• Energy Research
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A procedure is described that allows the rapid determination of ethanol in a wide variety of alcoholic beverages. Dynamic headspace analysis is employed and a fuel cell sensor is used for the quantitative determination of ethanol. The method is rapid and compares favourably in accuracy with distillation and gas-chromatographic procedures.

A theoretical model for simulation of conventional steam-heated cylinder dryers is developed by considering the heat and mass transfer in a porous sheet during drying. Expressions for sheet shrinkage as a function of mass of water removed and for reductions in sheet porosity are derived for inclusion in the model. The interface thermal contact conductance of moist paper handsheet/metal interfaces has been experimentally investigated. A resulting empirical correlation, representing the thermal contact conductance between the cast iron dryer surface and paper web, is incorporated into the drying simulation model to reflect reductions in heat input to the sheet during drying. Finite difference techniques are used to obtain the numerical solutions. Average sheet moisture content and temperature along the length of the dryer section as well as average evaporation rates per cylinder are predicted by the model. Consideration of the internal dynamics of the drying process allows profiles of sheet moisture content, temperature, liquid flux, and vapor flux through the sheet thickness to be developed throughout the dryer section. Drying results are consistent with actual production cases. The model can be used to design dryer sections, study changes in operating conditions or in layout of a multi-cylinder dryer, or simulate the application of enhanced drying devices to a conventional drying section. The effect of the drum/paper contact conductance on drying rates and resultant dryer section requirements is provided as an example application of the model.

Abstract A novel approach to the intensification of renewable and sustainable production of photoautotrophic ethanol from microalgae was investigated using periodic ultrasonication. The effect of utilizing ultrasonic pulsing during ethanol production using a metabolically engineered ethanol producing cyanobacterium Synechocystis PCC6803 strain NAV001 was analysed with an ultrasonic frequency of 20 kHz. Ultrasonic treatment resulted in enhancement of ethanol yields. The ethanol yield was found to be higher when ultrasonic pulsing was initiated during the exponential phase of growth. The optimum ultrasonic conditions for enhanced yield of ethanol within this model system was found to be 30 °C, 15% of power input (97.5 W) and 10 min pulse time. The cytotoxic effect of ultrasonic pulsation was investigated by analysing the survival percentage and auto-fluorescence of the cyanobacterium via imaging by confocal laser scanning microscopy. The overall effect of ultrasonic dose on ethanol production and growth rate of microalgae was analysed by using Haldane inhibition kinetics.

AbstractThis study aimed to enhance the properties of films produced from corn starch and gelatin recovered from chrome (III) tanned leather waste (CTLW) through the addition of transglutaminase enzyme (TGase) and phenolic extracts from Spirulina platensis (PESP). Mechanical, chemical, physical, and biological properties were analyzed and compared with control films elaborated in the same conditions but with commercial gelatin (COM). The possibility of applying the film as soil cover was analyzed through its degradation when exposed to the surface of a garden soil for a period of 60 days. The TGase caused a reduction of 50% in solubility in water, and 2% in the water vapor permeability (PWV), and PESP caused a reduction of 17% in solubility and 15% in PWV. The combined effect of TGase and PESP was a 60% reduction in solubility, 75% reduction in PWV, inhibition of contamination by Aspergillus niger, and reduction of film degradation on soil covering, evidenced by stability analysis using Fourier transform infrared (FTIR) spectrometry. The combined effect of TGase with PESP led to an improvement in the characteristics of the film produced with CTLW gelatin, rendering its application possible due to a higher lifespan, contributing to environmental sustainability and diminishing leather waste disposal at landfills. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

In this work the compound obtained from yeast culture extract (YCE) that stimulated the activity of an anaerobic cellulolytic consortium (ACC) was characterized. YCE were obtained at different pH (4, 7 and 10) and ultra-filtered 300 and 30 kDa membranes (UYE). The 30 kDa UYE was heated to 60 °C, 90 °C and 120 °C and gel filtered (GYF). Mid infrared spectroscopy, protein and carbohydrate analysis of GYF were conducted. Results showed that YCE, UYE and GYF significantly stimulated (p < 0.05) the biomass production, acetate concentration and carboxymethyl cellulase activity of the ACC, in relation to the control. The GYF had an estimated molecular mass of 4 kDa. Mid-infrared and biochemical analysis of GYF suggested that the active compound is a peptide.

