Oxidation products of cyanidin 3-O-β-d-glucoside with a free radical initiator

Recently, we have reported that anthocyanins show strong antioxidative activity, but no attention has been paid to anthocyanins from the viewpoint of the reaction mechanism of alkylperoxyl radicals; therefore, we investigated the reaction products of antioxidative anthocyanins (cyanidin 3-O-β-d-glucoside). Cyanidin 3-O-β-d-glucoside was reacted with 2,2′-azobis(2,4-dimet hylvaleronitrile) to generate the alkylperoxyl radicals, and the reaction products were isolated by high-performance liquid chromatography. The products were identified as 4,6-dihydroxy-2-O-β-d-glucosyl-3-oxo-2,3-dihydrobenzofuran and protocatechuic acid. Based on reaction products, the antioxidative mechanism of cyanidin 3-O-β-d-glucoside may be different from that of α-tocopherol; cyanidin 3-O-β-d-glucoside would produce another radical scavenger, as it would break down the structure and scavenge the radicals.     

Sub-millimeter-long carbon nanotubes repeatedly grown on and separated from ceramic beads in a single fluidized bed reactor

A semi-continuous fluidized-bed process is reported which rapidly converts acetylene into carbon nanotubes (CNTs). Catalysts are first immobilized on ceramic beads and CNTs are then grown on the beads and then separated from them in a repetitive process accomplished within a single reactor simply by switching gases at a fixed temperature. CNTs of 6–10 nm diameter, three walls on average, 0.4 mm length and 99 wt.% purity were synthesized at an yield of over 70% in a reactor residence time shorter than 0.3 s. The easy and efficient production of such CNTs with in situ separation from the catalysts may accelerate the development of CNT-based nanotechnology industries.     

Odor Significance of the Volatiles Formed During Deep-Frying With Palm Olein

Palm olein is currently considered to be one of the best options for deep-frying, but as with any other edible oil, during frying, deteriorative reactions produce off-flavor compounds that reduce the oil sensory quality. This study assessed the odor significance of the volatiles formed during 136 h of deep-frying a chicken product in palm olein, aiming to identify potential markers of the oil sensory quality during frying. The volatiles were isolated by solid phase microextraction, and identified by GC–MS. Trained judges assessed the odor intensity and quality of the volatiles formed during frying, evaluating the GC effluents through a GC–olfactometry technique called OSME. Two hundred and eight volatiles were detected by GC/MS in the palm olein after 136 h frying. Of these, heptanal, t-2-heptenal, decanal and t-2-undecenal were identified as potential markers of the sensory quality of palm olein during frying. Hexanal, pentanal and pentane, usually associated with lipid oxidation, showed no odor impact in the GC effluents, and were thus proven not to be good markers of the sensory quality of palm olein when used for a long frying period.     

Performance analysis of partial response systems for nonreturn-to-zero recording

An analysis is presented of the performance of partial response (PR) systems of types PR(1, 0, 0, . . . , 0, -1) and PR(1, 0, 0, . . . , 0, 1) for nonreturn-to-zero recording. The error probability is obtained as a function of the signal-to-noise ratio (SNR) at the reading point, the phase margin, the linear density, and the roll-off factor of a Nyquist equalizing waveform. Then as a numerical example a performance comparison of the PR systems is made by obtaining the relation between the phase margin and the SNR required to achieve the prescribed error probability.     

Screening of patients with maternally transmitted diabetes for mitochondrial gene mutations in the tRNA[Leu(UUR)] region

To investigate the prevalence and clinical characteristics of diabetes mellitus caused by mitochondrial gene mutations in the tRNA[Leu(UUR)] region, a known 'hot spot' for pathogenic mutations, we screened 440 diabetic patients with diabetic mothers for 11 mitochondrial gene mutations reported in mitochondrial neuromuscular disorders; nucleotide pairs (np) 3250, 3251, 3252, 3254, 3256, 3260, 3271, 3291, 3302 and 3303 in addition to an A to G transition at np 3243. The dot-blot hybridization method using 32P-labelled sequence-specific oligonucleotides as probes was used. One subject carrying a T to C transition at np 3271 and seven carrying the A to G transition at np 3243 were identified, while none of the other diabetic patients screened had these mutations in the tRNA[Leu(UUR)] region. The patient with the 3271 mutation, a 39-year-old male, had excellent glycaemic control with diet alone and had neither hearing impairment nor symptoms suggesting mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Thus, among patients with maternally transmitted diabetes, the prevalence of the 3271 mutation was approximately one-seventh that of the 3243 mutation, and other mutations are even more rare in the mitochondrial tRNA[Leu(UUR)] region.     

