Hybrid Plasmonic Waveguide Fed Broadband Nano-antenna for Nanophotonic Applications

In this paper, we propose a novel hybrid plasmonic waveguide fed broadband optical patch nano-antenna for nanophotonic applications. Through full wave electromagnetic simulation, we demonstrated our proposed antenna to radiate and receive signal at all optical communication windows (e.g. $\lambda$ = 850nm, 1310nm & 1550nm) with around 86% bandwidth within the operational domain. Moreover numerical results demonstrate that the proposed nano-antenna has directional radiation pattern with satisfactory gain over all three communication bands. Additionally, we evaluated the antenna performances with two different array arrangements (e.g. one dimensional and square array). The proposed broadband antenna can be used for prominent nanophotonic applications such as optical wireless communication in inter and intra-chip devices, optical sensing and optical energy harvesting etc.Comment: 4 Page, 7 figure

Present Status of Corporate Environmental Accounting (CEA) in Bangladesh: A Study Based on Some Selected Textile Companies

This paper is aimed to analysis the present status of CEA of private sector textile mills of Bangladesh.For the study a sample of 25% of population has been taken. Environment has become a crucial factor in today’s ecological, social and economical set up.Managers who can influence decisions regarding eenvironment express the view that more environmental accounting work is needed, but very little such work is done. A semi-structured questionnaire was prepared and followed direct interview method to know the relevant information. Managers are positive about environmental issues. This paper revealed different problems for not adopting CEA in full swing. Key Words: Environment, Corporate Environmental Accounting(CEA), Corporate Environmental Accounting in Bangladesh

Foreign Direct Investment (FDI) and Gross Domestic Product (GDP) in Bangladesh: A Cointegration Analysis

This paper investigates the long-run relationship between GDP and FDI in Bangladesh for a period of 42 years ranges from 1972 to 2013 by using time series econometric technique. The empirical results show that there is a significant positive correlation between GDP and FDI. The results also show that FDI and GDP are cointegrated in the long-run. For the supplement of the results of cointegration analysis, this study also examine the causal relationships by using Granger causality test and find strong evidence for unidirectional causality running between GDP through FDI in the long run. Keywords: FDI, GDP, Unit Root, Cointegration, Granger Causality

Traversing hot jet ignition delay of hydrocarbon blends in a constant volume combustor

