Biopolymer-based trimetallic nanocomposite synthesis,characterization and its application in the catalytic degradation of 4-nitrophenol

Journal of Materials Science: Materials in Electronics - Gum kondagogu (GK), a natural biopolymer was successfully employed in the synthesis of trimetallic (AgAuPd) nanocomposites and characterized...     

ResearchGate and Google Scholar: how much do they differ in publications,citations and different metrics and why?

ResearchGate has emerged as a popular professional network for scientists and researchers in a very short span. Similar to Google Scholar, the ResearchGate indexing uses an automatic crawling algorithm that extracts bibliographic data, citations, and other information about scholarly articles from various sources. However, it has been observed that the two platforms often show different publication and citation data for the same institutions, journals, and authors. While several previous studies analysed different aspects of ResearchGate and Google Scholar, the quantum of differences in publications, citations, and metrics between the two and the probable reasons for the same are not explored much. This article, therefore, attempts to bridge this research gap by analysing and measuring the differences in publications, citations, and different metrics of the two platforms for a large data set of highly cited authors. The results indicate that there are significantly high differences in publications and citations for the same authors captured by the two platforms, with Google Scholar having higher counts for a vast majority of the cases. The different metrics computed by the two platforms also differ in their values, showing different degrees of correlation. The coverage policy, indexing errors, author attribution mechanism, and strategy to deal with predatory publishing are found to be the main probable reasons for the differences in the two platforms.

     

Impression creep behavior of different zones in friction stir welded Mg–Zn–Mn wrought alloy

The friction stir welded joint of wrought ZM21 alloy was divided into five parts, and their localized creep behavior was studied via the impression method. The tests were carried out in the stress range of 300–450 MPa (σ_imp/G ≈ 0.02–0.03) and in the temperature range of 448–523 K. Optical and SEM micrographs and EDS taken before and after the impression tests were used to study the microstructure of various zones of the FS welded joint. Power law was found to satisfactorily relate the stress and strain rates. The steady-state impression velocity was found to vary significantly between the advancing and retreating sides of TMAZ and HAZ. For TMAZ, the creep exponent on the AS was 4.8, and on the RS, it was 7.8. The activation energy on the AS was ~?133 kJ/mol, and on the RS, it was ~?101 kJ/mol. Similarly, for HAZ, the creep exponent on the AS was found to be 5.5 and on the RS, it was 4.9. The activation energy on the AS was ~?86 kJ/mol and on the RS, it was ~?232 kJ/mol. The cross-over of steady-state impression velocity of different zones indicates that the weak zone was temperature and stress dependent. Within the stresses and temperatures studied, the weld zone's creep resistance (i.e., lower minimum impression velocity) was found to be better than the base material. As it is with most magnesium alloys, dislocation climb was found to be the operative mechanism in the FS weldments of ZM21 alloy. The rate-controlling mechanism remains to be identified because the wide variation in n and Q values suggests that different creep mechanisms are in operation in different zones.

Graphical abstract

     

Annealing temperature-dependent structural and electrical properties of (Ta2O5)1-x - (TiO2)x thin films,x ≤ 0.11

(Ta₂O₅)_1-x- (TiO₂)_x (TTO_x) thin films, with x = 0, 0.03, 0.06, 0.08, and 0.11, were deposited using magnetron direct current (DC) sputtering method onto the P/boron-silicon (1 0 0) substrates by varying areas of Tantalum and Titanium metallic targets, in oxygen environment at ambient temperature. The as-deposited thin films were annealed at temperatures ranging from 500 to 800 °C. Generally, the formation of the Ta₂O₅ structure was observed from the X-ray diffraction measurements of the annealed films. The capacitance of prepared metal– oxide– semiconductor (MOS) structures of Ag/TTO_x/p-Si was measured at 1 MHz. The dielectric constant of the deposited films was observed altering with varying composition and annealing temperature, showing the highest value 71, at 1 MHz, for the TTO_x films, x = 0.06, annealed at 700 °C. With increasing annealing temperature, from 700 to 800 °C, the leakage current density was observed, generally decreasing, from 10^?5 to 10^?8 A cm^?2, for the prepared compositions. Among the prepared compositions, films with x = 0.06, annealed at 800 °C, having the observed value of dielectric constant 48, at 1 MHz; and the leakage current density 2.7 × 10^?8 A cm^?2, at the electric field of 3.5 × 10⁵ V cm^?1, show preferred potential as a dielectric for high-density silicon memory devices.     

