in a square enclosure with a phase change material (PCM) suspension using the implicit finite difference method. The following parameters are considered: aspect ratio of the physical model = 1; ratio of the buoyancies caused by temperature and concentration gradients = 1; Rayleigh number = 103-106; initial mass fraction (or concentration) of PCM particles = 0–0.1; Stefan number = 0.005–0.1; and subcooling factor = 0–1.0. The results show that high Rayleigh numbers can easily cause oscillations in the flow field and temperature distribution. However, even under low Rayleigh number conditions, when the initial mass fraction or subcooling is increased or the Stefan number is decreased, oscillations occur. • Heat transfer in an enclosure with PCM suspension was numerically investigated. • Oscillatory natural convection phenomena are found. • High Rayleigh numbers can easily cause the oscillations in the flow and temperature. • High initial mass fraction or subcooling can cause, even under low Rayleigh numbers. • Low Stefan numbers cause too, under low Rayleigh numbers. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates how cutting conditions affect dynamic cutting factor and system process damping in a dynamic milling process. By considering variation of edge plowing force, a frequency domain method is presented to identify the dynamic cutting factor through measured vibration in a milling process, and cutting conditions most suitable for the identification experiments are also discussed. A series of experiments are carried out to investigate the effects of cutting conditions on the dynamic cutting factor. This factor is shown to be significantly affected by the cutting speed, but relatively independent of the feed per tooth and the radial depth of cut. An average process damping model is further constructed and shown to be effective in representing the time-varying damping function. The average process damping is shown to increase rapidly at lower cutting speed, but remain constant as the cutting speed beyond a critical value. [Copyright &y& Elsevier]

Abstract: We used Poynting fluxes and densities to investigate the stormtime thermosphere on November 10, 2004. Thermospheric energy, E th which is derived from , consists of two sources, solar ultraviolet radiation (E th UV) and the solar wind (E th SW). Responses of E th SW to interplanetary driving suggest that the thermosphere can be described by the equation dE th SW/dt=αε VS−(E th SW/τ), where ε VS represents the electric field; α and τ are constants. We show that: (1) E th SW is three times the ring-current energy; (2) αε VS is comparable with model predictions; (3) signatures of equatorward propagating disturbances were detected in neutral density profiles. [Copyright &y& Elsevier]

Abstract: The influence of penetration electric fields (PEF) on storm-time energetic particles in the inner magnetosphere and on the stability of plasma in the low-latitude ionosphere is widely recognized. We describe two consequences of PEFs, regularly observed during magnetic storms that indicate their persistence throughout the main phases. These are (1) the presence of equatorial plasma bubbles (EPB) across the evening local time sector during main phases and their absence throughout recovery, and (2) detections of low-energy ion precipitation in the dawn sector equatorward of the auroral electron boundary. [Copyright &y& Elsevier]

Abstract: The Al2O3 structure ceramics have been investigated extensively in previous studies. In order to compare micron- with submicron-scale powder on forming and sintering behaviors, three commercial α-Al2O3 powders were studied: 0.15μm (denoted S as small in the paper) (granulating), 0.43μm (denoted M as middle) (granulating), and 1.8μm (denoted L as large) (granulate-free) at d 50 (median size). Although the (M) powder contains hard agglomerates, it forms more easily than the (S) powder. This is principally because the (M)''s soft agglomeration strength (0.03MPa) is weaker than (S) (7MPa). The (L) bulk formed easily with lower pressure 10MPa because of wider starting-particle size distribution, 0.2–15μm. The (S) primary particles rearranged before sintering, so it postponed its sintering onset temperature to about 1200°C. Additionally, its shrinkage rate becomes maximal and concentrated at the 2nd stage of sintering from 1300 to 1400°C. (M) bulk revealed the longest shrinkage range from 1000 to 1500°C because the sintering occurred with its hard agglomerates at first. Although (L) powder formed rather easily, its sintering was impeded by a much wider particle size distribution. [Copyright &y& Elsevier]

