Peraluminous sapphirine-cordierite pods in Mg-rich orthopyroxene granulite from southern India: Implications for lower crustal processes

Sapphirine-cordierite intergrowths occur as pods within garnet-absent, high-Mg orthopyroxene-granulite xenoliths in the Kambam valley, Madurai Block, southern India. Whereas the cores of the pods are composed of sapphirine (X-Mg = 0.871-0.897) - cordierite (X-Mg = 0.892-0.931) intergrowth along with rutile, zircon and monazite, the rims are characterized by cordierite, apatite, plagioclase, K-feldspar, quartz and minor calcite. The surrounding matrix comprises orthopyroxene (maximum Al2O3 4.1 wt.%, X-Mg 0.848-0.850), plagioclase, biotite and quartz, similar to the assemblage in the surrounding charnockites. Sapphirine in the Kambam rocks is characterized by high Al contents with an end-member composition in the range of 7:9:3 and 3:5:1. The occurrence of peraluminous sapphirine in association with cordierite and in the absence of phases such as sillimanite and garnet is distinct from ultrahigh-temperature assemblages in other localities within the Madurai Block. The peraluminous composition of the pods suggests that these domains could represent cryptic pathways through which aluminous melts migrated. The reaction of such peraluminous melts with Mg-rich orthopyroxene in the host granulite at temperatures of 1025 degrees C and pressures around 8 kbar as computed from phase equilibria modeling followed by an isobaric cooling is inferred to have generated the sapphirine-cordierite pods. The unusual high-Mg orthopyroxene granulite suggests interaction of supracrustal rocks with mafic magmas, which probably acted as the heat source for the partial melting of lower crust and UHT metamorphism.

From Molecular to Supramolecular: An Exploration into the Modes of Self-assembly in Conformationally Locked Polycyclitols

This brief account highlights the notable findings of our investigation into the supramolecular chemistry of conformationally locked polycyclitols in the solid state. The study was aimed at analyzing the crystal packing and unraveling the modalities of non-covalent interactions (particularly, intramolecular vis-a-vis intermolecular OH center dot center dot center dot O hydrogen bonds) in polyols. The know-how obtained thereof, was successfully utilized to engineer self-assemblies of designer polycyclitols, having hydrogen bond donors and acceptors fettered onto a trans-decalin scaffold. The results seek to draw particular attention to the intrinsic attribute of this rigid carbocyclic framework to lock functional groups into spatially invariant positions and bring potential intramolecular hydrogen bonding partners into favorable interaction geometry to engender predictability in the self-assembly patterns.

On the recurrence of great subduction zone earthquakes

The last decade has witnessed two unusually large tsunamigenic earthquakes. The devastation from the 2004 Sumatra Andaman and the 2011 Tohoku-Oki earthquakes (both of moment magnitude >= 9.0) and their ensuing tsunamis comes as a harsh reminder on the need to assess and mitigate coastal hazards due to earthquakes and tsunamis worldwide. Along any given subduction zone, megathrust tsunamigenic earthquakes occur over intervals considerably longer than their documented histories and thus, 2004-type events may appear totally `out of the blue'. In order to understand and assess the risk from tsunamis, we need to know their long-term frequency and magnitude, going beyond documented history, to recent geological records. The ability to do this depends on our knowledge of the processes that govern subduction zones, their responses to interseismic and coseismic deformation, and on our expertise to identify and relate tsunami deposits to earthquake sources. In this article, we review the current state of understanding on the recurrence of great thrust earthquakes along global subduction zones.

Probable maximum precipitation estimation for catchments in Mahanadi river basin

Probable maximum precipitation (PMP) is a theoretical concept that is widely used by hydrologists to arrive at estimates for probable maximum flood (PMF) that find use in planning, design and risk assessment of high-hazard hydrological structures such as flood control dams upstream of populated areas. The PMP represents the greatest depth of precipitation for a given duration that is meteorologically possible for a watershed or an area at a particular time of year, with no allowance made for long-term climatic trends. Various methods are in use for estimation of PMP over a target location corresponding to different durations. Moisture maximization method and Hershfield method are two widely used methods. The former method maximizes the observed storms assuming that the atmospheric moisture would rise up to a very high value estimated based on the maximum daily dew point temperature. On the other hand, the latter method is a statistical method based on a general frequency equation given by Chow. The present study provides one-day PMP estimates and PMP maps for Mahanadi river basin based on the aforementioned methods. There is a need for such estimates and maps, as the river basin is prone to frequent floods. Utility of the constructed PMP maps in computing PMP for various catchments in the river basin is demonstrated. The PMP estimates can eventually be used to arrive at PMF estimates for those catchments. (C) 2015 The Authors. Published by Elsevier B.V.

