Desenvolvimento de uma termobalança para ensaios sob pressão de macropartículas

Dissertação (mestrado) —Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2013.O Brasil é o maior produtor e consumidor mundial de carvão vegetal, dos quais 75% vão somente para a indústria siderúrgica. Os processos de carbonização usam geralmente tecnologias de pequena escala com baixos rendimentos gravimétricos e de difícil controle. Novas tecnologias de produção estão sendo desenvolvidas para melhorar esses números. Estudos recentes têm mostrado que o uso de pressão pode aumentar os rendimentos gravimétricos em 50% e reduzir consideravelmente o tempo de carbonização. Para uma melhor compreensão das reações químicas que ocorrem durante o processo projetou-se uma termobalança com capacidade maior que 200g, onde macro-partículas serão suspensas e carbonizadas em ambiente controlado. O projeto conceitual foi baseado em tecnologias existentes e foi desenvolvido após uma revisão bibliográfica. Para evitar danos ao subsistema de medição de massa, que estará em contato direto com a atmosfera do reator de pirólise ou a realização de ensaios em condições de operação impróprias, um trocador de calor e um subsistema de injeção de gás inerte também foram projetados. A instalação experimental permitirá o monitoramento da perda de massa da amostra de madeira, o controle da temperatura e da pressão interna durante a carbonização. Com foco em aspectos técnicos do equipamento e seus subsistemas, essa dissertação apresenta os primeiros estudos realizados para o desenvolvimento de uma balança termogravimétrica além de uma descrição das etapas cumpridas. ________________________________________________________________________________________ ABSTRACTBrazil is the world’s leadind producer and consumer of charcoal, 75% of which goes to the steel industry alone. The carbonization processes are generally small-scale technologies that are difficult to control and have relatively low gravimetric yields. New technologies are currently being developed to improve those figures. Recent studies have shown that using pressure can increase gravimetric yields by 50% and considerably reduce carbonization time. For a better understanding of the chemical reactions that occurs during the process, a “macro-thermogravimetric” apparatus, with >200g capacity, was developed. Macro-particles will be suspended and carbonized in a controlled environment. The conceptual project was based on existing technology and was developed after a bibliographic revision. To prevent damage the measurement weight subsystem, which is in direct contact with the atmosphere of the pyrolysis reactor, or the testing of an improper operating conditions a heat exchanger and an inert gas injection subsystem were also designed. The experimental set-up allows the overall weight loss of the wood sample, the control of internal temperature and pressure during carbonization. With a focus on technical aspects of equipment and their subsystems, this dissertation presents the first studies to develop a thermogravimetric balance and a description of steps taken

Structure and composition of the benthic macroinvertebrate community on wetland and irrigated rice cultivation.

Wetlands are environmentally and economically important ecosystems. The irrigated rice crops are considered artificial wetlands, because they offer food and refuge to different aquatic communities. The benthic macroinvertebrates are used to study environmental quality. The knowledge from the organisms which inhabit the natural and artificial wetlands can help to verify less harmful management practices in the agroecosystems. AIM: The aim of this research was to analyze and compare the benthic macroinvertebrate community from a wetland and an experimental kind of rice cultivation. METHODS: It was used dip nets 1 mm mesh every 15 days, with six repetitions in each place, from January to March 2010. After washing and screening them in the laboratory, the organisms were identified using stereoscope microscope and identification keys, and classified according to their functional trophic group. RESULTS: The whole organisms collected were 33,293 specimens. It was found 34 taxa, being 26 founded in the rice crops and 31 on the wetland. The natural wetland shows greater abundance, being responsible for 90.47% from the total abundance in this study. In the rice crop the abundance and the richness increased in the course of collection. However, it did not reach the values founded in the wetlands during the cultivation period. The most found groups in the two environmental were Belostomatidae and Planorbidae, while Hyalellidae and Elmidae were found only in the wetland, being a stress indicator in the wetland. CONCLUSIONS: The community structure including abundance, richness and composition was statistical different between wetlands and rice cultivation

Índice de qualidade da água para monitoramento do recurso hídrico em pequenas propriedades rurais das bacias hidrográficas Mirim São Gonçalo e Camaquã.