Abstract: Amorphous (Al2O3) x –(TiO2)1−x composite films are prepared using r.f. unbalanced magnetron sputtering in an atmosphere of argon and oxygen at room temperature. The optical constants of (Al2O3) x –(TiO2)1−x composite films are linearly dependent on the Al2O3 mole fraction in the Al2O3–TiO2 composite film. The optical constants of these Al2O3–TiO2 composite films can be made to meet the optical requirements for a high transmittance attenuated phase shift mask (HT-APSM) blank by tuning the Al2O3 mole fraction. The Al2O3 mole fraction range that would allow the films to meet the optical requirements of an HT-APSM blank for ArF immersion lithography is calculated to be between 76% and 84%. One π-phase-shifted Al2O3–TiO2 composite thin film to be used as an HT-APSM blank for ArF immersion lithography is fabricated and is shown to satisfy the optical requirements. [Copyright &y& Elsevier]

Abstract: Using the Buckingham Pi theorem, this study derives dimensionless correlations to characterize the heat transfer performance of the corrugated channel in a plate heat exchanger. The experimental data are substituted into these correlations to identify the flow characteristics and channel geometry parameters with the most significant influence on the heat transfer performance. Simplified correlations by omitting the factors with less influence are then obtained. The results show that Nu x is affected primarily by Re, R/D h, x/D h, and β. Neglecting the minor effect of factors on Nu x, it is shown that Nu m is determined primarily by Re, R/D h and β. [Copyright &y& Elsevier]

Abstract: During the Halloween storm of October 29–31, 2003, four defense meteorological satellite program (DMSP) satellites detected fluxes of low-energy ions precipitating well equatorward of auroral electrons in the dawn/morning magnetic local time sector during the main phase. There were three southward turnings of the interplanetary magnetic field (IMF), leading to three intensifications of the ring current to DST values of −125, −310 and −350nT. In each case the ion fluxes weakened dramatically and/or vanished during DST recoveries. DMSP only encountered short-lived episodes of subauroral ion precipitation in the dusk/evening sector. A brief survey of the DMSP database reveals that near-dawn, ion precipitation is a main-phase characteristic of all large magnetic storms. DMSP satellites also detected similar ion precipitation during the main phase of the March 1991 magnetic storm. During an outbound pass of the combined release radiation effect satellite (CRRES) through the inner magnetosphere it detected low energy (<1keV) ion fluxes that were collocated with, but spectrally separated in energy from the ring current “nose structure”. As CRRES moved toward perigee in the dawn sector, it crossed similar low-energy (⩽500eV) ions embedded in a broad ion population, located earthward of plasma sheet electrons. Simultaneously the DMSP F8 satellite detected spectrally similar low-energy ions precipitating at subauroral latitudes near dawn at the same invariant latitudes. To reconcile DMSP/CRRES observations with elementary concepts of allowed ion drift paths, the data suggest two source populations. The lowest-energy ions, of ionospheric origin, were initially energized earthward of the plasma sheet electron boundary in the evening local-time sector then co-rotated eastward. Higher-energy ions originated in the plasma sheet and drifted close to the Earth under the combined influences of time-varying convective electric fields and azimuthal gradients in the Earth''s magnetic field generated by the stormtime ring current [Tsyganenko, N.A., Singer, H. J., Kasper, J. C., 2003. Storm-time distortion of the inner magnetosphere: how severe can it get? Journal of Geophysical Research, 108 (A5), 1209]. [Copyright &y& Elsevier]

Ultra-thin Cr2O3 well-crystallized thin films are deposited on UV grade fused silica substrates and Si wafers by using r.f. reactive unbalanced magnetron sputtering from a Cr metal target in an atmosphere of Ar and O2 at 350 °C. The optical constants of such thin films were found to be a sensitive function of oxygen-to-argon flow rate ratio. At the ratio of 0.2, a Cr2O3 well-crystallized thin film with appropriate refractive index and extinction coefficient at a wavelength of 365 nm can be used as attenuated phase-shifting mask (APSM) blank as well as being good for inspection. The simulated thickness range of a Cr2O3 well-crystallized thin film was found to be between 28.2 and 30.3 nm. This meets the optical requirements for high transmittance APSM (HT-APSM) with a transmittance of 18–20% at 193 nm for the pattern fabrication and with transmittance less than 50% at 365 nm for the mask inspection. One such Cr2O3 well-crystallized thin film that satisfies the optical requirements was fabricated. [Copyright &y& Elsevier]

