2,947 research outputs found
Feasibility of a Carbon Consumption Tax for Sustainable Development – a Case Study of India
Global climate change is a major issue confronting policymakers worldwide, and there is widespread scientific acceptance of the reality of climate change and its adverse consequences In terms of economic analysis, greenhouse gas emissions (GHG), which cause planetary climate changes, represent both an environmental externality and the overuse of a common property resource. The paper is premised around the hypothesis that tax policy can be used to address climate concerns by making less Green House Gas intensive purchases and investments more financially attractive. However, in the absence of an International framework capping GHG emissions, countries adopting mitigation policies incur costs that would not exist under global cooperation such as the loss of competitiveness and emissions leakage. A consumption tax based on the carbon footprint of a product levied on all products at the point of purchase by the final end-user, regardless of where the goods are produced using a Credit-method would be capable of addressing these concerns of emissions leakage and loss of competitiveness, while being WTO compliant. The author intends to test the feasibility and effectiveness of such a carbon consumption tax in the Indian Context. The author shall test the feasibility of levy of such a consumption tax in the context of India and evaluate the effectiveness in mitigating climate change and catering to the goal of sustainable development
Phase transitions in LuIrSi
We report the results of our investigations on a polycrystalline sample of
LuIrSi which crystallizes in the UCoSi type structure
(Ibam). These investigations comprise powder X-ray diffraction, magnetic
susceptibility, electrical resistivity and high temperature (120-300 K) heat
capacity studies. Our results reveal that the sample undergoes a
superconducting transition below 3.5 K. It also undergoes a first order phase
transition between 150-250 K as revealed by an upturn in the resistivity, a
diasmagnetic drop in the magnetic susceptibility and a large anomaly (20-30
J/mol K) in the specific heat data. We observe a huge thermal hysteresis of
almost 45 K between the cooling and warming data across this high temperature
transition in all our measurements. Low temperature X-ray diffraction
measurements at 87 K reveals that the compound undergoes a structural change at
the high temperature transition. Resistivity data taken in repeated cooling and
warming cycles indicate that at the high temperature transition, the system
goes into a highly metastable state and successive heating/cooling curves are
found to lie above the previous one and the resistance keeps increasing with
every thermal cycle. The room temperature resistance of a thermaly cycled piece
of the sample decays exponentialy with time with a decay time constant
estimated to be about 10 secs. The anomaly (upturn) in the resistivity and
the large drop (almost 45%) in the susceptibility across the high temperature
transition suggest that the observed structural change is accompanied or
induced by an electronic transition.Comment: 7 figures, 1 table and 18 reference
Study of Ni and Zn doped CeOFeAs: Effect on the structural transition and specific heat capacity
We have systematically studied the substitution of nonmagnetic Zn and
magnetic Ni at iron sites in Ce based oxypnictide. The parent compound
(CeOFeAs) shows an anomaly in resistivity around 150 K due to structural
transition from tetragonal (space group: P4/nmm) to orthorhombic structure
(space group: Cmma). Substitution of Zn suppresses this anomaly to lower
temperature (~130 K) but Ni substitution does not show any anomaly around this
temperature and the compound behaves like a metal. Further, we find that non
magnetic (Zn) doping leads to higher impurity scattering as compared to
magnetic Ni doping. Similar to the resistivity measurement, the specific heat
shows another jump near 4 K for CeOFeAs. This is attributed to the ordering of
Ce3+ moments. This peak shifts to 3.8 K for Zn substituted compound and there
is no change in the ordering temperature in the Ni substituted CeOFeAs. These
peaks are broadened in applied magnetic field (5 T) and the calculated magnetic
entropy tends to saturate at the same value for 0 T and 5 T external magnetic
field.Comment: 16 pages Text+Fig
Study of Eutectic Etching Process for Defects Analysis in n type 4H SiC
Silicon Carbide (SiC) is a wide bandgap material with unique properties attractive for high power, high temperature applications. The presence of defects in the crystal is a major issue prior device fabrication. These defects affect the performance of the device. To delineate and identify the defects an easy and quick method is desirable. In this study defects delineation in n-type 4H-SiC has been carried out by KOH, KOH+NaOH and KOH+Na2O2 melts. Variation in etch pits size was found at various concentrations of the NaOH in KOH and for different total etching times in the KOH+Na2O2 melt. The eutectic solution etching technique is found to be more efficient to delineate defects and provides control on etching and surface roughness. The etching rates have been estimated under different experimental conditions. Detailed morphological investigations have been performed by wide field high resolution optical microscopy and scanning electron microscopy
Evaluation of CSM-CERES-wheat in simulating wheat yield and its attributes with different sowing environments in Tarai region of Uttarakhand
