450 research outputs found
Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and Liquid Chromatography-Multiplexed Collision Induced Dissociation-Mass Spectrometry
No full textThermochemical pretreatment of cellulosic biomass improves cell wall enzymatic digestibility, while simultaneously releasing substantial amounts of soluble oligosaccharides. Profiling of oligosaccharides released during pretreatment yield information essential for choosing glycosyl hydrolases necessary for cost-effective conversion of cellulosic biomass to desired biofuel/biochemical end-products. In this report we present a methodology for profiling of soluble neutral oligosaccharides released from ammonia fiber expansion (AFEXTM)-pretreated corn stover. Our methodology employs solid phase extraction (SPE) enrichment of oligosaccharides based on porous graphitized carbon (PGC), followed by high performance liquid chromatography (HPLC) separation using a polymeric amine based column (Prevail Carbohydrate ES) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) in both positive and negative modes. For structural elucidation on the chromatographic time scale, nonselective multiplexed collision-induced dissociation was performed for quasi-simultaneous acquisition of accurate molecular and fragment masses of neutral oligosaccharids in a single analysis. These analyses directly revealed presence of glucans up to degree of polymerization (DP) 22 without side-chain modifications. Additionally, arabinoxylans with DP up to 6 were detected in the pretreated biomass samples (post-enzymatic digestion). All linkages between sugar units in glucans and arabinoxylans were identified to be p-1-4 linkages based on cross-ring fragment masses. Comprehensive profiling of soluble oligosaccharides also demonstrated that arabinoxylan acetylation was reduced by greater than 85% post-AFEXTM treatment.Published version: Vismeh, Ramin, Humpula, James F., Chundawat, Shishir P. S., Balan, Venkatesh, Dale, Bruce E. & Jones, A. Daniel. (2013). Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and LC-TOF MS. Carbohydrate Polymers 94(2), 791-799. http://dx.doi.org/10.1016/j.carbpol.2013.02.00
Probing the nature of AFEX-pretreated corn stover derived decomposition products that inhibit cellulase activity
No full textSequential fractionation of AFEX-pretreated corn stover extracts was carried out using ultra-centrifugation, ultra-filtration, and solid phase extraction to isolate various classes of pretreatment products to evaluate their inhibitory effect on cellulases. Ultra-centrifugation removed dark brown precipitates that caused no appreciable enzyme inhibition. Ultra-filtration of ultra-centrifuged AFEX-pretreated corn stover extractives using a 10 kDa molecular weight cutoff (MWCO) membrane removed additional high molecular weight components that accounted for 24–28% of the total observed enzyme inhibition while a 3 kDa MWCO membrane removed 60–65%, suggesting significant inhibition is caused by oligomeric materials. Solid phase extraction (SPE) of AFEX-pretreated corn stover extractives after ultra-centrifugation removed 34–43% of the inhibition; ultra-filtration with a 5 kDa membrane removed 44–56% of the inhibition and when this ultra-filtrate was subjected to SPE a total of 69–70% of the inhibition were removed. Mass spectrometry found several phenolic compounds among the hydrophobic inhibition removed by SPE adsorption.Published version: Humpula, James F., Uppugundla, Nirmal, Vismeh, Ramin, Sousa, Leonardo, Chundawat, Shishir P. S., Jones, A. Daniel, Balan, Venkatesh, Dale, Bruce E. & Cheh, Albert M. (2014). Probing the nature of AFEX-retreated corn stover derived decomposition products that inhibit cellulase activity. Bioresource Technology 152, 38-45. http://dx.doi.org/10.1016/j.biortech.2013.10.08
Balan?a adaptada para aulas experimentais inclusivas de Qu?mica
No full textCom a inclus?o de alunos com necessidades especiais em salas de aula da rede regular de ensino, novas metodologias de ensino t?m sido propostas para facilita??o do processo de ensino-aprendizagem para esta nova classe de alunos. No que diz respeito a alunos com baixa ou nenhuma vis?o, a utiliza??o de recursos como grafia braille, material em alto-relevo e uso de tecnologias assistivas como softwares e teclados de leitura de telas de computadores, calculadoras sonoras, linhas braile, entre outras, t?m permitido a facilita??o da inclus?o destes alunos em salas de aula de ensino regular. Para o ensino de Qu?mica, estes recursos facilitam a assimila??o do conte?do te?rico apresentado em sala, mas pouco ajudam no desenvolvimento de habilidades pr?ticas. Assim, situa??es que para alunos normovisuais s?o simples como a medida de pesos de materiais e medidas de volumes de l?quidos s?o impratic?veis por alunos n?o videntes por falta de instrumenta??o adequada. Desta forma, o objetivo deste trabalho foi desenvolver metodologias de medidas de massas de s?lidos e volumes de l?quidos utilizando-se uma balan?a adaptada para uso por alunos n?o videntes de modo a permitir que estes possam desenvolver aulas experimentais que necessitem medidas de pesos e de volumes de l?quidos. As metodologias foram desenvolvidas por um aluno n?o vidente de um curso de licenciatura em Qu?mica de n?vel superior e podem ser aplicadas em salas de aula de n?vel m?dio. Com a mesma foi poss?vel ao aluno n?o vidente medir massas de s?lidos e de l?quidos e preparar solu??es dentro da precis?o permitida pela balan?a (?0,25g). Al?m do car?ter cognitivo relativo aos conhecimentos adquiridos pelo aluno, outros aspectos como quebra de paradigmas quanto ao ensino de qu?mica experimental para alunos n?o videntes e melhoria da autoestima do aluno foram observados
Changing portrayal of a woman in Bollywood cinema: special reference of movies of Vidya Balan
No full textBollywood cinema had a stereotype image of woman in its movies since the beginning. Women were loaded with the patriarchal values. There portrayal matched with the image of woman which the society had in its mind like that of Sita and Radha (Hindu goddesses). Majority of the roles were those of obedient housewives or obedient daughters.