Nesse estudo foram amostradas duas pequenas propriedades rurais, de base familiar com o objetivo de avaliar a qualidade de água através do ÍQA desenvolvido pela National Sanitation Foundation ( verificando a adequação para os usos dados à água na propriedade

Erarbeitung betriebsindividueller Handlungsempfehlungen zur Verbesserung der Euter- und Stoffwechselgesundheit im Rahmen einer interdisziplinären Interventionsstudie

Kernziel des im Rahmen des Bundesprogramms Ökologischer Landbau initiierten Forschungsvorhabens „Gesundheit und Leistungsfähigkeit von Milchkühen im ökologischen Landbau interdisziplinär betrachtet“ (FKZ 07OE012 - 07OE022) ist - neben der Abschätzung des Risikos für Stoffwechselstörungen und Eutererkrankungen - die Entwicklung eines praxistauglichen, präventiv orientierten Tiergesundheitsmanagements für die Praxis der ökologischen Milchviehhaltung. Basierend auf einer Interventionsstudie auf 106 repräsentativ ausgewählten Milchviehbetrieben soll dieses Managementkonzept in einer zweijährigen Praxisphase validiert und auf seine Praxistauglichkeit überprüft werden. Als Grundlage für die Identifikation einzelbetrieblicher Interventionsmaßnahmen dienen zentrale Indikatoren der Euter- und Stoffwechselgesundheit, deren Abgleich mit im Vorfeld definierten Zielgrößen sowie Informationen zur Haltungsumwelt und zum Herdenmanagement. Das entwickelte Konzept soll eine einzelbetriebliche Einschätzung des Gesundheitsstatus der Milchviehherde bezüglich der Euter- und Stoffwechselgesundheit ermöglichen, auf deren Basis Handlungsempfehlungen zur nachhaltigen Verbesserung der Milchviehgesundheit abgeleitet werden können. Die Projektbetriebe setzten zwei Drittel der empfohlenen Maßnahmen um; eine abschließende Effektivitätskontrolle in Bezug auf die Verbesserung der Euter- und Stoffwechselgesundheit auf den Betrieben auf Basis der Daten des letzten Projektjahres steht noch aus

Caracterização física da bacia de contribuição da Estação de Tratamento de Água Sinnott por meio de geoprocessamento.

bitstream/item/186813/1/DOCUMENTO-460.pd

High-resolution measurement of the time-modulated orbital electron capture and of the β+\beta^+ decay of hydrogen-like 142^{142}Pm60+^{60+} ions

The periodic time modulations, found recently in the two-body orbital electron-capture (EC) decay of both, hydrogen-like $^{140}$Pr$^{58+}$ and $^{142}$Pm$^{60+}$ ions, with periods near to 7s and amplitudes of about 20%, were re-investigated for the case of $^{142}$Pm$^{60+}$ by using a 245 MHz resonator cavity with a much improved sensitivity and time resolution. We observed that the exponential EC decay is modulated with a period $T = 7.11(11)$s, in accordance with a modulation period $T = 7.12(11)$ s as obtained from simultaneous observations with a capacitive pick-up, employed also in the previous experiments. The modulation amplitudes amount to $a_R = 0.107(24)$ and $a_P = 0.134(27)$ for the 245 MHz resonator and the capacitive pick-up, respectively. These new results corroborate for both detectors {\it exactly} our previous findings of modulation periods near to 7s, though with {\it distinctly smaller} amplitudes. Also the three-body $\beta^+$ decays have been analyzed. For a supposed modulation period near to 7s we found an amplitude $a = 0.027(27)$, compatible with $a = 0$ and in agreement with the preliminary result $a = 0.030(30)$ of our previous experiment. These observations could point at weak interaction as origin of the observed 7s-modulation of the EC decay. Furthermore, the data suggest that interference terms occur in the two-body EC decay, although the neutrinos are not directly observed.Comment: In memoriam of Prof. Paul Kienle, 9 pages, 1 table, 5 figures Phys. Lett. B (2013) onlin

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal