A 3D generalized rigid particle contact model for rock fracture

Detailed rigid particle models have been proposed for modeling fracture in quasibrittle materials. The rigid particle circular models proposed in the literature do not properly reproduce the known rock friction angle and the observed rock tensile strength to compression strength ratio. In this article, a 3D rigid particle contact model, 3D-GCM, is presented which has been developed to study fracture phenomena in rock. The 3D-GCM contact model incorporates in a straightforward manner the force versus displacement relationships of the traditional contact point contact model model, PCM. Furthermore it provides both moment transmission and simple physical constitutive models based on standard force displacement relationships. The 3D-GCM model is validated against known triaxial and Brazilian tests of a granite rock. It is shown that the enhanced rigid particle model leads to a better agreement with the experimental results

Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter

NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm-1 torr-1 in the drift region, demonstrating negligible recombination luminescence. A primary scintillation yield of 81 \pm 7 photons was obtained for 5.9 keV X-rays, corresponding to a mean energy of 72 \pm 6 eV to produce a primary scintillation photon in xenon.Comment: 16 pages, 10 figures, accepted for publication in JINS

Valoração econômica da perda de solo na cultura de cana-de-açúcar colhida crua e queimada no município de Campos dos Goytacazes.

Este trabalho foi realizado no Município de Campos dos Goytacazes, RJ e teve como objetivo valorar economicamente as perdas de solo em relação aos nutrientes perdidos na cultura de cana-de-açúcar sob dois sistemas distintos de colheita, cana-de-açúcar crua e queimada em áreas de baixada e de tabuleiro. Utilizou-se a Universal Soil Loss Equation ? USLE e o método do custo de reposição de nutrientes, para realizar a estimação econômica das perdas de solo. Os resultados mostram que a taxa de perda de solo da cana-de-açúcar queimada foi quatro vezes maior quando comparada à taxa para cana-de-açúcar colhida crua para ambas as áreas estudadas. O custo de reposição dos nutrientes perdidos no cultivo da cana-de-açúcar sob sistema de colheita com queima prévia apresentou um valor de R$10,53 por hectare, já o custo para área com cana crua foi de R$ 2,61 por hectare em área de baixada e de R$43,59 por hectare para cana queimada e R$ 10,89 para cana crua em tabuleiro. Dessa forma, o sistema de manejo da colheita da cana crua contribui ambientalmente e economicamente para a preservação da fertilidade do solo

Mercapturate Pathway in the Tubulocentric Perspective of Diabetic Kidney Disease

BACKGROUND: The recent growing evidence that the proximal tubule underlies the early pathogenesis of diabetic kidney disease (DKD) is unveiling novel and promising perspectives. This pathophysiological concept links tubulointerstitial oxidative stress, inflammation, hypoxia, and fibrosis with the progression of DKD. In this new angle for DKD, the prevailing molecular mechanisms on proximal tubular cells emerge as an innovative opportunity for prevention and management of DKD as well as to improve diabetic dysmetabolism. SUMMARY: The mercapturate pathway (MAP) is a classical metabolic detoxification route for xenobiotics that is emerging as an integrative circuitry detrimental to resolve tubular inflammation caused by endogenous electrophilic species. Herein we review why and how it might underlie DKD. Key Messages: MAP is a hallmark of proximal tubular cell function, and cysteine-S-conjugates might represent targets for early intervention in DKD. Moreover, the biomonitoring of urinary mercapturates from metabolic inflammation products might be relevant for the implementation of preventive/management strategies in DKD.info:eu-repo/semantics/publishedVersio

Space and Ground Based Pulsation Data of Eta Bootis Explained with Stellar Models Including Turbulence

The space telescope MOST is now providing us with extremely accurate low frequency p-mode oscillation data for the star Eta Boo. We demonstrate in this paper that these data, when combined with ground based measurements of the high frequency p-mode spectrum, can be reproduced with stellar models that include the effects of turbulence in their outer layers. Without turbulence, the l=0 modes of our models deviate from either the ground based or the space data by about 1.5-4.0 micro Hz. This discrepancy can be completely removed by including turbulence in the models and we can exactly match 12 out of 13 MOST frequencies that we identified as l=0 modes in addition to 13 out of 21 ground based frequencies within their observational 2 sigma tolerances. The better agreement between model frequencies and observed ones depends for the most part on the turbulent kinetic energy which was taken from a 3D convection simulation for the Sun.Comment: 13 pages, 7 figures, ApJ in pres

An experimental study of gill net and trammel net 'ghost fishing' off the Algarve (southern Portugal)

Four 100 m lengths of both monofilament gill nets and trammel nets were deployed at depths between 15 and 18 m off the coast of the Algarve (south of Portugal) between April 1995 and June 1996. The nets were set on a natural rocky bottom with one end cut loose to simulate lost nets. Changes in net structure (net height, effective fishing area, movement, colonisation, wear and tear) and their catches (species, sizes, numbers, and biomass) were monitored by divers. Similar patterns were observed in all the nets, with a sharp decrease in net height and effective fishing area, and an increase in visibility within the first few weeks. Net movement was negligible except in the case of interference from other fishing gears. Catch rates were initially comparable to normally fished gill nets and trammel nets in this area, but decreased steadily over time. No sea birds, reptiles or mammals were caught in any of the 8 nets. Catches were dominated by fish (89 % by number, at least 27 species), in particular by sea breams (Sparidae) and wrasses (Labridae). Under the conditions experienced throughout the study the fishing Lifetime of a 'lost' net is between 15 and 20 wk. Based on an exponential model, we estimated that 100 m lengths of gill net and trammel net will catch 314 and 221 fish respectively over a 17 wk period. However, we consider this to be an underestimate due to high rates of predation and scavenging by octopuses, cuttlefish, moray eels, conger eels, and other fish such as the wrasse Coris julis. When the nets were surveyed in the following spring, 8 to 11 mo after being deployed, they were found to be completely destroyed or heavily colonised by algae and had become incorporated into the reef

Avaliação do Potencial Anti-helmíntico do Extrato Etanólico e Óleo Essencial de Chenopodium Ambrosioides L. no Controle de Ancylostoma Spp. de Cães

A fitoterapia é frequentemente utilizada no controle das parasitoses de diversas espécies animais. Objetivou-se avaliar as larvas infectantes (L3) de Ancylostoma spp. imersas em extrato etanólico e óleo essencial de Chenopodium ambrosioides L. no teste in vitro. Utilizou-se água destilada (controle negativo) e albendazole e associação comercial de praziquantel, pamoato de pirantel e febantel (controles positivos). O extrato etanólico de C. ambrosioides L. nas concentrações 0,5%, 1,0%, 2,0%, 3,0%, 4,0%, 5,0%, 6,0%, 8,0%, 10,0%, 12,0% e 20% apresentaram insuficiente atividade para o efeito larvicida. O óleo essencial na concentração de 150µL.mL-1 foi eficaz contra L3. A formulação de biscoito manipulado com a concentração de 37,5µL.g-1 do óleo essencial C. ambrosioides L reduziu o número de ovos por grama de fezes dos cães. O teste in vivo 26 cães adultos foram divididos em três grupos: F1 (biscoito sem princípio ativo), F2 (biscoito com princípio ativo de C. ambrosioides L.), F3 (biscoito com princípio ativo alopático). No hemograma, houve diferença significativa no F1 para os valores de hemácias, hematócrito e concentração de hemoglobina corpuscular média (CHCM) e albumina na bioquímica sérica. O F2 apresentou diferença no CHCM e na bioquímica a proteína sérica e globulina. O F3, os valores para linfócitos e monócitos no hemograma e a albumina e globulina foram diferentes entre o M1 e M2. No exame parasitológico o F1 manteve-se parasitado, enquanto o F2 reduziu de forma significativa a infecção e o F3 apresentou resultado negativo no M2. Conclui-se que a formulação de biscoito manipulado com óleo essencial C. ambrosioides L reduziu a infecção de Ancylostoma spp. em cães naturalmente parasitados

Hematologia, bioquímica e cortisol de gatos tratados com prednisolona

A utilização de glicocorticóides pode desencadear diversas alterações em animais, entretanto, a espécie felina é citada como menos susceptível aos efeitos colaterais deste fármaco. Este ensaio clínico teve como objetivo verificar as possíveis alterações em gatos tratados com corticóides através da avaliação do hemograma, bioquímica sérica e urinária e cortisolemia. Foram utilizados oito gatos, os quais receberam 6mg/kg de prednisolona pelo período de 14 dias consecutivos. No hemograma verificou-se aumento significativo no volume corpuscular médio (VCM), plaquetas e diminuição dos linfócitos entre o momento inicial (M1) e final (M2), mas os resultados estavam dentro dos limites fisiológicos. Os monócitos apresentavam-se acima dos valores de normalidade antes e após o tratamento. Na avaliação bioquímica sérica e urinária houve significante elevação entre os dois momentos avaliados para aspartato amino transferase (AST), colesterol (Col), gama-glutamiltransferase urinária (?-GTur), enquanto que os níveis séricos de potássio e cortisol diminuíram. Pode-se concluir que o uso de prednisolona nas condições desta pesquisa, provoca alterações precoces, em apenas duas semanas de tratamento, que indicam efeitos adversos como linfopenia, redução da produção endógena de cortisol e aumento da excreção de potássio observado nos valores encontrados nos exames laboratoriais. Adicionalmente, pela hipocortisolemia observa-se supressão do eixo pituitário-hipotalâmico-adrenal

Defining child maltreatment among lay people and community professionals: exploring consensus in ratings of severity

The way in which laypeople and community professionals define child maltreatment in a family context is essential in decision-making on its referral and assessment. Despite differences found in the perspectives of the two groups, operating definitions are needed, which integrate them. The purpose of this work is to define types of maltreatment, integrating both perspectives (study 1) and to analyse the assessment of the severity of these practices (study 2). In study 1, a consensual qualitative research method was used to analyse 123 interviews of laypeople and 9 annual reports of social and health community services. A joint analysis of 1235 record units allowed us to obtain an integrated definition comprised of 6 types and 20 subtypes of maltreatment. In study 2, with the material gathered in study 1, a scale was created with 4 degrees of severity, based on the Maltreatment Classification System. Next, a sample of 159 interns, from health and social science areas with or without contact with situations of maltreatment, evaluated the severity of the items. An analysis of Kendall's coefficient of concordance showed a lack of consensus in 9 of the 20 subtypes, with physical abuse and sexual abuse being the most consensual types, as opposed to psychological abuse and neglect. These studies underscore the importance of understanding this phenomenon at a community level, and suggest that public awareness may facilitate the referral of these practices, minimizing the over-reporting and under-reporting of cases, and encouraging early and preventive intervention.info:eu-repo/semantics/acceptedVersio