Formation of double ring patterns on Co2MnSi Heusler alloy thin film by anodic oxidation under scanning probe microscope

Double ring formation on Co2MnSi (CMS) films is observed at electrical breakdown voltage during local anodic oxidation (LAO) using atomic force microscope (AFM). Corona effect and segregation of cobalt in the vicinity of the rings is studied using magnetic force microscopy and energy dispersive spectroscopy. Double ring forma-tion is attributed to the interaction of ablated material with the induced magnetic field during LAO. Steepness of forward bias transport characteristics from the unperturbed region of the CMS film suggest a non equilibrium spin contribution. Such mesoscopic textures in magnetic films by AFM tip can be potentially used for memory storage applications.Comment: 7 pages, 5 figure

Shuffling a Stacked Deck: The Case for Partially Randomized Ranking of Search Engine Results

In-degree, PageRank, number of visits and other measures of Web page popularity significantly influence the ranking of search results by modern search engines. The assumption is that popularity is closely correlated with quality, a more elusive concept that is difficult to measure directly. Unfortunately, the correlation between popularity and quality is very weak for newly-created pages that have yet to receive many visits and/or in-links. Worse, since discovery of new content is largely done by querying search engines, and because users usually focus their attention on the top few results, newly-created but high-quality pages are effectively ``shut out,'' and it can take a very long time before they become popular. We propose a simple and elegant solution to this problem: the introduction of a controlled amount of randomness into search result ranking methods. Doing so offers new pages a chance to prove their worth, although clearly using too much randomness will degrade result quality and annul any benefits achieved. Hence there is a tradeoff between exploration to estimate the quality of new pages and exploitation of pages already known to be of high quality. We study this tradeoff both analytically and via simulation, in the context of an economic objective function based on aggregate result quality amortized over time. We show that a modest amount of randomness leads to improved search results

Design and Implementation of PRBS Generator using VHDL

Pseudo random binary sequence is essentially a random sequence of binary numbers. So PRBS generator is nothing but random binary number generator. It is ‘random’ in a sense that the value of an element of the sequence is independent of the values of any of the other elements. It is 'pseudo' because it is deterministic and after N elements it starts to repeat itself, unlike real random sequences. The implementation of PRBS generator is based on the linear feedback shift register (LFSR). The PRBS generator produces a predefined sequence of 1's and 0's, with 1 and 0 occurring with the same probability. A sequence of consecutive n*(2^n -1) bits comprise one data pattern, and this pattern will repeat itself over time

Monitoring the status of Human-wildlife conflict and its impact on community based conservation in Bandhavgarh tiger reserve, Madhya Pradesh, India

The Bandhavgarh Tiger Reserve is one of the famous tiger reserve in India. The human wildlife conflict is on rise for few years. A total of 194 human casualties and 1960 livestock depredation were reported between 2001 to 2011. Out of 194 casualties, 6.7% were lethal which caused death and 93.3% were injuries. Out of these maximum 37.57% (68) were reported by Jackal (Canis aureus) followed by 27.64% (50) of Sloth bear (Melursus ursinus), 20.99% (38) by Wild boar (Sus scrofa), 8.84% (16) by Tiger (Panthera tigris), 3.31% (6) by Leopard (Panthera Pardus) and 1.65% (3) by other carnivores. Out of 194 casualties 71.13% were male and 28.87% were female. The livestock killings were reported to be 1960 out of which maximum 81.78% (1603) were by tiger followed by 17.60% (345) by leopard and rest 0.62% (12) by other carnivores. The mean livestock killing was 178.182±42.82 (SE) per year. Discussions and surveys were made with affected peoples to know the views about conflict and its alleviation by using Close ended questionnaire. Total 180 individuals were surveyed.  Out of these 151 (83.89 %) respondent felt that wildlife should be conserved while 29 (16.11 %) felt there is no need for conservation. Adequate compensation, habitat management practices, livestock and crop insurance scheme and bio fencing around the affected villages and conservation awareness could be the way to mitigate existing conflict.&nbsp

Structural, transport, optical and electronic properties of Sr2_2CoNbO6_6 thin films