Crop Environment Resource Synthesis (CSM-CERES)-Wheat model was used to simulate responses of two wheat varieties with various sowing environments. In this context, during the year 2007-08 and 2008-09, experiments on three sowing dates viz. November 20, December 15, and January 9 and two varieties (PBW-343 and WH-542) with three replications were conducted at the Norman E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture & Technology, Pantnagar (29°N, 79.29°E with 243.80 m above msl). Soil, plant, management and climatic data were collected from the experimental field. The data of 2007-08 and 2008-09 were used for model calibration and validation, respectively. Results revealed that the for model outputs were in good agreement with their corresponding observed values with 20th November sown crop than other sowings of crop in terms of phenological events, biomass accumulation and grain yields. However, variety PBW-343 showed close proximity between simulated and observed outcomes with all sowing dates. The percent root mean square error (% RMSE) values ranged from 5.9 – 15.6%, 2.2 – 7.6% for days to attain anthesis and physiological maturity, respectively. Moreover, %RMSE and t-value ranged from 5.7–12.2% (t= -4.5 to 1.8), 1.6 – 3.3% (t= -4.1 to 4.5) and 1.9 – 5.8% (t= -3.7 to 1.5) for product weight, vegetative weight and product harvest index, respectively. Inspite of that, model fails to simulate maximum leaf area index having % RMSE from 53.2 – 62.9%. These results indicate that CERES-Wheat model can be used as a tool to support decision-making for wheat production in Tarai region of Uttarakhand
Physico-chemical attributes and organoleptic assessment of guava (Psidium guajava L.) cultivars grown in eastern Uttar Pradesh
A study was conducted to evaluate the different guava cultivars for their physico-chemical composition and organoleptic assessment during the year 2012-2013. Results of study indicated that Gorakh Bilas Pasand cultivar proved to be superior on the basis of physical characters (Length-7.64 cm, Breadth-7.79 cm , Weight-240.60 g, Number of seeds per fruit-251 etc.) followed by Lucknow-49. However, Lucknow-49 was found noteworthy in respect of chemical composition (TSS-13.00 oBrix, Acidity-0.50%, pH-5.86, Vitamin C-300.36 mg/100g etc). In organoleptic assessment, it was found that ‘liked very much’ rating was provided by consumer to Lucknow-49. On the basis of overall findings, it was concluded that ‘Lucknow-49’ was superior in most of characters studied and might be one of the promising cultivars for quality fruits under eastern Uttar Pradesh conditions
Determination of precise crystallographic directions for mask alignment in wet bulk micromachining for MEMS
In wet bulk micromachining, the etching characteristics are orientation dependent. As a result, prolonged etching of mask openings of any geometric shape on both Si{100} and Si{110} wafers results in a structure defined by the slowest etching planes. In order to fabricate microstructures with high dimensional accuracy, it is vital to align the mask edges along the crystal directions comprising of these slowest etching planes. Thus, precise alignment of mask edges is important in micro/nano fabrication. As a result, the determination of accurate crystal directions is of utmost importance and is in fact the first step to ensure dimensionally accurate microstructures for improved performance. In this review article, we have presented a comprehensive analysis of different techniques to precisely determine the crystallographic directions. We have covered various techniques proposed in the span of more than two decades to determine the crystallographic directions on both Si{100} and Si{110} wafers. Apart from a detailed discussion of each technique along with their design and implementation, we have provided a critical analysis of the associated constraints, benefits and shortcomings. We have also summed up the critical aspects of each technique and presented in a tabular format for easy reference for readers. This review article comprises of an exhaustive discussion and is a handy reference for researchers who are new in the field of wet anisotropic etching or who want to get abreast with the techniques of determination of crystal directions
Nanowires, Nanowire Junctions, and Methods of Making the Same
Disclosed is a nanostructure including a first set of nanowires formed from filling a plurality of voids of a template. The nanostructure also includes a second set of nanowires formed from filling a plurality of spaces created when the template is removed, such that the second set of nanowires encases the first set of nanowires. Several methods are also disclosed. In one embodiment, a method of fabricating a nanostructure including nanowires is disclosed. The method may include forming a first set of nanowires in a template, removing a first portion of the template, thereby creating spaces between the first set of nanowires, forming a second set of nanowires in the spaces between the first set of nanowires, and removing a second portion of the template
Raman anomalies as signatures of pressure induced electronic topological and structural transitions in black phosphorus: Experiments and Theory
We report high pressure Raman experiments of Black phosphorus up to 24 GPa.
The line widths of first order Raman modes A, B and A of the
orthorhombic phase show a minimum at 1.1 GPa. Our first-principles density
functional analysis reveals that this is associated with the anomalies in
electron-phonon coupling at the semiconductor to topological insulator
transition through inversion of valence and conduction bands marking a change
from trivial to nontrivial electronic topology. The frequencies of B and
A modes become anomalous in the rhombohedral phase at 7.4 GPa, and new
modes appearing in the rhombohedral phase show anomalous softening with
pressure. This is shown to originate from unusual structural evolution of black
phosphorous with pressure, based on first-principles theoretical analysis.Comment: 13pages, 12figure
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