Chromium-promoted preparation of forsterite refractory materials from ferronickel slag by microwave sintering

The chromium-promoted preparation of forsterite refractory materials from ferronickel slag was investigated by microwave sintering of the slag with the additions of sintered magnesia and 0–10 wt% chromium oxide (Cr₂O₃). The thermodynamic calculations revealed that the addition of Cr₂O₃ can promote the formations of spinel and liquid phase and maintain high content of forsterite below 1500 °C. The experimental results showed that there existed a stronger promoting effect of Cr₂O₃ additive on the properties of refractory materials in the microwave field than that in conventional sintering. It was attributed to the preferential formation and growth of spinel with stronger microwave absorption than other phases (e.g., enstatite), the existence of more forsterite, and the enhanced densification in association with the presence of more liquid phase at the same temperature. By microwave sintering of the mixture of ferronickel slag, 25 wt% sintered magnesia, and 4 wt% Cr₂O₃ at 1350 °C for 20 min, a superior refractory material with refractoriness of 1801 °C, thermal shock resistance of 6 times, bulk density of 2.97 g/cm³, apparent porosity of 1.4%, and compressive strength of 197 MPa was obtained. Compared with that prepared by conventional sintering at 1350 °C for 2 h, the refractoriness and thermal shock resistance were increased by 175 °C and 100%, respectively. The present study provided a novel method for preparing high-quality refractory materials from ferronickel slag and relevant industrial wastes.     

A new strategy to reduce edge chipping using stress wave impedance matching

To restrain edge chipping and elucidate its mechanism during machining, the initiation of edge chipping was investigated in this study from the propagation properties of stress waves in the fractured media. Three technological principles of the support for chipping suppression were proposed to reduce the intensity of reflected extension waves, namely, the wave impedance matching, the smaller residual gap and the higher viscosity of the gap filler between the workpiece and the support. As demonstrated from the experimental results, using brass support with non-solid epoxy gap filler can significantly restrain the edge chipping of pressureless sintered silicon carbide during grinding.     

An embedded FPGA-SoC framework and its usage in moving object tracking application

Design Automation for Embedded Systems - Moving object tracking is a computation-intensive operation that requires accelerating hardware solution. In this work, a high-performance design for mean...     

Evaluation of Non-Ambiguous Critical Micelle Concentration of Surfactants in Relation to Solution Behaviors of Pure and Mixed Surfactant Systems: A Physicochemical Documentary and Analysis

Critical micelle concentration (CMC) is a fundamental physical parameter of surfactant aggregation in solution. The CMC is determined by different methods, tensiometry, conductometry, microcalorimetry, fluorimetry, and so on. However, it is known that though CMC is reported as a single value, in reality, micelle formation occurs over a narrow range of concentration for different experimental procedures produce different results. We shall discuss about a unique procedure of measuring correct CMC applicable to all potential methods used in practice. This is essential for the evaluation of thermodynamic properties of the micelle forming process in pure and mixed states in terms of solution theories. As we in this short documentary want to deal with various aspects of Milton Rosen's research—wherein we have also worked—a few other facets of surfactant chemistry research, besides the micelle formation, are also briefly discussed. In mixed surfactant systems, synergistic effects in various surfactant properties like detergency, foaming, solubilization, and so on are found whereas in some others non-synergistic effects are observed. Dehydration of micelles with an increase in temperature or by the addition of hydrophilic substances may cause clouding to the system. Soluble amphiphilic systems produce Gibbs monolayer at the air/water interface; insoluble amphiphiles form Langmuir monolayers. A documentary of the above aspects will be herein presented and discussed. We mention that this article is neither an original research article nor a review article. This is a mixture of the two: a documentary of both original research and some review of our works presented in memory of Prof. Milton Rosen.     

Investigation of Microstructures,Mechanical Properties of AZ91E Hybrid Composite Reinforced with Silicon Carbide and Fly Ash

Silicon - In this study, the stir casting processing technique was used to produce the AZ91E hybrid composite reinforced with Silicon Carbide (SiC) and Fly ash (FA) particles in different weight...