We study the effect of substrate induced strain on the structural, transport, optical and electronic properties of Sr$_2$CoNbO$_6$ double perovskite thin films. The reciprocal space mapping, $\phi$-scan and high-resolution $\theta$-2$\theta$ scans of x-ray diffraction patterns suggest the epitaxial nature and high-quality of the films deposited on various single crystal ceramic substrates. A systematic enhancement in the dc electronic conductivity is observed with increase in the compressive strain, while a sharp reduction in case of tensile strain, which are further supported by change in the activation energy and density of states near the Fermi level. The optical band gap extracted from two distinct absorption bands, observed in the visible-near infrared spectroscopy show a non-monotonic behavior in case of compressive strain while significant enhancement with tensile strain. Unlike the bulk Sr$_2$CoNbO$_6$ (Co$^{3+}$ and Nb$^{5+}$), we observe different valence states of Co namely 2+, 3+ and 4+, and tetravalent Nb (4$d^1$) in the x-ray photoemission spectroscopy measurements. Moreover, a reduction in the average oxygen valency with the compressive strain due to enhancement in the covalent character of Co/Nb--O bond is evident. Interestingly, we observe sharp Raman active modes in these thin films, which indicates a significant enhancement in structural ordering as compared to the bulk.Comment: submitte

Performance Characterization of Recycled Asphalt Pavements with Warm Mix Asphalt Technologies

This study evaluated the laboratory performance characteristics of Recycled Asphalt Pavements (RAP) with Warm Mix Asphalt (WMA) Technologies. RAP was introduced in mixtures at three levels: 0, 15 and 35% of RAP contents. Five WMA technologies were evaluated against all the mentioned levels of RAP content. The study was conducted in two phases, each phase with a separate aggregate and RAP source. Standard Marshall Mix design method was followed for the mix design purpose, with some modification to introduce RAP and WMA. Rheological properties of both the virgin and recovered asphalt binders were determined. Laboratory designed mixtures were evaluated for moisture resistance, dynamic modulus, rutting resistance and thermal resistance behavior. Moisture resistance of the mixtures were evaluated by performing the indirect tensile strength test for 0 and 1 freeze-thaw cycles. Resistance to rutting was evaluated by determining flow number using the Asphalt Mixture Performance Tester (AMPT) machine. Finally, thermal resistance of the mixtures were evaluated by conducting Uniaxial Thermal Stress and Strain Test (UTSST). The study determined that the moisture susceptibility of the mixtures increased with the increase in number of freeze thaw cycles. Dynamic modulus of the mixtures were higher for a higher RAP content. Further, HMA mixtures were determined to have higher dynamic modulus and tensile strengths than the WMA mixtures. Even though, the strength values for WMA mixtures were lower than the HMA mixtures, WMA mixtures satisfied the required criteria defined by agency. HMA mixtures were found to have higher rutting resistance than WMA mixtures, and this resistance increased with the increase in RAP content. Even though HMA mixtures with higher RAP content performed better in terms of rutting, such mixtures exhibited a huge drop in thermal resistance capacity. Varying aggregate source did not significantly influenced the performance of mixtures, except in the case of rutting. Further study is need in order to validate the use of higher RAP content in the mixtures

PHYSIOLOGICAL AND BIOCHEMICAL CHANGES ASSOCIATED WITH THE DEVELOPMENT OF BROWN SPOT DISEASES IN RICE LEAVES

The healthy and diseased leaves of twelve rice samples collected from six localand six improved cultivars, were assessed for physiological and biochemical changes duringbrown spot infection. The photosynthetic related parameters like chl a, chl b and carotenoidswere studied using spectrophotometry and changes in ionic composition like sodium,potassium, magnesium, calcium and iron were evaluated using flame photometry. The resultreveals reduction in calcium, potassium, iron, chl.\u27a\u27, chl.\u27b\u27 and total chlorophyll andincrease in magnesium, sodium, total soluble sugar and carotenoids contents after brown spotincidence. The study concludes that understanding of host-plant interaction for developing arelevant defense mechanism must be given priority and use of resistance cultivars by localgrowers is highly recommende