Múltiplos processos de evolução geoquímica para as rochas alcalinas do complexo intrusivo de Rio Bonito, Estado do Rio de Janeiro, Brasil: idades 40Ar/39Ar e U-Pb e isótopos Lu-Hf em zircão – considerações sobre assinatura crustal

This article presents geochemical characteristics of the alkaline rocks of Rio Bonito intrusive complex, State of Rio de Janeiro, Brazil, which is constituted mainly by nepheline syenite. The fractional crystallisation of this magma decreases K2O/(Na2O + K2O) and increases (Na + K)/Al. The TiO2, Fe2O3*, MgO, CaO, and P2O5 contents indicate fractionation of titanite, ilmenite, and clinopyroxene or amphibole. The total rare earth elements (REEs) are high, and the REE pattern is linear with negative gradient. The nepheline syenite aplite has low REEs, concave REE pattern, and positive Eu anomaly. The ultrabasic and basic mela-nepheline syenite samples have total REEs and light REEs higher than the felsic alkaline rocks. Therefore, the nepheline syenite magma is not derived directly from the alkaline ultrabasic magma. Laser-spot step‑heating 40Ar/39Ar ages for biotite and amphibole are 65.03 ± 0.70 and 65.03 ± 0.46. U-Pb ages LA-ICP-MS for two samples are 65.49 ± 0.30 and 65.18 ± 0.30. Values of εHf are negative for both samples, indicating an important crustal component in the evolution of Rio Bonito.Este artigo apresenta características geoquímicas das rochas alcalinas do complexo intrusivo de Rio Bonito, estado do Rio de Janeiro, Brasil, que é constituído principalmente por nefelina sienito. A cristalização fracionada desse magma diminui K2O/(Na2O + K2O) e aumenta (Na + K)/Al. Os conteúdos de TiO2, Fe2O3*, MgO, CaO e P2O5 indicam fracionamento de titanita, ilmenita, clinopiroxênio e anfibólio. O total de terras raras é alto, e o padrão é linear com gradiente negativo. O nefelina sienito aplito tem concentrações de terras raras baixas com padrão côncavo e anomalia positiva de Eu. As amostras de mela-nefelina sienito ultrabásico e básico têm total de terras raras e terras raras leves maiores que as rochas alcalinas félsicas. Portanto, o magma nefelina sienítico não é derivado diretamente do magma alcalino ultrabásico. Idades 40Ar/39Ar step-heating para biotita e anfibólio são 65,03 ± 0,70 e 65,03 ± 0,46. Idades U-Pb LA-ICP-MS de duas amostras são 65,49 ± 0,30 e 65,18 ± 0,30. Os valores de εHf são negativos para ambas as amostras, indicando um importante componente crustal na evolução de Rio Bonito

Alquimia, Ocultismo, Maçonaria: o ouro e o simbolismo hermético dos cadinhos (Séculos XVIII e XIX)

Este artigo apresenta a arqueologia das enigmáticas marcas impressas na base de cadinhos dos séculos XVIII e XIX recuperados nas escavações da Casa da Moeda do Rio de Janeiro, na década de 1980, e a explanação do seu significado simbólico à luz da alquimia, do ocultismo e da Maçonaria. Espraiando-se extraordinariamente mundo afora através de uma bem-sucedida estratégia de comunicação visual, a Maçonaria utilizou símbolos herméticos para a difusão de seus princípios nos mais diferentes suportes. Aparentemente estamos diante de um sinal de reconhecimento maçônico, o sinal exterior de uma organização oculta, só partilhado por iniciados e incompreensível para os demais, que contribuiu para difundir veladamente a doutrina maçônica por diferentes pontos do globo

M?ltiplos processos de evolu??o geoqu?mica para as rochas alcalinas do complexo intrusivo de Rio Bonito, Estado do Rio de Janeiro, Brasil : idades 40Ar/39Ar e U-Pb e is?topos Lu-Hf em zirc?o ? considera??es sobre assinatura crustal.

