Bioconversion of Cellulose to Hydrogen by dark fermentation

Hydrogen is known as a clean energy resource. The biological production of hydrogen has been attracting attention as an environmentally friendly processs that does not consume fossil fuels. Cellulosic plant and waste materials are potential resources for fermentative hydrogen production. Cellulose is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires the presence of cellulase. The present study aimed to investigate the efficiency of acid pretreatment on ruminal fluid in order to enrich H2 producing bacteria consortia to enhance biohydrogen rate and substrate removal efficiency. In this study, fermentative hydrogen producers were enriched on cellulose (2g/L) in a modificated Del Nery medium (DNM) at 37ºC and initial pH 7.0 using rumen fluid (10% v/v) as inoculum. To increase the hydrogen production it was added cellulose (10mL) to the medium. The gas products (mainly H2 and CO2) was analyzed by gas chromatography (Shimadzu GC 2010) using a thermal conductivity detector. The volatile fatty acids and ethanol were also detected by GC using a flame ionization detector. Cellulose degradation was quantified by using the phenolsulfuric acid method. Analysis showed that the biogas produced from the anaerobic fermentation contained only hydrogen and carbon dioxide, without detectable methane after acid pretreatment test. On DNM the hydrogen production started with 4 h (5,3 x 105 mmol H2/L) of incubation, and the maximum H2 concentration was observed with 34 h (7,1 x 106 mmol H2/L) of incubation. During the process, it was observed a predominance of acetic acid and butyric acid as well as a low production of acetone, ethanol and nbutanol in all experimental phases. Butyrate accounted for more than 77% of total. As a result of the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system was reduced to 4,0. On microscopy analyses there were observed rods with endospores. The batch anaerobic fermentation assays performed on anaerobic mixed inoculum from rumen fluid demonstrated the feasibility of H2 generation utilizing cellulose as substrate. Based on the results, it can be concluded that the acid treatment was efficient to inhibit the methanogenic archaea cells present in rumen fluid. The rumen fluid cells present a potential route in converting renewable biomass such as cellulose into hydrogen energy.

Biological Hydrogen production from environmental sample in tropical countries

The hydrogen gas is regarded as clean and renewable energy source, since it generates only water during combustion when used as fuel. It shows 2.75 times more energy content than any hydrocarbon and it can be converted into electrical, mechanical energy or heat. Inoculum sources have been successfully tested for hydrogen biological production in temperate climate countries as sludge treatment plants sewage, sludge treatment plant wastewater, landfill sample, among others. However, hydrogen biologic production with inoculum from environmental samples such as sediment reservoirs, especially in tropical countries like Brazil, is rarely investigated. Reservoirs and fresh water lake sediment may contain conditions for the survival of a wide variety of microorganisms which use different carbon sources mainly glucose and xylose, in the fermentation. Glucose is an easily biodegradable, present in most of the industrial effluents and can be obtained abundantly from agricultural wastes. A wide variety of wastewater resulting from agriculture, industry and pulp and paper processed from wood may contain xylose in its constitution. Such effluent contains glucose and xylose concentrations of about 2 g/L. In this sense, this work verified hydrogen biological production in anaerobic batch reactor (1L), at 37 ° C, initial pH 5.5, headspace with N2 (100%), Del Nery medium, vitamins and peptone (1 g/L), fed separately with glucose (2g/L) and xylose (2 g/L). The inoculum was taken from environmental sample (sediment reservoir Itupararanga - Ibiúna - SP-Brazil). It was previously purified in serial dilutions at H2 generation (10-5, 10-7, 10-10), and heat treated (90º C - 10 min) later to inhibited the H2 consumers. The maximum H2 generations obtained in both tests were observed at 552 h, as described below. At the reactors fed with glucose and xylose were observed, respectively, 9.1 and 8.6 mmol H2/L, biomass growth (0.2 and 0.2 nm); consumption of sugar concentrations 53.6% (1.1 glucose g/L) and 90.5% (1.8 xylose g/L); acetic acid generation (124.7 mg/L and 82.7 mg/L), butyric acid (134.0 mg/L and 230.4 mg/L) and there wasn’t methane generation in the reactors. Microscopic analysis of biomass in anaerobic reactors showed the predominance of Gram positive rods and rods with endospores, whose morphology is characteristic of H2-generating bacteria, in both tests. These species were selected from the natural environment. In DGGE analysis performed difference were observed between populations from inoculum and in tests. This analysis confirmed that some species of bacteria were selected which remained under the conditions imposed on the experiment. The efficiency of the pre-treatment of inoculum and the imposition of pH 5.5 inhibited methane-producing microorganisms and the consumers of H2. Therefore, the experimental conditions imposed allowed the attainment of bacterial consortium of producer H2 taken from an environmental sample with concentration of xylose and glucose similar to the ones of the industrial effluents.

