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Purpose To investigate the long-term progression of pericentral hydroxychloroquine retinopathy. Design Multicenter, retrospective cohort study. Participants Eighty eyes (60 with pericentral pattern) of 41 Korean patients with hydroxychloroquine retinopathy followed up for 2 years or more after drug cessation. Methods Patients were screened for hydroxychloroquine retinopathy using spectral-domain or swept-source OCT, fundus autofluorescence (FAF), and Humphrey visual field (VF) tests. Follow-up was divided into short-term (≤2 years) and subsequent periods, and progression was evaluated in each period and severity group. Retinopathy progression on OCT was defined as increased length of the ellipsoid zone defect, decreased distance from the fovea to the photoreceptor defects, or newly developed or enlarged retinal pigment epithelium defects. On FAF, progression was defined as an increase in the area of hyperautofluorescence or hypoautofluorescence. Functional progression was defined as a regression coefficient of less than 0 dB/year for mean deviation and more than 0 dB/year for pattern standard deviation, based on linear regression analysis of 3 or more VF tests. Structural and functional progression rates were calculated using the slopes of retinal thicknesses on the Early Treatment Diabetic Retinopathy Study grid and perimetric parameters over time, respectively. Main Outcome Measures Structural and functional progression of retinopathy. Results Approximately one third of eyes with early pericentral retinopathy showed limited progression during the short-term period after drug cessation, but they subsequently showed stable or improved photoreceptors. Most eyes with moderate pericentral retinopathy showed continuous progression, particularly when converted to the severe stage. Severe eyes showed progressive damage throughout the follow-up period. In all severity groups, the rates of retinal thinning decreased over time. In eyes with pericentral retinopathy showing progression, circumferential enlargement of retinal damage was prominent in earlier stages, whereas centripetal enlargement of the ring-shaped lesion was noted in advanced stages. Functional progression, noted in 58.7% of the pericentral eyes, corresponded with structural progression. Conclusions Pericentral hydroxychloroquine retinopathy showed severity-dependent progression. Moderate pericentral retinopathy usually progressed, but centripetal progression threatening the fovea was remarkable mostly in severe retinopathy. Our results suggest that early detection of retinopathy may minimize the risk of progression to foveal involvement in pericentral retinopathy.

Undoped and Mn-doped ZnO samples with different percentages of Mn content (1, 5 and 10 at%) were synthesized by a dip coating sol–gel method. We have studied the structural, chemical and optical properties of the samples by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible spectroscopy. The XRD spectra show that all the samples are hexagonal wurtzite structures. We note that doping favors c-axis orientation along (002) planes. Up to 5 at% of Mn doping level, the c- axis lattice parameter shifts towards higher values with the increase of manganese content in the films. The expansion of the lattice constant of ZnO–Mn indicates that Mn is really doped into the ZnO. The SEM investigations of all samples revealed that the crystallites are of nanometer size. The sur- face quality of the ZnO–Mn film increases with Mn doping but no significant change of the grain size is observed from SEM images. The transmittance spectra show that the trans parency of all the samples is greater than 85 %. We note, also, that a small doping (1 %) lowered the refractive index while the thickness of the layers and the gap increase. However, on raising the proportion of Mn beyond 5 %, practically the same values of index and gap as pure ZnO are found.

Herein, we introduce the infusion direction manipulation technique and the infusion off technique. These relatively simple methods control intra-vitreal fluid flow direction and turbulence and release negative pressure in the microforceps to facilitate handling of the internal limiting membrane. The aim of this study is to introduce an effective and uncomplicated method to handle the internal limiting membrane (ILM) during the temporal inverted ILM flap and free ILM flap techniques in macular hole surgery by controlling the direction and status of the infusion.The direction of the infusion flow was controlled with a free finger (usually the 4th finger) during the inverted ILM flap surgery to stabilize the flap location during the fluid-air exchange. A valved trocar was used, and the infusion was discontinued during the free ILM flap surgery. Turbulence was minimized, and negative pressure around the head-shaft junction of the microforceps was released.The ILM flap remained stable in all patients who underwent macular hole surgery with our technique.Infusion direction manipulation technique and infusion off technique are efficient and simple methods to handle the ILM during ILM surgery.