BaTiO3 crystals are important photorefractive materials due to their self-pumped phase-conjugation and large electro-optic coefficient. High gain, fast response time and proper beam fanning BaTiO3 crystals are desirable. We fabricated photorefractive BaTiO3:Ru single crystals and then investigated their optical and photorefractive properties. In as-grown Ru-doped BaTiO3 single crystals, the absorption shoulder is around 450 nm. The dark conductivity is dominant in the crystal and much higher than the photo conductivity at a low intensity pumping beam. [Copyright &y& Elsevier]

This paper characterizes fracture strength of a silicon die as a first step to predict and prevent die cracking during package assembly, reliability tests, and operation life. Die strength is measured via the three-point bend test conducted using a micro-force tester. Strength reduction due to surface defects, such as tiny notches or micro-cracks that are introduced through wafer backside grinding is evaluated. It is observed that die strength strongly depends on the grinding patterns, i.e. minimum die strength in a wafer is found if the grinding mark is in parallel with the loading axis. Furthermore, fracture strength of dies with different wafer surface conditions like polishing and no treatment (grinding) are also examined. Polished wafers possess the highest silicon strength owing to its minimum surface flaws. On the other hand, untreated wafers contain the most severe surface defects; hence exhibit the lowest die strength. Geometrical factors (square vs. rectangular) and die thickness (4 vs. 6 mils) are probed as well, however these factors do not contribute to die strength degradation. Surface morphology and roughness studies of silicon dies via scanning electron microscope and atomic force microscope also confirmed that die strength degradation is mainly controlled by surface defect (roughness) levels. Observed fracture modes also correlate well with measured die strength. [Copyright &y& Elsevier]

The instability mechanisms of passivated and non-passivated low-temperature polycrystalline silicon thin film transistors (LTPS TFTs) under various bias stress conditions have been investigated. Irrespective of plasma treatment, the degradation was more severe under negative gate bias stress than that under positive gate bias stress. This could be due to Fowler–Nordheim tunneling electron induced impact ionization. For hot carrier stress, TFTs with NH3 plasma treatment degraded more severely than those without plasma treatment. This might be attributed to collapsing of weak Si–H bonds in NH3-plasma passivated devices. For the high current stress, it showed the opposite results against hot carrier stress. [Copyright &y& Elsevier]

Sandwich structures with a soft core typically exhibit multiple deformation modes such as bending, twisting and compression when subjected to transverse loads. Compressive behavior of soft core significantly affects the structural response, which is usually neglected in conventional plate theories. Additionally, conventional plate theories do not take into account transverse shear stress continuity. In order to address this concern and precisely characterize the characteristics of arbitrary multilayer laminated structures, a novel electromechanical coupled finite element model is developed. This model is based on a compressible layerwise third-order shear deformation theory with a soft core. Notably, the proposed model theory requires only twelve degrees of freedom for each quadratic element node. The accuracy of the model is validated first. Afterwards, several numerical investigations are carried out for piezolaminated sandwich structures with different width-to-thickness ratios, reinforcement angle and skew angle. The results demonstrate the applicability of the current model in predicting the behavior of laminated sandwich plates. [ABSTRACT FROM AUTHOR]

Many studies have shown that a positive attitude or beliefs towards life are associated with health. This study aims to investigate the predictors associated with self-reported health and to exam the impact of self-reported health towards negative feelings in the general population. Three latent variables (healthy food, self-health, and negative feeling) were constructed to investigate the relationship between self-reported health and people's negative feeling. [Extracted from the article]

To describe the trajectory of self-perceived health, use of hypnotic drugs, and total health care costs among patients with a reported diagnosis of anxiety disorders. Among anxiety patients exhibiting higher comorbidity scores (>11), our model predicted that using hypnotics might save total health care costs comparing patients not being prescribed when holding other variables constant. [Extracted from the article]