Formação inicial de professores de ciências: reflexões a partir das abordagens das estratégias de ensino e aprendizagem em um curso de licenciatura

We developed a case study aimed to identify and to analyze how the approach to teaching and learning strategies occurs in a science teaching degree course and what are the possible influences of this formation on the pedagogical practice of these educators. The analysis focused on documents, questionnaires and interviews with lecturers and students. There is reduced diversity of strategies in the disciplines of the specific area, with prevalence of expository classes and of laboratory, and the lecturers seem to believe that a good knowledge of specific content is enough for teaching. Despite that pedagogical disciplines do explore diverse practices, many students incorporate the academic view prevailing in the course, repeating the model of their lecturers. We stress the need for initial teacher training to take into account both aspects, the domain of the specific contents and the best ways to mediate them, forming intellectuals able to discuss and to redraw their educative actions in a perspective of transformation of the reality.

As Tecnologias de Informação e Comunicação TIC na formação de professores em educação sexual: o caso das E-Oficinas na I COES

This article aims to describe how ICT can contribute to the training of teachers on sex education through the lived experience with the implementation of Workshops, which occurred on I COES - I Conference online of sexual education. This Conference was organized by the University of Lisbon-PT, in partnership with UNESP, SP and SC-UDESC. I COES involved education professionals, who work directly in the school to discuss and exchange their experiences related to sexuality education and related fields, through an online space. The research on teacher formation, initial and continuing on sexuality, sex education, gender and sexual diversity, have demonstrated the need to promote and encourage teachers from all areas, to adopt an intentional and emancipatory, their role as sexual educators . Through web conferencing tool Cisco System, I COES was enable the interaction and questioning of ninety five teachers from various parts of Brazil and Portugal, providing opportunities for rich moments of dialogue and reflection on the issues already mentioned, referring to the brazilian and portuguese realities.

Educação ambiental e contexto escolar: questões para um programa de pesquisas

In this paper are systematized the discussions conducted by GDP "Research in EA and School Context", in VII EPEA, which have had, as its main axis, themes, authors and theoretical perspectives privileged in research presented at the event and declared themselves affiliated to this GDP. The dialogue with researches from previous meetings and other, aims to deepen the questions posed by the research group. The discussions allowed to identify themes and issues that present themselves as significant and challenging for research in EA in the school context, namely the conversion of schools into sustainable educational spaces; public-private partnerships, with great interest from companies and NGOs in school spaces, waving kits with educational materials produced for the school; lack of investment in public policies for teacher training in EA; tendency to an adherence to critical environmental education, without, however, have clear theoretical and methodological commitments under this option.

Os projetos político-pedagógicos dos cursos de pedagogia e os temas ambientais: o caso das Universidades Federais brasileiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Corpo e escola: o cuidado de si como atitude moderna

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ENGA: trajetória, memória e perspectivas

A Geografia brasileira ainda carece de sua história. Nos anos mais recentes, numerosos artigos têm aparecido, tentando recuperar essa falha, mas nota-se, ainda, a falta de um documento mais abrangente, que recupere os momentos fundamentais, os acertos e os erros, os avanços e as crises no progresso do conhecimento geográfico desenvolvido entre nós. E a lacuna se faz sentir, também, em termos de informações precisas sobre pesquisas, eventos, trabalhos publicados e teses defendidas, sem as quais não se pode reconstruir, de forma segura, a trajetória da Geografia brasileira. (DINIZ et al., 1987, p. 3)

