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En route to Khardung La with Dhak Dhak
Dhak Dhak uses the trope of a motorcycle road trip to discuss several societal and emotional barriers women ought to overcome to forge their own paths and blossom into their authentic selves. 2024 Economic and Political Weekly. All rights reserved. -
Tb-doped strontium aluminate nanophosphor: Cytotoxicity, phytotoxicity, and bioimaging in plant cells
This study explores the novel application of terbium-doped strontium aluminate nanoparticles for fluorescence imaging in plant cells. The study encompasses microwave assisted solid state synthesis as well as the structural and optical characterization of terbium-doped strontium aluminate nanophosphors, their toxicity studies in plant and animal cells and their use as a fluorescent dye for plant imaging. The X-ray diffraction pattern analysis, along with Rietveld refinement studies, show the formation of SrAl2O4 as a dominant crystalline phase. Photoluminescence investigations demonstrate green emission from Tb3+ transition levels. In vitro biocompatibility of terbium-doped strontium aluminate nanophosphors was studied using L929 fibroblast cells. The plant Clitoria ternatea was used to examine phytotoxicity. The samples' potential for bioimaging was further investigated. Our findings reveal improved growth of seedlings, positioning these nanoparticles as promising tools in plant-related research. This study advances our understanding of nanoparticle-plant interactions and holds potential for transformative applications in agriculture. 2024 The Authors -
Fluorescence bioimaging applications of europium-doped strontium aluminate nanoparticles
Fluorescence bioimaging is widely used for physiological studies to visualise intercellular molecular events due to its highly selective, sensitive, and non-destructive nature. However, its application in in vivo live imaging is often limited by the scarcity of biocompatible fluorescent probes possessing optimal properties. Our study focuses on developing europium-based nanoparticles for in vivo bioimaging, especially imaging of plants. Eu-doped strontium aluminate nanoparticles were synthesised through a conventional solid-state reaction. Structural characterisation of samples using XRD confirmed the prevalence of SrAl2O4 as the prominent phase. The FTIR spectrum, SEM and TEM images were recorded for further characterization. Photoluminescence studies showed orange red emission of sample. The antibacterial activity of the nanophosphors was studied, demonstrating no antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. Furthermore, in vitro cytotoxicity studies conducted using Neuro-2A cells showed no indications of cytotoxicity associated with europium doped strontium aluminate nanoparticles. When incorporated into the plant tissue culture medium, these nanoparticles were found to have no effect on seed germination and plant growth, and it demonstrated no phytotoxicity. Imaging studies have shown the uptake of nanoparticles by plants and their subsequent transport through the vascular system. Our results emphasise the direct integration of nanophosphors into plant tissues from the growth medium, eliminating the necessity for traditional staining methods in fluorescence bioimaging. Incorporation of nanophosphors into living organisms holds promise for non-invasive and long-term fluorescence imaging, with potential applications in biological studies and diagnostics. The outstanding fluorescence properties and biocompatibility of europium doped strontium aluminate nanoparticles broaden its potential for various applications in fluorescence bioimaging. 2024 Elsevier Ltd and Techna Group S.r.l. -
Concentration-dependent luminescence characterization of terbium-doped strontium aluminate nanophosphors
The present investigation describes the synthesis of luminescent terbium-doped strontium aluminate nanoparticles emitting bright green light, which were synthesized through a solid-state reaction method assisted by microwave radiation. Various samples containing different concentrations of Tb were synthesized, and an analysis of their structural and morphological features was conducted using powder x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The band gaps of the samples were determined utilizing the KubelkaMunk method. The quenching mechanism observed was identified to be due to dipoledipole interaction using the Dexter theory. The optimized sample with a terbium concentration of 4at.% has a luminescence lifetime of 1.05 ms with 20.62% quantum efficiency. The results of this study indicate that the terbium-doped strontium aluminate fluorescent nanoparticles exhibit promising potential for a wide range of applications, including bioimaging, sensing and solid-state lighting. 2024 John Wiley & Sons Ltd. -
