Mid-infrared chiral metsurface coupling with molecular vibration

“The mid-infrared design of chiral metamaterial shows a tremendous absorption capability of infrared rays, and it has the significant application of circular dichroism based device development. Plasmon-phonon coupling is one of the application of metamaterial that provides a new path for tailoring the surface in the nanoscale, which is also applicable in molecules detection. It is possible to change the Plasmon-Phonon coupling strength not only through the chemical change of molecules but also by changing the metamaterial light-matter interaction property. So far, linearly polarized light shows the strong coupling between metamaterial and molecules. However, it is possible to observe strong coupling in circularly polarized light by fabricating the chiral metasurface. In this research, we introduce two types of new chiral metasurface that has strong interaction with the molecules in different circular polarization of light, which exhibits over 58% and 65% circular dichroism (CD) in the mid-infrared region (5- 6 μm). By adjusting the geometric parameters of the new chiral structure of single-sized unit cells, it is possible to shift the absorption peak in the various midinfrared range. Besides that, we design the broadband resonator by combining the multiple chiral structures. For the molecule’s detection, It also shows a higher splitting gap in the right circularly polarized light in compare to Left circular polarized light. Our numerical and experimental result of the C=0 bands signals which emits from polymethyl methacrylate (PMMA) film using chiral metasurface unveils the effective way for tuning the coupling strength of molecules in circular polarization of light”--Abstract, page iii

Problems Faced by Garments Workers: A Study on Matrix Sweaters Limited

This paper examines the problems confronted by Matrix Sweaters Limited workers. The study also attempts to identify the possible reasons for dispute among the workers. Results from the study have revealed that wage discrimination is the main problem for Garments workers and low salary for garments worker is the vital reason for industrial dispute. The analysis have also exposed that workload is not justifiable to labor act. The hypothesis test has proved that female garments workers faced more problems in compare to male workers. Keywords: Garment Industry, Wage Discrimination, Industrial Dispute, Bangladesh

Plasmon-Phonon Coupling between Mid-Infrared Chiral Metasurfaces and Molecular Vibrations

Plasmon-phonon coupling between metamaterials and molecular vibrations provides a new path for studying mid-infrared light-matter interactions and molecular detection. So far, the coupling between the plasmonic resonances of metamaterials and the phonon vibrational modes of molecules has been realized under linearly polarized light. Here, mid-infrared chiral plasmonic metasurfaces with high circular dichroism (CD) in absorption over 0.65 in the frequency range of 50 to 60 THz are demonstrated to strongly interact with the phonon vibrational resonance of polymethyl methacrylate (PMMA) molecules at 52 THz, under both left-handed and right-handed circularly polarized (LCP and RCP) light. The mode splitting features in the absorption spectra of the coupled metasurface-PMMA systems under both circular polarizations are studied in PMMA layers with different thicknesses. The relation between the mode splitting gap and the PMMA thickness is also revealed. The demonstrated results can be applied in areas of chiral molecular sensing, thermal emission, and thermal energy harvesting

Design, Construction and Performance Study of a Solar Assisted Tri-cycle

Solar energy is one of the important sources of renewable energy which can be a feasible alternative to fossil fuels. There are many works has been done in order to incorporate solar energy to everyday transportation including tricycle. However, most of the tricycle develops are expensive and not feasible for developing countries. In this study, a cheaper solar tricycle with more capability of utilizing the solar energy is designed for developing countries. The main content of the tricycle is Solar PV panel, Brushless PMDC motor, controller, and battery. The power transmission of the solar tricycle is also simple. It is found that tricycle serves 24% back up for running, by the solar panel. Also, the total construction cost of the tricycle is only 240$ with near about zero impact on the environment. This paper highlights the advantages of the dual mode of charging, including the economic and environmental feasibility of the tricycle

iBUST: An intelligent behavioural trust model for securing industrial cyber-physical systems

