Improved Synthesis of Superconducting Carbon-Doped MgB2 Using a Biopolymer for Simultaneous Crystallite Size Control and Chemical Reduction

This study represents a key evolution in the synthesis of the superconductor MgB₂, as it is the first to demonstrate that templated synthesis can be carried out successfully without a sealed reaction vessel. This is possible owing to the strong chelating ability of the biopolymer dextran, whose morphological complexity effectively cocoons the reaction, preventing oxygen ingress. This synthetic protocol demonstrates that not only can this important material be synthesized as nanoparticles but that, as the morphological template is calcined, it effectively carbon-dopes the superconducting phase, thereby improving the critical current density by a factor of five.     

Self‐Healing of a Confined Phase Change Memory Device with a Metallic Surfactant Layer

Understanding and possibly recovering from the failure mechanisms of phase change memories (PCMs) are critical to improving their cycle life. Extensive electrical testing and postfailure electron microscopy analysis have shown that stuck–set failure can be recovered. Here, self‐healing of novel confined PCM devices is directly shown by controlling the electromigration of the phase change material at the nanoscale. In contrast to the current mushroom PCM, the confined PCM has a metallic surfactant layer, which enables effective Joule heating to control the phase change material even in the presence of a large void. In situ transmission electron microscope movies show that the voltage polarity controls the direction of electromigration of the phase change material, which can be used to fill nanoscale voids that form during programing. Surprisingly, a single voltage pulse can induce dramatic migration of antimony (Sb) due to high current density in the PCM device. Based on the finding, self‐healing of a large void inside a confined PCM device with a metallic liner is demonstrated for the first time.     

An investigation on specific absorption rate reduction materials with human tissue cube for biomedical applications

The objective of this study is to investigate the impact of human exposure due to electromagnetic fields and to reduce the specific absorption rate (SAR). This work focuses on the implementation of different electromagnetic shield materials such as conductive materials, dielectric materials, ferrite materials, and metamaterials that are currently used for SAR reduction. The experimental analysis is performed with the global system for mobile communication (GSM) dipole antenna operating at 900 MHz as its radiation source. The designed dipole is placed in front of a cube with similar dielectric properties of human tissue. The computation, implementation, and evaluation are performed by using the method of moments. Further calculation of SAR reduction factor (SRF), SAR 1 g, gain, directivity, and beamwidth are estimated for 15 different shield materials. There is a need for an ideal shield material that could reduce SAR and does not compromise the performance of the radiation structure. This work investigates and proposes the nanomaterials and composites as suitable shield materials for SAR reduction. This novel approach of implementation of nanomaterials has proved to increase the SRF over 90% than conventional reduction materials. In addition, gain and directivity are also increased by 50% than the existing shield materials. The currently used materials are compared with the proposed nanomaterials, and the results are analyzed. The results indicate that the nanomaterials and its composites are ideal shield material for SAR reduction.     

Sorption Properties of Organo Modified Montmorillonite Clay for the Reclamation of Chromium (VI) from Waste Water

Silicon - The natural Montmorillonite (Mt) clay was modified with three newly synthesized cationic surfactants such as 2-(dodecanoyloxy)-N,Nbis(2-hydroxyethyl)-N(oxiran-2-ylmethyl)ethane-1-ammonium...     

Thermally stable collagen from Piranha and Rohu with improved physical,biochemical, and morphological properties

Collagen is the most common structural protein pertinent to the skin and other tissues in humans. The market for collagen extends from food, cosmetics to therapeutics and is estimated to be $6.63 billion by 2025. Piranha and Rohu are some of the primarily consumed fish varieties in South India and the extraction of collagen from the scales of Piranha is reported for the first time through this study. Physical, biochemical, and morphological properties of the collagen extracted were compared with a freshwater variant, Rohu. The UV, IR spectra, amino acid, SDS PAGE analysis confirmed the presence of triple helical native conformation. Further, higher degree of solubility was observed at low pH and salt concentrations. The T_d was 38.27 and 37.4°C and T_m was 92.37 and 94.04°C for the scale collagen of Piranha and Rohu respectively and was comparable to bovine sources. Electron micrograph presented loose, parallel oriented long fibers with interconnected fibrils. Hence the collagen extracted, having retained the helical conformation and higher thermal stability, can be a safe alternative for various biomedical applications.     

The UK Climate Change Risk Assessment 2012: Assessing the Impacts on Water Resources to Inform Policy Makers

The Climate Change Act 2008 requires a series of assessments of the risks of climate for the UK, under both current conditions and over the long term, to 2100. This paper describes the research completed on the impacts of climate change on the UK water sector, involving stakeholder engagement and a mix of literature review, expert elicitation and broad-scale quantitative analysis to develop ten climate change risk metrics. These include measures of the demand for water, impacts on supply, water quality and asset performance using future scenarios based on the UK Climate Projections 2009 and future population projections from the Office for National Statistics. The analysis has resulted in a number of key findings that can help to inform policy in different parts of the UK. Overall the assessment showed that there is likely to be increased pressure on water resources in the UK. These pressures need to be considered in long term plans so that the needs of different users are met without impacting on the environment.     

Superconductivity in MgB2: Phonon modes and influence of carbon doping

Following a brief overview, results of our investigations on phonon modes in MgB₂, and superconducting transition in carbon doped MgB₂ are presented. The superconducting transition temperature in MgB_{2 x}C_x as obtained from susceptibility and resistivity measurements is observed to decrease systematically from 39-4 K forx = 0 to 26 K forx = 0.5. It is shown the changes in lattice volume, as obtained from x-ray diffraction measurements, can account only partially for the observed decrease inT _c . The observed variation ofT _c with carbon content is seen to correlate with the Debye temperatures, obtained from an analysis of the resistivity data. Investigation of the phonon modes in MgB₂, through infrared absorption measurements indicate three modes at 410,475 and 560 cm^-1. The former two are associated with the infrared active modes, and the third component is associated with the Raman mode, that gets activated due to disorder. A study of the temperature dependence of these modes indicates no changes across the superconducting transition. The mode at 560 cm^-1 shows a significant hardening and a corresponding decrease in linewidth, with the lowering of temperature, that can been accounted in terms of anharmonicity.     

Physicochemical and sensory attributes of gluten-free sourdough breads produced from underutilised African cereal flours and flour blends

To seek potential alternative(s) for imported wheat in the African baking industry, the physicochemical parameters and sensory attributes of sourdough breads developed from locally sourced underutilised cereals and their blends were assessed. Processed sorghum (Sorghum bicolour), finger millet (Eleusine coracana) and pearl millet (Pennisetum glaucum) and their composites (50:50) were used to produce sourdough. Sourdough and flour-sourdough blends (30% sourdough) were used in making gluten-free breads. The protein content of the breads ranged from 16.29% to 39.26%, whereas the fat, crude fibre, ash and carbohydrate contents fell between 14.02–18.80%, 0.55–1.22%, 1.90–3.32% and 42.16–65.61%, respectively. The calculated energy value of the gluten-free breads (405.99–446.39 Kcal per 100 g) exceeded that of wheat bread (396.43 Kcal per 100 g), while the specific loaf volume varied from 1.46 to 1.80 cm³ g⁻¹. Although the produced gluten-free breads have improved nutritional content compared to conventional wheat bread, they were at best moderately liked. This is perhaps due to the non-cohesive nature of the crumbs and psychological preference for known products. Further research targeted at improving the organoleptic properties of these sourdough breads is recommended.