Generalized thermostatistics and wavelet analysis of solar wind and proton density variability

In this paper, we analyze the probability density function (PDF) of solar wind velocity and proton density, based on generalized thermostatistics (GT) approach, comparing theoretical results with observational data. The time-series analyzed were obtained from the SOHO satellite mission where measurements were sampled every hour. We present in the investigations data for two years of different solar activity: (a) moderate activity (MA) period (1997) and (b) high activity (HA) period (2000). For the MA period, the results show good agreement between experimental data and GT model. For the HA period, the agreement between experimental and theoretical PDFs was fairly good, but some distortions were observed, probably due to intermittent characteristics of turbulent processes. As a complementary analysis, the global wavelet spectrum (GWS) was obtained, allowing the characterization of the predominant temporal variability scales for both periods and the stochastic aspects of the nonlinear solar wind variability are discussed.     

Deep exploration using long-offset transient electromagnetics: interpretation of field data in time and frequency domain

In the framework of the Deep Electromagnetic Soundings for Mineral Exploration project, we conducted ground-based long-offset transient-electromagnetic measurements in a former mining area in eastern Thuringia, Germany. The large-scale survey resulted in an extensive dataset acquired with multiple high-power transmitters and a high number of electric and magnetic field receivers. The recorded data exhibit a high data quality over several decades of time and orders of magnitude. Although the obtained subsurface models indicate a strong multi-dimensional subsurface with variations in resistivity over three orders of magnitude, the electrical field step-on transients are well fitted using a conventional one-dimensional inversion. Due to superimposed induced polarization effects, the transient step-off data are not interpretable with conventional electromagnetic inversion. For further interpretation in one and two dimensions, a new approach to evaluate the long-offset transient-electromagnetic data in frequency domain is realized. We present a detailed workflow for data processing in both domains and give an overview of technical obstructions that can occur in one domain or the other. The derived one-dimensional inversion models of frequency-domain data show strong multi-dimensional effects and are well comparable with the conventional time domain inversion results. To adequately interpret the data, a 2.5D frequency-domain inversion using the open source algorithm MARE2DEM (Modeling with Adaptively Refined Elements for 2-D EM) is carried out. The inversion leads to a consistent subsurface model with shallow and deep conductive structures, which are confirmed by geology and additional geophysical surveys.     

WISE USE OF WETLAND FOR SUSTAINABLE LIVELIHOOD THROUGH PARTICIPATORY APPROACH： A CASE OF ADAPTING TO CLIMATE CHANGE

1INTRODUCTION Hydroponics(aGreekword,hydromeanswater andponos,labour),asoil-lessagriculture,isa termtobedescribedinseveralwaysinwhichplants cangrowwithoutsoil,byuseofaninertmedium whereplantcantakeupessentialnutrients,either fromwaterinwhichanutrientsolutionisaddedor fromorganicmaterialsthatexistsinthemedium.Thesemediacanbegravel,sand,peat,vermiculate,prelite,sawdustorotherplantmatters(organiccom ponents).Therefore,theprocessinwhichaquatic weedsaredumpedonwatertoconstructfloatingbed orart…     

Formation of corundum megacrysts during H<Subscript>2</Subscript>O-saturated incongruent melting of feldspar: P–T pseudosection-based modelling from the Skattøra migmatite complex,North Norwegian Caledonides

Corundum megacryst-bearing rocks associated with the high-pressure migmatites of the Skattøra migmatite complex (SMC) belonging to the Nakkedal Nappe Complex, North Norwegian Caledonides, display a classical example of incongruent melting of plagioclase under water-saturated conditions. Petrography and micro-textures suggest that several centimetre long corundum megacrysts formed from the silicate melt along with amphibole (pargasite) and plagioclase (X_An ~ 0.47). The corundum-bearing leucosomes are rich in biotite compared to the other mafic units of SMC. Locally, margarite occurs in coronas around corundum megacrysts. Geochemically, the corundum-bearing rocks are enriched in Al, K, Rb and Ba and depleted in Fe, Mg and Ca compared to the leucogabbroic host rock. A P–T pseudosection of the leucogabbro indicates that feldspar breakdown and corundum formation occurred at temperatures >850 °C and pressure >1.2 GPa. The calculated equilibrium P–T of the corundum-bearing rock corresponds to 750–825 °C and 0.9–1.1 GPa. The P–T pseudosection of margarite indicates that margarite formed after cooling and decompression to P–T conditions corresponding to 600 °C at 0.5 GPa. Based on geochemical and mineral chemical analysis coupled with thermodynamic modelling, we suggest that formation of corundum occurred as a result of high-pressure incongruent melting of plagioclase in the presence of a K-, Rb- and Ba-rich external fluid. It is also suggested that the external fluid transported out portions of Ca, Fe and Mg, resulting in an increase of the peraluminousity of the melt and promoting further growth of corundum.     