This article presents geochemical characteristics of the alkaline rocks of Rio Bonito intrusive complex, State of Rio de Janeiro, Brazil, which is constituted mainly by nepheline syenite. The fractional crystallisation of this magma decreases K2 O/(Na2 O + K2 O) and increases (Na + K)/Al. The TiO2 , Fe2 O3 *, MgO, CaO, and P2 O5 contents indicate fractionation of titanite, ilmenite, and clinopyroxene or amphibole. The total rare earth elements (REEs) are high, and the REE pattern is linear with negative gradient. The nepheline syenite aplite has low REEs, concave REE pattern, and positive Eu anomaly. The ultrabasic and basic mela-nepheline syenite samples have total REEs and light REEs higher than the felsic alkaline rocks. Therefore, the nepheline syenite magma is not derived directly from the alkaline ultrabasic magma. Laser-spot step-heating 40Ar/39Ar ages for biotite and amphibole are 65.03 ? 0.70 and 65.03 ? 0.46. U-Pb ages LA-ICP-MS for two samples are 65.49 ? 0.30 and 65.18 ? 0.30. Values of ?Hf are negative for both samples, indicating an important crustal component in the evolution of Rio Bonito.Este artigo apresenta caracter?sticas geoqu?micas das rochas alcalinas do complexo intrusivo de Rio Bonito, estado do Rio de Janeiro, Brasil, que ? constitu?do principalmente por nefelina sienito. A cristaliza??o fracionada desse magma diminui K2 O/(Na2 O + K2 O) e aumenta (Na + K)/Al. Os conte?dos de TiO2 , Fe2 O3 *, MgO, CaO e P2 O5 indicam fracionamento de titanita, ilmenita, clinopirox?nio e anfib?lio. O total de terras raras ? alto, e o padr?o ? linear com gradiente negativo. O nefelina sienito aplito tem concentra??es de terras raras baixas com padr?o c?ncavo e anomalia positiva de Eu. As amostras de mela-nefelina sienito ultrab?sico e b?sico t?m total de terras raras e terras raras leves maiores que as rochas alcalinas f?lsicas. Portanto, o magma nefelina sien?tico n?o ? derivado diretamente do magma alcalino ultrab?sico. Idades 40Ar/39Ar step-heating para biotita e anfib?lio s?o 65,03 ? 0,70 e 65,03 ? 0,46. Idades U-Pb LA-ICP-MS de duas amostras s?o 65,49 ? 0,30 e 65,18 ? 0,30. Os valores de ?Hf s?o negativos para ambas as amostras, indicando um importante componente crustal na evolu??o de Rio Bonito

CAD Detection in Patients With Intermediate-High Pre-Test Probability Low-Dose CT Delayed Enhancement Detects Ischemic Myocardial Scar With Moderate Accuracy But Does Not Improve Performance of a Stress-Rest CT Perfusion Protocol

