bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Helium Accumulation on the Spent Fuel Microstructure
Authors: Ferry Cecile , Piron Jean-Paul , Stout Ray
Published: October 2011

The rapid release of activity when water firsts contacts the spent fuel surface in disposal will depend on the pellet microstructure at the arrival time of water in the container. Research performed on spent fuel evolution in a closed system has shown that the evolution of microstructure under disposal conditions should be governed by helium behavior with the cumulated α{decay damage. The evolution of fission gas bubble characteristics under repository conditions has been assessed. In UO2 fuels with a burnup of 47.5 GWd/t, the pressure of fission gas bubbles with the input of helium atoms should not reach the critical bubble pressure, thus micro-cracking in grains is not expected.
Perspectives on Localized Corrosion in Thin Layers of Particulate
Authors: Payer Joe H. , Kelly Robert G.
Published: October 2011

The requirements for the initiation and propagation of localized corrosion are reviewed, and the stability criteria for sustained localized corrosion are discussed. A conceptual framework is applied to a specific scenario of a hot metal surface covered by a thin layer of particulate containing dissolvable salts in the presence of air of limited humidity. A number of processes are demonstrated to affect the crevice corrosion propagation, stifling and arrest. Contributions of the particulate layer properties, the anode, cathode and coupled processes are identified, showing that any of these can control localized corrosion propagation. The findings add to the technical basis for the analysis of localized corrosion by a decision tree methodology.
Application of Neutron-Absorbing Structural-Amorphous Metal (SAM) Coatings for Spent Nuclear Fuel (SNF) Container to Enhance Criticality Safety Controls
Authors: Choi Jor-Shan , Lee Chuck , Farmer Joseph , Day Dan , Wall Mark , Saw Cheng , Boussoufi Moe , Liu Ben , Egbert Halold , Branagan Dan , D'Amato Andy
Published: October 2011

Spent nuclear fuel contains fissionable materials (235U, 239Pu, 241Pu, etc.). To prevent nuclear criticality in spent fuel storage, transportation, and during disposal, neutron-absorbing materials (or neutron poisons, such as borated stainless steel, Boral™, Metamic™, Ni-Gd, and others) would have to be applied. The success in demonstrating that the High-Performance Corrosion-Resistant Material (HPCRM) can be thermally applied as coating onto base metal to provide for corrosion resistance for many naval applications raises the interest in applying the HPCRM to USDOE/OCRWM spent fuel management program. The fact that the HPCRM relies on the high content of boron to make the material amorphous – an essential property for corrosion resistance – and that the boron has to be homogenously distributed in the HPCRM qualify the material to be a neutron poison.
Mechanisms of Inhibition of Crevice Corrosion in Alloy 22
Authors: Rebak Raul B.
Published: October 2011

Alloy 22 may be susceptible to crevice corrosion in chloride-containing environments, especially at temperatures above ambient. The presence of oxyanions, especially nitrate, minimizes or eliminates the susceptibility of Alloy 22 to crevice corrosion. Other anions such as sulfate, carbonate and fluoride were also reported as inhibitors of crevice corrosion in Alloy 22. It is argued that the occurrence of crevice corrosion is due to the formation of hydrochloric acid solution in the creviced region. Inhibitors act by eliminating the occurrence of hydrochloric acid or by hampering its action.
Enhancement of Zirconolite Dissolution Due to Water Radiolysis
Authors: Toulhoat Nelly , Toulhoat Nelly , Moncoffre Nathalie , Toulhoat Pierre , Jegou Christophe , Corbel Catherine , Bardez Isabelle , Leturcq Gilles
Published: October 2011

Zirconolite is a candidate host material for conditioning minor tri- and tetra-valent actinides arising from enhanced nuclear spent fuel reprocessing and partitioning, in the case of disposal of the nuclear waste. Its chemical durability has been studied here under charged particle-induced radiolysis (He2+ and proton external beams) to identify the possible effects of water radiolysis on the dissolution rates in pure water and to describe the alteration mechanisms. Two experimental geometries have been used in order to evaluate the influence of the following parameters: solid irradiation, water radiolysis. In the first geometry the beam gets through the sample before stopping at the surface/water interface. In the second one the beam stops before the surface/water interface. Results on the elemental releases due to the enhanced dissolution of the zirconolite surface during charged particle-induced irradiation of water are presented. Under radiolysis, an increase of one order of magnitude is observed in the Ti, Zr and Nd elemental releases. No difference in the total elemental releases can be noticed when the solid is also irradiated.
Characterisation of Plasma Vitrified Simulant Plutonium Contaminated Material Waste
Authors: Hyatt Neil Christian , Morgan Suzy , Stennett Martin C. , Scales Charlie R. , Deegan David
Published: October 2011

The potential of plasma vitrification for the treatment of a simulant Plutonium Contaminated Material (PCM) was investigated. It was demonstrated that the PUO2 simulant, CeO2, could be vitrified in the amorphous calcium iron aluminosilicate component of the product slag with simultaneous destruction of the organic and polymer waste fractions. Product Consistency Tests conducted at 90ºC in deionised water and buffered pH 11 solution show the PCM slag product to be durable with respect to release of Ce.
Simulation of Self-Irradiation of High-Sodium Content Nuclear Waste Glasses
Authors: Ojovan Michael I. , Batyukhnova Olga G. , Ojovan Michael I. , Lee William E.
Published: October 2011

Alkali-borosilicate glasses are widely used in nuclear industry as a matrix for immobilisation of hazardous radioactive wastes. Durability or corrosion resistance of these glasses is one of key parameters in waste storage and disposal safety. It is influenced by many factors such as composition of glass and surrounding media, temperature, time and so on. As these glasses contain radioactive elements most of their properties including corrosion resistance are also impacted by self-irradiation.