The most important requirements of biomedical substitutes used in muscle tissue regeneration are appropriate topographical cues and bioactive components for the induction of myogenic differentiation/maturation. Here, we developed an electric field-assisted 3D cell-printing process to fabricate cell-laden fibers with a cell-alignment cue. Methods: We used gelatin methacryloyl (GelMA) laden with C2C12 cells. The cells in the GelMA fiber were exposed to electrical stimulation, which induced cell alignment. Various cellular activities, such as cell viability, cell guidance, and proliferation/myogenic differentiation of the microfibrous cells in GelMA, were investigated in response to parameters (applied electric fields, viscosity of the bioink, and encapsulated cell density). In addition, a cell-laden fibrous bundle mimicking the structure of the perimysium was designed using gelatin hydrogel in conjunction with a 4D bioprinting technique. Results: Cell-laden microfibers were fabricated using optimized process parameters (electric field intensity = 0.8 kV cm-1, applying time = 12 s, and cell number = 15 × 106 cells mL-1). The cell alignment induced by the electric field promoted significantly greater myotube formation, formation of highly ordered myotubes, and enhanced maturation, compared to the normally printed cell-laden structure. The shape change mechanism that involved the swelling properties and folding abilities of gelatin was successfully evaluated, and we bundled the GelMA microfibers using a 4D-conceptualized gelatin film. Conclusion: The C2C12-laden GelMA structure demonstrated effective myotube formation/maturation in response to stimulation with an electric field. Based on these results, we propose that our cell-laden fibrous bundles can be employed as in vitro drug testing models for obtaining insights into the various myogenic responses.

BACKGROUND AND PURPOSE The rate at which the chance of a good outcome of endovascular stroke therapy (EVT) decays with time when eligible patients are selected by baseline diffusion-weighted magnetic resonance imaging (DWI-MRI) and whether ischaemic core size affects this rate remain to be investigated. METHODS This study analyses a prospective multicentre registry of stroke patients treated with EVT based on pretreatment DWI-MRI that was categorized into three groups: small [Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS)] (8-10), moderate (5-7) and large (

Cell-laden structures are widely applied for a variety of tissue engineering applications, including tissue restoration. Cell-to-cell interactions in bioprinted structures are important for successful tissue restoration, because cell-cell signaling pathways can regulate tissue development and stem cell fate. However, the low degree of cell-cell interaction in conventional cell-laden bioprinted structures is challenging for the therapeutic application of this modality. Herein, a microfluidic device with cell-laden methacrylated gelatin (GelMa) bioink and alginate as a matrix hydrogel is used to fabricate a functional hybrid structure laden with cell-aggregated microbeads. This approach effectively increases the degree of cell-to-cell interaction to a level comparable to cell spheroids. The hybrid structure is obtained using a one-step process without the exhausting procedure. It consists of cell bead fabrication and an extrusion process for the cell-bead laden structure. Different flow rates are appropriately selected to develop cell-laden struts with homogeneously distributed cell beads for each hydrogel in the process. The hybrid struts exhibit significantly higher cellular activities than those of conventional alginate/GelMa struts, which are bioprinted using similar cell densities and bioink formulations. Furthermore, hybrid struts with adipose stem cells are implanted into mice, resulting in significantly higher myogenesis in comparison to normally bioprinted struts.

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is widely used in Korea and the main ingredient of kimchi. To retain the freshness of two different cultivars of Chinese cabbage harvested at spring or summer season, plasma treatment was applied for 2 h a day during storage at 2°C. Changes in weight loss, softening, decay rate, freshness and yellowing score were investigated during storage. The measured ozone concentration by plasma treatment was stabilized after 10 min and occurred on average 0.5 to 1 ppm during operation. Chinese cabbage treated with plasma had significantly lower decay rate during storage compared to the control, and higher freshness until the last storage day compared to the control. However, severe shriveling and slightly higher weight loss during storage time were shown. The yellowing score of Chinese cabbage treated with plasma had significantly low discoloration. These results indicate that plasma treatment seemed to be effective in controlling the softening, freshness, discoloration and decay rate.

