Development of carbon composite bike fork using finite element analysis and a new pressure molding process

The aim of this study was to develop a new carbon composite part for a road bike. Through finite element analysis, an optimum structure of the bike fork including a lay-up sequence of each ply was obtained. The designed part was manufactured using a new press molding process called a “double blowing process”, which uses dual air bladders to remove voids inside the resin. The mechanical properties of the composite fork were characterized and compared with the analysis results, showing a reasonable agreement between them. The failure analysis was carried out using the Tsai-Wu criterion, demonstrating that the composite bike fork was well designed using the current methodology involving prototype design based on expert knowledge, refined design using finite element method, manufacture of the design part, and comparison between the experiment and simulation.     

New genetic recombination in hypervariable regions of the white spot syndrome virus isolated from Litopenaeus vannamei (Boone) in northwest Mexico

The white spot syndrome virus (WSSV) is a pathogen of great concern to the worldwide shrimp culture. In comparative studies on the WSSV genome, regions such as the open reading frame (ORF) 14–15 and ORF 23–24, prone to deletions and recombination, had been useful to study the evolutive relationships among viral strains. When looking for the WSSV strains infecting Litopenaeus vannamei (Boone) in northwest Mexico, we found evidence of a genetic similarity in ORF 14–15 to a strain from India and a recombination involving ORFs 78, 79 and 80. Two genotypes were found involving the insertion of a 265 base‐pair segment of ORF 108 into ORF 78 with inversions and deletions within ORFs 78, 79 and 80. The WSSV has an Asian origin and the mutations found could be an adaptation strategy to infect L. vannamei and other crustacean species of the American continent.     

Assessing the Relative Contribution of Wastewater Treatment Plants to Levels of Metals in Receiving Waters for Catchment Management

The selection of control measures for reducing metal contamination in rivers has targeted point sources such as wastewater treatment plants (WWTPs) and industrial discharges without a proper evaluation of their relative contribution to metal loads at the catchment level. The necessity of controlling pollutant inputs in a sound and cost-effective way to prevent the deterioration of chemical and ecological quality of receiving waters has highlighted the need for appropriate source assessment. As metals in rivers emanate from a wide range of sources, it is necessary to understand their relative contribution in order to reduce effectively the concentrations in receiving waters. This study presents a simple method for calculating the relative contribution of WWTPs to levels of metals in receiving waters as applied to the Aire?CCalder catchment in the UK. In this catchment, the apportionments to WWTP effluents of metal levels in rivers were 37, 31, 36 and 60?% of total cadmium (Cd), lead (Pb), mercury (Hg) and nickel (Ni), respectively. Spatial metal distribution in rivers with maximum concentrations of 0.47???g?L^?1 for Cd, 8.54???g?L^?1 for Pb, 0.05???g?L^?1 for Hg and 10.17???g?L^?1 for Ni caused by the discharge of WWTP effluents was estimated. The findings demonstrate that the proposed approach using quantification of metal loads and estimation of concentrations in receiving waters could adequately calculate the relative contribution of WWTP effluents to metal levels in receiving waters. Applications to various river catchments using site-specific data would further validate the effectiveness of the approach proposed.     

Analysis of quantitative trait loci associated with leaflet types in two recombinant inbred lines of soybean

Leaf area, length and width affect the photosynthetic capability of a plant and so increasing the photosynthetic rate per unit leaf area may improve seed yield in soybean. In this study, simple sequence repeat (SSR) markers were used to identify the genomic regions significantly associated with the quantitative trait locus (QTL) that controls length, width and the length/width ratio of the terminal and lateral leaflet in two segregating F_2:10 recombinant inbred line (RIL) populations, ‘Keounolkong’ × ‘Shinpaldalkong’ (K/S) and ‘Keounolkong’ × ‘Iksan10’ (K/I). In the K/S population, one QTL was identified for terminal leaflet length (TLL), two for lateral leaflet length (LLL), four for terminal leaflet width (TLW), four for lateral leaflet width (LLW), two for terminal leaflet length/width ratio (TLR) and four for lateral leaflet length/width ratio (LLR), with total phenotypic variations of 7.43, 10.9, 26.57, 23.46, 20.25 and 23.31%, respectively. In the K/I population, two QTLs were identified for TLL, two for LLL, three for TLW, and two for LLW, four for TLR and two for LLR with total phenotypic variations of 29.89, 22.77, 18.5, 12.15, 22.96 and 17.85%, respectively. Only a few QTLs coincided among the leaflet traits and no relationships were observed between the two populations. Many QTLs were associated with leaflet traits but each single QTL made only a minimal contribution. Thus, pyramiding the favourable alleles for leaflet traits in soybean breeding programmes may accelerate vegetative growth and perhaps lead to higher yields by maximizing total photosynthetic performance.     

Comparison of Starch Pasting Properties at Various Cooking Conditions Using the Micro Visco‐Amylo‐Graph and the Rapid Visco Analyser

Pasting profiles of selected starches were compared by using a Micro Visco‐Amylo‐Graph (MVA) and a Rapid Visco Analyser (RVA). Effects of cooking (heating/cooling) rate and stirring speed on starch pasting properties were examined. The pasting viscosity of a starch suspension (8%, w/w, dsb) was measured at a fast (6°C/min) and slow (1.5°C/min) cooking rate while being stirred at either 75 rpm or 160 rpm. The pasting temperatures (PT) of all starches were higher when measured at the fast cooking rate than those at the slow cooking rate, except for wheat measured by using the RVA. PT was also higher when measured at the slow stirring speed (75 rpm) than at the fast stirring speed (160 rpm) in both RVA and MVA. When stirring speed increased from 75 rpm to 160 rpm, peak viscosity of all starch pastes except potato decreased measured by using the RVA, but increased by using the MVA. In general, amylograms of these starches obtained by using the MVA showed less breakdown, but greater setback viscosity than did that obtained by using the RVA. Differences in starch pasting properties between MVA and RVA, measured at the same cooking and stirring rates, were attributed mainly to the difference in spindle structure.     

Physicochemical Properties of Corn Starch Selectively Oxidized with 2,2,6,6‐Tetramethyl‐1‐Piperidinyl Oxoammonium Ion

This study was conducted to examine the characteristics of oxidation reaction on the primary alcohol groups in corn starch, when 2,2,6,6‐tetramethyl‐1‐piperidinyl oxoammonium ion (TEMPO) was used, and to determine the optimum conditions for the preparation of oxidized corn starch (OCS). Applicability of the OCS in the food system was also investigated. The effects of TEMPO, sodium bromide (NaBr), and temperature on oxidation reaction time, yield, and selectivity for primary alcohol groups were examined by response surface methodology. As the temperature and the levels of TEMPO and NaBr increased, reaction time and selectivity decreased. Yield decreased with increased NaBr and selectivity decreased with the increased temperature and NaBr. Selectivity increased with higher TEMPO levels up to a certain point and then decreased. Optimum levels of TEMPO, NaBr, and temperature for the preparation of OCS were determined as 0.6 mM/100 mM of anhydroglucose unit (AGU), 45 mM/100 mM AGU, and 7°C, respectively. Water binding capacity, emulsion stability, and viscosity of starch increased significantly by oxidation. Corn starch containing OCS had decreased initial pasting temperature, setback, and gelatinization and retro‐gradation enthalpy (ΔH). Corn starch gel containing OCS showed delayed staling during storage.