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Spectroscopic study of Herbig Ae/Be stars in the Galactic anti-centre region from LAMOST DR5
We study a sample of 119 Herbig Ae/Be stars in the Galactic anti-centre direction using the spectroscopic data from large sky area multi-object fiber spectroscopic telescope survey program. Emission lines of hydrogen belonging to the Balmer and Paschen series, and metallic lines of species such as Fe ii, O i, Ca ii triplet are identified. A moderate correlation is observed between the emission strengths of H? and Fe ii 5169 suggesting a possible common emission region for Fe ii lines and one of the components of H?. We explored a technique for the extinction correction of the HAeBe stars using diffuse interstellar bands present in the spectrum. We estimated the stellar parameters such as age and mass of these HAeBe stars, which are found to be in the range 0.1-10 Myr and 1.5-10 M, respectively. We found that the mass accretion rate of the HAeBe stars in the Galactic anti-centre direction follows the relation ?acc ? M?3.12-0.34+0.21, which is similar to the relation derived for HAeBe stars in other regions of the Galaxy. The mass accretion rate of HAeBe stars is found to have a functional form of ?acc ? t-1.10.02 with age, in agreement with previous studies. 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. -
Blockchain-Based Service Oriented Privacy-Preserving Data Sharing over Distributed Data Streams in Asynchronous Environment
Innovative city applications use information and communication technologies to function various operations efficiently. The widespread use of the Internet of Things (IoT) can be viewed in several applications like smart cars, smart cities, e-commerce, and cyber-physical systems. The huge amount of data produced and transmitted by these systems is handled by cloud-based storage services, which are vulnerable to multiple threats risking the privacy and security features of the application. Cloud storage services employ encryption algorithms to ensure data confidentiality, but it fails to address the privacy issues. Apart from the privacy risks, in these systems, the identity of a user who shares and accesses the data is traceable, as it is required to verify user eligibility before providing access. Also, a vast amount of daily data is stored on a centralized system that processes service requests from multiple users, posing considerable risks to the system's stability during peak periods. To address these challenges faced during the data sharing process in a centralized system, Service Oriented Privacy-Preserving Data Sharing (SOPPDS) platform based on a blockchain framework is proposed. The modified Key Policy-Attribute-based Encryption (MKP-ABE) technique is applied to securely share the data between the service owners and the service consumers. It was evident from the performance evaluation of the proposed SOPPDS platform that the encryption process takes lesser time than the decryption process. Also, the cryptographic operations performed on the prime order sets exhibited increased latency and computational cost. It was observed that comparatively, cryptographic operations performed on composite order sets could overcome the issues in prime order sets. SOPPDS platform works well in preserving the users' privacy, ensuring anonymity in the data sharing process, and maintaining the confidentiality of the data shared in the system. 2023, Ismail Saritas. All rights reserved. -
Probing the soft state evolution of 4U 1543-47 during its 2021 outburst using AstroSat