The effect of external gamma-irradiation on the short-term (up to 27 days) dissolution of waste borosilicate glasses at moderate temperatures (30¢X to 60¢XC) was studied. The glasses studied were Magnox Waste glass used for immobilisation of HLW in UK, and K-26 glass used in Russia for ILW immobilisation. Glass samples were irradiated under ×-source (Co-60) up to doses 1 and 11 MGy. Normalised rates of elemental release and activation energy of release were measured for Na, Li, Ca, Mg, B, Si and Mo before and after irradiation. Irradiation up to 1 MGy results in increase of leaching rate of almost all elements from both MW and K-26 with the exception of Na release from MW glass. Further irradiation up to a dose of 11 MGy leads to the decrease of elemental release rates to nearly initial value. Another effect of irradiation is increase of activation energies of elemental release.
Porous Alumina Silicate Matrix Gubka for Solidification of 137Cs Strip Product
Authors: Aloy Albert , Strelnikov Alexander , Essimantovskiy Vyacheslav
Published: October 2011

Separated liquid highâlevel radioactive waste (HLW) fractions, in particular, about 100 l of 137Cs strip product with activity up to ∼ 100 Ci/l (3.7 TBq/l) have been produced during the development and testing of partitioning technology and temporary stored at “V.G. Khlopin Radium Institute” (SaintâPetersburg, Russia). The benchâscale experimental unit designed for operation in the hot cell was developed for 137Cs strip product solidification with using of alumina silicate porous inorganic material (PIM) called Gubka.

Conditions of saturation, drying and calcinations of the salts into Gubka pores were optimized and the operations under remote control regime were executed during tests with using of simulated strip product doped with 137Cs. The volume reduction coefficients were equal by a factor of 3.2â3.9 and 137Cs discharge into offâgas system was not detected. 137Cs leach rates from Gubka blocks after calcination at 800 Â°C were 1.0â1.5*10-3 g/m2*day.
Effects of Compaction and Temperature on Sorption and Diffusion of Cs and HTO in Compacted Bentonite Saturated with Saline Water
Authors: Suzuki Satoru , Haginuma Masashi , Suzuki Kazunori
Published: October 2011

The sorption and diffusion of Cs and HTO in compacted bentonite was investigated at temperatures from 30 to 60°C. The apparent (Da) and effective (De) diffusion coefficients were determined by in-diffusion and through-diffusion experiments with a constant boundary concentration maintained. The temperature dependence of De and Da obeyed an Arrhenius-type equation, allowing determination of the activation energy for diffusion of Cs and HTO. The De value of Cs was three times the De of HTO, which is considered to be a result of surface-excess diffusion. Cs may be concentrated near the surface of the negatively charged clay, thus giving a large diffusive flux. The activation energies for Cs diffusion were 21.4×2.8 kJ/mol and 37.3×1.5 kJ/mol as determined based on De and Da, respectively. This difference was due to the temperature dependence of the distribution coefficient Kd of Cs.
Modeling Studies on Microbial Effects on Groundwater Chemistry
Authors: Tochigi Yoshikatsu , Yoshikawa Hideki , Yui Mikazu
Published: October 2011

The overall goal of this project is to develop a model to predict microbial effects on the performance of a high-level radioactive waste (HLW) repository. As a first step, the effects of microbes on groundwater chemistry have been evaluated with the numerical code 'MINT', using data collected from the borehole HDB-6 in the Horonobe underground research laboratory (URL) in Japan. The MINT code models biochemistry and geochemical equilibrium, with consideration of transport of solute and microbial activity. The MINT code simulates the activities of 6 major groups of microbes, classified by their metabolism as 'aerobic', 'denitrifying', 'manganese reducing', 'iron reducing', 'sulfate reducing' and 'methanogenic'. The specific activity of each of these groups will depend on the redox potential (Eh) of the groundwater.

Sensitivity analyses were performed to investigate the consequences of changes in groundwater composition on the effects of microbial activity. This indicates that the activities of Sulfate Reducing Bacteria (SRB) and methanogens are relatively high. The concentration of dissolved methane produced by such microbial activity is seen to be influenced by sulfate concentration. Based on the observed data from Horonobe URL, the concentration in oxygen is relatively high and the activity of denitrifying bacteria is the highest of the major 6 groups of microbes. This can, however, be attributable to chemical / microbial contamination of the groundwater during sampling. The modeling results indicate that the concentration of dissolved oxygen and nitrate ion should be quickly reduced by microbial metabolism, reducing the redox potential to a level low enough for active methanogenesis to commence. Such assessment can be important to evaluate the reliability of sampling and measurement techniques for sensitive geochemical parameters in general - and microbiology in particular.
Permeability Change of Crystalline Silicate Mineral-Packed Bed Column by Highly Alkaline Plume
Authors: Usui Hideo , Niibori Yuichi , Tochiyama Osamu , Mimura Hitoshi
Published: October 2011

For the construction of the geological disposal system, the use of the cementitious material may affect the permeability change of the natural barrier around the repository. In practice, the construction requires a large amount of cement to maintain the mechanical stability of the repository system, particularly in Japan. Since such material alters the pH of ground water to highly alkaline region, also the permeability change of natural barrier is one of the notable factors for the performance assessments of geological disposal system.

