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Fluorescent detection of Pb2+ pollutant in water samples with the help of Delonix regia leaf-derived CQDs /
Synthetic Metals, Vol.291, ISSN No: 0379-6779.
Heavy metals released from different sources into water bodies are a major concern in the view of environmental protection. Their non-biodegradability and the numerous health hazards add to the issue. Scientists worldwide have emphasized the issue and are trying to resolve it by different means. Among all the methods, the fluorescent method stands out for its simplicity and rapid results. Here, the study focuses on the development of an efficient and sustainable method for the detection of lead in waste-water effluents. Carbon quantum dots (GCDs), a highly non-toxic substance developed from <em>Delonix regia</em> leaves for the purpose via a simple hydrothermal method. -
Fluorescent detection of Pb2+ pollutant in water samples with the help of Delonix regia leaf-derived CQDs
Heavy metals released from different sources into water bodies are a major concern in the view of environmental protection. Their non-biodegradability and the numerous health hazards add to the issue. Scientists worldwide have emphasized the issue and are trying to resolve it by different means. Among all the methods, the fluorescent method stands out for its simplicity and rapid results. Here, the study focuses on the development of an efficient and sustainable method for the detection of lead in waste-water effluents. Carbon quantum dots (GCDs), a highly non-toxic substance developed from Delonix regia leaves for the purpose via a simple hydrothermal method. The prepared GCDs exhibited good photostability and water solubility; they also displayed a bright red emission when irradiated with ultraviolet (UV) light. Here, the authors propose the synthesized GCDs as an effective fluorescent probe for sensitive detection of lead ions in aqueous samples. Photoluminescence quenching of GCDs by the addition of lead was studied and a good detection limit of 3.3 nM with a linear range of 10180 M was achieved. Further, real sample analysis was also conducted to prove the applicability of the synthesized GCDs. 2022 Elsevier B.V. -
Fluorescent Carbonized Polymer Dots Derived from o-phenylenediamine and its Photonic Application
Optimizing the optoelectronic characteristics of low-dimensional carbon dots (CDs) through surface modifications and doping has proven instrumental in tailoring them for diverse applications. This study explores a facile and economical hydrothermal synthesis method for generating Carbonized Polymer Dots using o-phenylenediamine at different temperatures. The resulting materials exhibit structural and morphological variations linked to the synthesis temperature. A transition from carbon dots (CDs) embedded in reduced graphene oxide (rGO)-like sheet structures at low temperatures to the core-shell structure at the highest temperature is observed in HR-TEM, implying the formation of CPDs. X-ray photoelectron spectroscopy (XPS) corroborates these findings, showing an augmented degree of graphitization in alignment with HR-TEM results. The photoluminescence spectra of CPDs synthesized at the lowest temperature exhibit multiple emission peaks, resulting in a yellowish-orange color. Utilizing these CPDs to fabricate light-emitting diodes (LEDs) produces a vivid bright-green emission with CIE coordinates (0.378, 0.522). Moreover, the CPDs demonstrate solvatochromism across diverse solvents of varying polarity, covering the entire visible spectrum. This intriguing solvatochromic effect positions the CPDs as promising materials for polarity probing applications. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. -
Fluorescent carbon nanoparticles for catalytic and photocatalytic applications
In the present times, catalysis is ubiquitous in chemical processes. Catalysts range from macromolecules consisting of enzymes to nanoparticles, including metals/metal oxides and composite materials. Due to their harmlessness, biocompatibility, high stability, versatility, and ease of functionalization, carbon nanomaterials (CNMs) which are fluorescent in nature, are used extensively for catalytic applications. Several studies regarding the catalytic applications of CNMs have been reported. These applications range from homogeneous to heterogeneous catalysis, where CNMs are used as supports for metal/metal oxide nanoparticles. Extensive studies on nanocomposites, doping strategies, and their utility in catalysis have been carried out. Carbon-based electrocatalysts find applications in both storage and conservation of energy. The exceptional properties of these materials make them an apt choice for various environment-friendly organic transformations. Photocatalysis is another area in which CNMs have excelled. Photoluminescence, photostability, and electron transfer properties of CNMs make them potent candidates for several photoinduced reactions. Various CNMs, namely graphene, carbon dots, nanotubes, graphitic carbon nitride, fullerenes, and graphdiyne, find applications in medicine, catalysis, sensing, bioimaging, supercapacitors, and many more. This chapter focuses on the catalytic and photocatalytic applications of CNMs. 2025 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies. -
Fluorescent carbon nanoparticle hybrids: synthesis, properties and applications