ObjectivesThis study sought to compare computed tomography delayed enhancement (CTDE) against cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) for detection of ischemic scar and to test the additive value of CTDE as part of a comprehensive multidetector computed tomography (MDCT) stress–rest protocol including computed tomography perfusion (CTP) and computed tomography angiography (CTA) for the diagnosis of significant coronary artery disease (CAD).BackgroundCTDE has been recently described as a promising tool for noninvasive detection of myocardial scar, similarly to CMR-LGE techniques. Despite its theoretical potential as an adjunctive tool to improve MDCT accuracy for detection of CAD, its clinical performance has not been validated.MethodsOne hundred five symptomatic patients with suspected CAD (age 62.0 ± 8.0 years, 67% men) underwent MDCT, CMR, and x-ray invasive coronary angiography. The MDCT protocol consisted of calcium scoring, stress CTP under adenosine 140 μg/kg/min, rest CTP + CTA, and a low-dose radiation prospective scan for detection of CTDE. CMR-LGE was used as the reference standard for assessment of scar. Functionally significant CAD was defined as the presence of ≥90% stenosis/occlusion or fractional flow reserve measurements ≤0.80 in vessels >2 mm.ResultsCTDE had good accuracy (90%) for ischemic scar detection with low sensitivity (53%) but excellent specificity (98%). Positive and negative predictive values were 82% and 91%, respectively. On a patient-based model, MDCT protocol without integration of CTDE results had a sensitivity, specificity, and positive and negative predictive values of 90%, 81%, 80%, and 90%, respectively, for the detection of functionally significant CAD. Addition of CTDE results did not improve MDCT performance (90%, 77%, 77%, and 90%, respectively).ConclusionsCTDE has moderate accuracy for detection of ischemic scar in patients with suspected CAD. Integration of CTDE into a comprehensive MDCT protocol including stress–rest CTP and CTA does not improve MDCT accuracy for detection of significant CAD in intermediate-to-high pre-test probability populations

Magnetic coupling between Gd and Pr ions and magnetocaloric effect in Gd0.5Pr0.5Al2 compound.

In this work, we report the theoretical and experimental investigations on the magnetic and magnetocaloric properties for Gd 0.5 Pr 0.5 Al 2 compound in different magnetic fields. The magnetization features indicate that Gd 0.5 Pr 0.5 Al 2is ferrimagnetic at low temperatures. We also present data from X-ray magnetic circular dichroism (XMCD) experiments for this compound, with which we have confirmed that the magnetic moments of the Pr ions are antiparallel to the magnetic moments of the Gd ions. The magnetocaloric parameters, ΔT S and ΔS T , were obtained from calorimetric data and both curves present normal and inverse magnetocaloric effect. A theoretical model for ferrimagnetic coupling, including the crystalline electrical field anisotropy, was used to describe the ΔT S and ΔS Texperimental results

Continuous and Intermittent Drying of Rough Rice: Effects on Process Effective Time and Effective Mass Diffusivity

The choice of the drying process plays a key role in reducing the costs of electricity consumption in the food industry. Thus, this study aimed to evaluate continuous and intermittent drying of rough rice, using empirical and diffusion models to describe the drying kinetics, considering only effective time of operation to compare and evaluate these processes. Experiments were carried out during the month of April 2018, in Campina Grande, Paraiba Brazil, and were conducted with continuous and intermittent drying of rough rice grains (about 20 g, each experiment) using a fixed-bed dryer with constant power, at temperatures of 50 and 70 °C. For the intermittent experiments, the intermittency ratio was α = 2/3 and the drying periods were 10 and 20 min, with intermittency periods of 20 and 40 min, respectively. Comparison between continuous and intermittent drying kinetics indicated reduction in the effective time of all intermittent drying experiments, reaching up to 32.2%, hence promoting energy saving. It was also found that a one-dimensional diffusion model with boundary condition of the first kind properly described all rough rice drying processes and that the effective mass diffusivity is higher in intermittent drying, compared to continuous drying at the same temperature

Ambient Pressure Colossal Magnetocaloric Effect Tuned By Composition In Mn(1-x)fe(x)as.

The magnetocaloric effect (MCE) is the basis for magnetic refrigeration, and can replace conventional gas compression technology due to its superior efficiency and environment friendliness. MCE materials must exhibit a large temperature variation in response to an adiabatic magnetic-field variation and a large isothermal entropic effect is also expected. In this respect, MnAs shows the colossal MCE, but the effect appears under high pressures. In this work, we report on the properties of Mn(1-x)Fe(x)As that exhibit the colossal effect at ambient pressure. The MCE peak varies from 285 K to 310 K depending on the Fe concentration. Although a large thermal hysteresis is observed, the colossal effect at ambient pressure brings layered magnetic regenerators with huge refrigerating power closer to practical applications around room temperature.5802-