In the high pH region, the solubility of silicic acid is very high compared to that in the natural pH (around 8). Therefore, the highly alkaline groundwater would dissolve and alter a part of rock surface. Usui et al. (2005) reported that the change of the pore structure due to the chemical reaction is the key factor to consider the change of the permeability. Moreover, such a change of the pore structure was considered as the result of the spatial heterogeneity of chemical composition. Since such spatial heterogeneity exists also in the sedimentary rocks consisted of crystalline minerals such as quartz and feldspar, we need to examine natural rock, in order to obtain more reliable understanding about the change of permeability induced by the highly alkaline groundwater (plume).

In this study, as crystalline mineral, silica sand was packed in the column, and the effect of dissolution induced by the highly alkaline plume on the permeability-change was examined. The silica sand particles mainly consist of SiO2 partially including Al2O3, CaO, Na2O3, and K2O. The volumetric flow rate and the pressure difference between the inlet and outlet of the column were measured, and the permeability was calculated. At the same time, the concentration of elements in the fluid was measured by the ICP-AES.

The experimental result showed that permeability decreased gradually, although the silica sand was continuously dissolved in the column. The behavior of the permeability is considered to be the result from the rearrangement of the particles. In the column test using the silica sand as packed mineral, the flow-path seems to be clogged by the rearrangement of the particles rather than the increase of the pore between the particles.
Determination of Granites' Mineral Specific Porosities by PMMA Method and FESEM/EDAX
Authors: Siitari-Kauppi Marja , Penttinen L. , Siitari-Kauppi M. , Alanso U. , Garcia-Gutierrez M. , Missana T. , Patelli Alessandro
Published: October 2011

Over extended periods, long-lived radionuclides (RN) or activation products within geologic disposal sites may be released from the fuel and migrate to the geo/biosphere. In the bedrock, contaminants will be transported along fractures by advection and retarded by sorption on mineral surfaces and by molecular diffusion into stagnant pore water in the matrix along a connected system of pores and micro-fissures.

The objective of this paper was to determine the connective porosity and mineral-specific porosities for three granite samples by 14C methylmethacrylate (14C-PMMA) autoradiography. Scanning electron microscopy and energy-dispersive X-ray analyses (FESEM/EDAX) were performed in order to study the pore apertures of porous regions in greater detail and to identify the corresponding minerals. Finally, the porosity results were used to evaluate the diffusion coefficients of RNs from previous experiments which determined apparent diffusion coefficients for the main minerals in three granite samples by the Rutherford Backscattering technique.

The total porosity of the Grimsel granite (0.75%) was significantly higher than the porosities of the El Berrocal and Los Ratones granites (0.3%). The porosities of the Grimsel granite feldspars were two to three times higher than the porosities of the El Berrocal and Los Ratones granites' feldspars. However, there was no significant difference between the porosities of the dark minerals. A clear difference was found between the various quartz grains. Quartz crystals were nonporous in the El Berrocal and Los Ratones granites when measured by the PMMA method, but the quartz crystals in the Grimsel granite showed 0.5% intra granular porosity. The apparent diffusion coefficients calculated for uranium diffusion within Grimsel granite on different minerals were very similar (210-13 ± 0.5 m2/s), but differences within both Spanish granites were found from one mineral to another (9 ± 110-14 m2/s in feldspars and 4.5 ± 0.510-14 m2/s in quartz) - always presenting lower diffusion values than in the Grimsel granite.
Aqueous Dissolution of Silver Iodide and Associated Iodine Release under Reducing Conditions with Sulfide
Authors: Inagaki Yaohiro , Imamura Toshitaka , Idemitsu Kazuya , Arima Tatsumi , Kato Osamu , Asano Hidekazu , Nishimura Tsutomu
Published: October 2011

Aqueous dissolution tests of AgI were performed in Na2S solutions in order to evaluate, empirically, dissolution of AgI to release iodine under reducing conditions with sulfide. The results indicated that AgI dissolves to release iodine being controlled by mainly precipitation of Ag2S. However, the dissolution of AgI can be depressed to proceed, and the thermodynamic equilibrium cannot be attained easily. Solid phase analysis for the reacted AgI suggested that a thin layer of solid silver forming at AgI surface may evolve to be protective against transportation of reactant species, which can lead to the depression in the dissolution of AgI.
Chemistry of Water Collected from an Unventilated Drift, Yucca Mountain, Nevada
Authors: Marshall Brian D , Oliver Thomas A. , Peterman Zell E.
Published: October 2011

Water samples (referred to as puddle water samples) were collected from the surfaces of a conveyor belt and plastic sheeting in the unventilated portion of the Enhanced Characterization of the Repository Block (ECRB) Cross Drift in 2003 and 2005 at Yucca Mountain, Nevada. The chemistry of these puddle water samples is very different than that of pore water samples from borehole cores in the same region of the Cross Drift or than seepage water samples collected from the Exploratory Studies Facility tunnel in 2005. The origin of the puddle water is condensation on surfaces of introduced materials and its chemistry is dominated by components of the introduced materials. Large CO2 concentrations may be indicative of localized chemical conditions induced by biologic activity.
Geochemistry of Natural Components in the Near-Field Environment, Yucca Mountain, Nevada
Authors: Peterman Zell E. , Oliver Thomas A.
Published: October 2011

The natural near-field environment in and around the emplacement drifts of the proposed nuclear waste repository at Yucca Mountain, Nevada, includes the host rock, dust, seepage, and pore water. The chemical compositions of these components have been analyzed to provide a basis for assessing possible chemical and mineralogical reactions that may occur after nuclear waste is emplaced. The rock unit hosting the proposed repository has a relatively uniform chemical composition as shown by samples with a mean coefficient of variation (CV) of 9 percent for major elements. In contrast, compositional ranges of underground dust (bulk and water-soluble fractions), pore water, and seepage water are large with mean CVs ranging from 28 to 64 percent for major constituents.
Status of the French Research on Partitioning and Transmutation
Authors: Warin Dominique
Published: October 2011

The global energy context pleads in favour of a sustainable development of nuclear energy since the demand for energy will likely increase, whereas resources will tend to get scarcer and the prospect of global warming will drive down the consumption of fossil fuel sources.

How we deal with radioactive waste is crucial in this context. The production of nuclear energy in France has been associated, since its inception, with the optimization of radioactive waste management, including the partitioning and the recycling of recoverable energetic materials. The public's concern regarding the long-term waste management made the French Government to prepare and pass the December 1991 Law, requesting in particular the study for fifteen years of solutions for still minimizing the quantity and the hazardousness of final waste, via partitioning and transmutation.

At the end of these fifteen years of research, it is considered that partitioning techniques which have been validated on real solutions are at disposal. Indeed, aqueous process for separation of minor actinides from the PUREX raffinate has been brought to a point where there is reasonable assurance that industrial deployment can be successful. A key experiment has been the kilogram scale successful trials in the CEA-Marcoule Atalante facility in 2005 and this result, together with the results obtained in the frame of the successive European projects, constitutes a considerable step forward. For transmutation, CEA has conducted programmes proving the feasibility of the elimination of minor actinides and fission products: fabrication of specific targets and fuels for transmutation tests in the HFR and Phénix reactors, neutronics and technology studies for critical reactors and ADS developments. Scenario studies have also allowed assessing the feasibility, at the level of cycle and fuel facilities, and the efficiency of transmutation in terms of the quantitative reduction of the final waste inventory depending of the reactor fleet (PWR-FR-ADS).

Important results are now available concerning the possibility of significantly reducing the quantity and the radiotoxicity of long-lived waste in association with a sustainable development of nuclear energy. As France has confirmed its long-term approach to nuclear energy, the most effective implementation of P and T of minor actinides relies on the fast neutron GEN IV systems which are designed to recycle and manage their own actinides. The perspective to deploy a first series of such systems around 2040 supports the idea that progress is being made: the long-term waste would only be made up of fission products, with very low amounts of minor actinides.

In this sense, the new waste management Law passed by the French Parliament on June 28, 2006, demands that P and T research continues in strong connection to GEN IV systems and ADS development and allowing to assess the industrial perspectives of such systems in 2012 and to put into operation a transmutation demo facility in 2020.
Transmutation and the Global Nuclear Energy Partnership
Authors: Bresee James
Published: October 2011

In the January 2006 State of the Union address, President Bush announced a new Advanced Energy Initiative, a significant part of which is the Global Nuclear Energy Initiative. Its details were described on February 6, 2006 by the U.S. Secretary of Energy. In summary, it has three parts: (1) a program to expand nuclear energy use domestically and in foreign countries to support economic growth while reducing the release of greenhouse gases such as carbon dioxide. (2) an expansion of the U.S. nuclear infrastructure that will lead to the recycling of spent fuel and a closed fuel cycle and, through transmutation, a reduction in the quantity and radiotoxicity of nuclear waste and its proliferation concerns, and (3) a partnership with other fuel cycle nations to support nuclear power in additional nations by providing small nuclear power plants and leased fuel with the provision that the resulting spent fuel would be returned by the lessee to the lessor. The final part would have the effect of stabilizing the number of fuel cycle countries with attendant non-proliferation value. Details will be given later in the paper.
Na contramão do ensino médio inovador: propostas do Legislativo Federal para inclusão de disciplinas obrigatórias na escola
Authors: Amaral Daniela Patti do , Oliveira Renato José de
Published: October 2011

A proposta do Ministério da Educação (MEC) para um ensino médio inovador tem como perspectiva estimular as redes estaduais de educação a pensar novas soluções que diversifiquem os currículos e promovam articulação interdisciplinar voltada para o desenvolvimento de conhecimentos, saberes, competências, valores e práticas. No presente artigo foram analisadas 15 proposições apresentados na Câmara Federal no período posterior à aprovação da proposta do ensino médio inovador pelo MEC e pelo Conselho Nacional de Educação (CNE). Concluímos que, na contramão de uma proposta inovadora para o ensino médio, o Congresso brasileiro insiste na apresentação de projetos de lei que incluam disciplinas obrigatórias na escola, contemplando diferentes conteúdos, a partir de uma perspectiva fragmentada do currículo.
Jovens olhares sobre a escola do ensino médio
Authors: Leão Geraldo , Dayrell Juarez Tarcísio , Reis Juliana Batista dos
Published: October 2011

Este artigo discute os resultados de uma pesquisa realizada com estudantes do Pará sobre as relações entre projetos de vida de jovens e as escolas públicas de ensino médio. Os dados foram coletados em 2009, por meio de doze Grupos de Diálogos com 245 jovens, organizados em duas cidades do interior do estado (Moju e Santarém) e na capital. A partir dos depoimentos dos jovens, foi possível identificar algumas contribuições das escolas à realização de suas demandas e expectativas, mas também muitas lacunas e impasses. O texto parte de uma discussão geral sobre o contexto do ensino médio no país e a relação com a juventude para situar a realidade específica das escolas paraenses segundo o olhar dos jovens pesquisados, compreendendo assim as distâncias e aproximações entre as expectativas juvenis e as experiências oferecidas por suas escolas.
Jovens no ensino médio normal: apontamentos de trajetórias em formação
Authors: Azevedo Leny Cristina Soares Souza , Peixoto Maria Cristina dos Santos
Published: October 2011