Body condition score (BCS), energy content (EC), cumulative effective energy balance (CEEB), and blood serum concentrations of glucose, beta-hydroxybutyrate (BHBA), and nonesterified fatty acids (NEFA) were measured throughout first lactation in 497 Holstein cows raised on a large commercial farm in northern Greece. All these traits are considered to be indicators of a cow's energy balance. An additional measure of BCS, EC, and blood serum glucose, BHBA, and NEFA concentrations were taken approximately 2 mo (61 +/- 23 d) before first calving. During first lactation, first service conception rate, conception rate in the first 305 d of lactation, interval from calving to conception, number of inseminations per conception, incidence of metritis, and incidence of reproductive problems of these cows were recorded; interval between first and second calving, and second lactation first service conception rate were also recorded. Random regression models were used to calculate weekly animal breeding values for first lactation BCS, EC, CEEB, glucose, BHBA, and NEFA. Single trait animal models were used to calculate breeding values for these traits measured on pregnant heifers before calving. Reproductive records were then regressed on animal breeding values for these energy balance-related traits to derive estimates of their genetic correlations. Several significant estimates were obtained. In general, traits that are known to be positively correlated with energy balance (BCS, EC, CEEB, and glucose) were found to have a favorable genetic relationship with reproduction, meaning that increased levels of the former will lead to an enhancement of the latter. On the other hand, traits known to be negatively correlated with energy balance (BHBA and NEFA) were found to have an unfavorable genetic association with reproductive traits. Body condition score, BHBA, and NEFA recorded early in lactation, and glucose concentrations measured in pregnant heifers had the highest genetic correlation with future reproductive performance. Results suggest that genetic selection for body energy and blood metabolites could facilitate the genetic improvement of fertility and overall reproductive efficiency of dairy cows.

Changes in the physicochemical composition of wine vinegars produced by submerged culture system and aged in wood were followed. Five Sherry wine vinegars and a model vinegar solution were aged in six new American oak butts of 16.6 L capacity. A total of 24 phenolic compounds were monitored during the maturation study (24 months), along with other physicochemical parameters (total extract, acidity, residual alcohol and total phenolic index). Multivariate statistical analysis was applied to the data. From the sixth month on, significant changes were produced in most of the phenolic compounds, mainly aromatic aldehydes and 5-(hydroxymethyl)-2-furaldehyde. When all the phenolic compounds were considered as variables, cluster analysis grouped samples according to the wine substrate employed in the elaboration of vinegars under study. Within each subcluster, samples are arranged according to their aging status when phenolic compounds accounting significative changes at 180 days of aging are considered. Discriminant functions were constructed from the phenolic compounds data set. The validity of these functions was tested using 13 samples of aged commercial Sherry wine vinegars and 25 unaged vinegars. A total of 97.4% of the test samples was correctly classified within its respective group.

En Ecuador se propuso desde el 2010 como una meta a corto plazo incorporar 5% de bioetanol a la gasolina, a través del proyecto Ecopaís. Entre los objetivos de este proyecto está reducir la salida de divisas, ahorrar en subsidios, fomentar el empleo agrícola e industrial, disminuir las emisiones de CO2, entre otros. A la fecha la gasolina con 5% de bioetanol ha llegado solo a algunas provincias. Para lograr cubrir todo el país se requiere elevar la producción de bioetanol. La provincia de Chimborazo, ubicada en la sierra central de Ecuador, es una provincia con vocación agrícola, y en 2016 fue la provincia con mayor extensión de cultivo de papa en el país, duplicando la producción del rubro en comparación al 2015, lo que generó una sobreproducción y a su vez una disminución del 50% del precio de la papa en el mercado, ocasionando una significativa reducción de los ingresos a los productores. En la búsqueda de usos alternativos de la papa, se propuso evaluar la potencialidad de la provincia para la obtención de bioetanol a partir de este cultivo. Es por ello que se realizó una revisión de los principales aspectos que permitirían desarrollar esta actividad como lo son las características económicas-sociales de la provincia, producción de papa y la sustentabilidad de la producción de bioetanol. Se obtuvo a partir de cálculos teóricos, que del procesamiento de solo un 1% de la producción de la papa se podrían alcanzar volúmenes de bioetanol similares a los aportados por la provincia Cañar al proyecto Ecopaís. En términos generales, la provincia presenta un panorama favorable para el desarrollo de proyectos de producción de bioetanol a partir de la papa. Palabras clave: papa, bioetanol, Ecopaís. ABSTRACT: In Ecuador, it was proposed from 2010 as a short-term goal to incorporate 5% of bioethanol into gasoline, through the Ecopais project. Among the objectives of this project is to reduce the outflow of foreign exchange, save on subsidies, encourage agricultural and industrial employment, reduce CO2 emissions, among others. At this moment only some provinces count on gasoline with 5% of bioethanol. In order to cover the whole country, it is necessary to increase the production of bioethanol. The Chimborazo province, located in the sierra region of central Ecuador, is a province with an agricultural vocation, and in 2016 it was the province with the largest extension of potato cultivation in the country, doubling its production compared to 2015, which led to an overproduction and a 50% decrease in the price of potatoes in the market, causing a reduction in the economic income of producers. In the search for alternative uses of the potato, it was proposed to evaluate the potential of the province to obtain bioethanol from this crop. That is why a review of the main aspects that would allow this activity to be developed, such as the economic-social characteristics of the province, potato production and the sustainability of bioethanol production. It was obtained from the theoretical calculations that the processing of only 1% of the potato production was converted into bioethanol volumes similar to those contributed by the Cañar province to the Ecopaís project. In general terms, the province presents a favorable scenario for the development of bioethanol production projects from the potato. Key words: potato, bioethanol, Ecopais.