A procedure is proposed to analyze the structural failure of a composite wind blade subjected to quasi-static loads. The structural failure of a wind blade under extreme wind loads which can be treated as quasi-static loads is an important issue to be tackled when assessing the reliability of a wind turbine. In the proposed structural failure analysis procedure, the geometrically nonlinear finite element (FE) method together with several phenomenological failure criteria is used to investigate the possible failure modes such as incipient buckling, interfacial debonding, and first-ply failure of the blade via an incremental loading approach. The failure loads and locations associated with the possible failure modes for a number of small wind blades with different structural configurations are determined to study the appropriateness of the failure criteria. Static tests of several small glass-fabric composite wind blades were conducted to validate the suitability of the proposed procedure. It has been shown that the experimentally and theoretically predicted failure processes of the wind blades are in good agreement. The applications of the proposed procedure are demonstrated by means of a numerical example in which the failure process of a wind blade under quasi-static wind loads is simulated. [ABSTRACT FROM AUTHOR]

Infrared thermography and pressure measurements are presented of the detailed local Nusselt number ( Nu 0 ) distributions over top-endwall and the associated pressure drop coefficients ( f 0 ) of a stationary two-pass 90-deg ribbed parallelogram channel. The parallelogram cross-section has equal adjacent sides of 45.5 mm in length (aspect ratio = 1) and channel hydraulic diameter of 32.17 mm. The rib pitch-to-height ratio, rib width-to-height ratio and rib-height to channel-height ratio are 10, 1 and 0.1, respectively. It is aimed at exploring the effects of Reynolds number, Re = 5000–20,000, on Nu 0 and regionally averaged ( Nu ‾ 0 ) Nusselt numbers along the ribbed inlet/outlet legs and over the bend. To gain insight into the heat transfer augmentation mechanisms, the PIV measurements were also performed for correlating the fluid flow and heat transfer characteristics in the two legs and inside the bend at Re = 10,000 in terms of the streamwise main flow and cross-sectional secondary flow, turbulent kinetic energy as well as spanwise and streamwise Nu 0 and Nu ‾ 0 . It is found that the flow dynamic mechanisms responsible for the rib-top and mid-rib heat transfer enhancement are different for the inlet and outlet passes. The presences of a skewed high Nu 0 streak between the last inlet-leg rib and the bend as well as two high Nu 0 zones inside the bend are the new found features lacking in the corresponding two-pass 90-deg ribbed square channel. In addition, simple correlations of Nu 0 and f 0 with Re are acquired. Thermal performance factors are about 66% and 28% higher than the previous reported smooth-walled counterpart at Re = 5000 and 20,000, respectively. They are further compared with those of the corresponding square channels available from the literature. [ABSTRACT FROM AUTHOR]

This paper aims to measure and simulate the warpages of 3D through-silicon via (TSV) die-stacked dynamic-random-access-memory (DRAM) packages during the manufacturing process. The related die stresses and keep-out zone (KOZ) for the stacked dies in the packages at room temperature are further calculated with the validated simulation model. The out-of-plane deformations (or warpages) of the packages from the full-field shadow moiré are documented under temperature loading and found consistent with those from finite-element method (FEM). The results of the stresses and KOZs at the proximity of a single TSV for each die in the package at room temperature are presented. It is found that the sizes of KOZs in four-die stacked DRAM packages with and without epoxy molding compound (EMC) at room temperature are dominated by the horizontal pMOS transistors and more than double the size in wafer-level die. The sizes of KOZs at each die are similar in this four-die stacked DRAM package, even though the stresses at each die are apparently different. [ABSTRACT FROM AUTHOR]

Abstract: Variations in tetragonal distortion and the degree of crystallinity of ultrafine BaTiO3 particles—both industrially applied criteria qualifying their polar characteristics—upon growth during annealing were studied on powders, prepared by the hydrothermal synthesis and by the oxalate route respectively. Regardless of the synthetic route both these properties were found to develop approximately to the same extent with increasing primary particle size. The degree of crystallinity was detectable only above a critical value of c/a=1.007 at an average particle size of around 120nm. Intragranular porosity in hydrothermal powders and the stoichiometric Ba/Ti-ratio are of minor influence. However, distinct differences in particle growth behavior for both powders were observed. This discrepancy is ascribed to a special morphology of the hydrothermal product, where enhanced particle growth was found to be governed by oriented attachment of individual crystallites and by the motion of solid–solid interfaces. [Copyright &y& Elsevier]

