Superconductivity in correlated disordered two-dimensional electron gas

We calculate the dynamic effective electron-electron interaction potential for a low density disordered two-dimensional electron gas. The disordered response function is used to calculate the effective potential where the scattering rate is taken from typical mobilities from recent experiments. We investigate the development of an effective attractive pair potential for both disordered and disorder free systems with correlations determined from existing numerical simulation data. The effect of disorder and correlations on the superconducting critical temperature Tc is discussed.Comment: 4 pages, RevTeX + epsf, 4 figure

Electrospun Piezoelectric Polymer Nanofiber Layers for Enabling in Situ Measurement in High-Performance Composite Laminates

This article highlights the effects from composite manufacturing parameters on fiber-reinforced composite laminates modified with layers of piezoelectric thermoplastic nanofibers and a conductive electrode layer. Such modifications have been used for enabling in situ deformation measurement in high-performance aerospace and renewable energy composites. Procedures for manufacturing high-performance composites are well-known and standardized. However, this does not imply that modifications via addition of functional layers (e.g., piezoelectric nanofibers) while following the same manufacturing procedures can lead to a successful multifunctional composite structure (e.g., for enabling in situ measurement). This article challenges success of internal embedment of piezoelectric nanofibers in standard manufacturing of high-performance composites via relying on composite process specifications and parameters only. It highlights that the process parameters must be revised for manufacturing of multifunctional composites. Several methods have been used to lay up and manufacture composites such as electrospinning the thermoplastic nanofibers, processing an inter digital electrode (IDE) made by conductive epoxy-graphene resin, and prepreg autoclave manufacturing aerospace grade laminates. The purpose of fabrication of IDE was to use a resin type (HexFlow RTM6) for the conductive layer similar to that used for the composite. Thereby, material mismatch is avoided and the structural integrity is sustained via mitigation of downgrading effects on the interlaminar properties. X-ray diffraction, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, and scanning electron microscopy analyses have been carried out in the material characterization phase. Pulsed thermography and ultrasonic C-scanning were used for the localization of conductive resin embedded within the composite laminates. This study also provides recommendations for enabling internally embedded piezoelectricity (and thus health-monitoring capabilities) in high-performance composite laminates

Analysis of DRA with Performance Evaluation for High Speed System Applications Using Partial Differential Equation based Framework

A novel efficient design analysis has been proposed for a reduced-size dielectric resonator antenna (DRA) using perturbed system of partial differential equations. This has been done by using half-volume resonator with short-circuited plane of symmetry. The design serves as a new configuration of planar antenna, thus making integration of active devices easier. The antenna shows remarkable performance, having low cross-polarization levels and reasonably well radiation patterns. The antenna design has been simulated using a new analytical framework created in MATLAB giving accurate measurement details

Instability in Soft Sensitive Clays

Soft sensitive clays like quick clays are well known in Scandinavia and in some regions in Canada. The salt pore water of these marine clays has been leached out since last glaciations and left a brittle mineral structure. Slides in quick clays can be extremely disastrous, as in Verdal, Norway in 1893 or Rissa in 1978. The slides may be initiated by local overloading, river erosion or similar and can escalate in size in a retrogressive manner in which large volumes of clay finally may liquefy. Norwegian quick clay has a very low permeability and hence pore water pressure becomes a crucial parameter that can affect the stability of material. Failure in quick clay (with a post-peak strain softening behavior) is often associated with the development of shear bands, i.e. narrow zones of localized deformation, and the failure loads depend on the thickness of these shear bands. Plane strain compression tests were performed, at laboratory 3S, Grenoble France, to observe the formation and propagation of shear bands during undrained shearing. Biaxial plane strain tests were performed in quick clay having different sensitivity and local pore pressure variation throughout the test was monitored. Image analysis is done to detect shear band thickness and mode of failure. Further, usefulness of shear band analyses in landslide calculation using finite elements and consequence of such failure is also discussed numerically. A stability analysis of a quick clay slope is made to illustrate the progressive failure mechanism

Mathematical Analysis of Half Volume DRA with Performance Evaluation for High Speed System Applications

A novel efficient design analysis has been proposed for a reduced-size dielectric resonator antenna (DRA). This has been done by using half-volume resonator with short-circuited plane of symmetry. The design serves as a new configuration of planar antenna, thus making integration of active devices easier. The antenna shows remarkable performance, having low cross-polarization levels and reasonably well radiation patterns. The antenna design has been simulated using a new analytical framework created in MATLAB giving accurate measurement details

Phase diagram of the metal-insulator transition in 2D electronic systems

We investigated the interdependence of the effects of disorder and carrier correlations on the metal-insulator transition in two-dimensional electronic systems. We present a quantitative metal-insulator phase diagram. Depending on the carrier density we find two different types of metal-insulator transition - a continuous localization for rs=<8 and a discontinuous transition at higher rs. The critical level of disorder at the transition decreases with decreasing carrier density. At very low carrier densities we find that the system is always insulating. The value of the conductivity at the transition is consistent with recent experimental measurements. The self-consistent method which we have developed includes the effects of both disorder and correlations on the transition, using a density relaxation theory with the Coulomb correlations determined from numerical simulation data.Comment: 4 pages, RevTeX + epsf, 5 figures. New comments on conducting phase and on the conductivity. References updated and correcte

Microwave-Assisted Rapid Synthesis of Reduced Graphene Oxide-Based Gum Tragacanth Hydrogel Nanocomposite for Heavy Metal Ions Adsorption

This work aims to address the effectiveness and challenges of non-destructive testing (NDT) by active infrared thermography (IRT) for the inspection of aerospace-grade composite samples and seeks to compare uncooled and cooled thermal cameras using the signal-to-noise ratio (SNR) as a performance parameter. It focuses on locating impact damages and optimising the results using several signal processing techniques. The work successfully compares both types of cameras using seven different SNR definitions, to understand if a lower-resolution uncooled IR camera can achieve an acceptable NDT standard. Due to most uncooled cameras being small, lightweight, and cheap, they are more accessible to use on an unmanned aerial vehicle (UAV). The concept of using a UAV for NDT on a composite wing is explored, and the UAV is also tracked using a localisation system to observe the exact movement in millimetres and how it affects the thermal data. It was observed that an NDT UAV can access difficult areas and, therefore, can be suggested for significant reduction of time and cost

Fishery and biology of white sardine, Escualosa thoracata (Valenciennes) at Versova, Bombay

Gill net fishery exclusively for the white sardine, Escualosa thoracata, which started in mid eighties at Versova, is described. During 1987-88 to 1991-92 period the annual average landing of the species was 202.2 tons with year to year fluctuations. The peak fishing season was during April-May. The size range of the species in the gill net was 41-105 m

Testosterone levels in men with type 2 diabetes mellitus

Background: To study testosterone levels in men with type 2 diabetes mellitus in age group of 30-50 years.Methods: In this cross sectional study of 193 type 2 diabetes men aged between 30-50 years, total and free testosterone levels were calculated along with other relevant clinical variables like hypertension, BMI, dyslipidemia, peripheral neuropathy, retinopathy.Results: The study group had study out of 193 patients 34.7% have low total testosterone levels, 29.53% have low free testosterone levels and 23.3% have both low and free testosterone levels. Maximum number of patients with low total testosterone levels were in the age group between 46-50 years (41.0%) and with low free total testosterone levels were in the age group between 36-40 years (41.8%).Conclusions: Type 2 diabetes mellitus is associated with low levels of total and free testosterone. Obesity and dyslipidemia are also associated with low testosterone levels