Comprehensive investigations on spectral and temporal features of GX 5-1 using AstroSat observations
Comprehensive spectrotemporal analyses of the Z-type neutron star low-mass X-ray binary GX 5-1 were performed using 10 broad-band observations from AstroSat/Soft X-ray Telescope and Large Area X-ray Proportional Counter (LAXPC) instruments. The LAXPC-20 hardness-intensity diagram showed horizontal and normal branches (HBs and NBs) of the Z track which exhibited secular motion. The time-averaged spectra in the energy range 0.7-25.0 keV could be fitted with the model combination -Cconstant tbabs edge edge thcomp diskbb. This yielded ? ?2, kTe ?3.3 keV, and Fdisc/Ftotal ? 0.8 indicating the soft/intermediate spectral state of the source during the observations. Flux-resolved spectral analysis revealed a positive correlation between kTin and Fbol. However, a negative correlation was observed between them in one of the NBs. Time-averaged temporal analysis revealed multiple HB oscillations (HBOs) and NB oscillations (NBOs), and peaked noise components in the ?5-50 Hz range. Furthermore, flux-resolved temporal analysis showed that the frequency of the HBOs correlates positively whereas the strength of HBOs correlates negatively with Fbol, indicating their probable origin from the accretion disc. In contrast, the frequency and strength of NBOs remain fairly constant with Fbol, suggesting that they originate from a different region in the system. Using the relativistic precession model along with highest frequency of the HBO, the upper limits of the magnetic dipole moment (?) and field strength (B) at the poles of the neutron star in the system were found to be 25.60 1025G cm3 and 3.6408 G, respectively, for kA= 1. 2024 The Author(s). -
NuSTAR and AstroSat observations of GX 9+1: spectral and temporal studies
We have studied the spectro-temporal properties of the neutron star low-mass X-ray binary GX 9+1 using data from NuSTAR/Focal Plane Module and AstroSat/Soft X-ray Telescope and Large Area X-ray Proportional Counter (LAXPC). The hardness-intensity diagram of the source showed it to be in the soft spectral state (banana branch) during both observations. NuSTAR spectral analysis yielded an inclination angle (?) = 29 and inner disc radius (Rin) ? 19 km. Assuming that the accretion disc was truncated at the AlfvCrossed D sign ?0.9) with a monotonic increase in mass accretion rate () along the banana branch. The analysis also showed the presence of absorption edges at ?1.9 and ?2.4 keV, likely due to Si xiii and S xv, respectively. Temporal analysis with LAXPC-20 data in the 0.02-100 Hz range revealed the presence of noise components, which could be characterized by broad Lorentzian components. -
Spectro-temporal and type I X-ray burst analysis of GX 3+1 using AstroSat observations
GX 3+1, an atoll type neutron star low-mass X-ray binary, was observed four times by Soft X-ray Telescope and The Large Area X-ray Proportional Counter on-board AstroSat between 2017 October 5 and 2018 August 9. The hardness-intensity-diagram of the source showed it to be in the soft spectral state during all the four observations. The spectra of the source could be adequately fit with a model consisting of blackbody (bbody) and powerlaw (powerlaw) components. This yielded the blackbody radius and mass accretion rate to be ?8 km and ?2 10?9 M? y?1, respectively. In one of the observations, a type I X-ray burst having a rise and e-folding time of 0.6 and 5.6 s, respectively, was detected. Time-resolved spectral analysis of the burst showed that the source underwent a photospheric radius expansion. The radius of the emitting blackbody in GX 3+1 and its distance were estimated to be 9.19 +?00.8297 km and 10.17 +?00.1807 kpc, respectively. Temporal analysis of the burst yielded upper limits of the fractional root mean square amplitude of 7 per cent, 5 per cent, and 6 per cent during burst start, burst maximum, and right after the radius expansion phase, respectively. 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. -
Spectral Properties of the Soft X-Ray Transient MAXI J0637-430 Using AstroSat
Soft X-ray transients are systems that are detected when they go into an outburst, wherein their X-ray luminosity increases by several orders of magnitude. These outbursts are markers of the poorly understood change in the spectral state of these systems from the low/hard state to the high/soft state. We report the spectral properties of one such soft X-ray transient: MAXI J0637-430, with data from the SXT and LAXPC instruments on board the AstroSat mission. The source was observed for a total of ?60 ks in two observations on 2019 November 8 and 21 soon after its discovery. Flux-resolved spectral analysis of the source indicates the presence of a multicolor blackbody component arising from the accretion disk and a thermal Comptonization component. The stable low temperature (?0.55 keV) of the blackbody component points to a cool accretion disk with an inner disk radius of the order of a few hundred kilometers. In addition, we report the presence of a relativistically broadened Gaussian line at 6.4 keV. The disk-dominated flux and photon power-law index of ?2 and a constant inner disk radius indicate the source to be in the soft state. From the study we conclude that MAXI J0637-430 is a strong candidate for a black hole X-ray binary. 2022. The Author(s). Published by the American Astronomical Society. -
