16 research outputs found

    Depithers for Efficient Preparation of Sugar Cane Bagasse Fibers in Pulp and Paper Industry

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    Abstract Among the by-products originated in the agro-industrial process of sugar cane, bagasse is one of the most relevan

    Evaluación de hidrolizados de granos de sorgo y granos de destilería secos con solubles para la producción de transglutaminasa microbiana

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    Sorghum grains can be used as a source of fermentable sugars to reduce the culture media cost for microbial growth of Streptomyces and the production of microbial transglutaminase (MTGase). In the production of ethanol from corn, dried distillers grains with solubles (DDGSs) are generated as waste. The aim of this work is to elucidate the biotechnological production of transglutaminase by Streptomyces mobaraensis NRRL-3191 grown in a medium containing sorghum grains hydrolysates and DDGS is feasible. The results showed that casein has a great effect on the production of MTGase while DDGS did not show any significant effect on the range of study. The model obtained predicts 0.66 U/mL of MTGase activity using enzymatic hydrolysates of sorghum grains supplemented with yeast extract (2 g/L), DDGS (2 g/L), and casein (19.5 g/L)Los granos de sorgo se pueden utilizar como fuente de azúcares fermentables para reducir los costes de medios de cultivo para el crecimiento microbiano de Streptomyces y la producción de transglutaminasa microbiana (MTGasa). En la producción de etanol a partir de maíz, se generan como residuos granos de destilería secos con solubles (DDGS). El objetivo de este trabajo fue determinar si la producción biotecnológica de transglutaminasa por Streptomyces mobaraensis NRRL-3191 cultivados en un medio que contiene hidrolizados de granos de sorgo y DDGS es factible. Los resultados mostraron que la caseína tiene un gran efecto en la producción de MTGasa mientras que DDGS no mostraron un efecto significativo en el intervalo de estudio. El modelo obtenido predice 0.66 U/mL de actividad MTGase usando hidrolizados enzimáticos de granos de sorgo suplementados con extracto de levadura (2 g/L), DDGS (2 g/L) y caseína (19,5 g/L)A scholarship from CONACyT and IPN (Mexico) to G. C. Rodríguez-Castillejos is gratefully acknowledged. The authors are grateful for the financial support from the co-ordinator of Fundación Produce A.C.S

    Stress and worry in the 2020 coronavirus pandemic: Relationships to trust and compliance with preventive measures across 48 countries in the COVIDiSTRESS global survey

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    The COVIDiSTRESS global survey collects data on early human responses to the 2020 COVID-19 pandemic from 173 429 respondents in 48 countries. The open science study was co-designed by an international consortium of researchers to investigate how psychological responses differ across countries and cultures, and how this has impacted behaviour, coping and trust in government efforts to slow the spread of the virus. Starting in March 2020, COVIDiSTRESS leveraged the convenience of unpaid online recruitment to generate public data. The objective of the present analysis is to understand relationships between psychological responses in the early months of global coronavirus restrictions and help understand how different government measures succeed or fail in changing public behaviour. There were variations between and within countries. Although Western Europeans registered as more concerned over COVID-19, more stressed, and having slightly more trust in the governments' efforts, there was no clear geographical pattern in compliance with behavioural measures. Detailed plots illustrating between-countries differences are provided. Using both traditional and Bayesian analyses, we found that individuals who worried about getting sick worked harder to protect themselves and others. However, concern about the coronavirus itself did not account for all of the variances in experienced stress during the early months of COVID-19 restrictions. More alarmingly, such stress was associated with less compliance. Further, those most concerned over the coronavirus trusted in government measures primarily where policies were strict. While concern over a disease is a source of mental distress, other factors including strictness of protective measures, social support and personal lockdown conditions must also be taken into consideration to fully appreciate the psychological impact of COVID-19 and to understand why some people fail to follow behavioural guidelines intended to protect themselves and others from infection. The Stage 1 manuscript associated with this submission received in-principle acceptance (IPA) on 18 May 2020. Following IPA, the accepted Stage 1 version of the manuscript was preregistered on the Open Science Framework at https://osf.io/g2t3b. This preregistration was performed prior to data analysis

