447 research outputs found

    High-pressure behavior of superconducting boron-doped diamond

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    This work investigates the high-pressure structure of freestanding superconducting (TcT_{c} = 4.3\,K) boron doped diamond (BDD) and how it affects the electronic and vibrational properties using Raman spectroscopy and x-ray diffraction in the 0-30\,GPa range. High-pressure Raman scattering experiments revealed an abrupt change in the linear pressure coefficients and the grain boundary components undergo an irreversible phase change at 14\,GPa. We show that the blue shift in the pressure-dependent vibrational modes correlates with the negative pressure coefficient of TcT_{c} in BDD. The analysis of x-ray diffraction data determines the equation of state of the BDD film, revealing a high bulk modulus of B0B_{0}=510±\pm28\,GPa. The comparative analysis of high-pressure data clarified that the sp2^{2} carbons in the grain boundaries transform into hexagonal diamond.Comment: 7 pages, 4 figure

    Hyperfine interaction and electronic spin fluctuation study on Sr2x_{2-x}Lax_xFeCoO6_6 (x = 0, 1, 2) by high-resolution back-scattering neutron spectroscopy

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    The study of hyperfine interaction by high-resolution inelastic neutron scattering is not very well known compared to the other competing techniques viz. NMR, M\"ossbauer, PACS etc. Also the study is limited mostly to magnetically ordered systems. Here we report such study on Sr2x_{2-x}Lax_xFeCoO6_6 (x = 0, 1, 2) of which first (Sr2_2FeCoO6_6 with x = 0) has a canonical spin spin glass, the second (SrLaFeCoO6_6 with x = 1) has a so-called magnetic glass and the third (La2_2FeCoO6_6 with x = 2) has a magnetically ordered ground state. Our present study revealed clear inelastic signal for SrLaFeCoO6_6, possibly also inelastic signal for Sr2_2FeCoO6_6 below the spin freezing temperatures TsfT_{sf} but no inelastic signal at all for for the magnetically ordered La2_2FeCoO6_6 in the neutron scattering spectra. The broadened inelastic signals observed suggest hyperfine field distribution in the two disordered magnetic glassy systems and no signal for the third compound suggests no or very small hyperfine field at the Co nucleus due to Co electronic moment. For the two magnetic glassy system apart from the hyperfine signal due only to Co, we also observed electronic spin fluctuations probably from both Fe and Co electronic moments. \end{abstract

    An Experimental Investigation on Treatment of Tannery Effluent Using Azadirachta Indica

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    A preliminary investigation was carried out for the feasibile use of Azadirachta indica leafs powder as a natural coagulant to the treatment of tannery effluent. In this paper, Azadirachta indica leafs powder of 1, 2, 3 and 4mg/L dosages were used. Floc formation in coagulation process had been studied in the laboratory scale to determine the optimum dosage of natural coagulant. The above dosages were used in pre-treated tannery effluent with coagulants were considered to evaluate the percentage removal efficiency on the major pollutants of concern in in tannery effluent such as turbidity, TSS, TDS, COD and BOD. From the observed results, dosage of 3 mg/L gives better removal efficiencies with respect to turbidity, TSS, TDS, COD and BOD and appears to be suitable for tannery effluent treatment, when compared with other dosages