4U 1543-47 underwent its brightest outburst in 2021 after two decades of inactivity. During its decay phase, AstroSat conducted nine observations of the source spanning from 2021 July 1 to September 26. The first three observations were performed with an offset of 40 arcmin with AstroSat/LAXPC, while the remaining six were on-axis observations. In this report, we present a comprehensive spectral analysis of the source as it was in the High/Soft state during the entire observation period. The source exhibited a disc-dominated spectra with a weak high-energy tail (power-law index ?2.5) and a high inner disc temperature (?0.84 keV). Modelling the disc continuum with non-relativistic and relativistic models, we find inner radius to be significantly truncated at >10 Rg. Alternatively, to model the spectral evolution with the assumption that the inner disc is at the innermost stable circular orbit, it is necessary to introduce variation in the spectral hardening in the range ?1.5-1.9. 2023 The Author(s). -
A Scoping Review on Integration of Electroencephalogram Neurofeedback Training for Alcohol Use Disorder: Clinical and Neurocognitive Outcomes
Background. The conventional treatment for alcohol use disorder (AUD) consists of dual treatment encompassing pharmacotherapy and psychotherapy. Nonetheless, the impact of these treatments on clinical and neurocognitive outcomes is only low to medium efficacy. Research studies substantiate the integration of electroencephalogram neurofeedback training (EEG-NFT) as an add-on tool with significant improvements in clinical and neurocognitive outcomes. Methods. A scoping review of the existing literature on EEG-NFT and AUD, which are open access, including review papers and empirical studies in the English language, and with human subjects are deemed worthy of the scope of this study. The keywords electroencephalogram neurofeedback training, alcohol use disorder, stress, neurocognition, and relapse were used. The primary sources of the literature search were Science Direct, Scopus, PubMed, and Google Scholar. A total of 35 articles have been included in the scoping review. Studies from the last 15 years were considered for the same. Results. This review revealed that EEG-NFT is a promising tool with significant improvements in stress levels, cognitive deficits, and relapse rates for individuals with AUD when used in integration with conventional treatments. Conclusion. Chronic alcohol use affects cognitive functions, escalates relapse rate, and increases stress experienced by the individual. The present study highlights the significance of NFT as a potent add-on treatment modality to improve clinical and cognitive outcomes, thereby facilitating abstinence and reducing relapse rates in individuals with AUD. Copyright: 2023. -
Molecular architecture of PANI/V2O5/MnO2 composite designed for hydrogen evolution reaction
An ever increasing demand for energy has mandated scientists towards exploring innovative and environmentally friendly energy production techniques that can meet the needs of human beings and the world at large. Among the various techniques, hydrogen evolution reaction (HER) is a cost-effective and efficient method that produces hydrogen, a better fuel, for meeting our energy requirements. The large surface area, good redox capacity, high electroactivity, and tunable bandgap of polyaniline (PANI) makes it a preferred candidate for various energy-related applications. Incorporating mixed metal oxides into a polymer enhances its catalytic activities and can be used as an electrocatalyst for HER. In situ chemical oxidative polymerization method has been carried out to synthesize PANI/V2O5/MnO2 composite. The characterization studies of PANI/V2O5/MnO2 composite are done using XRD, FT-IR, BET, XPS, and FE-SEM analysis. The PANI/V2O5/MnO2 composite is used for linear sweep voltammetry studies and shows that it acts as an efficient electrocatalyst which gives an overpotential of 130 mV at 10 mA/cm2. The high electrocatalytic activity of the composite is due to the better surface phenomenon that is enhanced by the high porosity and surface area. The electrochemical impedance spectroscopy also shows lower charge transfer resistance for the PANI/V2O5/MnO2, confirming its excellent electroactivity. 90% of the current density is retained even after 7200 seconds, validating its stability. 2023 Elsevier B.V. -
Why is the size of discouraged labour force increasing in India?