A metáfora fundamental do discurso de John Dewey

This work aims to identify the rootmetaphor of John Dewey’s philosophical and educational discourse, by means of rhetorical analyses parameters. This methodology is founded in Aristotle and in the works of Chaïm Perelman and other contemporary authors involved in the revision of Aristotelian philosophy. The article examines the essays “The philosophical work of Herbert Spencer” and “The influence of darwinism on philosophy”, published by John Dewey respectively in 1904 e 1909. They were written in the early years of Dewey in Columbia University, which intellectual environment was not dominated by Pragmatism, and for this reason they can be considered seminal in the structuring of the author’s arguments. The analysis reveals that Dewey is favorable to Darwinian evolutionism thesis and opposite to Spencer’s one. This positioning suggests that Dewey’s discourse is bound to the metaphor “undetermined route” because it situates evolution as a process devoid of previously listed purposes at a pre-determined plan, subject only to the relations that are established, so unpredictable, between organisms and the environmental conditions that surround. Analyzing Dewey’s ideas about education, the article concludes that “undetermined route” is the rootmetaphor of Dewey’s discourse, hypothesis that can contribute to discuss Dewey in the context of contemporary philosophy.

Desafios da universidade pública na hipermodernidade

This article supposes that the Brazilian public university has dilemmas and challenges due to a more complex process that affects the whole society: Brazil has to deal with specific problems of its modernization process, at the same time that it is under pressure by the new challenges that are resulted from the globalization process. Based on a specialized literature, the aim of this article is to show how this interweaving modern/hypermodern process is challenging Brazilian public university toward more and more complex and diversified demands.

Entre vanguarda e a participação: a democracia no programa político da esquerda brasileira (1930-1935)

This paper examines the conceptions of democracy in the Brazilian left among 1930-1935, in particular those expressed in the manifestos of the National Liberative Alliance (ANL) and the texts written by Luis Carlos Prestes, Virgínio Santa Rosa and Caio Prado Jr. I argue that the Brazilian left started from a common troubled field, according to which land concentration represented the biggest obstacle to genuine political expression of the Brazilian people. Despite the convergence towards land reform, designed as a sine qua non condition to democracy in Brazil, the left has developed two different answers to the practical implementation of the principle of the people's government: the first, which I call altruist vanguard, which is more emphasized on texts of Virgínio Santa Rosa and Luís Carlos Prestes, and the second, the Republican participacionismo, which is explored on the writings of Caio Prado Jr. and ambiguously in the manifests of the National Liberative Alliance.

Os valores políticos da democracia nas opiniões dos vereadores de São Bernardo do Campo, Santo André e São Caetano do Sul

The objective of this paper is to analyze the values of democracy in the opinions of the councillors of the cities of São Bernardo do Campo, Santo André and São Caetano do Sul. This paper analyzes the period of 2010 and the technique of collection and analysis data were based on the main research methods in the Social Sciences. The results were: i) democracy is stable, ii) it is superior to any other type of regime, iii) content support in some public policy and the use of voting and iv) democracy has the support of the various ideological options.

Redes Sociais e capital político: uma proposta teórico-metodológica para análise das organizações partidárias brasileiras

As questões que motivaram o desenvolvimento deste trabalho foram decorrentes do debate permanente acerca do significado dos partidos políticos na atualidade. Partiu-se da hipótese de que a dinâmica organizacional do partido político poderia ser explicada por meio da análise das relações entre os seus filiados, substancialmente dos vínculos estabelecidos com os líderes partidários, com vistas a atenderem os objetivos políticos dos respectivos atores e, ao mesmo tempo, do partido. Assim, foi adotada uma abordagem e uma metodologia de análise que compreende a dinâmica organizacional a partir do capital político que circula no interior do partido, considerando os elementos orientadores das estratégias políticas: as relações entre os atores políticos, os aspectos institucionais e os resultados eleitorais. Para demonstrar o potencial teórico- metodológico da análise de redes sociais na compreensão do capital político, intra-organizacional, dos partidos políticos brasileiros, o texto apresenta resultados referentes a um estudo de caso: o Partido da Social Democracia Brasileria no estado de São Paulo (PSDB-SP), período entre 1988 e 2006.

Anísio Teixeira: apontamentos sobre democratização e qualidade do ensino

Anísio Teixeira: notes on democratization and quality of education. The work of Anísio Teixeira is the support of this study in a discussion of the democratization process in Brazilian education. We raised elements to contrast the idea of access democratization as a trigger to the process of decrease in quality of the public education offered in the country. The discussion initially presented the journey of this renowned Brazilian educator. Subsequently, we presented data on the early 20th century public education, period when he leads important positions in public education. We conclude the study by presenting the “School-park” proposed as he idealized the organization of elementary school.