Transient thermal stresses in a composite hollow cylinder subjected to γ-ray heating

Transient temperature and thermal-stress distributions arising in an infinite long composite hollow circular cylinder subjected to internal heat generation decaying exponentially along the wall thickness resulting from γ-ray radiation are analyzed, under the thermal conditions of cooling by convection on the inner surface and insulation on the outer surface. Numerical calculations of the transient temperature and thermal-stress distributions are carried out for the case of a composite cylinder of stainless steel and carbon steel. The influence of the absorption coefficient, the Biot number and the splicing radius on the results are considered.     

Interfacial Electrical Properties of Nanodiamond Colloidal Species in Aqueous Medium as Examined by Acid-Base Indicator Dyes

This study was aimed at further examining of a detonated nanodiamond hydrosol, produced by the NanoCarbon Research Institute, Japan. In the concentrated solution, this colloidal system consists mainly of 3 nm-sized primary particles. These particles are positively charged and tend to associate into larger colloidal species on dilution. The species adsorb, first of all, the anionic dyes and readily coagulate on adding electrolytes. Some properties of the sol are changed during prolonged ageing but may be restored by adding small HCl amounts. Besides measuring the electrokinetic potential, the interfacial electrical potential was estimated by using acid-base indicators.     

Creep rupture properties of homopolymer,copolymer, and terpolymer based on poly(oxymethylene)

Polyacetal copolymers were prepared by cationic ring‐opening copolymerizations of 1,3,5‐trioxane (TOX) with 1,3‐dioxolane (DOX), and polyacetal terpolymers were prepared by terpolymerizations of TOX, DOX, and 2‐ethylhexyl glycidyl ether (EHGE). Polyacetal polymers with three different structures such as polyacetal homopolymers, polyacetal copolymers, and polyacetal terpolymers were compared in the mechanical properties and the creep characteristics, and discussed from the view point of the polymer structure. The polyacetal copolymers and the polyacetal terpolymers were determined by ¹H‐MNR measurement. About 80 mol % of DOX and EHGE amounts in feed were incorporated randomly into the each polymer. From the plots of the degree of crystallinity (X_c) versus the tensile strength, the tensile strength and crystallintiy of the polyacetal homopoymers are higher than those of the polyacetal copolymers and the polyacetal terpolymers. However, the tensile strength does not decrease linearly with a decrease in the crystallinity among the polyacetal polymers with three different structures, the polyacetal homopolymer, the polyacetal copolymers, and the polyacetal terpolymers. Creep rupture was characterized by the activation volume, υ_c, value in Zhurkov's equation, which can be estimated from the slope in the plots of load versus log (rupture time) at 80°C. The polyacetal polymers with higher molecular weight have larger values of the activation volume than those with lower molecular weight. When the activation volume values are compared among the polyacetal polymers with the same molecular weights, they increase in the following order: the polyacetal homopolymers < the polyacetal copolymers < polyacetal terpolymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Proton-conducting electrolyte membranes based on hyperbranched polymer with a sulfonic acid group for high-temperature fuel cells

The hyperbranched polymers (HBP-SA-Acs) with both a sulfonic acid group as a functional group and an acryloyl group as a cross-linker at terminals in different ratios of sulfonic acid group/acryloyl group (SO₃H/Ac) were successfully synthesized as a new thermally stable proton-conducting electrolyte. The cross-linked hyperbranched polymer electrolyte membranes (CL-HBP-SAs) were prepared by thermal polymerizations of the HBP-SA-Acs using benzoyl peroxide, and their ionic conductivities under dry condition and thermal properties were investigated. The ionic conductivities of the CL-HBP-SAs were found to be in the range of 2.2 × 10⁻⁴ to 3.3 × 10⁻⁶ S/cm, depending upon the SO₃H unit contents, at 150 °C under dry condition, and showed the Vogel-Tamman-Fulcher (VTF) type temperature dependence, indicating that proton transfer is cooperated by local polymer chain motion. All CL-HBP-SAs were thermally stable up to 260 °C, and they had suitable thermal stability as electrolyte membranes for the high-temperature fuel cells under dry condition. Fuel cell measurement using a single membrane electrode assembly cell with a cross-linked electrolyte membrane was successfully performed under non-humidified condition. It was demonstrated that applying the concept of dry polymer system to proton conduction is one possible approach toward high-temperature fuel cells.     

Production of Fullerenes by Combustion

The progress in the production of fullerenes from flaming soot is reviewed in terms of the experimental conditions, characteristics in the product distribution, and formation mechanisms.