Abstract: Even though recently published results indicated that residual strains of the epoxy molding compound (EMC) play a key role on the warpage values and shapes of the plastic ball grid array (PBGA) packages, it is still unknown about how these residual strains build up and change during the manufacturing and infrared (IR) solder reflow processes. The purpose of this study is to quantify the residual strains of the EMC in the PBGA packages during the aforementioned processes using a combination of experimental, theoretical and numerical approaches. In the experiments, a full-field shadow moiré is used for measuring their real-time out-of-plane deformation (warpage), during heating and cooling conditions, of two types of the PBGA specimens (without a silicon chip inside) with the same EMC but different substrates (with glass transition temperature T g =172 and 202°C). Furthermore, Timoshenko’s bi-material theory associated with the measured and temperature-dependent elastic moduli and coefficients of thermal expansion for the EMC and substrates is applied for extracting residual strains of the EMC from shadow moiré results. In the analysis, the finite element method cooperating with those determined residual strains is employed to numerically simulate the thermal-induced deformations of the PBGA specimens, in order to verify mechanics. The full-field warpage of the specimens from shadow moiré is documented before and after post-mold curing, solder reflow and during the temperature cycling (from room temperature to 260°C). The residual strains of the EMC for the specimens with low-T g and high-T g substrates after post-mold curing are found to be 0.059% and 0.134%, respectively, which double those before post-mold curing, and further down to 0.035% and 0.08% after the first thermal cycling. After the first cycling, the residual strains remain almost constant during heating and cooling processes. This phenomenon is also observed at lead-free solder reflow processes. Therefore, the residual strains of the EMC induced by the chemical shrinkage of the EMC curing and possibly mold flow pressure are different between the specimens with low-T g and high-T g substrates, and these residual strains could change during post-mold curing and the first solder reflow processes. [Copyright &y& Elsevier]

Abstract: Three Ni-free Zr-based BMGs with composition of Zr60Nb5Cu20Fe5Al10, Zr60Nb5Cu22.5Pd5Al7.5, Zr60Ti6Cu19Fe5Al10 were fabricated by suck copper-mould casting. All the BMGs prepared exhibit good glassy forming ability and wide supercooled liquid region ranging from 38 to 99K. These BMGs also show good mechanical properties under static compression with yield strength of over 1350MPa, Young''s modulus of 70–80GPa, and plastic strain of 3.6–9.5%. Friction and wear tests revealed that the BMGs exhibit much better wear resistance than the medical alloy Ti6Al4V, although BMGs have a higher friction coefficient. In addition, the in vitro test indicated that the BMGs have a similar or even better cell viability and proliferation activity as compared with Ti6Al4V. Finally, the in vivo evaluation of the BMGs was carried out by the implantation of BMG samples into white rabbits. It is shown that the BMG implants performed as well as the Ti alloy, demonstrating that the Ni-free Zr-based BMGs developed in this work are promising in medical applications. [Copyright &y& Elsevier]

Abstract: In this study we are able, using a copper grid substrate, to successfully grow separate nanowires with a high level of crystallinity, for a length of up to 10μm. They were synthesized under various temperatures. We compare and contrast three types of geometries (micron-, nano-scale, and tip-like single CuO nanowires), to identify their potential for monitoring the size effects of quantum confinements. The confocal Raman spectrometry results confirm the expected outcome, that reducing of the diameter of a cylindrical cross-section of a single nanowire results in Raman frequency downshifts. The results can be explained by the bond polarizability model. The applicability of investigating the size effects of the quantum confinement of the tip-like geometry of a single nanowire without any preparation for different sizes of nanoparticles is possible because the detection is relatively straightforward and the reproduced Raman signals can be observed. [Copyright &y& Elsevier]

