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Enhancing mechanical properties of glass fabric composite with surfactant treated zirconia nanoparticles
No full textSignificantly enhanced specific mechanical properties of Glass Fabric Composite (GFC) by optimal dispersion of yttria stabilized zirconia (YSZ) nanoparticles in matrix-fabric system is reported. Dispersion of as low as 3 wt% of YSZ is found to be optimal for the developed processing condition. The enhancement is due to two-fold effects, one is the nano-cluster segregation by surfactant and the other one is an optimal interfacial stress/fracture modification in the matrix-fabric system via optimal length-scale effects of nano-composite with respect to the fabric interface. A detailed understanding is developed with the help of microscopic characterization and finite element simulation results. Specific modulus and strength increased by similar to 18% and similar to 17% (compressive), similar to 14% and similar to 17% (tensile) and similar to 34% and similar to 64% (flexural), respectively. The developed nanocomposite has potential applications in light-weight thermal management
An Exploratory Framework for Cyclone Identification and Tracking
No full textAnalyzing depressions plays an important role in meteorology, especially in the study of cyclones. In particular, the study of the temporal evolution of cyclones requires a robust depression tracking framework. To cope with this demand we propose a pipeline for the exploration of cyclones and their temporal evolution. This entails a generic framework for their identification and tracking. The fact that depressions and cyclones are not well-defined objects and their shape and size characteristics change over time makes this task especially challenging. Our method combines the robustness of topological approaches and the detailed tracking information from optical flow analysis. At first cyclones are identified within each time step based on well-established topological concepts. Then candidate tracks are computed from an optical flow field. These tracks are clustered within a moving time window to distill dominant coherent cyclone movements, which are then forwarded to a final tracking step. In contrast to previous methods our method requires only a few intuitive parameters. An integration into an exploratory framework helps in the study of cyclone movement by identifying smooth, representative tracks. Multiple case studies demonstrate the effectiveness of the method in tracking cyclones, both in the northern and southern hemisphere
Thermodynamic picture of vitrification of water through complex specific heat and entropy: A journey through ``no man's land''
No full textWe investigate thermodynamic properties of supercooled water across the ``no man's land'' onto the formation of amorphous ice. The calculations are aided by very long computer simulations, often more than 50 mu s long, with the TIP4P/2005 model potential. Density fluctuations that arise from the proximity to a putative liquid-liquid (LL) transition at 228 K, cast a long shadow on the properties of water, both above and below the LL transition. We carry out the calculations of the quantum mechanical static and frequency-dependent specific heats by combining seminal studies of Lebowitz, Percus, and Verlet and Grest and Nagel with the harmonic approximation for the density of states. The obtained values are in quantitative agreement with all available experimental and numerical results of specific heats for both supercooled water and ice. We calculate the entropy at all the state points by integrating the specific heat. We find that the quantum corrected-contributions of intermolecular vibrational entropy dominate the excess entropy of amorphous phases over the crystal over a wide range of temperatures. Interestingly, the vibrational entropy lowers the Kauzmann temperature, T-K, to 130 K, just below the experimental glass-to-liquid water transition temperature, T-g, of 136 K and the calculated T-g of 135 K in our previous study. A straightforward extrapolation of high temperature entropy from 250 K to below however would give a much higher value of T-K similar to 190 K. The calculation of Lindemann ratios shows the melting of amorphous ice similar to 135 K. The amorphous state exhibits an extremely short correlation length for the distance dependence of orientational correlation. Published under license by AIP Publishing
Charge disproportionate antiferromagnetism at the verge of the insulator-metal transition in doped LaFeO3
No full textWe explore the effects of electron doping in lanthanum ferrite, LaFeO3 by doping Mo at the Fe sites. Based on magnetic, transport, scanning tunneling spectroscopy, and x-ray photoelectron spectroscopy measurements, we find that the large gap, charge-transfer, antiferromagnetic (AFM) insulator LaFeO3 becomes a small gap AFM band insulator at low Mo doping. With increasing doping concentration, Mo states, which appear around the Fermi level, is broadened and become gapless at a critical doping of 20%. Using a combination of calculations based on density functional theory plus Hubbard U (DFT+U) and x-ray absorption spectroscopy measurements, we find that the system shows charge disproportionation (CD) in Fe ions at 25% Mo doping, where two distinct Fe sites, having Fe2+ and Fe3+ nominal charge states appear. A local breathing-type lattice distortion induces the charge disproportionation at the Fe site without destroying the antiferromagnetic order. Our combined experimental and theoretical investigations establish that the Fe states form a CD antiferromagnet at 25% Mo doping, which remains insulating, while the appearance of Mo states around the Fermi level is showing an indication towards the insulator-metal transition
Experimental and numerical investigation of evaporation from line sources of water in low porosity surfaces
No full textWe report evaporation characteristics due to higher heating from above from surfaces having an array of line sources. The line sources are created by vertically stacked rectangular plates in a box with water. Two different types of plates were used. In one case line source or film thickness was 66 mu m and open area ratio was 4%, and in the second case film thickness was 28 mu m and 20% was the open area ratio. Even at the 4% open area ratio the evaporation rate was similar to 85% compared to a bare water surface, at the same heat flux. Lateral conduction of heat from the impervious hotter regions to the line sources and the 2-D nature of diffusion near these tiny line sources enhances the evaporative flux, owing to increase in the concentration gradient of water vapour, explains the high evaporation rate, observed in the present work. This system bridges the gap between the understanding of evaporation from bare water surfaces (1-D vapour diffusion) and leaf surfaces (3-D vapour diffusion). Evaporation rates for the fully saturated conditions are in good agreement with the theoretical predictions of Suzuki and Maeda (1968) and Schlunder (1988). The computed surface temperatures and its width-wise variation match well with the experimental values. We also propose a simple film model for the unsaturated condition of the porous medium and show that the temperature distribution obtained using this model is in reasonably good agreement with the measured values
Hybrid epithelial/mesenchymal phenotypes promote metastasis and therapy resistance across carcinomas
No full textCancer metastasis and therapy resistance are the major unsolved clinical challenges, and account for nearly all cancer-related deaths. Both metastasis and therapy resistance are fueled by epithelial plasticity, the reversible phenotypic transitions between epithelial and mesenchymal phenotypes, including epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET). EMT and MET have been largely considered as binary processes, where cells detach from the primary tumor as individual units with many, if not all, traits of a mesenchymal cell (EMT) and then convert back to being epithelial (MET). However, recent studies have demonstrated that cells can metastasize in ways alternative to traditional EMT paradigm; for example, they can detach as clusters, and/or occupy one or more stable hybrid epithelial/mesenchymal (E/M) phenotypes that can be the end point of a transition. Such hybrid E/M cells can integrate various epithelial and mesenchymal traits and markers, facilitating collective cell migration. Furthermore, these hybrid E/M cells may possess higher tumor-initiation and metastatic potential as compared to cells on either end of the EMT spectrum. Here, we review in silico, in vitro, in vivo and clinical evidence for the existence of one or more hybrid E/M phenotype(s) in multiple carcinomas, and discuss their implications in tumor-initiation, tumor relapse, therapy resistance, and metastasis. Together, these studies drive the emerging notion that cells in a hybrid E/M phenotype may occupy `metastatic sweet spot' in multiple subtypes of carcinomas, and pathways linked to this (these) hybrid E/M state (s) may be relevant as prognostic biomarkers as well as a promising therapeutic targets. (C) 2018 Elsevier Inc. All rights reserved
A brief review on ceria based solid electrolytes for solid oxide fuel cells
No full textDuring the last decades, advanced energy conversion and storage technologies have attracted growing attention due to increase in the energy demand and environmental retrogression. Solid oxide fuel cells (SOFCs) are such kind of devices which converts chemical energy in fuels into electrical energy with high efficiency and no environmental issues. SOFCs have some unique advantages over other fuel cells such as multi fuel choice and the fast electrode kinetics due to high operating temperature. However, high operating temperature curbs their wide-scale commercialization. In order, many efforts have been made to reduce the working temperature which led to development of solid electrolytes showing promising conductivity at relatively low temperature. Ceria based solid electrolytes show promising conductivity in the temperature range, 500-700 degrees C. Moreover, the formation of nanocomposites of doped/co-doped ceria with alkali salts further reduces working temperature. SOFCs have three main components; anode, cathode and electrolyte. In this review, a brief history of development of conventional solid electrolytes along with detail insights into the recent developments regarding ceria based solid electrolytes with emphasis on the ionic conductivity has been discussed in the detail. (C) 2018 Elsevier B.V. All rights reserved