O texto apresenta reflexões acerca de uma pesquisa desenvolvida nos anos de 2008 a 2010, com sessenta jovens do Curso de Formação de Professores, dos segundos e terceiros anos do ensino médio normal, do estado do Rio de Janeiro. Os resultados da pesquisa apontaram para a explicitação da complexidade da formação, composta a partir do percurso escolar, permeada de sentidos e de valorações feitas pelas alunas, predominantemente colocando um imenso contingente de jovens no exercício do magistério, à busca de profissionalização.
Tratamento das fraturas do processo odontóide
Authors: Pontin Pedro Augusto , Bumlai Renam Urt Mansur , Letaif Olavo Biraghi , Damasceno Marcelo Loquette , Cristante Alexandre Fogaça , Marcon Raphael Martus , Iutaka Alexandre Sadao , Oliveira Reginaldo Perilo , Barros Filho Tarcísio Eloy Pessoa de
Published: October 2011

OBJETIVO: Este artigo faz a avaliação retrospectiva clínica e radiológica das fraturas do odontóide de 20 pacientes atendidos no IOT-HCFMUSP, durante o período de 2004-2010. MÉTODOS: Foi realizado a estratificação destas fraturas segundo sua classificação (AO/Anderson e D'Alonzo), perfil epidemiológico, tipo de tratamento, tempo de consolidação e complicações. RESULTADOS: Observou-se maior número de casos da fratura do odontóide em pacientes do sexo masculino (4:1), com idade entre 3ª e 4ª década de vida (60%), vítimas de quedas de altura (60%) e acidentes automobilísticos (25%) como principais mecanismos de trauma, e 15% dos casos apresentaram-se com déficit neurológico. A fraturas do odontóide de maior prevalência foram as do tipo II (55%), seguidas pelas fraturas do tipo III (40%). Os tratamentos mais empregados nas fraturas do tipo II e III foram, respectivamente, o cirúrgico (73%) e conservador (87,5%). A consolidação ocorreu em até 16 semanas para 87,5% dos casos de tratamento cirúrgico e para 54,5% dos tratados conservadoramente. Não houve casos de pseudoartrose. CONCLUSÃO: O tratamento cirúrgico das fraturas do odontóide do tipo II apresentou resultados satisfatórios em relação ao tempo consolidação e baixa incidência de complicações, bem como o tratamento conservador destinado às fraturas do tipo III.Nivel de Evidência IV, série de casos.
Tratamento conservador da fratura toracolombar explosão e Classificação de McComack
Authors: Carvalho Alexandry Dias , Meves Robert , Rezende Rodrigo , Caffaro Maria Fernanda Silber , Landim Élcio , Avanzi Osmar
Published: October 2011

OBJETIVO: Correlacionar a classificação de McCormack e o resultado funcional nos portadores de fratura toracolombar explosão tratados com gesso em hiper-extensão ou ortese toracolombossacra. MÉTODOS: Análise retrospectiva de prontuários, radiografias e de tomografia de 31 pacientes no período de 1996 a 2005. O resultado funcional ao final do tratamento obtido mediante as escalas funcionais de dor e trabalho de Denis. RESULTADOS: Dos 31 pacientes avaliados, cinco apresentavam incapacidade total ou parcial para retorno ao trabalho ao final do período de segmento; 26 (83,9 %) estavam aptos ao trabalho com ou sem mudança da atividade trabalhista. Em relação à dor (r=0,258;p=0,161) e função (r=0,204;p=0,272), não houve correlação entre a pontuação da classificação e a função no final do acompanhamento. CONCLUSÃO: Considerando critérios funcionais centrados nos pacientes, não observamos correlação entre a Classificação de McCormack e os resultados do tratamento conservador. Nivel de Evidência IV, série de casos.
O ultrassom terapêutico na medula espinhal acelera a regeneração do nervo ciático de ratos
Authors: Jatte Fernanda Guadallini , Mazzer Nilton , Monte-Raso Vanessa Vilela , Leoni Anita Sofia Leite , Barbieri Cláudio Henrique
Published: October 2011

OBJETIVO: Estudar os efeitos da irradiação ultrassônica de baixa intensidade aplicada sobre a medula espinhal na regeneração do nervo ciático de ratos após lesão por esmagamento controlado, avaliando os resultados pelo índice funcional do ciático (SFI), medido nas imagens vídeo-filmadas das plantas das patas. MÉTODOS: Dezoito ratos foram submetidos a esmagamento controlado (do nervo ciático direito e divididos em dois grupos de acordo com o tratamento: Grupo 1 (n=9), irradiação simulada; Grupo 2 (n=9), irradiação efetiva. Irradiação ultrassônica de baixa intensidade foi iniciada no 7º dia pós-operatório e aplicada diariamente por 6 semanas. Imagens das plantas das patas dos animais foram vídeo-filmadas em uma esteira transparente sob velocidade controlada a intervalos semanais até a 6ª semana de irradiação e o correspondente SFI medido com um programa de computador específico. RESULTADOS: O SFI durante a 1ª e a 6ª semana de tratamento foi de -59,12 e -12,55 no Grupo 1, e -53,31 e -1,32 no Grupo 2, indicando uma melhora de 79% e 97%, respectivamente, mas as diferenças entre os grupos somente foram significantes (p<0,05) durante a 3ª semana de tratamento. CONCLUSÃO: Os autores concluem que o ultrassom terapêutico de baixa intensidade estimula a regeneração nervosa, com significância durante a 3ª semana de tratamento. Nivel de Evidência II, Prospectivo Comparativo.
Gerenciamento do lado da demanda no bombeamento de água para perímetro irrigado
Authors: Moraes Maria J. de , Oliveira Filho Delly , Vieira Gustavo H. S. , Scarcelli Ricardo de O. C.
Published: October 2011