Abstract: Four etching solutions used on support materials and two coating methods of TiO2 were conducted to investigate the effects of catalytical preparing methods on the photocatalysis of 2,2′,3,4,4′,5′-hexachlorobiphenyl (PCB congener 138). The results of XRD analyses confirmed that various etching solutions used on support substrates did not influence the characteristics of titanium(IV) oxide. The XRD patterns of crystallization for the catalysts before and after purification remained unchanged. Hydrofluoric acid used as an etching solution for the support substrates provided the best adhesion stability for the catalysts that demonstrated the highest photocatalytic efficiency for congener 138. Xenon and ultraviolet lamps were used to compare the irradiation effect on photocatalysis. The shortest half-lives of congener 138 were 7.4 and 12.2h using xenon and UV reactors, respectively. Lower chlorinated biphenyls (lower congener numbers) were identified through the continuous dechlorination of congener 138. PCB congeners 99, 87, 66, 49, 28, 17, 9, and 7 were detected as a result of dechlorination from higher chlorinated congeners to lower chlorinated congeners along with the extension of exposure times. The concentrations of chloride ion were increased with increasing exposure time through dechlorination, while the concentrations of organic chlorine of congener 138 were decreased. Meta-dechlorination was the most commonly found mechanism for the photocatalysis of PCB 138. The activation energy of the photocatalysis of congener 138 was 70.8kJmol−1. [Copyright &y& Elsevier]

Abstract: Amorphous (ZrO2) x –(SiO2)1−x and (Al2O3) x –(ZrO2) y –(SiO2)1−x−y composite films were prepared using r.f. unbalanced magnetron sputtering in an atmosphere of argon and oxygen at room temperature. The (ZrO2) x –(SiO2)1−x and (Al2O3) x –(ZrO2) y –(SiO2)1−x−y composite films were completely oxidized when an O2/Ar flow rate ratio of 2.0 was used. The optical constants of these thin films depend linearly on the mole fraction of corresponding films. By tuning the (x, y) mole fractions of (Al2O3, ZrO2) in the (Al2O3) x –(ZrO2) y –(SiO2)1−x−y composite films, the optical constants can meet the optical requirements for a high transmittance attenuated phase shift mask (HT-AttPSM) blank. The n–k values in the quadrangular area in the (x, y) plane, where x and y represent the mole fractions of Al2O3 and ZrO2, respectively, meet the optical requirements for an HT-AttPSM blank with an optimized transmittance of 20±5% in ArF lithography. It is noted that the quadrangular area is bounded by (0, 0.31), (0, 0.62), (0.26, 0) and (0.57, 0). All the films also met the chemical and adhesion requirements for an HT-AttPSM application. One (Al2O3)0.1–(ZrO2)0.52–(SiO2)0.38 composite film was fabricated with optical properties that meet the optimized optical requirements of ArF-line HT-AttPSM blanks. Combined with these HT-AttPSMs, ArF-line (immersion) lithography may have the potential of reaching 65-, 45-nm and possibly the 32-nm technology nodes for the next three generations. [Copyright &y& Elsevier]

The impact of heavy metal contamination on crop growth and water quality has become a public concern in southern China where variable charge soils are widespread. A laboratory experiment was designed with contaminated levels of copper (Cu) to estimate the distribution of anthropogenic Cu in different constituents of two variable charge soils using a sequential extraction procedure (SEP) and to evaluate Cu extractability with a single extraction procedure. Soil Cu was chemically fractionated into water-soluble, exchangeable, weakly specifically adsorbed, Fe/Mn oxide-bound, organically bound, and residual fractions using the SEP. One mole NH4Ac l-1 (ammonium acetate, pH 5.0), 0.1 mol HCl l-1, and Mehlich 3 were employed as the single extractant to evaluate the mobility or availability of anthropogenic Cu added in the variable charge soils. The two soils were an inceptisol (clayey mixed siliceous thermic typic Dystrochrept) and an ultisol (clayey kaolinitic thermic Plinthudults), and the Cu levels were treated at 250, 500, 1000 or 1500 mg Cu kg-1 soil as Cu(NO3)2. During a 6-week incubation, most of the anthropogenic Cu was associated with the mobile fractions, i.e. water-soluble, exchangeable, and weakly specifically adsorbed fractions in the inceptisol, whereas in the ultisol the mobile fractions became dominant only at the Cu amendments of 1000 and 1500 mg Cu kg-1 soil. The Fe/Mn oxide-bound fractions that are relatively stable prevailed in both soils except for the high Cu level treatments. Soil organic matter had a minimal effect on the anthropogenic Cu distribution in the soils because of its low concentration range. Transformations between the mobile fractions and Fe/Mn oxide-bound fraction occurred during the 6-week incubation in both soils. The 1 mol NH4Ac l-1 (pH 5.0) and Mehlich 3 extractable Cu in both Cu-amended soils were statistically associated with the mobile fractions according to the stepwise multiple regressions. However, the 0.1 mol HCl l-1 extractions resulted in an overestimation of Cu availability in these soils due to the dissolution of Fe/Mn oxides, which released part of the adsorbed Cu that may not be available to plants under normal soil conditions. [Copyright &y& Elsevier]