Background The measure of processes of care (MPOC) is a widely used instrument to assess parents' perception of the extent to which healthcare services they and their child receive are family centred. The purpose of this study was to examine the reliability and validity of the Korean translation of the MPOC (Korean MPOC). Methods The Korean MPOC was completed by 198 parents of children receiving rehabilitation services in five provinces in South Korea. According to the Canadian validation procedures, analyses for internal consistency, construct and concurrent validity, and test-retest reliability were performed. Results The Korean MPOC demonstrated adequate internal consistency, with Cronbach's alpha ranging from .85 to .98. Confirmative analyses of the scale structure support the construct validity of the Korean MPOC. The Pearson correlations r between the MPOC scale scores and Client Satisfaction Inventory score ranged from .60 to .83, supporting the concurrent validity of the Korean MPOC. The intraclass correlation coefficients were greater than .80 for all five scales, demonstrating good test-retest reliability. Conclusions The Korean MPOC has good psychological properties and can be recommended for evaluation of processes of paediatric rehabilitation in Korea.

Green tea (GT) is a widely consumed beverage with health benefits, including antiobesity effects; however, the efficacy of GT on lipid levels associated with obesity is not clearly understood. Here, we examined the impact of GT consumption on lipid metabolism in the livers of high-fat diet (HFD)-induced obese mice. We performed lipid profiling using ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry in C57BL/6J mice fed a normal diet (ND), HFD and HFD with GT for 12 weeks. The partial least squares discriminant analysis score plot showed a difference among the groups and revealed that the levels of several lipid metabolites were altered in mice fed HFD with GT. The decreased levels of lysophospholipids (LPLs), such as lysophosphatidylcholine, lysophosphatidylethanolamine and lysophosphatidylserine, in HFD mice compared to those of the ND group were recovered by supplementation of GT. In agreement with these lipid metabolites changes, hepatic lysophosphatidylcholine acyltransferase 2/4 was significantly increased in HFD mice. This study showed abnormal changes in lipid species associated with obesity, and these levels were attenuated by GT intake, suggesting a relationship between the reduction of hepatic LPL levels and inflammation in obesity.

An alpha imaging detector acquires a two-dimensional distribution of a sample that emits alpha particles. For the quantitative analysis of the image of an alpha-emitting sample, the individual energies of the alpha particles must be identified, which can be achieved using the spectrometric method after detector calibration. In this study, an energy and efficiency calibration method was investigated to assess an alpha imaging detector. The calibration was performed using a single standard source of Am-241 based on the energy loss characteristic of an alpha particle. The feasibility of the calibration method was evaluated using another source, Ac-225. The calibrated alpha imaging detector was evaluated in terms of energy resolution and detection efficiency, and the alpha imaging detector was found to be efficiently calibrated using a single standard source. The calibrated alpha imaging detector appears promising for the quantitative analysis of samples that emit alpha particles.

The visual cell of the retina in the Korean loach Kichulchoia multifasciata, a bottom-dwelling freshwater loach in shallow water, contains double cones and large rods. With light microscopy, the cones form a row mosaic pattern in which the partners of double cones are linearly oriented with a large rod. In a double cone or twin cone, the two members are unequal such that one cone may be longer than the other. An anatomical unit is apparent which consists of 5 rod cells and 15 double cone cells per 20 × 20 μm area. We found that the cone cells of outer segments are linked to the inner segment by so-called "calyceal process" using a scanning electron microscopy, unlike rod cells. In the transmission electron microscopy, the outer membrane shows piles of membrane discs surrounded by double membranes.