Indiana University-Purdue University Indianapolis (IUPUI)A chemically reactive turbulent traversing hot-jet issued from a pre-chamber to a relatively long combustion chamber is experimentally investigated. The long combustion chamber represents a single channel of a wave rotor constant-volume combustor. The issued jet ignites the fuel-air mixture in the combustion chamber. Fuel-air mixtures are prepared with different hydrocarbon fuels of different reactivity, namely, methane, propane, methane-hydrogen blend, methane-propane blend and methane-argon blend. The jet acts as a rapid, distributed and moving source of ignition, traversing across one end of the long combustion chamber entrance, induces complex flow structures such as a train of counter rotating vortices that enhance turbulent mixing. In general, a stationary hot-jet ignition process lack these structures due to absence of the traversing motion. The ignition delay of the fuels and fuel blends are measured in order to obtain insights about constant-volume pressure-gain combustion process initiated by a moving source of ignition and also to glean useful data about design and operation of a wave rotor combustor. Reactive hot-jets are useful to ignite fuel-air mixtures in internal combustion engines and novel wave rotor combustors. A reactive hot-jet or puff of gas issued from a suitably designed pre-chamber can act as rapid, distributed and less polluting ignition source in internal combustion engines. Each cylinder of the engine is provided with its own pre-chamber. A wave rotor combustor has an array of circumferentially arranged channels on a rotating drum. Each channel acts as a constant-volume combustor and produces high pressure combustion products. Implementation of hot-jet igniter in a wave rotor combustor offers utilization of available high temperature and high pressure reactive combustion products residing in each of the wave rotor channels as a distributed source of ignition for other channels, thus requiring no special pre-chamber in ultimate implementation. Such reactive products or partially combusted and radical-laden gases can be issued from one or more channels to ignite the fuel-air mixture residing in another channel. Due to the rotation of the rotor channels, the issued hot-jet would have relative motion with respect to one end of the channels and traverse across it. This thesis aims to investigate the effects of jet traverse time experimentally on ignition delay along with other important factors that affect the hot-jet ignition process such as fuel reactivity, fuel-air mixture preparation quality and stratification and equivalence ratio. In this study, the traversing motion of the hot-jet at one end of the main combustion chamber is implemented by keeping the main combustion chamber stationary and rotating a pre-chamber at speeds of 400 RPM, 800 RPM and 1200 RPM. The rotational speeds correspond to jet traverse times of 16.9 ms, 8.4 ms and 5.6 ms respectively. The fuel-air mixture inside the channel is at room temperature and pressure initially and its equivalence ratio is varied from 0.4 to 1.3. The cylindrical pre-chamber is initially filled with a 50%-50% methane-hydrogen blend fuel and air mixture at room pressure and temperature and at an equivalence ratio of 1.1. These conditions were chosen based on prior evidence of ignition rapidity with the jet properties. The hot-jet is issued by rupturing a thin diaphragm isolating the chambers. Using high frequency dynamic pressure transducer pressure histories, the diaphragm rupture moment and onset of ignition is measured. Pressure traces from two transducers are employed to measure the initial rupture shock speed and ignition delay. Schlieren images recorded by a high speed camera are used to identify ignition moment and validate the measured ignition delay times. Ignition delay is defined as time interval from the rupture moment to onset of ignition of fuel-air mixture in the main combustion chamber. The ignition system is designed to produce diaphragm rupture at almost exactly the moment when jet traverse begins. Ignition delay times are measured for methane, propane, methane-hydrogen blends, methane-propane blend and methane-argon blend. The equivalence ratio of the fuel-air mixtures varied from 0.4 to 1.3 in steps of 0.1 for stationary-hot jet ignition experiments and in steps of 0.3 for traversing hot-jet ignition experiments. Hot-jet ignition delay of fuel-air mixtures, for both stationary hot-jet ignition process and traversing hot-jet ignition process, generally increased with increasing equivalence ratio. For stationary hot-jet ignition delay, the minimum ignition delay occurs between Ф = 0.4 to Ф = 0.6 for the tested fuel-air mixtures. Both stationary and traversing hot-jet ignition delay depended on fuel reactivity. In particular, the shortest ignition delay times were observed for a fuel blend containing hydrogen. Among pure fuels propane exhibited slightly shorter ignition delay times, on average, compared to pure methane fuel. The addition of argon to pure methane, intended to control fuel density and buoyancy, increased the ignition delay. The traversing hot-jet ignition delay generally increased with increasing jet traverse times. To explain the variations in the measured hot-jet ignition delay and investigate qualitatively the effect of buoyancy on flame propagation and mixture stratification, the fuel-air mixture inside the main combustion chamber was ignited using a spark plug to generate a propagating laminar flame. The laminar flame propagated within the flammable regions of the channel in ways that sensitively reveal variations in local fuel-air mixture equivalence ratio. Flame luminosity images from a high speed camera and schlieren images revealed the fuel-air mixture being highly stratified depending on the density difference between the fuel and air and provided mixing time (0 s, 10s ,30s for most fuels). The lack of buoyancy-driven spreading caused the fuel to remain in the vicinity of the fuel injector resulting in significant longitudinal stratification of the fuel-air mixture. Lighter fuels stratified to the top of the chambers and heavier fuel stratified to the bottom of the chamber. Increasing the mixing time, which is defined as the time interval from end of fuel injection into the chamber to the triggering of the spark plug, improved the buoyancy-driven spreading and extended the flammable region as evidenced by the schlieren and flame luminosity images. The maximum pressure developed in the combustor for the three ignition processes, namely, stationary hot-jet ignition, traversing hot-jet ignition and spark ignition process in laminar flame propagation experiments were compared. Stationary hot-jet ignition process generally exhibited the highest pressure being developed in the chamber. Variations in heat loss, fuel-air mixture leakage and mass addition mechanisms reduced the maximum pressure for spark ignition and traversing hot-jet ignition process

Agritourism, Community Attachment and Their Contributions to Tourism and Community: An Empirical Study