Constraining the physical parameters of XTE J1701-462 through NuSTAR observations
The spectral properties of the transient neutron star low-mass X-ray binary XTE J1701-462 were studied using the data obtained from FPMA/B detectors onboard NuSTAR during its second known outburst (2022 September). The physical parameters of the system were derived from the analysis of the data in the 3.0-30.0 keV energy range. The patterns displayed on the hardness-intensity diagram of the three observations closely resembled the banana branch/normal branch, a vertex of horizontal and normal branch of the Z-track and a transition from normal branch to flaring branch. Spectral analysis of the source revealed the presence of Fe K emission complex. The source spectra were fitted with a multitemperature blackbody () component in conjunction with the reflection model (). The values of temperature (kTin) and radius (Rin) of the inner accretion disc obtained from the spectral fitting with the model combination - + showed the source to be in its soft spectral state during the observations. The inclination angle (?) of the source was estimated to be between 19 and 33 and the inner disc radius (Rin) was found to be 17.4 km. Assuming the case of magnetic truncation of accretion disc, the upper limits for the magnetic dipole moment (?) and the magnetic field strength (B) at the poles of the neutron star in the system were found to be 5.78 1026 G cm3 and 8.23 108 G, respectively, for kA = 1. 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. -
Comprehensive spectro-temporal studies of GX 17+2 using AstroSat observations
We performed a comprehensive spectro-temporal study of the Z-type neutron star low-mass X-ray binary GX 17+2 using long term data from the AstroSat/Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC). The hardnessintensity diagrams (HIDs) of the source revealed a positive correlation between the hardness and intensity, characteristic of soft spectral state. Additionally, the LAXPC-20 HID showed the presence of secular shifts in both hardness and intensity. Time-averaged spectral modelling in the 0.7 ? 30.0 keV energy range indicated that the spectra could be well fitted with the model combination: constant edge edge tbabs thcomp bbodyrad. This analysis yielded a blackbody radius (Rbb) of ?59 km, photon index (?) of ?2.84 and electron temperature (kTe) of ?4.84 keV. Time-averaged temporal analysis revealed normal branch oscillations (NBOs) at ? 7 Hz in Observations 1 and 3, flaring branch oscillation (FBO) at ?15 Hz in Observation 2, and horizontal branch oscillation (HBO) at ?36 Hz in Observation 5. Flux resolved spectro-temporal analysis indicated that the source remained in the soft spectral state throughout all observations. A positive correlation was observed between kTbb, Fbb and Fbol, whereas an anti-correlation was noted between kTe and Fbol. The constant frequency of NBOs with an increase in Fbol suggests that their origin lies in a region strongly influenced by the corona, as explained by the radiation-hydrodynamic model. The origin of FBOs may be attributed to the damped radiation-hydrodynamic mode of radial flow, while the origin of HBOs is supported by the beat-frequency model. 2024 Elsevier B.V. -
A novel automated method for coconut grading based on audioception
The quality of the coconuts used for various purposes is of utmost importance. Demand for better quality products is constantly on the rise due to the improvements in the standard of living of people. There is a possibility that a bad coconut goes unnoticed by the traders, as it is hard to decide if a coconut is good or bad by relying only on its external appearance. Traditionally, quality assessment is carried out manually with the help of three senses; sight, hearing and smell. In the proposed work, a sound processing technique is used in an attempt to automate this process which overcomes the drawbacks of manual processing, which can be used in large godowns and warehouses. This proposed method provides the quality assessment of the coconut purely based on audioception. While creating the database, coconuts varying in size, shape, color and water content were taken from several places as a source for the dataset. Features are extracted from the sound pattern produced by the dropped coconut, which forms the basis for classification. Sequential Minimal Optimization (SMO), Dagging and Naive Bayes classifiers were used and the results obtained were found to be encouraging. 2005 ongoing JATIT & LLS. -