To meet the demand of the world's largest population, smart manufacturing has accelerated the adoption of smart factories—where autonomous and cooperative instruments across all levels of production and logistics networks are integrated through a Cyber-Physical Production System (CPPS). However, these networks are comprised of various heterogeneous devices with varying computational power and memory capabilities. As a result, many secure communication protocols – that demand considerably high computational power and memory – can not be verbatim employed on these networks, and thereby, leaving them more vulnerable to security threats and attacks over conventional networks. These threats can largely be tackled by employing a Trust Management Model (TMM) by exploiting the behavioural patterns of nodes to identify their trust class. In this context, ML-based models are best suited due to their ability to capture hidden patterns in data, learning and improving the pattern detection accuracy over time to counteract and tackle threats of a dynamic nature, which is absent in most of the conventional models. However, among the existing ML-based solutions in detecting attack patterns, many of them are computationally expensive, require a long training time, and a considerably large amount of training data—which are seldom available. An aid to this is the association rule learning (ARL) paradigm, whose models are computationally inexpensive and do not require a long training time. Therefore, this paper proposes an ARL-based intelligent Behavioural Trust Model (iBUST) for securing the CPPS. For this intelligent TMM, a variant of Frequency Pattern Growth (FP-Growth), called enhanced FP-Growth (EFP-Growth) algorithm is developed by altering the internal data structures for faster execution and by developing a modified exponential decay function (MEDF) to automatically calculate minimum supports for adapting trust evolution characteristics. In addition, a new optimisation model for finding optimum parameter values in the MEDF and an algorithm for transmuting a 1D quantitative feature into a respective categorical feature are developed to facilitate the model. Afterwards, the trust class of an object is identified employing the Naïve Bayes classifier. This proposed model is evaluated on a trust evolution-supported experimental environment along with other compared models taking a benchmark dataset into consideration, where it outperforms its counterparts

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A New Generalized Step-Down Single-Stage AC/AC Power Converter

Most traditional AC/AC power converters suffer from power quality problems and multi-stage power conversion losses. The rectifier and inverter-based AC/AC converter topology not only increases multi-stage power conversion losses, but also increases the volume, weight, and cost, and decreases the longevity of the converter due to the DC-link capacitor, line filter and electromagnetic interference (EMI) filter. High-frequency (about 10 kHz) switching advanced pulse width modulation techniques are generally used in order to compensate the power quality problems, which increase the switching losses and introduce the EMI problems. In this paper, a new generalized step-down single-stage line-frequency switching AC/AC power converter topology is proposed. The proposed converter uses line-frequency switching, and does not require any pulse width modulation techniques. The proposed topology offers promising performances in terms of lower order harmonics, total harmonic distortion, the elimination of DC-link capacitors and EMI filters, and switching losses. The circuit was designed and simulated in a MATLAB/Simulink environment. A scaled-down laboratory prototype of the proposed topology was developed in order to validate the feasibility. The experimental and simulation results reveal the feasibility of the proposed generalized step-down single-stage converter topology, and its excellent features

Study of Incident Drag Response of Hyperloop Pod Based on Change in Aerodynamic Brake Plate Orientation

The idea for the Hyperloop has received significant attention, with expectations of it becoming a revolutionary and potentially the fastest mode of land transportation on the planet. The low-pressure tube through which the pod travels at expected speeds close to Mach 1.0, presents a unique case among other transport models, and as such, braking of the pod is of critical importance if passenger safety protocols are to be maintained. The high-speed flow around the pod exerts high adverse pressure gradients on the pod surface, resulting in boundary layer separation, increasing drag and affecting the acceleration of the pod. Numerical simulations have shown that the placement of an aerodynamic brake plate on the pod surface at the point at which boundary layer separation occurs provides the necessary drag required for safe deceleration. This study was aimed to find the best angle for the aerodynamic brake positioned at a fixed point on the pod, allowing for the maximum generation of drag, using numerical simulations. After various trials, it was observed that angling the brake 15 backwards while increasing its length to keep incident brake profile constant, the drag value obtained was the highest.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author