Equilibrium, creep, and dynamic behaviors of agarose gels (2.0–14.8%) in confined compression were investigated in this study. The hydraulic permeabilities of gels were determined by curve-fitting creep data to the biphasic model (J. Biomech. Eng. 102 (1980) 73) and found to be similar in value to those published in the literature (AIChE J. 42 (1996) 1220). A new relationship between intrinsic permeability and volume fraction of water was found for agarose gel, capable of predicting deformation-dependent permeabilities of bovine articular cartilage and 2% agarose gel published in literature. This relationship is accurate for gels and cartilage over a wide range of permeabilities (four orders of magnitude variation). The dynamic stiffness of the gels increases with gel concentration and loading frequency (0.01–1.0 Hz). The increase in dynamic stiffness with loading frequency is less pronounced for gels with higher concentrations. The results of this study provide a new insight into deformation-dependent permeability behavior of agarose gel and cartilage, and are important for understanding biological responses of cells to interstitial fluid flow in gel or in cartilage under dynamic mechanical loading. [Copyright &y& Elsevier]

Because of its excellent anodic bonding property and surface integrity, borosilicate glass is usually used as the substrate for micro-electro mechanical systems (MEMS). For building the communication interface, micro-holes need to be drilled on this substrate. However, a micro-hole with diameter below 200 μm is difficult to manufacture using traditional machining processes. To solve this problem, a machining method that combines micro electrical-discharge machining (MEDM) and micro ultrasonic vibration machining (MUSM) is proposed herein for producing precise micro-holes with high aspect ratios in borosilicate glass. In the investigations described in this paper, a circular micro-tool was produced using the MEDM process. This tool was then used to drill a hole in glass using the MUSM process. The experiments showed that using appropriate machining parameters; the diameter variations between the entrances and exits (DVEE) could reach a value of about 2 μm in micro-holes with diameters of about 150 μm and depths of 500 μm. DVEE could be improved if an appropriate slurry concentration; ultrasonic amplitude or rotational speed was utilized. In the roundness investigations, the machining tool rotation speed had a close relationship to the degree of micro-hole roundness. Micro-holes with a roundness value of about 2 μm (the max. radius minus the min. radius) could be obtained if the appropriate rotational speed was employed. [Copyright &y& Elsevier]

Second (board) level reliability of a stacked chip scale package (SCSP) under cyclic bending is conducted to evaluate the structural integrity of solder interconnects. The test vehicle (on-board SCSP) is simply supported at both ends and subjected to repetitive deflection in the middle (three-point bend). Cyclic deformation histories such as sinusoidal, triangular, and square waveforms are examined. Tremendous joint damage is observed as square-wave loading history was applied. Approximately 80% fatigue life degradation is found by bending several thermally aged samples having Ni/Au surface finish on Cu pads of package substrates and printed circuit boards. The observed failure mode is a brittle type fracture of intermetallic compound system, which is also known as effects of solder embrittlement.Measured fatigue life is characterized by two-parameter Weibull model with cumulative damage plot for each test condition. In addition to the comparisons of characteristic fatigue life for various package configuration and cyclic bending conditions, failure analysis is also employed to identify failure sites and mechanisms such as crack initiation and continuous growth to the complete fracture of solder joints. [Copyright &y& Elsevier]

Approximately 33% of stroke survivors suffer depression and depression is associated with disability, poor quality of life and mortality. We examined association between depression and healthcare expenditures among stroke survivors. Conclusions Depression in stroke survivors was associated with increased prescription expenditure, but not other expenditures. [Extracted from the article]