Factors influencing career decision of undergraduate and postgraduate students: an Indian context
Purpose: The objective of the study was to explore the factors influencing the career decisions of students doing the students' undergraduate (UG) and postgraduate (PG) programmes from urban private universities/colleges in the Indian context. Design/methodology/approach: Career decision-making is determined by different factors and is contextual. The present study explores and identifies the prominent factors influencing career decision-making. A pool of 33 questions was developed, and these questions were initially administered to a sample of 233 students. Principal component analysis with Varimax Rotation identified salient factors. In the second study, confirmatory analysis was performed based on the opinion of 304 students. Findings: The study shows that the student's career deciding factors include (1) career clarity, (2) career exploration, (3) career reward and recognition and (4) career initiative for professional and personal growth. Originality/value: The study focussed on career-deciding factors for UG and PG students from urban universities/colleges in the Indian context and the findings can be used for planning career counselling interventions. 2023, Emerald Publishing Limited. -
Dynamic Offloading Technique for Latency-Sensitive Internet of Things Applications using Fog Computing
Internet of Things (IoT) has evolved as a novel paradigm that provides com-putation power to different entities connected to it. IoT offers services to multiple sectors such as home automation, industrial automation, traffic management, healthcare sector, agriculture industry etc. IoT generally relies on cloud data centers for extended analytics, processing and storage support. The cloud offers highly scalable and robust platform for IoT applications. But latency sensitive IoT applications suffer delay issues as the cloud lies in remote location. Edge/fog computing was introduced to overcome the issues faced by delay-sensitive IoT applications. These platforms lie close to the IoT network, reducing the delay and response time. The fog nodes are usually distributed in nature. The data has to be properly offloaded to available fog nodes using efficient strategies to gain benefit from the integration. Differ-ent offloading schemes are available in the literature to overcome this prob-lem This paper proposes a novel offloading approach by combining two effi-cient metaheuristic algorithms, Honey Badger Algorithm (HBA) and Fla-mingo Search Algorithm (FSA) termed as HB-FS algorithm. The HB-FS is executed in an iterative manner optimizing the objective function in each it-eration. The performance evaluation of the proposed approach is done with different existing metaheuristic algorithms and the evaluations show that the proposed work outperforms the existing algorithms in terms of latency, response time and execution time. The methodology also offers better degree of imbalance with proper load balancing under different conditions. 2023 Authors. All rights reserved. -
A USB- bluetooth two factor mutual authentication security protocol for wireless sensor networks
Wireless sensor networks are easy to deploy, effective, and can monitor unattended environments. As the data transmitted through these networks is highly sensitive, the security of the networks is important and strong authentication measures must be in place. Authentication is done by means of a security protocol, wherein a user is authenticated through certain factors such as a smartcard or a password, and several mathematical calculations such as hashing, and XOR operations. Several previously proposed authentication protocols and their flaws are discussed in this paper. We propose a new two factor mutual authentication protocol using a USB-Bluetooth token as the second factor, to overcome the security flaws seen in previous schemes. We also provide security analysis as well as Scyther results in support of the proposed protocol. The proposed protocol can be used across various fields such as healthcare, agriculture, traffic monitoring etc. BEIESP. -
An individualised psychosocial intervention program for persons with MND/ALS and their families in low resource settings
