412 research outputs found
Magneto-Optical Visualisation for High-Resolution Forensic Data Recovery Using Advanced Thin Film Nano-Materials
We develop and characterise new high-performance nano-engineered magneto-optic materials for use in laser-microscopy- based magnetic field visualisers featuring high sensitivity and resolution, low cost and small size. This type of visualisers will make it possible for forensic experts to recover erased data previously stored in high- and ultrahigh-density magnetic disks and hard disk drives
Light reflection loss reduction by nano-structured gratings for highly efficient next-generation GaAs solar cells
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This paper mainly focuses on increasing the conversion efficiency of GaAs solar cells by reducing the light reflection losses. The design of nano-structured gratings and their light trapping performance are modelled and optimised by using the finite-difference time-domain (FDTD) method. The sunlight directly impinges on the solar panel or cells, then a portion of the incident sunlight reflects back to the air from the surface of the panel, thus leading to a reduction in the light absorption capacity of the solar cells. In order to proliferate the light absorption capacity of solar cells nano-grating structures are employed, as they are highly capable of capturing the incident sunlight compared to a conventional (or flat type) solar cell, which results in generating more electrical energy. In this study, we design three different types of nano-grating structures, optimise their parameters and their performance in light capturing capacity. From the simulation results, we confirm that that it is possible to reduce light reflection losses up to 27%, by using the nano-grating structures, compared to conventional type solar cells. This reduction of reflection losses helps to improve the conversion efficiency of next-generation GaAs solar cells significantly for a sustainable green Earth
Synthesis, Characteristics, and Material Properties Dataset of Bi:DyIG-Oxide Garnet-Type Nanocomposites
The fabrication, annealing crystallization processes, and material properties of (Bi,Dy)3(Fe,Ga)5O12:Bi2O3 nanocomposites are investigated and summarized. The stoichiometry of these nanocomposites is optimized for magnetooptic applications using the approach of stoichiometry adjustment (implemented by means of varying RF power densities applied to the sputtering targets used to prepare the nanocomposite thin films). The crystallization processes for all developed batches of as-deposited films are carried out by annealing runs at different temperatures and process durations. This paper describes the methodologies used to optimize the compositions (by calculating the volumetric fractions of excess bismuth oxide to be mixed with the garnet-stoichiometry species during cosputtering processes) and to obtain the optical and magnetooptical properties data and presents the materials properties summary of garnet-bismuth oxide thin film composites as well
Optical and chromaticity properties of metal-dielectric composite-based multilayer thin-film structures prepared by RF magnetron sputtering
Coated glass products, and especially the low-emissivity coatings, have become a common building material used in modern architectural projects. More recently, these material systems became common in specialized glazing systems featuring solar energy harvesting. Apart from achieving the stability of optical parameters in multilayer coatings, it is also important to have improved control over the design of visual color properties of the coated glass. We prepare metal-dielectric composite (MDC)-based multilayer thin-film structures using the radio frequency (RF)-magnetron sputtering deposition and report on their optical and chromaticity properties in comparison with these obtained using pure metal-based Dielectric/Metal/Dielectric (DMD) trilayer structures of similar compositions. Experimentally achieved Hunter L, a, b values of MDC-based multilayer building blocks of coatings provide a new outlook on the engineering of future-generation optical coatings with better color consistency and developing approaches to broaden the range of achievable color coordinates and better environmental stability
YIG: Bi2O3 Nanocomposite Thin Films for Magnetooptic and Microwave Applications
Y3Fe5O12-Bi2O3 composite thin films are deposited onto Gd3Ga5O12 (GGG) substrates and their annealing crystallization regimes are optimized (in terms of both process temperatures and durations) to obtain high-quality thin film layers possessing magnetic properties attractive for a range of technological applications. The amount of bismuth oxide content introduced into these nanocomposite-type films is controlled by adjusting the RF power densities applied to both Y3Fe5O12 and Bi2O3 sputtering targets during the cosputtering deposition processes. The measured material properties of oven-annealed YIG-Bi2O3 films indicate that cosputtering of YIG-Bi2O3 composites can provide the flexibility of application-specific YIG layers fabrication of interest for several existing, emerging, and also frontier technologies. Experimental results demonstrate large specific Faraday rotation (of more than 1°/µm at 532 nm), achieved simultaneously with low optical losses in the visible range and very narrow peak-to-peak ferromagnetic resonance linewidth of around ΔHpp= 6.1 Oe at 9.77 GHz
