Browsing by Publisher "North Carolina State University"

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    Ethanol production from vineplant waste hydrolysate sugars by native yeast strains
    (North Carolina State University, 2019) Kaya E.Ö.; Doğan Y.; Yalçin H.T.
    Biomass from agricultural waste can be an excellent source of sustainable energy, the most notable of which is bioethanol. This study aimed to adapt and improve bioethanol production using a yeast strain that ferments the sugar content in undiluted and non-added nutrient vineplant bunch hydrolysates. Yeasts that were previously isolated and molecularly characterized were screened for their pentose fermenting capabilities, first in solid and then liquid mediums. Then, 10 native xylose fermenting yeast strains were tested for their ability to produce ethanol from acid hydrolysates from vineplant lignocellulosic waste. The five strains that exhibited the highest ethanol production underwent fermentation in the pure (non-detoxified) hydrolysate. The strain Pichia kudriavzevii D12 in the undiluted hydrolysate medium gave the highest ethanol concentrations and yields. Hence, P. kudriavzevii was selected for adaptation with sequential fermentations. As a result, a 59% increase in the ethanol production (g/L) was recorded for the D12 strain in the undiluted hydrolysate medium during the adaptation studies. A 2.9-fold increase in the yield (g/g) was obtained for this sample when compared with the reference medium. This study determined that a nondetoxified, organic waste medium prepared from vineplant bunches without added nutrients is a suitable substrate alternative for bioethanol production. © 2018, BioResources.
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    Preparation and Characterization of Hydroxyethyl Cellulose/Nanolignin Composite Films
    (North Carolina State University, 2024) Zor M.; Yazici H.; Şen F.; Eroğlu E.; Candan Z.; Rodrigue D.; Wang X.
    Hydroxyethyl cellulose/nanolignin composite films were prepared and characterized. The composite films were produced via casting of synthesized nanolignin added to hydroxyethyl cellulose at different concentrations (2.5%, 5%, 10%, and 20% by mass). A control film without nanolignin was also prepared for comparison. The thermal properties of the composite films were examined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), while the mechanical properties were determined by tensile testing and the surface properties were determined by water contact angle measurements. In addition, the morphologies of the samples were examined by scanning electron microscopy (SEM). It was observed that with the addition of nano lignin, the glass transition temperature of the composite films increased from 109 °C to 262 °C; the elongation at break increased from 19% to 51%; and the contact angles increased from 53 °C to 73 °C. The results showed that the presence of nanolignin produced materials being more flexible and more hydrophobic with higher glass transition temperatures. © 2024, North Carolina State University. All rights reserved.