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Daneshvar S.,Osaka Prefecture University | Hidemi N.,National Institute of Technology, Nara College | Salak F.,Nara Prefecture Institute of Industrial Development | Mahinpey N.,University of Calgary
Canadian Journal of Chemical Engineering | Year: 2014

Decolourisation and decomposition of acid orange 7 as a model for textile wastewater was performed under subcritical water conditions in the presence of hydrogen peroxide. Hydrogen peroxide showed very efficient activity for decolourisation of AO7. Complete decolourisation temperature of AO7 declined from 275 to 135°C when a sufficient amount of hydrogen peroxide was used in the reaction medium. The effects of several other parameters were also investigated. Reaction time as well as the initial amount of hydrogen peroxide showed great effect on the decolourisation and decomposition reactions. At the higher temperatures, it was found utilising UV/Vis scanning spectra that the dye decomposed into very small molecules and gaseous products; consequently, total organic carbon (TOC) amount of the solutions after subcritical water treatment significantly declined. The reactions carried out without formation of any solid materials. At the optimum conditions treatment of several different types of dyes were also investigated. © 2013 Canadian Society for Chemical Engineering.

Miki Y.,Nara Prefecture Institute of Industrial Development | Nishimoto A.,Kansai University | Sone T.,Asahi Heat Treatment Corporation | Araki Y.,KAIBARA Corporation
Surface and Coatings Technology | Year: 2015

Diamond-like carbon (DLC) films were prepared and their residual stresses were measured nondestructively using Raman microprobe spectroscopy. The plasma-based ion implantation and deposition (PBIID) method was used to coat the DLC films on thin glass substrates using acetylene, a mixture of acetylene and toluene, or only toluene gas at 1.0Pa. Peaks in the Raman spectra of the DLC films were assigned as the D'(disordered) or C-C bonding peaks at 1150cm-1. The phonon deformation potentials (a') of the films were estimated from data for the phonon deformation potentials for pure graphite and diamond and calculated using the sp3/sp2 bonding ratio and the hydrogen content of the films. Thus, a relation was observed between the Raman shift of the G peak (ωG) and the residual stress (σc) in each film. The Raman shifts (ω0) of the G peak for the films with no deformation were 1554, 1556, and 1562cm-1 for the films deposited using acetylene, a mixture gas and toluene gas. Moreover, only toluene had stress constants of -0.378, -0.384, and -0.391GPa/cm-1. The residual stresses constant in each film using (8.2×10-4·a')-1ω0-1 were estimated as -0.379, -0.384, and -0.391GPa/cm-1. The Raman shift of the D peak remained stationary as the compressive σc in the films increased but changed when the deposition gas was varied. The distance the D peak moved from 1420cm-1 corresponded to that of the G peak from 1560cm-1 in the Raman spectra of the films in the stress-free state. In addition, the compressive residual stress in the DLC film had a major impact on the hardness. © 2015 Elsevier B.V.

Takagi H.,Nara Institute of Science and Technology | Hashida K.,Nara Institute of Science and Technology | Watanabe D.,Nara Institute of Science and Technology | Nasuno R.,Nara Institute of Science and Technology | And 4 more authors.
Journal of Bioscience and Bioengineering | Year: 2015

Awamori shochu is a traditional distilled alcoholic beverage made from steamed rice in Okinawa, Japan. Although it has a unique aroma that is distinguishable from that of other types of shochu, no studies have been reported on the breeding of awamori yeasts. In yeast, isoamyl alcohol (i-AmOH), known as the key flavor of bread, is mainly produced from α-ketoisocaproate in the pathway of l-leucine biosynthesis, which is regulated by end-product inhibition of α-isopropylmalate synthase (IPMS). Here, we isolated mutants resistant to the l-leucine analog 5,5,5-trifluoro-dl-leucine (TFL) derived from diploid awamori yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular l-leucine, and among them, one mutant overproduced i-AmOH in awamori brewing. This mutant carried an allele of the LEU4 gene encoding the Ser542Phe/Ala551Val variant IPMS, which is less sensitive to feedback inhibition by l-leucine. Interestingly, we found that either of the constituent mutations (LEU4S542F and LEU4A551V) resulted in the TFL tolerance of yeast cells and desensitization to l-leucine feedback inhibition of IPMS, leading to intracellular l-leucine accumulation. Homology modeling also suggested that l-leucine binding was drastically inhibited in the Ser542Phe, Ala551Val, and Ser542Phe/Ala551Val variants due to steric hindrance in the cavity of IPMS. As we expected, awamori yeast cells expressing LEU4S542F, LEU4A551V, and LEU4S542F/A551V showed a prominent increase in extracellular i-AmOH production, compared with that of cells carrying the vector only. The approach described here could be a practical method for the breeding of novel awamori yeasts to expand the diversity of awamori taste and flavor. © 2014 The Society for Biotechnology, Japan.