Motor Neuron Disease (MND) leads to significant psychosocial distress for the person with the illness and caregivers. Psychosocial factors influence the management and quality of life to a significant degree. Objective: To develop individualised psychosocial intervention program for people with MND and their families in India. Methods: People with MND and healthcare staff were constructively involved in co-designing the intervention program in four phases adapted from the MRC framework: 1. A detailed need assessment phase where 30 participants shared their perceptions of psychosocial needs 2. Developing the intervention module (synthesis of narrative review, identified needs); 3. Feasibility testing of the intervention program among seven participants; 4. Feedback from participants on the feasibility (acceptance, practicality adaptation). The study adopted an exploratory research design. Results: Intervention program of nine sessions, addressing psychosocial challenges through the different stages of progression of the illness and ways to handle the challenges, specific to the low resource settings, was developed and was found to be feasible. People with MND and families who participated in the feasibility study shared the perceived benefit through feedback interviews. Conclusion: MND has changing needs and challenges. Intervention programme was found to be feasible to be implemented among larger group to establish efficacy. The Author(s) 2022. -
Litchi inflicted child mortality in Bihar-a whistle blower to the pathetic public health system and other contributory factors
Introduction: Seasonal outbreak of a neurological illness called encephalopathy causing death among children has been reported since 1995 from the state of Bihar in India where in the year 2019 fifty-four children reportedly died due to this cause. Though this illness and its deadly consequences have been reportedly associated to consumption of a locally harvested fruit in the state called Litchi, still, it would not be appropriate to blame the fruit alone which is widely consumed by millions of people in India and all around the world without causing them any health hazards. Objectives: The study aims at exploring and reporting the prime contributory causes of encephalopathy among children due to consumption of the Litchi fruit in the state of Bihar. Methods: The article is based on review and analysis of secondary data gathered through scientific research papers, reports and statistics published by various ministries and departments of the Government of India, data published by recognised medical bodies, news journals and relevant research articles. Results: The findings of the report confirm that Litchi victimizes only those who are malnourished and feed in a considerable quantity to quench their hunger. The real causes of litchi inflicted child mortality is therefore poverty, malnutrition, lack of proper and equipped public health system leading to lack of timely and quality access to medical facilities, absence or lack of nutritious evening meal and high exposure to litchi orchards and large amount of time spent by children in these orchards without supervision and control. Conclusion: Strict monitoring and supervision should be executed in the health units of the state of Bihar and the same should be equipped with necessary equipment and manpower. The people in the state especially the uneducated should be made aware of the deadly outcomes of consuming large amount of litchi on an empty stomach. 2021 Elsevier Masson SAS -
Fuel coke derived nitrogen and phosphorus co-doped porous graphene structures for high-performance supercapacitors: The trail towards a brown-to-green transition
As the looming crisis of global energy market exponentially intensifies, the scientific community prompts the use of supercapacitors as a sustainable energy production/storage model and emission reduction strategy. Therefore, in this work, we present a cutting-edge approach for the high-value utilization of fossil fuel-derived materials in supercapacitor applications, promoting an integrated brown-to-green transition for energy, ecology, and the environment. Herein, nitrogen and phosphorus co-doped porous graphene sheets (a-NPGO) have been prepared from fuel coke, which exhibits outstanding electrochemical performance as a supercapacitor electrode material. The a-NPGO shows a high specific capacitance (322 F/g at 1 A/g) almost 11 times greater than the undoped coke-based graphene derivative. Furthermore, the symmetric supercapacitor assembled with a-NPGO-modified electrodes delivered an exceptional power density of 812 W/kg at energy density of 14 Wh/kg and an excellent capacitance retention of 90 % after 5000 charge-discharge cycles. This impression of coke-derived material in high-performance supercapacitors may broaden the horizon of the current electrochemical energy storage paradigm and afford the eco-conscious implementation of fossil fuel resources. 2023 Elsevier Ltd -