We report a fuel-dependent reactor electron antineutrino ($\overline{\nu}_e$) yield using six 2.8 GW$_{\text{th}}$ reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses $850\,666$ $\overline{\nu}_e$ candidate events with a background fraction of 2.0 % acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel $^{235}$U dependent variation of measured IBD yields with a slope of $(1.51 \pm 0.23) \times 10^{-43} $cm$^2$/fission and measure a total average IBD yield of $(5.84 \pm 0.13) \times 10^{-43} $cm$^2$/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6 $\sigma$. The observed IBD yield variation over $^{235}$U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 $\sigma$. The measured fuel-dependent variation determines IBD yields of $(6.15 \pm 0.19) \times 10^{-43} $cm$^2$/fission and $(4.18\pm 0.26) \times 10^{-43} $cm$^2$/fission for two dominant fuel isotopes $^{235}$U and $^{239}$Pu, respectively. The measured IBD yield per $^{235}$U fission shows the largest deficit relative to the HM prediction. Reevaluation of the $^{235}$U IBD yield per fission may mostly solve the Reactor Antineutrino Anomaly (RAA) while $^{239}$Pu is not completely ruled out as a possible contributor of the anomaly. We also report a 2.9 $\sigma$ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of $^{235}$U., Comment: 6 pages and 5 figures, v4 note: (1) data files for figure 1, figure 2, figure 5 are included for arXiv users (2) minor modifications in abstract and main text for clarification

The vibrational nonequilibrium in the electronically excited states of \( {\mathrm{O}}_2\left({X}^3{\Sigma}_g^{-}, {a}^1{\Delta}_g,{b}^1{\Sigma}_g^{+}\right) \) is investigated in the one-dimensional post-shock flows. The electronic and rovibrational state-to-state kinetics due to the heavy-particle collisions are employed to describe the electronic and rovibrational energy transitions. In the 1D post-shock flow calculations, it is observed that the vibrational relaxations of \( {\mathrm{O}}_2\left({X}^3{\Sigma}_g^{-}\right) \) are more significant than those of the \( {\mathrm{O}}_2\left({a}^1{\Delta}_g,{b}^1{\Sigma}_g^{+}\right) \) because the electronic excitation due to the heavy-particle collisions is not efficient.

Metabolomics is a powerful tool for the investigation of interactions between diet, nutrients, and human metabolism. Ecklonia cava is an edible brown alga that is abundantly found in Korea and Japan and contains unique polyphenols referred to as phlorotannins. However, there are few metabolomics studies related to the effects of polyphenols in humans. In this study, we performed a mass spectrometry-based metabolomics analysis of urine samples from participants with a body mass index (BMI) higher than 25 kg/m2 and lower than 30 kg/m2 to investigate the effects of the intake of seapolynol isolated from E. cava. Metabolomic profiling showed that the levels of riboflavin, urocanic acid, 5-hydroxy-6-methoxyindole glucuronide, and guanidino valeric acid were significantly increased in the seapolynol intake group compared with the placebo group. A correlation analysis was performed to identify the association between the metabolites&rsquo, levels and clinical characteristics related to body fat. Among the metabolites whose concentrations changed in the seapolynol intake group, riboflavin was associated with BMI, body weight, fat mass, and percent body fat. These findings suggest that the decreased body fat induced by the intake of seapolynol is related to an increase in the antioxidant effect of riboflavin.

A hierarchical micro/nanoscale scaffold fabricated using a combined method involving an electric-field (E-field)-assisted printing and plasma-treatment process was proposed for myoblast alignment and differentiation. By appropriately selecting various processing conditions, including the E-field strength and printing parameters, a uniaxially aligned bundle of polycaprolactone (PCL) consisting of microsized struts (diameter = 40–50 μm) was stably obtained. After the PCL struts were printed, oxygen-plasma treatment was applied, and eventually a chemically and physically modified nanoscale structure on their surfaces was achieved. To investigate the feasibility of the struts as a biomedical scaffold for muscle tissue regeneration, in vitro C2C12 myoblast activities, including the cell proliferation, cell alignment, and myotube formation, were evaluated. The unique fabricated structure exhibited significantly higher cellular activities, including myotube formation and myogenic gene expression, than non-hierarchical and flat surfaces.