Gotoh K.,Nara University | Nakatani H.,Nara University | Tsujisaka T.,Nara Prefecture Institute of Industrial Development
Textile Research Journal | Year: 2015

Ultrasonic cleaning in aqueous solutions was performed using various plain-woven fabrics soiled with oleic acid and/or carbon black as model oily and particulate contaminants. Detergency, which was evaluated from the change in the surface reflectance of the soiled fabrics due to cleaning, was promoted by applying ultrasound as the mechanical action for soil removal in the absence and the presence of anionic surfactant. Both soils were removed easily from the filament fabrics compared with the spun fabrics. Ultrasound, as mechanical action, was favorable for removing carbon black even in the absence of surfactant, whereas the addition of surfactant was effective for removing oleic acid without and with ultrasound. In most cases of soiled fabrics, the detergency obtained with ultrasonic washing for 1 min was comparable to that obtained with a drum-type washer, the Wascator (normal and gentle procedures). Heavy fabric damage was observed after washing with the Wascator, especially for the wool and silk fabrics, whereas there was little damage after ultrasonic washing for all fabrics. Conclusively, ultrasound can be effective in laundering for delicate textiles from the viewpoints of the processing time as well as detergency performance. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav

Gotoh K.,Nara University | Horibe K.,Nara University | Mei Y.,Nara University | Tsujisaka T.,Nara Prefecture Institute of Industrial Development
Journal of Oleo Science | Year: 2016

The effects of water hardness on textile detergency in aqueous solutions were systematically investigated using four surfactants: sodium oleate (OLNa), linear dodecylbenzene sulfonate (LAS), sodium dodecyl sulfate (AS), and polyoxyethylene (10) dodecyl ether (AE). Water hardness was adjusted according to the standard procedure described in IEC 60734:2012. As expected, by adding hardness salts the surface tension of the OLNa solution increased. Surprisingly, the addition of hardness salts lowers the surface tension for the LAS and AS solutions. In the case of the AE solution, hardness salt did not affect the surface tension. A decrease in transmittance and foamability after adding hardness salts was observed for every anionic surfactant solution, indicating that anionic surfactants can combine with divalent ions to form insoluble precipitates. Detergency experiments were performed using cotton plain-woven and towel fabrics soiled with a carbon black and oleic acid mixture. One piece each of untreated and soiled fabric were stacked and placed horizontally in detergent solution with or without hardness salts. As a mechanical action of soil removal, the shaking of 190 spm was applied. Soil removal and redeposition due to washing were evaluated from changes in values of the Kubelka–Munk function for both fabrics. With increasing water hardness, soil removal decreased and redeposition increased. In order of decreasing detergency, the surfactants were as follows: LAS> OLNa ≈ AS> AE. The results indicate that precipitates, formed by reaction of LAS or AS with hardness salts, are strongly adsorbed on the water surface because of their hydrophobicity, but they have no detergency power. The field emission scanning electron microscopic observation and X-ray photoelectron spectroscopic analysis showed that Ca(LAS)2 precipitation clung to fiber surfaces, and remained on the surfaces after washing. Significant changes in the cotton fabric due to washing were observed in mechanical properties and water absorbency. © 2016 by Japan Oil Chemists’ Society.

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