Effect of the surface modification of zinc powders with organosilanes on the corrosion resistance of a zinc pigmented organic coating

The surface modification of zinc particles using aqueous organosilane (OS) solutions was conducted to improve the anti-corrosion performance of zinc pigmented organic coatings (ZPC). The surfaces of modified zinc particles were characterized by scanning electron microscopy (SEM), the electrochemical polarization method and glow discharge spectrometry (GDS).     

Removal of soluble COD by a biofilm formed on a membrane in a jet loop type membrane bioreactor

The soluble chemical oxygen demand (COD) removal efficiency through a cake layer (biofilm) deposited on the surfaces of a membrane was investigated as a function of biofilm thickness in a jet loop type membrane bioreactor (JL-MBR). The mechanisms for the removal were investigated based on the microbial characteristics of the biofilm. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to identify the microbial community and a Specific oxygen uptake rate (SOUR) analysis was applied to determine the activities of microbial communities in a biofilm. Both the activities and community of microbial communities in the biofilm were similar to those found in a mixed liquor since, in JL-MBR all the substrates, dissolved oxygen, and nutrients are forced to flow through the biofilm, which differs from the biofilms grown on a non-permeable substratum in conventional biofilm process. The removal efficiency of soluble COD in a reactor through the active biofilm increased, reaching a constant value of approximately 92% despite the continuous increase in the thickness of active biofilm with the operation time. This might be attributed to (i) the presence of soluble COD that is not readily biodegraded, (ii) the presence of small and non-biodegradable organic molecules that could easily pass through the biofilm as well as the membrane, and (iii) too short a contact time of soluble solutes with the active microorganisms in the biofilm.     

Effects of dew point on selective oxidation of TRIP steels containing Si,Mn, and B

The selective oxidation of Si, Mn, and B on TRIP steel surfaces is a widely known phenomenon that occurs during heat treatment. However, the relationship between oxide formation and the annealing factors is not completely understood. This study examines the effect of the annealing conditions (dew point and annealing temperature) on oxide formation. A low dew point of −40 °C leads to the formation of Si-based oxides on the surface. A high dew point of −20 °C changes the oxide type to Mn-based oxides because the formation of Si oxides on the surface is suppressed by internal oxidation. Mn-based oxides exhibit superior wettability due to aluminothermic reduction during galvanizing.     

Hydrodynamics and microbial physiology affecting performance of a new MBR, membrane-coupled high-performance compact reactor

In this study, hydrodynamics and physiology of microorganisms were investigated in a new type membrane bioreactor, MHCR, which is a membrane coupled HCR (High performance Compact Reactor) having very high COD removal efficiency. The degree of interference caused by inserting a submerged membrane was evaluated quantitatively by measuring the air suction rate and overall oxygen transfer coefficient (k_L,a). Despite such interference, MHCR showed greater oxygen transfer efficiency than HCR under particular hydrodynamic conditions. Higher recirculation rate generally resulted in a higher turbulence and thus alleviated membrane fouling. When the recirculation rate was too high however, the microbial flocs were broken by fluid shear and membrane permeability was decreased rapidly. All these results were elucidated through not only physicochemical but also microbiological factors.     

Anti-obesity activity of peanut sprout extract

Sprouting of peanut usually promotes de novo biosynthesis of phenolic compounds such as resveratrol. As phenolic compounds have been reported to possess anti-obesity activity, we investigated the effect of peanut sprout extract (PSE) on weight gain induced by high-fat diet (HF) in C57BL/6J mice. Administration of PSE effectively suppressed the body weight gain induced by HF without altering food intake. Furthermore, blood parameters, including levels of TG and total cholesterol, were significantly improved by administration of 0.5 g/kg BW of PSE compared to mice fed HF alone. Although its mechanism of action remains unclear, the anti-obesity activity of PSE appears to be associated with its inhibition of carbohydrate digestion enzymes, as it dose-dependently inhibited the activities of α-amylase and α-glucosidase but not pancreatic lipase while PSE did not have any inhibitory effect against lipid accumulation in differentiated 3T3L1 adipocyte. In conclusion, PSE deserves further study as a health functional ingredient for body weight control.     

Simultaneous enhancement of free isoflavone content and antioxidant potential of soybean by fermentation with Aspergillus oryzae

In order to determine the fungal strain and fermentation period which produce the highest antioxidant activity of fermented soy product, soybean was fermented with Aspergillus oryzae NL 5 isolated from Korean traditional meju produced in Sunchang Yeastopia Land in Korea, and was subjected to analyzing isoflavone profiles and assaying antioxidant activity. Antioxidant potential of the samples was evaluated by ferric reducing antioxidant power assay, 2,2'-azinobis (2-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity and total phenolic contents. In addition, antioxidant assay using fluorescent probes, 2',7'-dichlorofluorescin diacetate and dihydroethidium, in HepG2 cells was conducted for the samples. The results showed that both high isoflavone variety Aga 3 and medium isoflavone variety Daewon of soybean fermented with Asp oryzae NL5 for 4 to 5 d showed the highest increase in free isoflavone contents, together with the highest antioxidant activity. In conclusion, the antioxidant activity of fermented soy was proportional to the concentration of free isoflavones, and was significantly influenced by total isoflavone content of soybean variety and fermentation period. Practical Application: Isoflavone profile and antioxidant capacity of soybean were widely variable during fermentation with Asp oryzae, and thereby it is recommended that meju (or koji) preparation condition, in particular, fermentation time is carefully optimized to maximize the antioxidant capacity of soy products fermented by Asp oryzae.     

A 0.18-/spl mu/m CMOS 3.5-gb/s continuous-time adaptive cable equalizer using enhanced low-frequency gain control method

This paper describes a high-speed CMOS adaptive cable equalizer using an enhanced low-frequency gain control method. The additional low-frequency gain control loop enables the use of an open-loop equalizing filter, which alleviates the speed bottleneck of the conventional adaptation method. In addition, combined adaptation of low-frequency gain and high-frequency boosting improves the adaptation accuracy while supporting high-frequency operation. The open-loop equalizing filter incorporates a merged-path topology and offers infinite input impedance, which are suitable for higher frequency operation and cascaded design. This equalizing filter controls its common-mode output voltage level in a feedforward manner, thereby improving bandwidth. A prototype chip was fabricated in 0.18-/spl mu/m four-metal mixed-mode CMOS technology. The realized active area is 0.48/spl times/0.73 mm/sup 2/. The prototype adaptive equalizer operates up to 3.5 Gb/s over a 15-m RG-58 coaxial cable with 1.8-V supply and dissipates 80 mW. Moreover, the equalizing filter in manual adjustment mode operates up to 5 Gb/s over a 15-m RG-58 coaxial cable.