Acid pH promotes bispecific antibody formation by the redox procedure
No full textBispecific antibodies (BsAbs), are potential theranostics. Chemical procedures of preparation of BsAbs, in which two monospecific antibodies are split into half molecules and heterodimerized, continue to attract attention in view of their simplicity. Poor dissociation of antibodies with reduced inter-heavy chain disulfides into half molecules under neutral conditions however restricts the BsAbs formation. In this study, we report that the heterodimerization of antibodies can be improved leading to over 6-fold increase in the yield of BsAbs, by carrying out the redox procedure at pH 4.0. In view of improvement in heterodimerization, BsAbs could be conveniently prepared starting from partially purified ion-exchange fraction of the antiserum and purified by twin affinity chromatography on antigen supports. The UV, CD, intrinsic and extrinsic fluorescence spectral analysis of BsAbs prepared by the modified redox procedure were comparable with the native IgG, which suggest the absence of significant acid-pH-induced damage. ThT binding studies and native size exclusion chromatography ruled out amyloid fibril formation. (C) 2018 Elsevier B.V. All rights reserved
Thermoelectric and electronic properties of chromium substituted tetrahedrite
No full textCr substituted tetrahedrites with the chemical formula Cu12-xCrxSb4S13 (x = 0.15, 0.25, 0.35, 0.5, 0.75, 1.0) have been synthesised for thermoelectric study. Cr substitutes at the Cu site to optimize the thermoelectric properties and achieve a higher figure of merit (zT). X-Ray diffraction (XRD) analysis revealed that the tetrahedrite is the major phase with minor impurity phases. Electron probe microanalysis (EPMA) shows the formation of tetrahedrite main phase with near stoichiometry and the presence of Cu3SbS4, CuSbS2 and Sb as secondary phases. X-ray photoelectron spectroscopy (XPS) shows the oxidation state of Cu, Sb and S as +1, +3 and -2, respectively, whereas for Cr, it could not be identified. Temperature-dependent magnetic susceptibility of sample x = 0.75 shows antiferromagnetic correlation originating from the Cr ion. The calculated effective magnetic moment of 2.83 mu(B) per Cr atom indicates the presence of Cr+4 in this sample. The decrease in the electrical resistivity upon doping indicates the compensation of holes due to the substitution of Cr at the Cu site. But the x = 0.35 sample is not following the trend due to larger compensation of holes with an activation energy of 124.6 meV. The temperature-dependent behaviour of electrical resistivity shows the shift in the Fermi level from the valance band towards the band gap. The absolute Seebeck coefficient is positive throughout the temperature range and follows a similar trend as that of electrical resistivity, with the exception of the x = 0.35 sample. The electronic thermal conductivity reduces due to hole compensation caused by Cr substitution. Moreover, the substitution of Cr effectively reduces the lattice thermal conductivity due to point defect scattering of phonons. A maximum zT of 1.0 is achieved for sample x = 0.35 at 700 K
Multi-gene testing in neurological disorders showed an improved diagnostic yield: data from over 1000 Indian patients
No full textBackground Neurological disorders are clinically heterogeneous group of disorders and are major causes of disability and death. Several of these disorders are caused due to genetic aberration. A precise and confirmatory diagnosis in the patients in a timely manner is essential for appropriate therapeutic and management strategies. Due to the complexity of the clinical presentations across various neurological disorders, arriving at an accurate diagnosis remains a challenge. Methods We sequenced 1012 unrelated patients from India with suspected neurological disorders, using TruSight One panel. Genetic variations were identified using the Strand NGS software and interpreted using the StrandOmics platform. Results We were able to detect mutations in 197 genes in 405 (40%) cases and 178 mutations were novel. The highest diagnostic rate was observed among patients with muscular dystrophy (64%) followed by leukodystrophy and ataxia (43%, each). In our cohort, 26% of the patients who received definitive diagnosis were primarily referred with complex neurological phenotypes with no suggestive diagnosis. In terms of mutations types, 62.8% were truncating and in addition, 13.4% were structural variants, which are also likely to cause loss of function. Conclusion In our study, we observed an improved performance of multi-gene panel testing, with an overall diagnostic yield of 40%. Furthermore, we show that NGS (next-generation sequencing)-based testing is comprehensive and can detect all types of variants including structural variants. It can be considered as a single-platform genetic test for neurological disorders that can provide a swift and definitive diagnosis in a cost-effective manner