Enhanced magneto-optic properties in sputtered Bi-containing ferrite garnet thin films fabricated using oxygen plasma treatment and metal oxide protective layers
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Magneto-optic (MO) imaging and sensing are at present the most developed practical applications of thin-film MO garnet materials. However, in order to improve sensitivity for a range of established and forward-looking applications, the technology and component-related advances are still necessary. These improvements are expected to originate from new material system development. We propose a set of technological modifications for the RF-magnetron sputtering deposition and crystallization annealing of magneto-optic bismuth-substituted iron-garnet films and investigate the improved material properties. Results show that standard crystallization annealing for the as-deposited ultrathin (sputtered 10 nm thick, amorphous phase) films resulted in more than a factor of two loss in the magneto-optical activity of the films in the visible spectral region, compared to the liquid-phase grown epitaxial films. Results also show that an additional 10 nm-thick metal-oxide (Bi2O3) protective layer above the amorphous film results in ~2.7 times increase in the magneto-optical quality of crystallized iron-garnet films. On the other hand, the effects of post-deposition oxygen (O2) plasma treatment on the magneto-optical (MO) properties of Bismuth substituted iron garnet thin film materials are investigated. Results show that in the visible part of the electromagnetic spectrum (at 532 nm), the O2 treated (up to 3 min) garnet films retain higher specific Faraday rotation and figures of merit compared to non-treated garnet films
Lack of Knowledge Is the Leading Key for the Growing Cervical Cancer Incidents in Bangladesh: A Population Based, Cross-Sectional Study
Introduction
Cervical cancer is the second most common gynecological cancer in Bangladesh. Lack of awareness of screening methods, risk factors, and symptoms may lead to presenting most cervical cancers at an advanced stage. We investigated knowledge and awareness of cervical cancer (CCa) among females at the Sheikh Hasina Medical College (SHMC) of Tangail district in Bangladesh.
Methods
A cross sectional survey was conducted to collect data via a structured questionnaire from SHMC during the period of February 2019 to January 2020. Data on socio-demographic characteristics and knowledge of cervical cancer were collected. Multivariable logistic regression models were used to identify factors associated with having heard and knowledge of cervical cancer. A p-value \u3c 0.05 was considered significant.
Result
Of all the interviews conducted, only 45.2% (493/1090) had heard of cervical cancer as a disease. Women were more likely to be aware of CCa if they were lived in urban areas, had higher education (university level education) and belong to high income families. The study revealed evidence of significant association between marital, literacy, residence and socio-economic status with women’s knowledge on cervical cancer (p\u3c 0.05).
Conclusion
This study serves to highlight that there was impoverished knowledge about cervical cancer among Bangladeshi women. Hence, this indicates the government should take proper steps to raise awareness and knowledge levels via educational programs and health counseling
RF-sputtered Bi-substituted iron garnet composite films for visible-range magneto-optics
Cellulosic rich biomass production with optimized process parameters by using glycerol pretreatment for biofuels applications
In this work, we conduct acidified aqueous glycerol pre-treatment (AAG) on rice husks (RH) and utilize the response surface methodology (RSM) to assess the impact of pre-treatment parameters. The primary objective of this research is to optimize the parameters to maximize the cellulose content within RH. The parameters under consideration encompassed temperature (ranging from 80 to 110 °C), retention time (spanning 15 to 45 min), and biomass loading (varying from 5 to 10 wt. %). To achieve this optimization, we perform the Box-Behnken Design (BBD) within the framework of RSM. Additionally, we scrutinize the interactive effects of these parameters on cellulose content. Our findings unveiled a remarkable increase in cellulose content, escalating from 40 % in untreated RH to an impressive 75 % in pre-treated RH under the optimized conditions of 110 °C for 45 min with a 5.0 wt. % biomass loading. To further evaluate the effectiveness of the pre-treatment process, we conduct scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses, shedding light on alterations in surface morphology and crystallinity of RH. This investigation yields valuable insights, presenting novel opportunities for the efficient conversion of readily available rice husks into high-value products, such as biofuels and composites
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