Sistemas de irrigação demandam quantidades significativas de energia elétrica, o que aumenta consideravelmente o custo de produção. Simularam-se o gasto com energia elétrica e as lâminas de irrigação, para um perímetro irrigado hipotético na região do Jaíba, MG, para as culturas: abacaxi, banana, goiaba, limão, mamão, manga, maracujá, melão, pinha e uva. A partir de dados das necessidades hídricas das culturas, calcularam-se as lâminas de irrigação mensal e para cada um dos lotes, simularam-se as alturas manométricas, as demandas hidráulicas e elétricas e o consumo de energia, para diferentes combinações de culturas nos lotes e, para as combinações, simulou-se o uso do inversor de frequência com restrição do número de horas de funcionamento diário em função da época do ano visando maximizar o índice de carregamento dos motores e o rendimento do conjunto motobomba. Concluiu-se que o uso do inversor de frequência e o gerenciamento do número de horas de disponibilidade da irrigação no sistema de fornecimento de água para irrigação no perímetro estudado, garantiram economia de energia elétrica, que variou em torno de 7% a 62% para as combinações estudadas.
Balanço de nutrientes em povoamento de Eucalyptus saligna implantado sobre Cambissolo Háplico no RS
Authors: Mazurana Michael , Baptista José , Levien Renato , Conte Osmar
Published: October 2011

A fragilidade de um sistema florestal pode ser avaliada através do balanço de nutrientes, destacando a eficiência da ciclagem sendo que, em certos casos, a adubação deve ser utilizada para manter ou elevar a produtividade do sistema. Objetivou-se com este estudo avaliar o comportamento de diferentes sistemas de preparo de solo em Cambissolo Háplico e sua influência nas perdas de nutrientes transportados por erosão em área cultivada com Eucalyptus saligna. Os tratamentos foram constituídos por quatro métodos de preparo do solo: subsolagem interrompida com resíduo (SIR), subsolagem contínua com resíduo (SCR), subsolagem contínua sem resíduo (SSR) e coveamento mecânico (CME), em delineamento de blocos ao acaso com três repetições por tratamento. O sistema SSR apresentou as maiores perdas de nutrientes quando comparadas com as dos outros métodos de preparo de solo. As maiores perdas de nutrientes pela erosão hídrica foram, pela ordem, K > Ca > Mg > P > Cu > B. Os sistemas de preparo SIR e SSR apresentaram os maiores teores de nutrientes contidos na parte aérea e o menor balanço nutricional, respectivamente.
Dependência espacial dos atributos físicos de três classes de solos cultivados com cana-de-açúcar sob colheita mecanizada
Authors: Carvalho Laércio A. de , Meurer Ismael , Silva Junior Carlos A. da , Cavalieri Karina M. V. , Santos Cristiane F. B.
Published: October 2011

Objetivou-se, neste trabalho, avaliar as propriedades físicas de três classes de solo cultivadas com cana-de-açúcar em sistema de colheita mecanizada na região de Mato Grosso do Sul. O local de estudo pertence à Usina Eldorado, Grupo ETH Bioenergia S/A, localizada no município de Rio Brilhante, MS. A amostragem em cada área experimental foi realizada a partir de uma malha, com 180 m de comprimento e 145,6 m de largura, totalizando 90 pontos em forma de grade, com 9 colunas e 10 linhas, onde foram coletadas amostras de estrutura indeformada nas camadas de 0-0,2 m e 0,2-0,4 m de profundidade nas entrelinhas da cultura. Após coleta, as amostras foram processadas para determinação da densidade do solo (DS), porosidade total (PT) e umidade do solo (q) para interpretação dos dados. A palhada deixada sobre superfície auxiliou na mantença de bom nível de matéria orgânica, corroborando na formação, agregação e estabilidade de poros, impedindo o aumento da densidade. A redução da porosidade total e consecutivo aumento na densidade do solo, principalmente na profundidade de 0,2-0,4 m, indicam compactação nesta camada, justificada pelo intenso tráfego de veículos e ausência de revolvimento do solo.
Dinâmica da umidade de um solo da Caatinga em função de sua condutividade térmica
Authors: Silans Alain M. B. P. de , Werlang Lovania M.
Published: October 2011