The Indian economy is currently passing through a critical phase of economic development as its structural transformation in employment has stalled, whilst both the youth unemployment rate and the number of youths Not in Employment, Education, and Training (NEET) have increased to an unprecedentedly high level. In the context in which the share of the youth population is continuing to rise despite the declining fertility rate to below the replacement rate, increased educated youth unemployment has caused an upsurge in the Discouraged Labour Force (DLF). This paper explores the trends, composition, and determinants of rising DLF in India using national level employment-unemployment surveys and macro-level panel data. Based on Multinomial logit and System GMM regression results, it is argued that policies aiming to enhance human capabilities through an improved base of technical education and the promotion of industry are necessary to enhance the growth of quality jobs in order to combat the problem of rising educated youth unemployment and DLF. Moreover, these measures could help in the process of harnessing the demographic dividend in India through an increased level of labour productivity in the long run. 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
ZnO doped SnO2 nano flower decorated on graphene oxide/polypyrrole nanotubes for symmetric supercapacitor applications
Due to their high power density, lengthy cyclability, quick charge-discharge rates, and environmentally friendly design, supercapacitors are incredibly effective electrochemical energy storage devices. A lot of work has been progressed in this direction to increase the specific power and cyclic stability of supercapacitor mainly by using various metal oxides with 2D composites and high concentration electrolytes. But, there are some challenging issues like low energy density, high production cost, and short cyclic life. In this work, we aimed to resolve the low energy density and operating voltage of electrodes by selecting multiphase inorganic-organic material with a suitable concentration of electrolyte. To create such supercapacitor electrodes for high energy storage applications, ZnO doped SnO2 nanoflower decorated on graphene oxide/polypyrrole nanocomposite, which are novel materials with large specific surface area and cyclic stability were studied. The electrochemical study of the nanocomposite materials is done by studying the cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance (EIS) techniques. The supercapacitor device fabrication is processed using ZS/GP2 electrode, and the analysis of supercapacitor performance is also studied. As a result, ZS/GP2 nanocomposite showed a good capacitive behavior with a maximum specific capacitance of 392 F g?1 at 75 mV s?1 scan rate with significantly high specific energy and power density of 31.6 Wh kg?1 and 5177 W kg?1, respectively after the 27,000 consecutive charge-discharge (GCD) cycles at the current density of 0.25 A g?1. The results evidence that these hybrid materials are highly promising electrode materials for energy storage applications. 2023 Elsevier Ltd -
An Objective Evaluation of Harris Corner and FAST Feature Extraction Techniques for 3D Reconstruction of Face in Forensic Investigation
3d reconstructed face images are the volumetric data from two dimensions, it can provide geometric information, which is very helpful for different application like facial recognition, forensic analysis, animation. Reconstructed face images can provide better visualization, than a two dimensional image can provide. For a proper 3d reconstruction one of primary step is feature extraction. The objective of this study is to conduct a comprehensive evaluation of two prominent traditional feature extraction techniques, namely Harris Corner and FAST (Features from Accelerated Segment Test), for the purpose of 3D reconstruction of face images in forensic analysis. In this research paper feature extraction was carried out using the Harris corner detection and FAST Feature technique. 3D reconstruction is completed using the retrieved features. In this study a comparative analysis was conducted assessing the aspect ratio, depth resolution. The results of the assessment provide valuable insights into the strengths and limitations of both techniques, aiding researchers and practitioners in selecting the most suitable method for 3D face image reconstruction applications. 2023, Ismail Saritas. All rights reserved. -
Synthesis of novel Se capped polymer photocatalyst mobilized under visible light: Exploration of piezoelectric effect and charge transfer mechanism in polymer matrix