The tourism industry has encountered various sustainable development functionalities, and nations seek to develop tourism while conserving nature and its resources. Agritourism strengthens a region’s competitive, cultural, and transformational resources while helping the rural community, economy, and society thrive sustainably. However, few studies have evaluated community attention toward agritourism in developing countries. This study bridges this gap using community attachment through agritourism-based resident perceptions of the economic, social, cultural, and environmental impacts of tourism support and its contributions to resident communities. A partial least squares method under structural equation modelling (SEM) was employed using SmartPLS 3.0. Results reveal that community attachment is significantly correlated with economic, social, cultural, and environmental impacts, which are also significantly associated with tourism support. These impacts were mainly related to contributions to the community, thus confirming all hypotheses except for the cultural implications, which were found to be insignificant. This study will help marketers, professionals, and decision-makers understand and predict the economic, social, cultural, and environmental impacts of agritourism and formulate policies to contribute to its development

Relationship between Risk-taking, Capital Regulation and Bank Performance: Empirical Evidence from Bangladesh

This paper attempts to analyse the relationships between risk-taking, capital regulation and performance in banking sector of Bangladesh. We use Generalized Methods of Moments (GMM) in an unbalanced panel data using 38 commercial banks of Bangladesh for a period of 2007-2016. The empirical results show a significant negative relation between risk taking and capital regulation. Results also reveal that there is a significant positive relation between capital regulation and performance, and a significant negative relation between risk and performance. This study provides various suggestions about risk management and capital adequacy for the regulators, stakeholders and government

Population parameters of Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia

An investigation of the population parameters of Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia was carried out from January to September 2013. The relationship between total length and body weight was estimated as W=0.006TL3.215 or Log W=3.215LogTL – 2.22 (R2=0.946). Monthly length frequency data of R. kanagurta were analyzed by FiSAT software to evaluate the mortality rates and its exploitation level. Asymptotic length (Lµ) and growth co-efficient (K) were estimated at 27.83 cm and 1.50 yr-1, respectively. The growth performance index (φ') was calculated as 3.07. Total mortality (Z), natural mortality (M) and fishing mortality (F) was calculated at 4.44 yr-1, 2.46 yr-1 and 1.98 yr-1, respectively. Exploitation level (E) of R. kanagurta was found to be 0.45. The exploitation level was below the optimum level of exploitation (E=0.50). It is revealed that the stock of R. kanagurta was found to be still under exploited in Marudu Bay

A Lightweight Deep Learning Based Microwave Brain Image Network Model for Brain Tumor Classification Using Reconstructed Microwave Brain (RMB) Images

Computerized brain tumor classification from the reconstructed microwave brain (RMB) images is important for the examination and observation of the development of brain disease. In this paper, an eight-layered lightweight classifier model called microwave brain image network (MBINet) using a self-organized operational neural network (Self-ONN) is proposed to classify the reconstructed microwave brain (RMB) images into six classes. Initially, an experimental antenna sensor-based microwave brain imaging (SMBI) system was implemented, and RMB images were collected to create an image dataset. It consists of a total of 1320 images: 300 images for the non-tumor, 215 images for each single malignant and benign tumor, 200 images for each double benign tumor and double malignant tumor, and 190 images for the single benign and single malignant tumor classes. Then, image resizing and normalization techniques were used for image preprocessing. Thereafter, augmentation techniques were applied to the dataset to make 13,200 training images per fold for 5-fold cross-validation. The MBINet model was trained and achieved accuracy, precision, recall, F1-score, and specificity of 96.97%, 96.93%, 96.85%, 96.83%, and 97.95%, respectively, for six-class classification using original RMB images. The MBINet model was compared with four Self-ONNs, two vanilla CNNs, ResNet50, ResNet101, and DenseNet201 pre-trained models, and showed better classification outcomes (almost 98%). Therefore, the MBINet model can be used for reliably classifying the tumor(s) using RMB images in the SMBI system. 2023 by the authors.This work was supported by the Universiti Kebangsaan Malaysia project grant code DIP-2021-024. This work was also supported by Grant NPRP12S-0227-190164 from the Qatar National Research Fund, a member of the Qatar Foundation, Doha, Qatar, and the claims made herein are solely the responsibility of the authors. Open access publication is supported by the Qatar National Library.Scopu

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London