    Electrochemical Assessment Of Steel Concrete Reinforced System Modified whit Natural Fiber for ITS Anticorrosion Protection

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    The deterioration in the steel-concrete structures is mainly due to chloride contamination, which causes corrosion problems that occasionally leads its partial or total destruction. In this work we propose adding fibers bagasse of sugar cane to the steel-concrete reinforced system. with the objective of provide the corrosion protection. Meanwhile, the sugar cane bagasse is the residue fibrous lingo-cellulosic remaining after grinding stalks the sugar cane at the mill to extract the juice

    Role of Preparation Method on the Microstructure and Mechanical Properties of PPy/Ni Organic–Inorganic Hybrid Bilayer Coatings on Carbon Steel

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    © 2015, The Minerals, Metals & Materials Society and ASM International. The efficacy of the conducting polymers as coating on a metallic substrate is strongly dependent on the manner how they are applied. Polypyrrole (PPy)/Ni organic–inorganic hybrid coatings were electropolymerized on commercial carbon steel (AISI 1018) by combining potentiostatic and potentiodynamic techniques. In first instance, it was analyzed the electrodeposition of PPy using a constant potential regime and cyclic voltammetry techniques evaluating different synthesis parameters such as deposition time, applied potential, and potential cycles, respectively. Thereafter, it was used a potentiostatic method to obtain PPy/Ni bilayer films. The morphological, mechanical, and adhesion properties of these films depend on the synthesis parameters. The results revealed that polypyrrole films formed by both methods provide a globular-type structure, although coatings produced by cyclic voltammetry are denser and slightly thicker than those produced potentiostatically. Ni (oxide/hydroxide) particles are capable of sealing the pores of globular PPy coatings, thus increasing the hardness of the carbon steel (CS)/PPy/Ni system. As a result of the study, we have seen that PPy/Ni bilayer films are more uniform, compact and enhanced the hardness when the PPy is obtained by cyclic voltammetry than that observed for potentiostatic approach. Specifically, when four potential cycles are used to electropolymerized pyrrole, the more convenience properties in the CS/PPy/Ni arrangement are obtained.The authors acknowledge the financial support provided by CONACYT through the 133618 and 132660 projects, SIP-IPN 2014-0992, 2014-0164, and SNI-CONACYT.Peer Reviewe

    Functionality of TERGO Powders during the Synthesis of PANI-Based Composites for Electrical Devices

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    In this work, hybrid composites were prepared using polyaniline (PANI) and electrochemically reduced graphene oxide (ERGO) by in situ polymerization. ERGO powders were obtained by a two-way route, Hummer’s method, and one-step potential (−2 V) followed by annealing process at 400°C (TERGO powders): different quantities of TERGO fine particles (10, 20, and 30 wt%) were added to the in situ PANI polymerization in order to produce the hybrid composites. The morphology and structure of the PANI/TERGO compounds were characterized by Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermal treatment of ERGO powders pointed out high-defect surfaces with a wrinkle-type morphology (ID/IG ratio~0.90). The emeraldine phase of PANI was obtained with a maximum value of 61%, which decreases with the amount of TERGO powders. It is also seen that composites displayed a combined morphology between PANI matrix and TERGO powders, confirming a physical interaction between both morphologies. The amount of TERGO particles into the polymeric matrix also modifies the sample microstructure from a semispherical shape to extend sheets, where PANI is sandwiched between TERGO layers. Electrical conductivity of composites slightly increases independent of the TERGO amount (30 S/m and 39 S/m) due to the rough TERGO surface that conditioned the homogeneous nucleation of a large amount of polymer (PANI) reducing the area to move the electrical charge
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