The catalytically supported combustor for lean mixtures

This study aims to investigate advantages that the catalytically supported combustor can have. A catalytic combustor was prepared which consisted of a catalyst bed and a thermal combustor downstream of the catalyst bed. The catalyst bed consisted of two stages, a Pd catalyst in the first stage and a Pt catalyst in the second stage. The results showed that the catalytically supported combustion had some advantages. One of them was that autoignition occurred in the thermal combustor so that an igniter was not necessary to start flame ignition. Another was that the catalytically supported combustor offered stable combustion for lean mixtures. NO_x emissions were low because of the stable lean combustion. Copyright © 1999 John Wiley & Sons, Ltd.     

Volume phase transition behavior of N‐isopropyl acrylamide–N‐cyanomethyl acrylamide copolymer gel particles: The effect of crosslinking density

We prepared submicron‐sized N‐isopropyl acrylamide (NIPA)–N‐cyanomethyl acrylamide (NCMA) copolymer gel particles by precipitation polymerization. Volume phase transition behaviors of gel particles with various compositions and crosslinking density were observed by using photon correlation spectroscopy (PCS). The experimental data showed that both the volume transition temperature and the swelling ratio of copolymer gel particles were varied with the mole ratio of NCMA and NIPA. We compared the swelling behaviors of given systems with the thermodynamic model based on the extended Flory–Huggins theory. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1091–1099, 1999     

Effect of dialcohols on properties of poly(ethylene 2,6‐naphthalate) copolymers

Properties of poly(ethylene 2,6‐naphthalate) (PEN) and its copolymers containing diethylene glycol (DEG), propanediol (PD), butanediol (BD), and bisphenol A ethoxylate (BSA) were investigated. The copolymer composition was determined by ¹H‐NMR spectroscopy. It has a higher value than the feed composition due to the high volatility of ethylene glycol (EG). The melting temperature of the copolymers was gradually depressed with the increase of dialcohol in the composition. The complex viscosity of the copolymers did not depend on the molecular weight, but on the chemical structure. The complex viscosity of the copolymers containing 3 mol % of DEG, BD, and 5 mol % of BD was lower than that of PEN, and the mechanical properties were similar with the value of PEN. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2900–2905, 1999     

Emerging View on the Molecular Functions of Sec62 and Sec63 in Protein Translocation

Most secreted and membrane proteins are targeted to and translocated across the endoplasmic reticulum (ER) membrane through the Sec61 protein-conducting channel. Evolutionarily conserved Sec62 and Sec63 associate with the Sec61 channel, forming the Sec complex and mediating translocation of a subset of proteins. For the last three decades, it has been thought that ER protein targeting and translocation occur via two distinct pathways: signal recognition particle (SRP)-dependent co-translational or SRP-independent, Sec62/Sec63 dependent post-translational translocation pathway. However, recent studies have suggested that ER protein targeting and translocation through the Sec translocon are more intricate than previously thought. This review summarizes the current understanding of the molecular functions of Sec62/Sec63 in ER protein translocation.     

Continuous glass-fiber reinforced nylon 6 by using a new impregnation die

This paper describes a process for the manufacture of thermoplastic composites reinforced with continuous fibers and the equipment for producing such a product. The process makes it possible to expand and reconsolidate the fibers of rovings by passing them into the impregnation die filled with molten thermoplastic. The die consists of three rollers and numerous pins fixed on the roller surfaces over which the roving is drawn under tension. The material chosen to illustrate the die process is a glass-fiber reinforced nylon-6, PA6. The void content and mechanical properties were measured to investigate the influence of processing variables on properties. These process experiences indicated that poor fiber resin impregnation and fiber damage, due to harsh prepreg fabrication, result in low values for longitudinal tensile strength and impact properties. However, the composites manufactured by this technique show a significant improvement in mechanical properties over conventionally prepared thermoplastic composites.     

Torsional stiffness requirements for diaphragm bracing of discretely braced I-girders

I-section girders are laterally interconnected by Torsional bracings that are discretely installed to increase resistance to lateral-torsional buckling. However, there are confusing discrepancies in the current design specifications for the stiffness of diaphragm-type bracings. The mathematical formula for determining the required torsional stiffness is still unclear. In this study, rigorous examinations were carried out to clarify the effects of the web distortional stiffness and the number of diaphragm bracings. To achieve the purpose of this study, the theoretical derivation of the stiffness equations was thoroughly examined. Three-dimensional finite-element analysis was used for the parametric numerical analyses of a series of feasible two-girder system models, and enhanced equations are proposed for achieving sufficient stiffness in the torsional bracings. The practical validity of the proposed equations are verified by statistical correlation analyses, which clearly prove their superiority compared to current design guidelines.     

Eleutheroside E,an active compound from Eleutherococcus senticosus,regulates adipogenesis in 3T3-L1 cells

In this study, we investigated the anti-adipogenic effects of Eleutherococcus senticosus and its active compounds in vitro to examine new functions. We first analyzed the active compounds in E. senticosus growing in Korea using HPLC and found that the concentration of eleutheroside B and E was higher in stems and roots than in other plant parts. There were no significant (p<0.05) differences in eleutheroside concentration between plant ages. Anti-adipogenic effects of E. senticosus on lipid accumulation in 3T3-L1 cells were examined. Extracts of stems and roots more effectively inhibited lipid accumulation in 3T3-L1 cells than extracts of other plant parts. Eleutheroside E was responsible for the pharmacological anti-adipogenic effects via regulation of the mTOR pathway. This is the first report of an anti-adipogenic effect of E. senticosus and the active compound eleutheroside E.