    A Study on Copper-Gate Integration with Titanium Interface Layers for IGZO TFTs

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    The continuous demand for ultra-high resolution and improved video performance on increasingly larger active-matrix displays has advanced the research field of thin film transistors (TFTs) materials, processes and devices. Performance improvements demonstrated by amorphous Indium-Gallium-Zinc-Oxide (IGZO) TSTs has enabled a commercialized backplane technology adopted for AM-OLED displays, providing advantage in device performance and uniformity at a much lower cost than Low Temperature Poly-crystalline Silicon (LTPS). However as the display size gets larger and the pixel density increases, charge transfer from the column driver to the pixel through the addressed row TFT within the required time interval becomes increasingly difficult. As the pixel size shrinks and the panel size grows, interconnects that must be scaled down in cross-section have to transport charge over longer distances.In addition, as the numbers of rows increase in a display, the time allowed for charge transfer decreases to maintain a high image refresh frequency. These challenges must be addressed by lower interconnect delay, thus the advantages in transitioning to Cu for long interconnect rows and columns. The gate electrodes are usually implemented as an appendage of the row interconnect, thus Cu-gate TFTS would avoid added process complexity while supporting high-speed interconnects and low production costs. The following work presents a study on Cu-gate integration and potential channel contamination on bottom-gate IGZO TSTs with a newly established baseline process. Cu was used in place to Mo as the gate electrode, with an underlying Ti layer to promote adhesion to the oxidized silicon substrate. The experimental design input factors included the option of a Ti capping layer on the Cu-gate, and the anneal conditions of the gate dielectric (PECVD SiO2) prior to IGZO sputtering. Distinct differences in physical and electrical responses over all treatment combinations were identified. Experimental results demonstrated that while the Ti capping layer promoted adhesion to the gate dielectric, it served as a source of contamination on pre-annealed treatments causing pronounced electrical characteristic shifting and dielectric failure. The anneal process was found to promote adhesion between the Cu-gate and the gate oxide without the use of Ti capping layer, as well as reduce oxide charge levels. Copper contamination did not appear to be an issue in treatment conditions at or below 400C, however pitting of the gate electrode occurred at anneal temperature above 400C, as well as electrical results that suggest evidence of Cu contamination. Visual observations and electrical characteristics are presented wit ha detailed discussion on comparisons between treatment combinations, with reference to the baseline IGZO devices

    Removal Of Residue Oil From Palm Oil Mill Effluent (Pome) Using Chitosan [TD899.I27 S955 2004 f rb] [Microfiche 7577].

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    Penyelidikan ini difokuskan untuk menyelidik dan mengkaji penggunaan kitosan sebagai bahan penjerap serta pengental minyak sisa berlebihan dalam sebarang air sisa berminyak. The focus of this research was to investigate and study the usage of chitosan as an adsorbent as well as a coagulant to adsorb and coagulate the excessive residue oil from an oily wastewater

    Mapping Pain: Domestic Violence and Intergenerational Trauma in Anuradha Roy’s An Atlas of Impossible Longing

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    This article explores the nexus between domestic violence and psychological trauma in Anuradha Roy’s An Atlas of Impossible Longing (2008). Set against the backdrop of an evolving Indian society, the novel examines how trauma operates within domestic spaces and across generations. Drawing on trauma theory, particularly Cathy Caruth’s work on the unassimilated nature of traumatic events and Judith Herman’s insights into interpersonal violence, the article investigates how domestic violence fragments identities and disrupts familial bonds. Through Roy’s evocative portrayal of characters like Kananbala and Mukunda, the novel critiques patriarchal structures and highlights the cyclical nature of trauma. This analysis ultimately demonstrates Roy’s profound engagement with the themes of suffering, resilience, and the possibility of healing amidst intergenerational strife

    Biochars as Potential Adsorbers of CH4, CO2 and H2S

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    Methane gas, as one of the major biogases, is a potential source of renewable energy for power production. Biochar can be readily used to purify biogas contaminants such as H2S and CO2. This study assessed the adsorption of CH4, H2S, and CO2 onto four different types of biochars. The adsorption dynamics of biochars were investigated in a fixed-bed column, by determining the breakthrough curves and adsorption capacities of biochars. The physicochemical properties of biochars were considered to justify the adsorption performance. The results showed that CH4 was not adsorbed well by the subjected biochars whereas CO2 and H2S were successfully captured. The H2S and CO2 breakthrough capacity were related to both the surface adsorption and chemical reaction. The adsorption capacity was in the following order: perilla > soybean stover > Korean oak > Japanese oak biochars. The simultaneous adsorption also leads to a competition of sorption sites. Biochars are a promising material for the biogas purification industry
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