The RENO experiment reports more precisely measured values of $\theta_{13}$ and $|\Delta m_{ee}^2|$ using $\sim$2\,200 live days of data. The amplitude and frequency of reactor electron antineutrino ($\overline{\nu}_e$) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103\,212 (850\,666) electron antineutrino candidate events with a background fraction of 4.7\% (2.0\%). A clear energy and baseline dependent disappearance of reactor $\overline{\nu}_e$ is observed in the deficit of the measured number of $\overline{\nu}_e$. Based on the measured far-to-near ratio of prompt spectra, we obtain $\sin^2 2 \theta_{13} = 0.0896 \pm 0.0048({\rm stat}) \pm 0.0048({\rm syst})$ and $|\Delta m_{ee}^2| =[2.68 \pm 0.12({\rm stat}) \pm 0.07({\rm syst})]\times 10^{-3}$~eV$^2$., Comment: 5 pages, 5 figures, updated with rephrase in the text for clarity

Objectives To determine the potential for immunodiagnostic application of two recombinant forms of Clonorchis sinensis omega-class glutathione transferases (rCsGSTo1 and rCsGSTo2) against human small liver-fluke C. sinensis and Opisthorchis viverrini infections. Methods Specific antibody levels against rCsGSTo1 and rCsGSTo2 in patients' sera of egg-positive opisthorchiasis ( n = 87) and clonorchiasis ( n = 120), as well as those in sera from patients with other helminthic infections ( n = 252) and healthy controls ( n = 40) were retrospectively analysed by ELISA. Results We observed highly positive correlation coefficients between specific antibody levels against rCsGSTo1 and rCsGSTo2 and egg counts per gramme of faeces (EPG) of patients with opisthorchiasis ( n = 87; r = 0.88 for rCsGSTo1 and r = 0.90 for rCsGSTo2). Sera from opisthorchiasis patients whose EPG counts >100 ( n = 43) revealed high antibody titres against both antigens. Patients' sera with low EPG counts ( n = 44) also exhibited reliable sensitivities of 93.2% and 97.7% for rCsGSTo1 and rCsGSTo2, respectively. Sera from clonorchiasis patients showed sensitivities of 90% (108/120 samples) and 89.2% (107/120 sera) for rCsGSTo1 and rCsGSTo2. Overall diagnostic sensitivities for liver-fluke infections were 92.3% for rCsGSTo1 (191/207 samples) and 93.2% for rCsGSTo2 (193/207 samples). Specificities were 89.7% (rCsGSTo1) and 97.6% (rCsGSTo2). Conclusions Detection of specific antibody levels against rCsGSTo1 or rCsGSTo2 might be promising for the serodiagnosis of patients infected with these two phylogenetically close carcinogenic liver-flukes.

Closely correlating with {200} plane of cubic phase, {103} plane of hexagonal phase of Ge(2)Sb(2)Te(5) plays a crucial role in achieving fast phase change process as well as formation of modulation structures, dislocations and twins in Ge(2)Sb(2)Te(5). The behaviors of {103} plane of hexagonal phase render the phase-change memory process as a nanoscale shape memory.

A novel two step electrochemical deposition method for the synthesis of ZnO/Cu2O heterojunctions is reported. ZnO nanorods were grown on seeded oxidized silicon substrates and were subsequently employed as working electrodes for the electrodeposition of Cu2O in the same aqueous formamide solution using Zn and Cu foils as counter-electrodes respectively. Single crystalline Cu2O particles grow on top of the single crystalline and vertical to the substrate ZnO nanorods. Varying the growth parameters different Cu2O morphologies can be obtained, ranging from isolated cube and truncated cube particles to a continuous layer.

Summary Ge2Sb2Te5, as the prototype material for phase-change memory, can be transformed from amorphous phase into nanoscale rocksalt-type GeTe provided with an electron irradiation assisted by heating to 520°C in a 1250 kV transmission electron microscope. This sheds a new light into structural and chemical cotailoring of materials through coupling of thermal and electrical fields. Lay Description In theory Ge2Sb2Te5 (GST) chalcogenide, known as the prototype material for phase-change memory, is a pseudo-binary (GeTe)m(Sb2Te3)n material but no evidence has shown if these the two components can be experimentally separated. Through high resolution transmission electron microscopy, image simulation and energy-dispersive X-ray spectroscopy, it was shown that GST can be transformed from amorphous phase into nanoscale rocksalt-type GeTe provided with an electron irradiation assisted by in situ heating to 520°C. The transition and phase separation has been achieved in a 1250 kV transmission electron microscope. The present result sheds a new light into structural and chemical co-tailoring of materials within the transmission electron microscope through coupling of thermal and electrical fields.

