Determination of total arsenic content and arsenic speciation in different types of rice

Food Science and Biotechnology - The objectives of this study was to examine the amount of total arsenic and arsenic speciation in different types of rice from two areas in Korea using inductively...     

Production of a fermented organic rice syrup with higher isomalto-oligosaccharide using Lactobacillus plantarum

Food Science and Biotechnology - Isomalto-oligosaccharide (IMO) syrup was prepared from organic rice, in which Lactobacillus plantarum as a starter was inoculated to raise its purity and also...     

Estimating the mechanical properties of polyurethane-impregnated felt pads

Chemical mechanical polishing (CMP) is an essential process in semiconductor fabrication. The results of CMP process are determined with the selection of consumables and process parameters. The polishing pad transports the slurry to the interface between the polishing pad and wafer and obtains material removal planarity. The mechanical properties of the polishing pad should be studied to analyze the material removal mechanism of CMP because polishing pad deformation is directly related to material removal rate and its uniformity. Various studies have investigated the stress distribution of the CMP process by using the elastic modulus and Poisson’s ratio of the polishing pad. However, these aspects of polishing pad have not been fully elucidated. In this study, we estimated the mechanical properties of commercial polyurethane-impregnated felt pads by comparing the experimentally measured compressive deformation amounts with finite element analysis results.     

Non-immersive Ultrasound Scanning and Inspection of Internal Defects Using a Water Droplet Coupling Device

This paper investigates a method for conducting conventional ultrasound image scanning (C-scan) in a non-immersive manner. An ultrasound coupling device is developed to couple a focusing ultrasound transducer with a sample under test through a water droplet. The transducer is immersed in a chamber filled with water. A hole-opening at the chamber’s bottom surface and a polymer film sealing the hole allow focused ultrasound to pass and reach the sample through a water droplet. An ultrasound scanning system is constructed and used for carrying out C-scan on two different samples containing pre-fabricated internal defects. By comparing the images obtained from using both conventional water immersion method and the proposed water-droplet coupling method, we demonstrate the feasibility and capability of this new type of non-immersive ultrasound image scanning method.     

Two-stage forming approach for manufacturing ferritic stainless steel bipolar plates in PEM fuel cell: Experiments and numerical simulations

Multi-stage micro-channel forming by stamping, as a method for cost effective and efficient for mass production, was performed for ultra-thin ferritic stainless steel sheets with thicknesses of 0.1 and 0.075 mm, as a good substitute for traditional graphite bipolar plates of proton exchange membrane fuel cell. Attention was directed to enhance the final forming depth and minimize localized thinning, extremely important aspects of the micro-channel on bipolar plate, by the proposed forming process. A forming depth at the first forming stage was chosen as a process variable, and its effect on the formability of the micro-channel at the second forming stage was experimentally investigated. Finite element simulations for the two-stage forming process were conducted to optimize the punch radius and forming depth at the first stage for improving the formability. The comparative study between the simulations and the experimental results could validate improvements in the formability by the proposed approach. In particular, this study could support the existence of an optimum forming depth at the first forming stage. Based on the simulation results, a mathematical model was established to identify the dominant factor needed for formability improvement and to propose a methodology for the process optimization of the multi-stage forming.     

Influences of elevated pressures on soot formation in coaxial ethylene–air diffusion flames under different ventilation conditions

The effect of elevated pressures on the soot formation in coaxial ethylene-diffusion flame was investigated under different ventilation conditions, i.e. one with a chamber valve closed and the other with a chamber valve open. Experimental measurements include the soot volume fraction and macroscopic flame behaviors such as visible height and flame shape. The presence of ventilation-assisted flow around the flame was found to further increase the visible flame radius and height at elevated pressures. The maximum soot volume fraction measured within the flame was also increased with the ventilation-assisted flow as well as with the ambient pressure. Experimental results clearly indicate that changes in the physical appearance of the flames altered by ventilation-assisted flow are an important factor to affect the sooting behavior in coaxial diffusion flames.     

Performance of four salmonids species in competition with Atlantic salmon

Economically and culturally important salmonid species often compete with Atlantic salmon (Salmo salar) released from stocking programs or that escaped during aquaculture production. Such competitive interactions may lower the individual fitness of these species by reducing survival and body growth. Here, we exposed juvenile brown trout (S. trutta), rainbow trout (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) to juvenile Atlantic salmon in artificial streams for 10 months. Survival and fitness-related traits of the four species were not negatively impacted by the presence of Atlantic salmon. The results suggest that brown trout and rainbow trout have better competitive abilities than Atlantic salmon, and that Chinook salmon and coho salmon have limited competitive interactions with Atlantic salmon. Although we discuss certain environmental conditions that can favor Atlantic salmon as a competitor at the juvenile life stage, Atlantic salmon may have little impact on the productivity of these four species.