A elaboração de modelos SVATs (Soil Vegetation Atmosphere Transfer - Transporte no sistema solo-vegetação-atmosfera) apropriados, é de grande importância para a compreensão dos mecanismos de transferência de fluxos à superfície, com aplicações na modelagem da circulação atmosférica, na modelagem hidrológica e na modelagem ecodinâmica da vegetação. Neste trabalho se utiliza um modelo SVAT desenvolvido especificamente na região do Cariri, estado da Paraíba, para analisar o efeito dos gradientes de temperatura na camada superficial do solo sobre a dinâmica da umidade volumétrica e se mostra como a baixa difusividade térmica obsevada no solo do experimento provoca altos gradientes de temperatura que freiam, durante o dia, o processo de evaporação, resultando no seu controle e como, apesar de relativamente baixa, a taxa de evaporação do solo desnudo é sensivel à variabilidade espacial observada em campo, da condutividade térmica. Os resultados obtidos recomendam maior atenção quanto à parametrização das propriedades termodinâmicas do solo no desenvolvimento de modelos SVATs, principalmente em regiões semi-áridas.
Age, growth, and reproductive aspects of the dusky grouper Mycteroperca marginata (Actinopterygii: Epinephelidae) in a man-made rocky habitat in southern Brazil
Authors: Seyboth Elisa , Condini Mario V , Albuquerque Cristiano Q , Varela Jr Antônio S , Velasco Gonzalo , Vieira João P , Garcia Alexandre M
Published: October 2011

The dusky grouper, Mycteroperca marginata, is an important commercial marine fish that is currently considered an endangered species worldwide and listed as overexploited in Brazil. Although its reproductive biology has been studied elsewhere, no information is available for populations in its southernmost distribution limit on the Brazilian coast. The present work investigates age structure, growth and reproduction of individuals inhabiting a pair of rocky jetties, about 4.5 km long each, located in the mouth of Patos Lagoon in the municipality of Rio Grande, in the southwestern Atlantic Ocean. A total of 130 individuals obtained between February 2007 and May 2009 were analyzed, with total length ranging from 260 to 800 mm. The growth coefficient found in the present study (K: 0.069) was lower than values reported for dusky grouper populations from the Mediterranean Sea (0.087) and southeast Africa (0.09). This difference could be related to higher average water temperatures in these regions compared to the current study site or due to poorer habitat quality in terms of the shelters available for dusky grouper individuals to establish their territories. Microscopic ovarian analyses of individuals during three years of sampling revealed only the occurrence of immature and resting females. The absence of ripe or post-spawning individuals, associated with low GSI values (<0.2) over the studied months, indicates that the dusky grouper did not use this man-made rocky substrate as a spawning site. The current L50 estimate of 451.3 mm indicates that most individuals captured in this area are immature. Such fishing pressure on immature specimens, associated with its slow growth rates and complex reproductive characteristics, threatens sustainability of the current dusky grouper fishery at the study site.
Extração semiautomática de contornos de telhado de edifícios com base em snakes e programação dinâmica
Authors: Fazan Antonio Juliano , Dal Poz Aluir Porfírio
Published: October 2011

Este trabalho apresenta um método para a extração de contornos de telhado de edifícios a partir de imagens digitais tomadas sobre cenas urbanas complexas. O método proposto é baseado na otimização de uma função de energia snakes, que representa contornos de telhado de edifícios em imagens digitais, através da técnica de otimização por programação dinâmica. Como a grande maioria dos contornos de telhado de edifícios possui lados retilíneos se interceptando em ângulos retos, foram aplicadas restrições à função de energia snakes de modo a atender esta condição geométrica. A principal vantagem de se usar o algoritmo de programação dinâmica para otimizar a função de energia snakes é o aumento do raio de convergência, quando comparado com o que é normalmente obtido na solução original baseada em cálculo variacional. A avaliação experimental foi realizada a partir de dados reais e os resultados obtidos na inspeção visual e análise numérica dos experimentos mostraram o potencial do método para a extração de contornos de telhado de edifícios a partir de imagens digitais.
Classificação de pontos LIDAR para a geração do MDT
Authors: Pacheco Admilson da Penha , Centeno Jorge Antonio Silva , Assunção Marcio Geovani Tavares de , Botelho Mosar Faria
Published: October 2011

Nos últimos anos tem se observado uma representativa evolução da tecnologia LIDAR (Light Detection and Ranging) na aquisição automática do MDT (Modelo Digital do Terreno) em áreas urbanas e rurais. Os métodos existentes na literatura remetem a regiões para casos específicos no hemisfério norte, onde as condições de vegetação e uso do solo são diferentes das encontradas no Brasil. O presente trabalho tem como objetivo investigar e discutir métodos de classificação de dados LIDAR utilizados para a geração automática do MDT, usando os conceitos de morfologia matemática no processo de filtragem e classificação dos pontos. O processo metodológico compreendeu: definição e caracterização da área de aplicação dos testes de verificação, bem como as condições de aquisição dos dados utilizados; descrição do método denominado Filtro Morfológico; e, por fim, o método para a análise e comportamento da metodologia proposta. A qualidade dos produtos gerados nos experimentos realizados mostrou-se satisfatória, considerando os aspectos numéricos relacionados com o erro médio e a variância das áreas testadas. Os resultados mostraram que a geração do MDT em áreas urbanas apresentou maior consistência em conseqüência, principalmente, da presença de áreas livres ao nível do terreno, favorecendo a viabilidade do uso do método de classificação.
Generalización de modelo digital de elevación condicionada por puntos críticos de terreno
Authors: Mena Frau Carlos , Molina Pino Leonardo , Ormazábal Rojas Yony , Morales Hernández Yohana
Published: October 2011