The present study has shown the original and promising usage of zero valent metallic selenium in the photocatalysis process under visible light. Selenium (Se) dispersed into the Polyvinyl Chloride (PVC) and Polyvinylidene Fluoride (PVDF) polymeric solution (Se-PVC/Se-PVDF matrix) by reflux-calcination method. The SEM and TEM results shows Se nanoparticles are well disseminated into the polymer solution and homogenously mixed to avert cluster of particles. The results shows that Se-PVC matrix effectively enhanced the generation rate of photoinduced electrons and reduced transfer resistance endorsed by photoluminescence, transient photocurrent, and electrical impedance spectroscopy techniques. Further, photocatalytic activity studied in presence of potassium iodide (KI) and isopropyl alcohol (IPA). The decrease in photocatalytic activity order is: Se-PVC > Se-PVDF > Se-PVC + KI > Se-PVDF + KI > Se-PVC + IPA > Se-PVDF + IPA systems. The piezoelectricity phenomena and Surface Plasmon Resonance (SPR) effect proposed for Se-PVC/Se-PVDF matrix and correlated with photocatalytic mechanism for the degradation of Methyl Orange (MO). 2023 Elsevier B.V. -
TelsNet: temporal lesion network embedding in a transformer model to detect cervical cancer through colposcope images
Cervical cancer ranks as the fourth most prevalent malignancy among women globally. Timely identification and intervention in cases of cervical cancer hold the potential for achieving complete remission and cure. In this study, we built a deep learning model based on self-attention mechanism using transformer architecture to classify the cervix images to help in diagnosis of cervical cancer. We have used techniques like an enhanced multivariate gaussian mixture model optimized with mexican axolotl algorithm for segmenting the colposcope images prior to the Temporal Lesion Convolution Neural Network (TelsNet) classifying the images. TelsNet is a transformer-based neural network that uses temporal convolutional neural networks to identify cancerous regions in colposcope images. Our experiments show that TelsNet achieved an accuracy of 92.7%, with a sensitivity of 73.4% and a specificity of 82.1%. We compared the performance of our model with various state-of-the-art methods, and our results demonstrate that TelsNet outperformed the other methods. The findings have the potential to significantly simplify the process of detecting and accurately classifying cervical cancers at an early stage, leading to improved rates of remission and better overall outcomes for patients globally. 2023, Universitas Ahmad Dahlan. All rights reserved. -
Structure of molecule, density gradient, orbital locator and reactivity of 5,6-dichloro-1-cyclopentyl-2-(methylsulfinyl)-1H-benzimidazole- potent inhibitor of map kinase
The present work consists of theoretical studies with the DFT technique on the benzo[d]imidazole derivative, 5,6-Dichloro-1-cyclopentyl-2-(methylsulfinyl)-1H-benzimidazole, and its biological evaluation in silico. The molecule is subjected to geometry optimisation and further DFT studies in gas and solvent phases. Upon solvation with polar solvents, gradual variation in properties result. Topological analyses are performed using Multiwfn software (ELF, LOL, RDG and charge transfer) to illustrate the electron density distribution, interactions, and excitation within the title molecule. ADMETLab 2.0, PreADMET, and SwissADME online tools compute the ADMET profile. Select MAP-kinase target proteins are docked against the title molecule using AutoDock Tools and PyMOL. Discovery Studio Visualizer software is run for visualisation and result analysis of the docked ligand-protein complex. 2023 Elsevier B.V. -
Corporate social responsibility: a cluster analysis of manufacturing firms in India
Purpose: This paper aims to identify the corporate social responsibility (CSR) patterns of Indian manufacturing firms using a CSR index based on ISO26000 and Indias National Voluntary CSR Guidelines. Design/methodology/approach: A total of 121 manufacturing enterprises in the national capital region (NCR) were surveyed. The questions related to the involvement of CSR in business strategy, involvement in CSR planning, involvement in environmental activities, involvement in social activities, monitoring, evaluation and involvement in CSR, reporting and policy and deployment of CSR. A two-step cluster analysis using log-likelihood measures was used to identify groupings in the data set based on their performance across the seven issues. Findings: The two distinctive segments identified adopted intermediate CSR activities, and one undertook advanced CSR activities. Research limitations/implications: This study has several limitations. First, the survey data were drawn exclusively from medium-sized enterprises in the NCR. Second, all the indicators in the CSR index were equally weighted. Originality/value: This paper contributes to the literature by grouping manufacturers CSR activities based on seven dimensions suggested in ISO26000 and Indias National Voluntary Guidelines. The results of this study can help managers, boards and regulators better understand CSR and identify ways to improve it further. 2023, Emerald Publishing Limited. -
Exploring the adsorption efficacy of Cassia fistula seed carbon for Cd (II) ion removal: Comparative study of isotherm models