In the last decade i.e. after 2010, in India, there are more women centric films with women in leading and meaningful roles like Highway (2004, Imtiaz Ali), No one killed Jessica (2011, Raj Kumar Gupta), Kahani (2012, Sujoy Ghosh), Mardani (2014, Pradeep Sarkar, Pink (2016, Aniruddha Roy Chowdhury), Chhapaak (2020, Meghna Gulzar) Thappad (2020, Anubhav Sinha) etc. These movies also have special messages for the Indian masses, and they are helpful in bringing positive changes in the society.
This change is interactive in nature. The changing scenario has made much more space for and options for women in cinema and at same time such cinema can be a useful tool in bringing positive changes in society and that too at a fast pace. These changes as well as this interactive nature need to be properly assessed. The impact of these movies can be used for gender sensitization. Some important events that took place in India will also be summarized as they are catalyst to production of women-centric movies in India.
We will review the famous women-centric movies from that focused on representing strong women and their specific achievements. Comparative study of these movies, film reviews, interviews of stars and actors/actresses as well as various articles and books are consulted for this study. Ultimately, through my research and readings, I will conclude that Bollywood Industry has been finally successful in giving proper roles to the Indian actresses. Also, actresses like Vidya Balan have done highly commendable work that has brought glory to heroines. I chose to include Vidya Balan in this Capstone Research as she is a trendsetter when it comes to top women- centric movies in India like Kahani (2012, Sujoy Ghosh) and Dirty Picture (2011, Milan Luthria).M.A.Includes bibliographical reference
Essays on river mechanics
No full textCER89-90-PYJ-14.Presented by the Graduate Students in CE 717 River Mechanics (Spring 1990).Instructor: P. Y. Julien.Includes bibliographical references.May 1990.Predicting Sediment Yield of a Watershed by Margaret Tauzer -- Particle Entrainment by River Flows by Kathy Chase -- Bed Forms and Resistance to Flow by Yasser Raslan -- An Examination of the Dynamic Loop Rating Curve in Alluvial Rivers by Phil G. Combs -- Scour Downstream of Hydraulic Structures by T. K. Burke -- Distorted Physical Hydraulic Models, Theory and Practice by Fred L. Ogden -- Life Expectancy of Reservoirs by T. G. Anthony Balan
Rapid quantification of major reaction products formed during thermochemical pretreatment of lignocellulosic biomass using GC–MS
No full textAccurate quantification of reaction products formed during thermochemical pretreatment of lignocellulosic biomass would lead to a better understanding of plant cell wall deconstruction for production of cellulosic biofuels and biochemicals. However, quantification of some process byproducts, most notably acetamide, acetic acid and furfural, present several analytical challenges using conventional liquid chromatography methods. Therefore, we have developed a high-throughput gas chromatography based mass spectrometric (GC-MS) method in order to quantify relevant compounds without requiring time-consuming sample derivatization prior to analysis. Solvent extracts of untreated, ammonia fiber expansion (AFEX) treated and dilute-acid treated corn stover were analyzed by this method. Biomass samples were extracted with acetone using an automated solvent extractor, serially diluted and directly analyzed using the proposed GC-MS method. Acetone was the only solvent amongst water, methanol and acetonitrile that did not contain detectable background levels of the target compounds or facilitate a buildup of plant-derived residues in the GC injector, which decreased analytical reproducibility. Quantitative results were based on the method of standard addition and external standard calibration curves.Peer reviewed
La restricción exterior al crecimiento económico español (1870-1913)