Monoclinic Li3V2(PO4)3, is a highly promising cathode material for lithium–ion rechargeable batteries. It has good ion mobility and high lithium capacity due to its ability to reversibly extract all three lithium ions. Here, we present, a systematic investigation of phase transitions and volume variations that occur during lithium extraction from the carbon-coated monoclinic phase of Li3V2(PO4)3 by synchrotron based in situ X-ray diffraction and X-ray absorption spectroscopy. This monoclinic Li3V2(PO4)3 illustrates complex behavior of four successive two-phase transitions upon extraction of all three lithium ions between 3.0 and 4.8 V vs. Li/Li+. Each XRD pattern of the intermediate compositions can be fully indexed in the monoclinic space group P21/n, with net volume reduction of 6.47%. In situ V K-edge XANES in combination with study of structural parameters is applied to find the vanadium valence state at plateau regions, which highlights the variations in electrochemical potential constraining to extraction of lithium ion from different crystal sites.

Sao Paulo State Univ UNESP, Ctr Human Reprod Prof Franco Jr, Paulista Ctr Diag Res & Training, Dept Gynecol & Obstet,Botucatu Med Sch, Ribeirao Preto, Brazil

In the present study, we investigated the behavior of an amorphous carbon film covering a Mo grid at high temperature. It was found that metastable nanosized particles were formed on the carbon film at 400 °C. They finally became nanosized α-Mo2C crystals with an average size of 3.5 nm at 700 °C. Moreover, modification of the amorphous carbon support film was observed. High-resolution TEM images showed that the carbon film was transformed to irregular and disordered lamellar structures at 300 °C and to short-range ordered and crystallized structures at 700 °C. Based on these experimental results, we suggest selecting suitable metal grids and support films for the TEM specimen preparation and performing a chemical analysis of nanostructure materials in in situ heating experiment. Finally, it is expected that these results will be helpful for the appropriate experimental designs for the in situ TEM studies.

We examine the effect of stochastic lead times on Just-in-Time (JIT) delivery. We find that with stochastic lead times there is a possibility of order crossover, and what order crossover does is to transform the original lead times into effective lead times, which is an AR(1) process that is an autoregressive process of Order 1. The mean of this process is the same as the mean of the original lead time, but its variance could be much smaller. The implication is that when we consider order crossover in the analysis, the cost could be less than otherwise (but never less than that with deterministic lead times). The literature on JIT with stochastic lead times has never considered order crossover, which produces the effective delivery times (EDT). Here, we demonstrate some important properties of the EDT: that it is a Cauchy sequence, and hence it converges; that it is an AR(1) process; and that it stochastically dominates the parent lead time distribution.

Discharge property of plasma jet devices is investigated for the application to the doping processes of crystalline solar cells and others. Current-voltage characteristics are shown as the typical normal-glow discharge in the various gas pressure of plasma jets, such as in the atmospheric plasma jets of Ar-discharge, in the ambient pressure of atmospheric discharge, and in the ambient Ar-pressure of Ar-discharge. The discharge voltage of atmospheric plasma jet is required as low as about 2.5 kV while the operation voltage of low pressure below 200 Torr is low as about 1 kV in the discharge of atmospheric and Ar plasma jets. With a single channel plasma jet, the irradiated plasma current on the doped silicon wafer is obtained high as the range of 10~50 mA. The temperature increasement of wafer is normally about . In the result of silicon wafers doped by phosphoric acid with irradiating the plasma jets, the doping profiles of phosphorus atoms shows the possibility of plasma jet doping on solar cells.

The corrosion properties were investigated for extruded Mg–3Al–1Zn (AZ31) alloy in alkaline NaCl solution which was manufactured by adding 0.5 wt% CaO without SF6 protective gas. The results of electrochemical tests showed that the addition of 0.5 wt% CaO drastically increased the pitting potential and charge transfer resistance of the specimen, indicating that CaO addition enhances the film stability of AZ31 alloy. As results of electron probe X-ray microanalysis (EPMA), Al2Ca phase and CaO was observed on the CaO-added specimen. The Al2Ca phase was precipitated by the reduction of CaO, and was known as an effective corrosion barrier and hinders the corrosion propagation. Also, the CaO raw particle was observed, and could be remained after reduction as Al2Ca phase. Meanwhile, the Mg17Al12 phase was not recognized due to the low content of Al in the AZ31 Mg alloy. The results of X-ray diffraction (XRD) showed that Ca(OH)2 and Al2Ca phase was observed on the CaO-added AZ31 Mg alloy after immersion for 5 days, which increased the protectiveness of Mg(OH)2 film of the CaO-added specimen.