The development of materials in nanoscale morphologies with novel compositions is one of the major focuses of nanoscience and technology, as these materials are imbibed with unique properties that make them suitable for specific applications in a large variety of fields. Combining two or more chemically distinct constituents into a single nanostructure helps to attain desirable attributes of physical and chemical responses that can be efficiently utilized for specific applications. Hybrid nanomaterials constituted as a combination of multiple components into single nanostructures are known to showcase the properties of the individual components in tandem or synergy. Novel functionalities are also known to arise from integrating Fluorescent carbon nanoparticles (FCNPs) with other counterparts. FCNPs, when combined with other materials to form nanohybrids, provide copious functional attributes due to their inherent properties and the augmentation in properties due to the presence of the other materials. Integrating hybrid counterparts with FCNs improves the functional properties, which can be utilized for various applications such as photocatalysis, bioimaging, bio/chemo sensing, and many more. Herein we present an overview of recent and relevant works related to the synthesis, properties, and applications of fluorescent carbon nanoparticle (FCNP) hybrids. Various synthetic routes of FCNP hybrids via physical and chemical methods are summarized. The properties of the hybrid systems and the influence of hybridization on the properties are discussed. Applications of FCNP hybrids in various fields are also discussed in detail. 2025 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies. -
Fluorescence diffuse optical tomography: Synthesis, characterization and imaging of a novel target specific near infra-red contrast agent for breast cancer detection /
A paradigm shift is seen for cancer treatment since many decades in developing safe and efficient techniques to prevent, detect, treat and cure cancer worldwide. However, there is still a long way to stabilize the rate of cancer occurrence. Breast cancer is found to be among the top three cancer types in terms of incidence and fifth in terms of mortality. An estimate of 2.1 million new cases of breast cancer was recorded in the International Agency for Research on Cancer [IARC] Report 2018. Close to a half (43.6%) of all breast cancers were diagnosed within the Asia-Pacific region (approximately 911014 cases), with the greatest number of those occurring in China, Japan and Indonesia. Although the prognosis is relatively favorable, at least in more developed countries, early diagnosis is the lifesaver. Diffuse Optical Tomography (DOT) is one of the emerging diagnostic tools for early detection of breast cancer. It uses near infra-red (NIR) light to probe human soft tissues and is capable of continuous monitoring of the patient. DOT is cheaper, compact and uses non-ionizing radiation unlike its counterparts like CT-Scan, Mammogram and PET scan. The potential of DOT can be enhanced by using a NIR exogenous contrast agents, and the system is known as Fluorescence-DOT (FDOT). Indocyanine Green (ICG) is a popular FDA approved dye available in the market which is explored for cancer detection using FDOT. But, with its non-specific nature, there was a need for a specific and functionally orientated dye to further improve the efficacy of FDOT imaging. -
fluorescence diffuse optical tomography : Synthesis characterization and imaging of a novel target specific near infra-red contrast agent for breast cancer detection
Contrast agents are finding profound application in optical imaging of breast cancer for an early detection. In the present work, a novel estrogen receptor (ER) targeted near infra-red fluorescent dye conjugate was synthesized, referred to as Novel Dye Conjugate (nDC) hereafter. nDC is a conjugate of 17and#946;-estradiol with a derivative of indocyanine green dye, bis-1,1-(4-sulfobutyl) indotricarbocyanine-5-carboxylic acid, sodium salt. Structural composition of nDC was validated using Liquid Chromatography Mass Spectrometry (LC-MS) and Hydrogen-1 Nuclear Magnetic Resonance (1H-NMR) technique. MCF-7 and MDA MB 231 Cell lines studies proved the special biding ability of nDC with estrogen receptor positive breast cancer cell lines and its photophysical properties were verified to be in near infrared region (NIR). Similar studies were conducted on ER expressing cancerous tissues like Non-Invasive Ductal Carcinoma, Non-Invasive Lobular Carcinoma, Non-Invasive Adenocarcinoma and Non-Invasive Medullary Carcinoma. In all the above tissues, nuclear level ER binding of nDC was observed leading to the validations of the unique binding properties of the novel dye. Mathematical modeling for tumor to background mapping using nDC was carried out through Fluorescence Diffuse Optical Tomography (FDOT) simulations. Simulation results were also validated using silicone phantom experiments. An array of 8*8 boundary data was collected using frequency domain-FDOT system which was setup indigenously. Commercially available fluorescent dye Indocyanine Green (ICG) was used in the present study for comparative analysis with nDC. When compared to ICG, proposed dye had 1.5-fold higher target to background contrast with respect to fluorescent lifetime in both simulation and phantom studies. Similarly proposed novel dye had a two-fold higher target to background contrast with respect to fluorophore absorption. Above results proved the superiority of nDC compared to ICG on target(tumor) to background ratio enhancement. -
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. -
Fluorescein Based Fluorescence Sensors for the Selective Sensing of Various Analytes
Fluorescein molecules are extensively used to develop fluorescent probes for various analytes due to their excellent photophysical properties and the spirocyclic structure. The main structural modification of fluorescein occurs at the carboxyl group where different groups can be easily introduced to produce the spirolactam structure which is non-fluorescent. The spirolactam ring opening accounts for the fluorescence and the dual sensing of analytes using fluorescent sensors is still a topic of high interest. There is an increase in the number of dual sensors developed in the past five years and quite a good number of fluorescein derivatives were also reported based on reversible mechanisms. This review analyses environmentally and biologically important cations such as Cu2+, Hg2+, Fe3+, Pd2+, Zn2+, Cd2+, and Mg2+; anions (F?, OCl?) and small molecules (thiols, CO and H2S). Structural modifications, binding mechanisms, different strategies and a comparative study for selected cations, anions and molecules are outlined in the article. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Flow of nanoliquid past a vertical plate with novel quadratic thermal radiation and quadratic Boussinesq approximation: Sensitivity analysis
The effects of quadratic thermal radiation and quadratic Boussinesq approximation are investigated on the heat transport of a 36 nm Al2O3 ? H2O nanofluid over a vertical plate. The modified Buongiorno model is used in the analysis that includes the effectual thermophysical properties of the nanofluid and the key slip mechanisms. Experimentally verified correlations are used for the thermophysical properties. The reduced nonlinear differential problem is solved numerically by the Finite Difference Method (FDM). Flow profiles are displayed and analyzed for changes in dimensionless parameters. Further, the heat transfer flux at the wall is analyzed for interactive impacts of the buoyancy ratio, Brownian random motion, and thermophoresis parameters using the face-centered Central Composite Design (CCD) of the Response Surface Methodology (RSM). A sensitivity analysis is carried out for the heat transfer flux of the nanoliquid. Quadratic thermal radiation was found to improve the temperature profile. Furthermore, the mechanisms of Brownian random motion and thermophoresis have a negative sensitivity towards the rate of heat transfer. In various thermal applications like solar collectors, the density variation in terms of temperature differences is significantly high. Such phenomena can be accurately modeled by utilizing the quadratic Boussinesq approximation and the novel quadratic thermal radiation aspect. 2020 Elsevier Ltd -
Flow of nanofluid past a stretching cylinder subject to Thompson and Troian slip in the presence of gyrotactic microorganisms
Incorporating the Thompson and Troian slip condition, this work studies the bioconvective flow of a nanofluid past a vertically stretching cylinder. The Thompson and Troian slip deals with the molecular scale interactions at the solidfluid interface, which plays a pivotal role in the fluid flow analysis. This study helps in understanding the behaviours of fluid flow in the presence of non-linear slip past a vertically stretching cylinder. The corresponding partial differential equations (PDEs) for momentum, energy, concentration of nanoparticles, and concentration of microbes are developed using Buongiornos model. A suitable similarity transformation is then applied to these PDEs, converting them into a set of ordinary differential equations (ODEs). The RungeKuttaFehlberg (RKF-45) method is utilized to calculate the numerical solution of the resulting ODE problem. The results demonstrate that the interaction of slip conditions, viscous dissipation, heat source, and bioconvection causes complex flow patterns and heat transfer characteristics. These observations are extremely relevant for applications including better oil recovery procedures, biomedical engineering, and microfluidic devices where exact control over nanofluid behaviour is necessary. Some of the major observations of the study include the enhancement of the temperature in the nanofluid for higher Eckert numbers, control of fluid flow through an external magnetic field, and Peclet number significantly decreased the motile density in the nanofluid. The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024. -
Flow Cytometry Analysis of In Vitro Induced Polyploidy in Plants
Polyploidy is the condition of having more than two sets of chromosomes. The mechanism of polyploidy helps in deriving special traits like an increase in biomass, an increase in the size of various organ systems, and secondary metabolite content for the progeny. Various chemical compounds (colchicine, trifluralin, and oryzalin) that have the capacity to alter the mitotic cycle were used for the purpose of inducing polyploidy. Various techniques, such as counting of chromosome number, chloroplast number, determination of pollen diameter, and estimation of leaf stomatal density and size, were developed to analyze the polyploidy of the plants. However, these methods are not reliable for their regular use. Thus, of all the above-mentioned approaches, the estimation of ploidy level by flow cytometry (FCM) has been the most popular over the last few decades. Flow cytometry is now extensively used for the verification of haploidy, aneuploidy, and polyploidy. The ease of sample preparation, fast acquisition, and accurate measurements have made the method popular in the domains of plant cell biology, systematics, evolution, genetics, and biotechnology. The current chapter discusses the induction of polyploidy and its importance in plant breeding. It also emphasizes the importance of FCM in the analysis of polyploidy and enumerates the various polyploidy studies involving the application of FCM. 2023, Bentham Science Publishers. -