Application of principal component analysis to gas sensing characteristics of Cr0.8Fe0.2NbO4 thick film array

The transient changes in resistances of Cr0.8Fe0.2NbO4 thick film sensors towards specified concentrations of H-2, NH3, acetonitrile, acetone, alcohol, cyclohexane and petroleum gas at different operating temperatures were recorded. The analyte-specific characteristics such as slopes of the response and retrace curves, area under the curve and sensitivity deduced from the transient curve of the respective analyte gas have been used to construct a data matrix. Principal component analysis (PCA) was applied to this data and the score plot was obtained. Distinguishing one reducing gas from the other is demonstrated based on this approach, which otherwise is not possible by measuring relative changes in conductivity. This methodology is extended for three Cr0.8Fe0.2NbO4 thick film sensor array operated at different temperatures. (C) 2015 Elsevier B.V. All rights reserved.

Effect of Microtopography, Slope Length and Gradient, and Vegetative Cover on Overland Flow Through Simulation

Overland flow on a hillslope is significantly influenced by its microtopography, slope length and gradient, and vegetative cover. A 1D kinematic wave model in conjunction with a revised form of the Green-Ampt infiltration equation was employed to evaluate the effect of these surface conditions. The effect of these conditions was treated through the resistance parameter in the kinematic wave model. The resistance in this paper was considered to be made up of grain resistance, form resistance, and wave resistance. It was found that irregular slopes with microtopography eroded more easily than did regular slopes. The effect of the slope gradient on flow velocity and flow shear stress could be negative or positive. With increasing slope gradient, the flow velocity and shear stress first increased to a peak value, then decreased again, suggesting that there exists a critical slope gradient for flow velocity and shear stress. The vegetative cover was found to protect soil from erosion primarily by enhancing erosion-resisting capacity rather than by decreasing the eroding capability of overland flow.

Calidad física –organoléptica del café (Coffea arabica L.), en manejo orgánico y manejo convencional en fincas de San Juan del Río Coco - Madriz, ciclo 2013-2014

El café (Coffeaarabica L.) de Nicaragua se caracteriza por su alta calidad, lo que lo lleva a competir entre los cafés especia les que son cotizados internacionalmente, mediante el concurso de taza de la excelencia del café. La calidad del café es un atributo multifactorial que puede ser afectado por la altura y factores de manejo en la etapa de producción, así como durante la cosecha, beneficiado y transporte. El objetivo del estudio fue evaluar la calidad física y organoléptica del café en fincas localizadas en tres zonas altitudinales de San Juan del Río Coco, Madriz , durante la zafra cafetalera 2013 - 2014 . Se colectaron muestras de café en seis fincas con manejo orgánico y seis fincas con manejo convencional, localizadas en tres niveles de altura (771 - 892; 984 - 1 ,064 y 1 , 209 - 1 , 327 msnm) . A las muestras se les hizo análisis físico y organoléptico en los laboratorios de calidad de la Central de Cooperativas PRODECOOP R.L. - Palacagüina - Madriz . Se hizo una caracterización de cada finca, incluyendo el manejo cultural y fitosanitario , tipo de suelo, incidencia de plagas y características socioeconómicas. Los resultados indican que de las muestras de las fincas la calificación obtenida osciló entre 79 y 82 puntos porcentuales de calidad, observándose una finca con manejo orgánico y una con manejo convencional con el mayor puntaje, ubicadas a 1 , 238 y 1 , 327 msnm respectivamente. Fincas a al turas medias mostraron resultados medios, sin embargo las muestras de fincas de baja altitud mostraron calificación alta y también la menor calificación.

Legislação sobre licitações e contratos administrativos

Lei nº 8.666, de 21 de junho de 1993, que regulamenta o art. 37, inciso XXI, da Constituição Federal; Lei nº 10.520, de 17 de julho de 2002, Decreto nº 5.450, de 31 de maio de 2005, Lei nº 12.232, de 29 de abril de 2010, Lei nº 12.462, de 4 de agosto de 2011 e Decreto nº 7.892, de 23 de janeiro de 2013.