Arsenic (As) is highly toxic and carcinogenic to humans. It is a frequently found contaminant in contaminated sites due to its many industrial applications such as tanning, wood preservation, pesticide and herbicide. We developed a combined process of dispersion and magnetic separation for the remediation of As contaminated soil. We collected the As contaminated silt loam soil from a smelting site. We tested the soil dispersion rate at various pH and concentrations of Na-orthophosphate, Na-pyrophosphate and Na-hexametaphosphate and determined an optimum dispersion condition. We also tested the change in As concentration of the soil after and before passing its suspension through a magnetic field. The dispersion rate increased with increasing phosphate concentration and showed the following order at the same concentration: hexametaphosphate > pyrophosphate > orthophosphate. The dispersion rate also sharply increased at the solution pH 11. We concluded that the optimum dispersion condition was pH 11 10mM Na-hexametaphosphate. The soil dispersed at the optimum conditions was separated into magnetic and nonmagnetic particles with a high gradient magnetic separator (HGMS) at 12,000 gauss. The bulk soil with 37.7 mg kg -1 of As was separated into 20% of magnetic fraction and 80% of nonmagnetic fraction. The magnetic fraction had a higher As concentration, 48.0 mg kg -1 but the nonmagnetic fraction had a lower As concentration, 20.0 mg kg -1 , comparing with the bulk soil. The result

We consider a problem of order-lot pegging in semiconductor wafer fabrication process. In the problem, we determine an assignment of wafers in lots to orders and a plan for input release of wafers into a wafer fabrication facility with the objective of minimizing total tardiness of the orders over a finite time horizon. The problem is formulated as a mixed integer linear program and proved to be strongly NP-hard. We find properties for an optimal order-lot assignment of the problem and develop a pegging method based on the properties. Also, we prove that an optimal order-lot assignment can be obtained by finding an optimal order sequence of assigning wafers to orders when using the pegging method developed in this study. In addition, we suggest two search heuristic algorithms for finding the optimal order sequence of assigning wafers to orders. The test results on randomly generated problems show that the suggested algorithms work fairly well compared to the commercial optimization software package and solve industrial-sized problems in a reasonable amount of time.

In this study, a novel ultra-lightweight frame for a flatbed trailer is developed; it has a completely different layout from conventional ladder-type frames and is developed by applying structural optimization using commercial computer aided engineering (CAE)-based software. The proposed process of design optimization consists of two main steps: an initial design step to obtain the optimum layout (or topology) of the structure and a size/shape optimization step to determine its detailed geometric dimensions. In the topology optimization step, an initial design of the frame is generated to obtain the maximized global system performance measures, such as static stiffness or natural frequencies, for which GENESIS, a commercial optimization software package, is used in this investigation. For size and shape optimization, thicknesses of the member plates and the boundary shapes are optimized by using the Taguchi method, in order to minimize further the mass of the frame without violating design constraints on local performance measures such as the allowable stress limit. In addition, manufacturability is also considered during the detail design step of size and shape optimization. As a result, the optimized lightweight frame has improved bending and torsional rigidities while its mass is reduced by 24.5 per cent as compared to that of the original model.

Four types of Mg–5Al alloy with various weight percentages of Sr ranging from 0 to 1.5 wt% were examined using electrochemical techniques and surface analyses. The electrochemical results indicated that the Mg–5Al alloy containing Sr to have a higher pitting potential and impedance than the Mg–5Al specimen with highest value being observed in the Mg–5Al–1Sr specimen. Sr addition induced the continuous precipitation of Al–Sr phases along with grain refinement and increased the formation of an Al(OH) 3 film on the surface.