Characterization of Dairy Waste Whey and Its’ Utilization for the Production of Ethanol
Issue:
Volume 9, Issue 5, September 2021
Pages:
112-118
Received:
24 August 2021
Accepted:
8 September 2021
Published:
23 September 2021
Abstract: The objective of this study was characterization of dairy waste whey and its’ utilization for the production of ethanol. Whey is a byproduct and not considered as a resource in many milk processing factories. Usually, it is discharged to rivers and surface water. The physiochemical characteristics of whey was determined by Lactoscan Milk Analyzer, Refractometer and Titration Methods. Dairy whey consisted of biological oxygen demand and chemical oxygen demand. It represents largely disaccharide sugar content which is known as lactose (0. 36 – 0. 48) g/mL and it could highly pollute the environment or water bodies. However, this whey waste was changed into ethanol by yeast strain, kluyveromyces delphensis. The experimental design was studied with central composite design to investigate the effects of significant factors including initial lactose concentration, yeast cell concentration, temperature and pH value on fermentation process. In the present work, the best operating conditions were found at 6.15g/L (initial lactose conc.), 10g/L (yeast cell conc.), 27oC (temperature) and 5.5 pH value respectively. The maximum ethanol yield obtained from cheese whey was 40.4 % (2.5g/L). Functionally, ethanol was determined by Fourier Transmission Infrared with the help of Infrared correlation charts and moreover, its characteristic was investigated. As a result, cheese whey is a good resource for a production of ethanol.
Abstract: The objective of this study was characterization of dairy waste whey and its’ utilization for the production of ethanol. Whey is a byproduct and not considered as a resource in many milk processing factories. Usually, it is discharged to rivers and surface water. The physiochemical characteristics of whey was determined by Lactoscan Milk Analyzer, ...
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On Novel Aspects of Hydrogen Effects on Applied Stress - Coupled Micromagnetic Activity in a Mild Steel After Exposure to NaCl – Water Solution: A Combined Approach
Victor Kytopoulos,
Alexandros Altzoumailis
Issue:
Volume 9, Issue 5, September 2021
Pages:
119-133
Received:
13 March 2021
Accepted:
27 March 2021
Published:
30 October 2021
Abstract: Hydrogen produced after exposure of a low – carbon steel to corrosive NaCl – Water solution may affect various its tensile mechanical and magnetic microstructural behaviour in a complex manner. This was investigated by introducing a relevant micromagnetic specific emission (ME) - response of this ferromagnetic material, where related processes and parameters of micromagnetic activity and mechanical response were implemented. In this manner, it was demonstrated that an increase in the hydrogen accumulation with corrosion time leads to an associated increase in the embrittling effect expressed by a substantial loss in the ductility of material. The competive and opposing effects of cumulative hydrogen, applied stress and plastic strain – induced microstructural damage were related to the specific ME- response parameter by which an increased magnetic hardening tendency of material with corrosion time was possible to establish. In this fashion and by using a stress as well as strain mode of presentation- aided combined approach, the complex interplay between micromagnetic activity, hydrogen accumulation and applied stress-strain was better revieled and analysed. It was also shown that the embrittlement is a product of hydrogen accumulation introduced by two highly localized processes. As such, accumulation occurs in two characteristic parallel ways: one of a common lattice diffusion and one of hydrogen transport and redistribution by moving dislocation towards the affected sites. Concerning the highly localized effects the dominating role of hydrogen – induced damage in form void initiation and growth over the hydrogen – assisted stress relief was reasonably demonstrated by using a simple modelling approach. Based on a mechanism of moving dislocation – assisted interaction between commulative hydrogen and magnetic domain walls, a Portervin – Le Chatelier – type micromagnetic process of a cooperative-corelated domain wall transport was proposed to explain certain subtle, quasiperiodic behaviour of ME- response. In the frame of the above findings the superior sensivity of ME – response compared to the mechanical one in early detecting cumulative hydrogen – assisted microstructural damage changes can be d educed.
Abstract: Hydrogen produced after exposure of a low – carbon steel to corrosive NaCl – Water solution may affect various its tensile mechanical and magnetic microstructural behaviour in a complex manner. This was investigated by introducing a relevant micromagnetic specific emission (ME) - response of this ferromagnetic material, where related processes and ...
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