The current study demonstrates the potential of Cassia fistula seed carbon (CFSC), a waste lignocellulosic biomass, to eliminate Cd (II) ion-from saturated liquid samples. The efficient removal of about 93.2% (w/v) of Cd (II) ions from 10 mg/L concentration was achieved within 80 min of treatment. The CFSC dosage of 100 mg/50 mL accounted as optimal for enhanced Cd (II) removal. Cd (II) adsorption onto CFSC was observed to be maximum at pH 6. The investigational trials were assessed with three isotherm models such Dubinin-Radushkevich, Freundlich, and Langmuir. The specifications obtained from this experimental study align well with the Langmuir isotherm model, which describes the maximal adsorption capacity of 68.02 mg/g. Cd (II) adsorption data from this study exhibited the R2 of 0.9 under pseudo-second-order. Maximum desorption (76.3% w/v) was obtained with 0.3 M HCL. This study revealed that thermally activated C. fistula seed carbon (CFSC) can be tuned to be lucrative adsorbent for Cd (II) elimination from water and waste-water. 2023 Elsevier Inc. -
Rayleigh-Bard convection in mono and hybrid nanoliquids in an inclined slot
Linear stability analysis is conducted to investigate the longitudinal and transverse rolls (TRs) generated in Rayleigh-Bard convection in mono and hybrid nanoliquids confined between two infinite inclined parallel slots. Thermophysical properties of six mono nanoliquids and fifteen hybrid nanoliquids are calculated for different volume fractions (0.5%, 1%, 2%) using phenomenological laws and mixture theory. The shooting method is used to solve boundary eigenvalue problems to obtain the eigenvalues for 16 different boundary conditions. It is observed that as the inclination angle is increased, it delays the onset of longitudinal rolls in the case of all boundary conditions. However, it advances the onset of TRs except when the lower plate is adiabatic. The addition of mono and hybrid nanoparticles results in the advancement of the onset of convection. The addition of SWCNT and SWCNT Al 2 O 3 accelerates the onset of convection the most while Cu and Cu-Ag accelerates the onset of convection the least amongst the mono and hybrid nanoparticles considered in the study. 2023 IOP Publishing Ltd. -
Fabrication of silver nanoparticle decorated graphene oxide membranes for water purification, antifouling and antibacterial applications
The quality of portable water is adversely affected by inadequate wastewater treatment, increase in domestic & industrial waste, and microbial contamination of surface water sources. Purification techniques such as sedimentation, precipitation, filtration, and ion exchange can be employed to recover clean water from various impurities. Among these, membrane-based purification methods have become more appealing in recent years due to its cost-effective and energy-saving features. However, fouling is a ubiquitous problem in membrane-based purification technologies, which leads to reduced water permeation and quality. Present study embodies the development of silver decorated graphene oxide coated nylon membrane with remarkable antibacterial and antifouling properties. Antibacterial analysis of bacteria Staphylococcus aureus and Escherichia coli, validates that higher concentration of silver in GO (GO A500) composites hinder the growth of bacteria. The antifouling properties of GO A500 membrane showed flux recovery ratio of 96 % with irreversible fouling ratio of 3 % during the filtration of BSA (Bovine serum albumin) protein. Further fabricated composite membrane exhibited pure water flux of 46.7 L m?2 h?1 with dye removal rate of 95 %, 88 % and 85 % for Congo red, Rhodamine-B and Methylene blue respectively. Catalytic studies conducted on GO A500 membrane demonstrated the efficacy of their antifouling properties. The investigations revealed that the composite (GO A500) membrane has excellent antibacterial and antifouling properties, making it a suitable option for wastewater treatment applications. 2023 Elsevier B.V. -
Synthesis, Mechanical Properties and Thermal Stability of Polydimethylsiloxane Nanocomposites
The polydimethylsiloxane/nano-graphite (PDMS-NG) nanocomposites were prepared via a two rolled mixing mill and subjected to characterization using techniques such as Transmission Electron Microscopy (TEM), stress-strain analysis during elongation, as well as thermal properties including Thermo-Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The transition temperature was observed to be below-70C for PDMS nanocomposites reinforced with Nano-Graphite (NG). The thermogram from the thermo-gravimetric analysis indicated that at 10%, 20%, 30%, and 50% weight loss, the temperatures for PDMS nanocomposites were higher compared to unfilled PDMS. These findings suggest a substantial improvement in the thermal stability of PDMS-NG nanocomposites. 2023, Books and Journals Private Ltd. All rights reserved. -
