Heat transfer in multi-layered media with temperature dependent sources

Summary The paper describes a theoretical investigation of heat transfer in stratified horizontal slab and spherical shell containing temperature dependent heat sources. The desired expressions of temperatures contain only ordinary functions suitable for high speed computation. The results can find applications in defining the local and global temperature distributions in the earth's crust.     

Integrated geospatial,geostatistical, and remote-sensing approach to estimate groundwater level in North-western India

The depletion of groundwater resources in Northwest India has been extensively studied. The top priority to meet the scarcity of water for irrigation, industrial and domestic purposes is supplemented by groundwater. Geostatistical modelling approach is considered to be beneficial tool for the assessment, evaluation, monitoring, and management of groundwater resources. This study is an attempt to analyze the spatio-temporal variability of groundwater level in semi-arid region of Panipat district, Haryana, India using kriging technique to fill the data gaps. Ordinary kriging was found optimal for the interpolation of groundwater levels. The results revealed that there was not much seasonal variation and also the groundwater flow direction remained almost constant in the study area during the assessment period. Spatial variability analysis showed significant variation in groundwater level and further depicted that the study area had undergone more or less decline in groundwater over the period of time. To validate the observations and results geo spatial and remote sensing techniques including normalised difference vegetation index and impervious surface relationships were worked out. It was further co-related with the rainfall data and the canal network existing in Panipat region. The integrated approach substantiated the observed results with the ground reality and helped in better understanding of the causes of declining groundwater trend in central part of Panipat.     

Determinants of CO2 emission for post-Soviet Union independent countries

This article analyses the determinants of CO₂ emission for 15 post-Soviet Union independent (PSI) countries given their recent transition to market-based economies and their relatively high levels of corruption. The direct and indirect effects of economic growth on CO₂ emission for the PSI countries are derived using a multiple-equation generalized method of moment (GMM) approach to account for simultaneity among corruption, growth and CO₂ emission. A linear relationship between gross domestic product (GDP) and CO₂ emission was observed from the analysis. Furthermore, GDP influences CO₂ emission directly, but also indirectly through its impact on corruption. Similarly, corruption affects CO₂ emission directly, as well as indirectly through its impact on GDP. Political democracy and economic freedom increase CO₂ emission indirectly through their impact on economic growth. Improved energy efficiency and the EU climate policy reduce CO₂ emission, while inflows of foreign direct investment tend to increase CO₂ emission.

Policy relevance

First, PSI countries need to invest more in efficient energy technologies to mitigate CO₂ emission levels significantly. Second, PSI policies aimed at reducing deforestation (thereby increasing population density) may help mitigate carbon emission. Third, PSI countries would be well served to recognize the detrimental effects of foreign direct investment before embarking on a misguided policy path that attracts such inflows at any cost.     

Manganese-chromium systematics in sulfides of unequilibrated enstatite chondrites

Abstract— We measured with a secondary ion mass spectrometer Mn/Cr ratios and Cr isotopes in individual grains of Mn-bearing sulfides (i.e., sphalerites, ZnS; alabandites, MnS; and niningerites, MgS) in nine unequilibrated enstatite chondrites (UECs). The goals were to determine whether live ⁵³Mn (half-life ～3.7 Ma) was incorporated in these objects at the time of their isotopic closure and to establish whether Mn-Cr systematics in sulfides in UECs can be used as a high-resolution chronometer to constrain formation time differences between these meteorites. Sulfide grains analysed in four of these UECs, MAC 88136 (EL3), MAC 88184 (EL3), MAC 88180 (EL3), and Indarch (EH4), have clear ⁵³Cr excesses. These ⁵³Cr excesses can be very large (δ⁵³Cr/⁵²Cr ranges up to ～18,400%, the largest ⁵³Cr excess measured so far) and, in some grains, are well correlated with the Mn/Cr ratios. Thus, they were most likely produced by the in situ decay of ⁵³Mn in the meteorite samples. In the remaining five meteorites, no detectable excesses of ⁵³Cr were found, and only upper limits on the initial ⁵³Mn/⁵⁵Mn ratios could be established. The four meteorites with ⁵³Cr excesses show variations in the inferred ⁵³Mn/⁵⁵Mn ratios in various sulfide grains of the same meteorite. The Mn-Cr systematics in these sulfides were disturbed (during and/or after the decay of ⁵³Mn) by varying degrees of reequilibration. Provided ⁵³Mn was homogeneously distributed in the region of the early solar system where these objects formed, the data suggest that the time of the last isotopic equilibration of sulfides in EL chondrites occurred at least 3 Ma after a similar episode in EH chondrites.     

Propagator matrices for some geothermal problems

Summary In problems of linear flow of heat in inhomogeneous media, the governing equation is a second order ordinary differential equation with variable coefficients. When transformed into a set of first order ordinary differential equations with variable coefficients, the problem becomes amenable to an elegant method of propagator matrices. In this paper the propagator matrices for some steady and unsteady heat conduction problems (including a case of heat generation by an irreversible first order reaction) having conductivity and heat generation functions as piecewise continuous, have been described.     

On the energy flux of Hide waves

Summary There are two ways to define the energy flux for Hide waves, one from its equations of motion and the other by multiplying its mean energy density by group velocity and these lead to different results FollowingLonguet-Higgins we point out that this is due to certain arbitrariness in the definition of the energy flux and that their difference is just a solenoidal vector.Dedicated to the memory of Dr.V. A. Wynne, 1945–1972.     

Propagator matrix formulation for earth currents of deep internal origin

Summary The problem of the distribution of the poloidal electric field in the mantle, originating from the core-mantle boundary, is formulated in terms of propagator matrices suitable for calculations for a wide variety of piece-wise continuous models of the mantle. The elements of the propagator matrix for some interesting variations of the electric conductivity are presented.