Flow and heat transport of nanomaterial with quadratic radiative heat flux and aggregation kinematics of nanoparticles
A numerical study of flow and heat transport of nanoliquid with aggregation kinematics of nanoparticles is carried out using the modified Buongiorno model (MBM). The MBM model is composed of random motion nanoparticles, heat diffusion of nanoparticles, and effective properties of nanoliquids. The effects of quadratic variation of density-temperature (quadratic convection), and the quadratic Rosseland thermal radiation are also studied. Inclined magnetism is also taken into account. The aggregation kinematics of nanoparticles is simulated using the modified Krieger-Dougherty model for dynamic viscosity and the modified Maxwell model for thermal conductivity. The main system of nonlinear partial differential equations is solved using the similarity technique and the finite difference method-based algorithm (FDM). The consequence of several key parameters on velocity, nanoparticle volume fraction, wall heat flux, and temperature are found in two cases, namely weak convective heating and strong convective heating. The study reveals that the suspension of the nanoparticles increases the thermal conductivity and, thus, improves the temperature and reduces the heat flux at the plate. The structures of the thermal and velocity surface layer are higher in the case of strong convective heating, while in the case of weak convective heating, the nanoparticle volume fraction layer is thicker. 2021 Elsevier Ltd -
Flourishing and work flow among working adults: A positive investigation from India
The demands in today's organizations are only growing at peaking high levels where turnover and burnout sets out to be major factors that challenge productivity. This is supported by previous findings which have identified turnover and burnout as a consequence of job demands. In today's demanding era of workforce, capacity to work effectively is a key component of employee's health, well-being and growth. Positive emotional and mental state of employees is a predictor of positive organization which will result in high performance, wellbeing and a conducive environment to flourish. Present study deals with workflow and its relationship with employee`s flourishing. This paper aims to explore the relationship between flourishing and experiences of work flow among working adults (n=105). Relationship among variables was analyzed through correlation and regression analysis. Results indicate that there is significant positive correlation between flourishing and experience of work flow (r (105) = 0.49, p<.01) and experience of work flow predicts the flourishing among employees. 2021 Ecological Society of India. All rights reserved. -
Floral waste as a potential feedstock for polyhydroxyalkanoate production using halotolerant Bacillus cereus TS1: optimization and characterization studies
The versatile properties and high degree of biodegradability of polyhydroxyalkanoates (PHA) have made them the ideal candidate for biomedical and other applications. Although extensive research on PHA-producing bacterial isolates from terrestrial environments is documented in the available literature, the potential of marine bacterial isolates in PHA production remains less explored and offers a great scope for future research. This research work primarily focuses on isolation and characterization of PHA-producing bacterial isolates from samples collected from coastal areas of Kerala, India. Furthermore, the possibility of PHA production from the most potential isolate Bacillus cereus TS1 using jasmine waste hydrolysate-based media was explored in this study. The utilization of floral waste hydrolysate (FWH) for PHA fermentation is not widely discussed in the available literature and is the major novelty factor of this research work. Under optimized conditions of glucose (1.2% w/v), yeast extract (0.15% w/v), NaCl (5.02% w/v), and incubation period (60h), a maximum PHA yield of 1.13g/L was achieved. The characterization of PHA polymer was done using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Thus, this research work integrates floral waste valorisation with microbial biopolymer production and highlights an innovative approach for sustainable development. The scale of this method on an industrial scale in future may prove helpful in the cost-effective production of PHA using cheap raw materials. Graphical Abstract: [Figure not available: see fulltext.]. 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. -
FloodWatch: Suggesting an IoT-Driven Flood Monitoring and Early Warning System for the Flood-Prone Cuddalore District in the Indian State of Tamilnadu