Newly designed single-stage dual leg DC-DC/AC buck-boost converter for grid connected solar system
This paper proposes a novel single-stage buck-boost inverter based on dual leg. Modulation techniques, working principle, guidelines for components design, and guidelines are discussed and presented. A theoretical concept is initially tested in Simulink platform and practically verified with a test bench model. A practical model is developed to verify the simulation model and tested different modes of operation are analyzed. The main advantages of the proposed work are as follows: The number of passive components is less, switching frequency components are not high so leakage current is very less, and voltage control in a wide range is achieved without using a DC link capacitor. High efficiency can be achieved due to multi-stage operation. This proposed work is suitable for high/low voltage PV-based energy conversion. Electromagnetic interference is also reduced due to continuous input current. 2023 John Wiley & Sons Ltd. -
Jugaad in organizational settings: exploring the Jugaad leadership competencies
The Hindi term 'jugaad' is closely linked to frugal innovation. In resource-scarce environments, organizations can thrive by developing jugaad-related leadership abilities. Previous research on jugaad has focused primarily on individual problem-solving and overlooked the leadership skills necessary to implement it in organizational settings. This study employs a theoretical lens of leadership competency models, interpretive phenomenology, purposive sampling, and an inductive data-driven coding approach to explore the jugaad leadership competencies of 28 Indian business leaders and managers. The study presents the Jugaad Leadership Competency (JLC) model, identifying ten competency clusters exhibited by jugaad leaders. This is the first study to develop a model for jugaad leadership in organizational settings. In environments characterized by scarcity and intense competition, the JLC model can aid individuals and organizations in acquiring the necessary competencies for frugal innovation. The study evaluates the theoretical and practical implications of the findings, their transferability, and limitations and offers suggestions for future research. 2023, Springer Nature Limited. -
COVID-19 pandemic and trade flows: empirical evidence from selected Asian Pacific countries
Purpose: This paper aims to investigate the effects of the COVID-19 crisis on trade flows in Asia Pacific countries and explores the causality between COVID-19-related shocks and trade. Design/methodology/approach: The authors used two novel techniques, namely, two-stage instrumental-variables (2SIV) approach and Juodis, Karavias and Sarafids (JKS) causality test, to examine trade dynamics in the Asia Pacific region during the pandemic. Findings: Using the monthly trade data of 17 Asia Pacific countries between January 2020 and December 2021, the results were threefold. Firstly, the empirical analysis showed that during the COVID-19 crisis, the flow of exports tended to persist idiosyncratically in comparison to the flow of imports. In particular, a specific finding was that the persistence level in exports was about 20%25% higher than that in imports. Secondly, the authors found that the past values of COVID-19 cases and COVID-19 deaths contain information that helps to predict exports/imports over and above the information contained in the past values of exports/imports alone. Finally, the study established that the government response and stringency indexes have a Granger-causal relationship with exports and imports. Research limitations/implications: For the foreseeable future, these findings have significant policy ramifications. Firstly, if a COVID-19 crisis-like situation emerges in the future, it will be critical for countries to maintain their competitiveness throughout the crisis, like the COVID-19 pandemic, while also rebuilding trade relationships wherever possible. Secondly, because information about government responses and measures can also be used to predict future trade flows, prudent management of government responses and stringent measures will be necessary in a crisis like COVID-19 to achieve the optimum level of exports and imports. At the same time, the trading partners should give up the idea of trade protection and focus on finding a way to balance the conflicting needs of imports and exports. Originality/value: To the best of the authors knowledge, the authors, for the first time, used a 2SIV approach and JKS causality test to examine trade dynamics in the Asia Pacific region during the pandemic. In addition, the authors present the first comprehensive analysis of the evolving relationships between export and import flows and governmental policy responses under COVID-19. As a result, it contributes uniquely to both public and international economics. 2023, Emerald Publishing Limited. -
The Champions Boat League A Race to Commercialise Festival Cultures
[No abstract available]