This method is termed Terminal branches portal vein Embolization Liver Partition Planned hepatectomy (TELPP). Of the 11 patients with hepatectomy, right hemihepatectomy(n=2), extended right hemihepatectomy (n=5), right trisecmentectomy(n=2), extended left hemihepatectomy (n=1) and left trisecmentectomy(n=1). It has the merit of ALPPS as extraordinarily rapid increasement of FLR volume, yet the morbidity and mortality is much lowe, as only single surgical operation is required. [Extracted from the article]

This method is termed Terminal branches portal vein Embolization Liver Partition Planned hepatectomy (TELPP). Of the 11 patients with hepatectomy, right hemihepatectomy(n=2), extended right hemihepatectomy (n=5),right trisecmentectomy(n=2), extended left hemihepatectomy (n=1) and left trisecmentectomy(n=1). It has the merit of ALPPS as extraordinarily rapid increasement of FLR volume, yet the morbidity and mortality is much lowe, as only single surgical operation is required. [Extracted from the article]

Microstructural characterization of deformation-induced martensite in its early stage of formation has been performed in an ultrafine-grained (UFG) medium Mn advanced high strength steel (AHSS). By using field emission scanning electron microscope (FESEM) and electron backscattered diffraction (EBSD), the nucleation site of deformation-induced martensite has been studied. Grain sizes, Schmid factors and aspect ratios of the parent austenite grains of deformation-induced martensite were measured in order to know their influence on the formation of deformation-induced martensite. Orientation relationship between deformation-induced martensite and its parent austenite has also been analyzed. Discussion on the effect of microstructural parameters on the formation of deformation-induced martensite in AHSS is given. [ABSTRACT FROM AUTHOR]

To explore the mechanical behavior and microstructure evolution of nanostructured bainite under deformation at high strain rates (> 10 3 s − 1 ), split Hopkinson pressure bar experiments were conducted. It was found that nanometer-sized twinning occurred in both blocky austenite and film austenite. In the former case, the intersections of different twin variants brought about strain-induced α’-martensite, while in the latter case, the lamellar twinned structures were occasionally accompanied by a small amount of ε martensite. It is concluded that twinning occurs first in blocky austenite, enhancing the initial work-hardening; subsequent twinning takes place in film austenite, promoting further straining. [ABSTRACT FROM AUTHOR]

In this work, a possible cause of the extraordinary low impact toughness of nanostructured bainite has been investigated. The microstructure of nanostructured bainite consisted chiefly of carbide-free bainitic ferrite with retained austenite films. X-ray diffractometry (XRD) measurement indicated that no retained austenite existed in the fractured surface of the Charpy-impact-tested specimens. Fractographs showed that cracks propagated mainly along bainitic ferrite platelet boundaries. The change in microstructure after impact loading was verified by transmission electron microscopy (TEM) observations, confirming that retained austenite was completely transformed to strain-induced martensite during the Charpy impact test. However, the zone affected by strained-induced martensite was found to be extremely shallow, only to a depth of several micrometers from the fracture surface. It is appropriately concluded that upon impact, as the crack forms and propagates, strain-induced martensitic transformation immediately occurs ahead of the advancing crack tip. The successive martensitic transformation profoundly facilitates the crack propagation, resulting in the extremely low impact toughness of nanostructured bainite. Retained austenite, in contrast to its well-known beneficial role, has a deteriorating effect on toughness during the course of Charpy impact. [ABSTRACT FROM AUTHOR]

Abstract: In this article, we have demonstrated 1-eV energy band gap In0.22GaAsN y /GaAs multi-quantum well (MQW) solar cells grown by a metal organic vapor phase epitaxy (MOVPE) system. With nitrogen incorporation, the equivalent band gap energy of quantum well structure will decrease and reach near 1eV. The structures of In0.22GaAsN y /GaAs MQWs were inserted into an intrinsic absorption layer for absorbing the incident light in the longer wavelength region. From the measurement results, the absorption band edge of In0.22GaAsN y /GaAs MQW solar cells is extended over 1300nm. On the other hand, in order to improve the device performance pre-deteriorated by nitrogen incorporation, a hybrid structure which consists of In0.22GaAs/GaAs and In0.22GaAsN0.043/GaAs quantum wells is adopted; with this hybrid quantum well structure as the absorption layer, consequently the short circuit current is enhanced from 10.85 to 15.29mA/cm2. [Copyright &y& Elsevier]