Simple statistical and mineralogical studies as petrogenetic indicator for neoproterozoic mylliem porphyritic granites of east Khasi Hills,Meghalaya, Northeastern India

The porphyritic granite body (∼ 600 Ma) around Mylliem (25°32′N: 91°52′E), east Khasi hills district, Meghalaya occurs as a distinct intrusive body into the host rock of low- grade meta-sediments belonging to Proterozoic Shillong Group. The porphyritic granite body manifests prominent lath- shaped feldspar phenocrysts giving rise to dominant porphyritic texture. Further, this porphyritic granite body is characterized by primary foliation (defined by parallely arranged feldspar laths), tongues and appophyses and xenoliths of older metamorphics. Petrographically, the Mylliem porphyritic granite is grey leucocratic, coarse grained, phanerocrystalline with modal variants ranging from granite to granodiorite tending to tonalite. Simple statistical studies based on correlation coefficient values involving modal variables of the Mylliem porphyritic granite bodies appear significant in majority of the cases indicating magmatic crystallization. Use of relevant thermometric method indicates temperature of equilibration of the body in the range of 369°C to 507°C. The crystallization of the Mylliem porphyritic granite pluton initiated at an average lithostatic pressure in the tune of ∼11 Kb followed by dominant P_H2O controlled milieu. Spatially projected mineralogical parameters suggest a general trend of the magmatic cooling of the body from margin inward with sudden influx of volatile matters that occasionally offsets mineralogical trends.     

Role of Turbulent Bursts over Mobile Sand Beds under Dynamic Equilibrium Flow Conditions

Water Resources - Turbulent burst corroborate many significant events of bed-load transport in open channel flows. Present study aims to focus the role of turbulent bursting occurrences in an...     

National Inventory of Rabi Pulses in India Using Remotely Sensed Data

A scheme called National Food Security Mission was launched by Government of India in 2007 for wheat, rice and pulses crops. At the request of Ministry of Agriculture for monitoring intensification of pulses a project called Pulses Intensification was taken up in Rabi season 2012–2013. Reliable statistics using advanced methods is very important for variety of pulse crops. Remotely sensed data can help in pre-harvest area estimation of pulse crops. Pulses in India are grown as partly scattered and partly contiguous crop. Growth in scattered areas and poor vegetation canopy of some of the pulse crops poses a challenge in its identification and discrimination using remotely sensed data. National Inventory of Rabi pulse crops in major growing regions of northern and southern parts of India was attempted. Multi-date AWiFS data and multi-date NDVI products of AWiFS of Rabi season 2014–2015 were used to study spectral-temporal behavior of pulse crops. Pulse crops accuracies of more than 95 % was observed in contiguous areas and 50–80.77 % in scattered regions. All India area estimate of Rabi pulses for the year 2014–2015 was 8963.327 ‘000 ha.     

回线源瞬变电磁法有限体积三维任意各向异性正演及分析

目前,瞬变电磁法(TEM)数据基本都是基于各向同性模型进行反演解释,这对于存在明显电性各向异性的勘探区域会产生较大的反演解释误差.为分析电各向异性对回线源瞬变电磁信号的影响方式与程度,本文通过求解离散化的全张量电导率时间域Helmholtz方程,实现了基于有限体积法的TEM任意各向异性的三维正演算法.该算法采用基于交错网格的拟态有限体积法(MFV)对时域Maxwell方程组进行空间域离散,并利用后退欧拉算法(Backward Euler Method)进行时间域离散.为提高时域电磁场的求解精度与效率,该算法将时间分段等步长算法与方程直接求解法相结合.通过对一维各向异性模型以及三维复杂各向同性模型进行测试,验证了本算法对于回线源瞬变电磁响应计算的正确性及有效性.最后,通过对几类典型电各向异性介质中大回线源瞬变电磁信号响应的分析,总结了不同电各向异性类型对TEM电磁信号的影响模式,结果表明,主轴各向异性情况下TEM信号主要受水平方向电导率的影响,倾斜各向异性对TEM信号的影响程度远大于水平各向异性,而通过水平各向异性信号能较清晰判断出各向异性主轴方向.