Floods continue to pose significant threats to communities worldwide, causing loss of life, property damage, and disruption of vital services. Timely and accurate flood monitoring and early warning systems play a critical role in mitigating these impacts. This chapter presents FloodWatch, an innovative IoT-based flood monitoring and early warning system designed to enhance community resilience and response capabilities for the Cuddalore district, classified as one of the multi-hazard-prone districts of Tamilnadu. The Cuddalore district has a coastal line of 68 km, hence it is vulnerable to cyclones, and heavy rainfall, in turn causing floods. FloodWatch leverages the power of the Internet of Things (IoT) technology and provides real-time data collection, analysis, and dissemination for flood-related parameters. FloodWatch integrates a network of smart sensors strategically deployed in flood-prone areas, including rivers, streams, and urban drainage systems. These sensors continuously measure key variables, such as water level, rainfall intensity, weather conditions, and soil moisture content. The collected data is transmitted to a centralized cloud-based platform, where advanced data analytics and machine learning algorithms are employed to process and analyze the information. FloodWatch utilizes historical data and predictive modeling to assess the risk of flooding and generate accurate early warnings. Through intuitive interfaces and mobile applications, relevant stakeholders, including local authorities, emergency responders, and residents, receive real-time alerts and notifications, enabling timely decision-making and appropriate response actions. Key features of FloodWatch include its scalability, adaptability, and user-friendliness. The system can be easily customized to cater to different geographical and environmental conditions, ensuring its applicability in diverse regions. Additionally, FloodWatchs intuitive interfaces provide actionable insights in a visually comprehensible manner, facilitating effective communication and community engagement. The implementation of FloodWatch offers several notable benefits, including improved flood preparedness, reduced response time, and enhanced disaster management. By equipping communities with the tools to monitor, predict, and respond to floods, FloodWatch contributes to minimizing the impact of flood-related disasters, ultimately fostering greater resilience and safeguarding lives and property. FloodWatch represents a significant advancement in flood monitoring and early warning systems, harnessing IoT technology to provide accurate and timely information to communities at risk. This chapter highlights the architecture, functionality, and advantages of FloodWatch, underscoring its potential to enhance resilience and contribute to more effective flood management strategies on a global scale. 2025 selection and editorial matter, A. Daniel, Srinivasan Sriramulu, N. Partheeban, and Santhosh Jayagopalan; individual chapters, the contributors. -
Floating rafters for wetland treatment /
Patent Number: 351985-001. Applicant: S. Shrimathy. -
Flipped Classroom Strategy in Online Teaching: Challenges Faced by Higher Education Teachers
Flipped classroom model has gained increasing interest among university teachers in recent years [1] (Stohr et al.). The reason for its popularity is attributed to its bearing on Vygotskys constructivism theory and for the student centered approach [2] (Ziling Xu et al.). Countries in the world are affected by COVID-19 including India. Hence higher education institutes have begun their online classes. Flipped classroom teaching has been quite prevalent in Indian higher education recently. Online class initiation from higher education institutes in India has pushed faculty members to teach online and faculty have begun flipped classroom teaching online. Flipped classroom teaching in online differs from the face to face mode. There are challenges and issues while using flipped classroom in online mode by the faculty members of higher education. This leads to the present study to find out the challenges of flipped classroom teaching in online mode by teachers of higher education. The present study adopted qualitative research method. Structured interviews and focus group discussion were conducted to answer the research question. Study was able to discuss the challenges of flipped classroom in online mode. These challenges are to be dealt with by the stake holders to bring teaching efficacy. The Author(s), under exclusive license to Springer Nature Switzerland AG 2025. -
Flight Arrival Delay Prediction Using Deep Learning
This project is aimed to solve the problem of flight delay prediction. This problem does not only affect airlines but it can cause multiple problems in different sectors i.e., commercial (Cargo aviation), passenger aviation, etc. There are a number of reasons why flights can be delayed, with weather being the main one. Our goal in this study is to forecast flight delays resulting from a variety of reasons, such as inclement weather, delayed aircraft, and other issues. The dataset gives itemized data on flight appearances and postponements for U.S. air terminals, classified via transporters. The information incorporates metrics such as the number of arriving flights, delays over 15 minutes, cancellation and diversion counts, and the breakdown of delays attributed to carriers, weather, NAS (National Airspace System), security, and late aircraft arrivals. For the purpose of predicting flight delays, the outcomes of several machine learning algorithms are examined, including Ridge, Lasso, Random Forest, Decision Tree, and Linear regression. With the lowest RMSE score of 0.0024, the Random Forest regressor performed the best across all scenarios. A deep learning model using a dense neural network is built to check how accurate a deep learning model will be while predicting the delay and the result was an RMSE score of 0.1357. 2024 IEEE. -
Flexible Teaching - Learning Systems in Indian Higher Education System through Technology - A Study on Demographic Impact
International Journal of Computer Application Vol. 5, Issue 2, pp 178-182, ISSN No. 2250-1797