Doable production of highly fluorescent, heteroatom-doped graphene material from fuel coke for cellular bioimaging: An eco-sustainable cradle-to-gate approach
The manifold usage of fluorescent materials and their pliable association with optical imaging techniques have made great strides in unfolding the incredible potential of biotechnological research, particularly in cancer treatment, from point-of-care assay to clinical applications. Enlarged nuclei or numerous counts often indicate tumor growth activity, and these expressions can be visualized with the aid of fluorescence imaging. Therefore, developing highly fluorescent, biocompatible, and sustainable biomarkers for imaging is a vital necessity for their extensive application in cancer diagnosis and therapy. In this work, we have demonstrated the cradle-to-gate transformation of abundant and cheap fossil fuel coke into a fluorescent probe for bioimaging. Herein, for the first time, a facile strategy for modulating the emission characteristics of coke-derived graphene system via doping of heteroatoms has been reported. It is found that the doping of nitrogen atoms could strongly influence photophysical properties, giving rise to increased quantum yield (16%), extended fluorescence lifetime (8.51 ns), and higher photostability (92%). Moreover, the as-synthesized nitrogen-doped graphene derivative is used as a potential labelling agent for the cellular imaging of cancerous cells, as well as normal cells, at concentrations ranging from 0 to 100 ?g/mL. For 24h incubation, the cells cultured with a concentration of 25 ?g/mL were observed to have an appreciable fluorescence accompanied by significant biocompatibility, with a viability value of ?85%. Considering the heteroatom-induced emission characteristics and bioanalytical acuities, it is prospective that the coke-derived graphene system can be further explored to elucidate its significance in biomedical applications, without compromising on economic and environmental sustainability. 2022 Elsevier Ltd -
Heteroatom engineered graphene-based electrochemical assay for the quantification of high-risk abused drug oxytocin in edibles and biological samples
The naive detection of scheduled H drug oxytocin is a vital requisite, owing to its deleterious impact on societal affluence prompted by unconstrained usage. Therefore, a reliable, cost-effective, and quick-to-respond analytic technique for this drug is in ample demand. In this work, we report electrochemical detection of oxytocin employing novel nitrogen, phosphorus co-doped coke-derived graphene (NPG) modified electrode. The electro-oxidation behavior of oxytocin was investigated on the NPG modified electrode by square wave stripping voltammetry (SWSV) in 0.1 M phosphate buffer of pH 7. The oxidation peak current was linear in two ranges, spanning from 0.1 nM to 10 nM and 15 nM to 95 nM. The limit of detection at the NPG electrode was calculated to be 40 pM. The practical application of developed sensor for the determination of oxytocin was examined in edible products and body fluids, hence signifying the possibility of having real-time surveillance over its misusage. 2022 Elsevier Ltd -
Luminescence and energy storage characteristics of coke-based graphite oxide
The substantial escalation in both energy consumption and ecological crisis prompts the utilization of conventional pollution-causing energy resources towards a proficient mode of energy production and storage. The most polluting fossil fuel like coal possesses a highly ordered sp2 carbon clusters, that can be easily tailored into graphene derivatives promising for energy-related applications. However, the impact of crystallinity and quality of the precursor coke on the physicochemical characteristics of extracted carbon nanostructures need to be identified. Herein, we have prepared graphite oxide structures (GrO) from high-quality coal, coke via Improved Hummers' method eliminating the need for toxic NaNO3. The inherent defect states own by coke are also of high significance as it performs the role of various photoluminescence emission centers. The sp2 domains and different surface defects promote excitation independent and dependent luminescence substantiating the distinct multi-emission property of GrO. The extent of functionalization during the oxidation process has also significantly affected the thermal stability of the carbogenic structure. The symmetric galvanostatic charge-discharge curves and lower internal resistance present superior stability and fatser ion transport of as-synthesized GrO. A specific capacitance of 193F/g was obtained at 0.2A/g with excellent capacitance retention over 2500 cycles. The versatile attributes of the coke derived GrO validate its realizable optoelectronics and energy storage applications. 2020 Elsevier B.V.