Los Modelos Digitales de Elevación (MDE) son productos geomáticos esenciales en el estudio, manejo y administración del territorio. Su uso, así como la disponibilidad de datos de alta resolución, ha ido en crecimiento sostenido en las últimas décadas, permitiendo diversos y variados análisis cuyos resultados permiten cualificar y cuantificar los características propias del terreno. No obstante la disponibilidad creciente de datos de elevación, existen ocasiones donde estudios del territorio requieren el uso de modelos digitales de terreno con resolución espacial más gruesa que la resolución de los datos disponibles. La evaluación de un método de generalización de MDE que considera la retención de puntos críticos del terreno es abordado en el presente documento. Este método es comparado con otro método que considera solamente una interpolación bilineal aplicada al cambio de resolución del MDE. En la evaluación son utilizados datos del proyecto SRTM (Shuttle Radar Topography Mission) para una zona de 111 km por 91 km aproximadamente, en la Región del Maule, Chile. Los resultados evidencian que el método de generalización condicionada por puntos críticos presenta mejor desempeño al preservar la posición espacial de los rasgos evaluados dentro de la escala del MDE generalizado.
Identificação de embarcações em imagens aerotransportadas de radar de abertura sintética (R-99 SAR) na área marítima do Brasil
Authors: Gamba Sérgio Roberto Horst , Sano Edson Eyji , Rocha Marcelo Peres
Published: October 2011

O objetivo deste trabalho foi identificar embarcações em imagens de radar obtidas pela aeronave R-99 da Força Aérea Brasileira. Dados de amplitude, obtidas na banda L e nas polarizações HH, HV, VH e VV da região de Porto de Tubarão, ES, foram processados por meio de diferentes tipos de realces, filtros, classificadores e transformadores espectrais. As imagens com maior potencial para identificar embarcações foram ainda analisadas para diferenciar embarcações militares de mercantes, considerando-se os cinco elementos de interpretação (forma, tamanho, sombra, tonalidade e fatores associados, isto é, o contexto em que as embarcações se encontram nas imagens) e as cinco fases de interpretação de imagens (detecção, reconhecimento, análise, dedução e classificação). A combinação de processamentos mais favoráveis foi o realce com contraste 50-200, seguido de filtro abertura ou erosão e classificador SVM (Support Vector Machine) ou transformação SCI (Synthetic Color Image). Foi possível discriminar embarcações nas fases de detecção e reconhecimento, enquanto a diferenciação entre embarcações mercantes e militares foi obtida nas fases de análise e dedução. No nível de classificação, não foi possível definir o tipo de embarcação militar (e.g., fragata ou contratorpedeiro) ou o tipo de embarcação mercante (e.g., petroleiro ou graneleiro).
ECD Management in a Middle East well with the aid of Formation Pressure While Drilling
Authors: Janjua Inamullah , Faizal Syed Abu , Al Dabyah Ali
Published: October 2011

One of the main challenges that today’s drilling operation faces is uncertainty in formation pressures. Excessive overbalance between the Equivalent Circulating Density (ECD) and formation pressure causes unnecessary, often detrimental formation breakdown, while underbalance drilling increases the risk of drilling kicks which can lead to catastrophic blowouts at the worst case scenario. Due to the uncertainty in formation pressures, managing the ECD becomes quite challenging and difficult. The ECD presents a significant drilling parameter particularly in wells that have a narrow window between the fracture gradient and pore-pressure gradient. Therefore, as early as possible knowledge of pore pressures, is highly sought after by the operating company.

Formation pressure while drilling (FPWD) technology has proved over the past few years to provide accurate formation pressures during drilling. Apart from the use of formation pressures to calculate fluid gradients, mobilities and identify tight zones, it has also found its usefulness in ECD management.

This paper presents a case study from an onshore horizontal well in the Middle East, which discusses the successful application of FPWD in ECD management. Due to the lack of reservoir formation pressure data, a heavier mud than necessary was used to drill the reservoir section to avoid risk of formation fluid influx. However, accurate measurements of pore pressures in real time recorded from a FPWD tool indicated lower pore pressures than expected. Consequently, based on that real time data, decision was made to significantly reduce the ECD, which resulted in improved hole cleaning, performance, increased rate of penetration, among other benefits.
Assessing performance in the management of the urban water cycle
Authors: Picazo-Tadeo Andrés J. , Sáez-Fernández Francisco J. , González-Gómez Francisco
Published: October 2011

This paper proposes the use of directional distance functions and Data Envelopment Analysis techniques to assess technical efficiency in the provision of the different stages of the urban water cycle in Andalusia, a Southern European region. Evaluating performance in the management of specific stages of the urban water cycle provides utility managers and regulating authorities with relevant information that may not be detected by more conventional approaches based on assessing performance at utility level. We find that Andalusian water and sewage utilities could achieve significant increases in the volume of water delivered without diminishing the output of their other services and using the same quantities of inputs. Potential increases are also important for the volume of sewage collected, thus entailing significant environmental benefits in a territory where water scarcity has seen the efficient management of this natural resource become a pressing obligation.
The urban water reform project: a critical discourse analysis of the water policy making process in Delhi, India
Authors: Asthana Vandana
Published: October 2011

Making sense of policy processes in India requires an understanding of how particular ways of thinking about water have gained ascendancy in national and state discourses, and how they have determined the frame through which water is perceived, defined and handled. The way in which the concept of water is framed has important implications for the ways in which water reform policies come to be shaped. Shifting narratives of the causes and solutions to water issues in a neoliberal India both drive and produce policy processes, making available or constraining policy choices in which different forms of water knowledge can be available and mobilized. Using methods of critical discourse analysis, this paper uses the Delhi Water Reform Project as a basis for understanding how power and knowledge define spaces of engagement among a range of positioned actors like the World Bank, the Government of Delhi, and civil society. It argues that their strategies are constructed in a way that permits intervention in a manner so as to promote a particular kind of technical and managerial approach that lends persuasiveness to policy instruments.