Characterization of sputtered SmCo thin films for light element contamination using RBS and HIERDA techniques

Samarium cobalt films were prepared on silicon substrates with and without a chromium buffer layer at room temperature and 600°C using direct current unbalanced magnetron sputtering. For obtaining ideal magnetic properties, the films should be free from impurities, such as O, Al and others. Rutherford backscattering spectrometry and heavy ion elastic recoil detection analysis were used to determine the composition and film thickness and to monitor the light element contamination across film thickness. X-ray diffractometer and superconducting quantum interference device were employed to characterize the structure and magnetic properties of the films, respectively. The results obtained led to an improved design of the ground shield and the use of a sorption pump to effectively minimize aluminium and oxygen concentration in the films, respectively.     

Metabolomic Evidence for Peroxisomal Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating disease characterized by unexplained physical fatigue, cognitive and sensory dysfunction, sleeping disturbances, orthostatic intolerance, and gastrointestinal problems. People with ME/CFS often report a prodrome consistent with infections. Using regression, Bayesian and enrichment analyses, we conducted targeted and untargeted metabolomic analysis of plasma from 106 ME/CFS cases and 91 frequency-matched healthy controls. Subjects in the ME/CFS group had significantly decreased levels of plasmalogens and phospholipid ethers (p < 0.001), phosphatidylcholines (p < 0.001) and sphingomyelins (p < 0.001), and elevated levels of dicarboxylic acids (p = 0.013). Using machine learning algorithms, we were able to differentiate ME/CFS or subgroups of ME/CFS from controls with area under the receiver operating characteristic curve (AUC) values up to 0.873. Our findings provide the first metabolomic evidence of peroxisomal dysfunction, and are consistent with dysregulation of lipid remodeling and the tricarboxylic acid cycle. These findings, if validated in other cohorts, could provide new insights into the pathogenesis of ME/CFS and highlight the potential use of the plasma metabolome as a source of biomarkers for the disease.     

Availability analysis of steam and power generation systems in the thermal power plant

The paper discusses the availability analysis of a steam generation system consisting of three subsystems A, B and D and a power generation system consisting of four subsystems E, F, G and H arranged in series, with three states viz., good, reduced and failed. Taking constant failure and repair rates for each working unit, the mathematical formulation is done using the Birth-Death process. Expressions for steady state availability and the MTBF (mean time between failure) are derived. The graphs are given, depicting the effect of failure and repair rates on the system availability. The results are supplied to the plant personnel, to plan the policies for failure free running of the systems for a long duration.     

BUBBLE TEMPERATURE MEASUREMENTS ON THE BINARY MIXTURES OF 1,4-DIMETHYLBENZENE WITH ISO -, SEC -, AND TERT - BUTANOLS AT 95 kPa

Bubble temperatures at 95 kPa over the entire composition range were measured for the three binary systems formed by 1,4-dimethylbenzene with iso-, sec-, and tert- butanols. A Swietoslawski-type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model.     

Synthesis,Characterization and Wire Electric Erosion Behaviour of AA7178-10 wt.% ZrB2 Composite

Silicon - In this work, AA7178-10 wt.% ZrB2 Metal Matrix Composite was produced using stir casting route and the mechanical properties of the composites were studied. The microstructure and...     

Effects of carbon nanofibers on cell morphology, thermal conductivity and crush strength of carbon foam

The effects of low volume fractions of carbon nanofibers on the structure, thermal conductivity and crush strength of carbon foam were examined. Bulk density of the foam increased linearly with the fiber fraction reflecting the morphological changes in the cells. Thermal conductivity increased at low fiber fractions, but dropped at higher fiber fractions. Crush strength increased linearly with fiber fraction for short length fibers, but decreased for the longer length fibers. Scanning electron microscopy, petrography, and X-ray diffraction illustrated the complex effects of the carbon nanofibers on the foam. Available models for thermal conductivity and crush strength have been extended to accommodate these effects incorporating cell structure and morphology (macroeffect), presence of fibers (microeffect), and graphite crystal d-spacing (nanoeffect). This research has shown that the nanofibers have a complex role in the macro, micro, and nanoproperties of the composite foam.     

Experimental Study of Parameters of a Plasma Antenna

A plasma column excited by a surface wave can act as a plasma antenna. Experiments are carried out to study the current and conductivity distributions, field, power patterns, directivity and efficiency of such a plasma antenna. In addition, an equivalent metallic copper antenna is built up and its antenna parameters are compared with that of the plasma antenna. Our findings indicate that the power content in the harmonics of the plasma antenna is more prominent as compared to the copper antenna (which only generates a fundamental frequency). However, the power patterns for both antennae are quite similar. To provide a more qualitative understanding regarding the generation of harmonics in the field of the plasma antenna, a bi-spectral analysis is performed to study the nonlinear interactions in the current fluctuations. Some specific features of the plasma antenna are investigated in our study, which may enhance the application prospect of the plasma antenna with respect to the conventional metallic antenna.     

Letter to the editor: Design of FIR notch filters by using Bernstein polynomials

In this paper, Bernstein polynomials have been used to derive an explicit formula for the coefficients of linear phase FIR notch filters which are maximally flat at ω=0 and π. The approach is relatively simple and enables us to design the filter for a specific notch frequency and bandwidth. © 1997 by John Wiley & Sons, Ltd.     

Review on recent advances of zinc substituted cobalt ferrite nanoparticles: Synthesis characterization and diverse applications

Researchers have taken a prodigious consideration in characterizing and synthesizing zinc substituted cobalt ferrite nanoparticles because of their substantial applications across diverse technological and industrial fields. Zinc substituted cobalt ferrite nanoparticles are a class of lenient magnetic nanomaterials, which have potentially high magnetic, optical, electrical, and dielectric properties. These properties include a high value of permeability, low power losses, permittivity, saturation magnetization, coercivity, resistivity, and other beneficial properties that make them promise candidates for applications in various fields. These ferrites are also used in biomedical areas such as MRI and cancer treatments. In electronic fields, zinc substituted cobalt ferrite nanoparticles are used to make transducers, transformers, biosensors, and sensors. Apart from these advantages, they are found in our everyday electronic and electrical appliances like LED bulb, refrigerator, mobile charger, TV, microwave oven, juicer, washing machine, mixer, iron, printer, laptop, mobile, desktop, etc. Hence, the current review reports some properties of these spinel ferrites and emphasizes the different synthesis techniques that can be used to prepare them. Afterward, the impact of dopant on the materials' properties, the characterization techniques, and the momentous application in the present era have been well discussed.