No full textEditada en la Fundación Empresa PúblicaEn este artículo se realiza una estimación de las funciones de largo plazo del comercio exterior español en los años que van de 1870 a 1913. De entre los resultados obtenidos se destaca que la mayor elasticidad renta de la demanda de importaciones frente a la de exportaciones es un indicador de que, en ausencia de otros mecanismos compensatorios, la economía española se enfrentaba a estrangulamientos en sus pagos exteriores siempre que creciera a un ritmo comparable al de sus socios comerciales. Esta restricción, asociada al grado de desarrollo de la economía española, suponía una presión constante sobre la cotización de la peseta. La contrastación de esta situación permite aportar nuevos elementos a los debates actuales sobre la política económica de la época: los asociados a la incorporación de España al patrón oro y a la polémica sobre el proteccionismo.In this paper we estimate long-term functions of Spanish foreign trade from 1870 to 1913. We find the income elasticity of the Spanish import demand to be higher than the income elasticity of the export demand. This implies that, in the absence of compensation mechanisms, the Spanish economy was condemned to balance-of-payments constraints when its growth was similar to its trade partners'. These constraints implied a constant pressure over the peseta's exchange rate. These findings allow us to contribute to some present debates about Spanish economic policy of that period, particularly those dealing with the adoption of the gold standard and foreign trade liberation.Publicad
Competition Law and Human Rights:Striking a Balance Between Business Freedom and Regulatory Intervention
No full textPresented at The Limits of Competition Law, Santorini, Greece (jointly organised by UCL Faculty of Laws and IMEDIPA)</p
'Cradle-to-grave' assessment of existing lignocellulose pretreatment technologies
No full textPretreatment is considered to be a central unit process in a biorefinery to convert lignocellulosic biomass into fuels and chemicals, affecting all other operations in the process. A variety of technologies to pretreat lignocellulosic biomass are available today, which encompass a wide range of physical, chemical, and biological based processes. Among these, chemical based pretreatments are considered to be the most promising for future biorefineries. However, several key criteria regarding technical, economical, and environmental considerations should be critically analyzed when adapting these technologies for the nascent biorefinery industry. This review will discuss the most important pretreatment methods available today and will highlight key criteria for the development of a future ideal pretreatment.Peer reviewed
Optimizing Harvest of Corn Stover Fractions Based on Overall Sugar Yields following AFEX Pretreatment and Enzymatic Hydrolysis
No full textBackground: Corn stover composition changes considerably throughout the growing season and also varies between the various fractions of the plant. These differences can impact optimal pretreatment conditions, enzymatic digestibility and maximum achievable sugar yields in the process of converting lignocellulosics to ethanol. The goal of this project was to determine which combination of corn stover fractions provides the most benefit to the biorefinery in terms of sugar yields and to determine the preferential order in which fractions should be harvested. Ammonia fiber expansion (AFEX) pretreatment, followed by enzymatic hydrolysis, was performed on early and late harvest corn stover fractions (stem, leaf, husk and cob). Sugar yields were used to optimize scenarios for the selective harvest of corn stover assuming 70% or 30% collection of the total available stover.
Results: The optimal AFEX conditions for all stover fractions, regardless of harvest period, were: 1.5 (g NH(3) g(-1) biomass); 60% moisture content (dry-weight basis; dwb), 90 degrees C and 5 min residence time. Enzymatic hydrolysis was conducted using cellulase, beta-glucosidase, and xylanase at 31.3, 41.3, and 3.1 mg g(-1) glucan, respectively. The optimal harvest order for selectively harvested corn stover (SHCS) was husk > leaf > stem > cob. This harvest scenario, combined with optimal AFEX pretreatment conditions, gave a theoretical ethanol yield of 2051 L ha(-1) and 912 L ha(-1) for 70% and 30% corn stover collection, respectively.
Conclusion: Changing the proportion of stover fractions collected had a smaller impact on theoretical ethanol yields (29 - 141 L ha(-1)) compared to the effect of altering pretreatment and enzymatic hydrolysis conditions (150 - 462 L ha(-1)) or harvesting less stover (852 - 1139 L ha(-1)). Resources may be more effectively spent on improving sustainable harvesting, thereby increasing potential ethanol yields per hectare harvested, and optimizing biomass processing rather than focusing on the selective harvest of specific corn stover fractions.Peer reviewed
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