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Sunova spirulina Powder as an Effective Environmentally Friendly Corrosion Inhibitor for Mild Steel in Acid Medium
Abstract: Spirulina, blue green algae is a rich source of proteins and vitamins with excellent antioxidant properties. Sunova spirulina powder an effective, green corrosion inhibitor was used to evaluate its inhibition efficiency towards mild steel in 1M HCl medium. Weight loss studies of mild steel showed an inhibition efficiency of 96% for 600ppm concentration of inhibitor solution and 12h of immersion period at 303K. The percentage of inhibition efficiency increased with a step up of 10K raise in temperature from 303 to 333K and thereafter decreased. The results obtained were further validated by inductively coupled plasma optical emission spectrometric (ICP-OES) measurements and electrochemical techniques that included Tafel polarisation, linear polarisation and AC impedance studies. Potentiodynamic polarisation study marked the inhibitor to be a mixed type inhibiting both cathodic and anodic reactions. The adsorption studies proved that the adsorption process was spontaneous and followed Langmuir adsorption isotherm. The thermodynamic activation and adsorption parameters calculated showed that the mechanism of inhibition involved a physisorption process initially and then it slightly shifted towards chemisorption process at higher temperature. The protective layer formed on the metal surface was studied using FTIR and SEM. The complex formation between the Fe2+ and the active constituents of the spirulina extract was verified using UV visible spectra and fluorescence spectra. The effect of inhibitor concentration and temperature on corrosion rate was tested statistically using two-way analysis of variance (ANOVA) technique. Graphic Abstract: [Figure not available: see fulltext.]. 2020, Springer Nature Switzerland AG. -
Preparation, characterization, and evaluation of corrosion inhibition efficiency of sodium lauryl sulfate modified chitosan for mild steel in the acid pickling process
The polar head and a hydrophobic long alkyl chain end of surfactants show effective adsorption on the metal surfaces and metal/solution interfaces. The present study deals with the investigation of corrosion inhibition efficiency of chitosan modified with an anionic surfactant, namely sodium lauryl sulfate. The modified chitosan was characterized using spectral techniques such as ATR- FTIR and NMR, thermal analytical methods that include TGA and DSC. The surface charge and particle size distribution were analyzed using Zeta potential analyzer. The corrosion inhibition efficiency of the water-soluble modified chitosan was evaluated using gravimetric and electrochemical methods. A maximum corrosion inhibition efficiency of 96.44% for 6 h of immersion period at 303 K was obtained. The adsorption process obeyed Langmuir isotherm. The adsorption mechanism involved both physisorption and chemisorption. Tafel and impedance studies showed results in agreement with the gravimetric method. Tafel plot indicates the inhibitor controlled both cathodic hydrogen evolution and anodic metal dissolution reactions. AC impedance study supports the increase in surface coverage of the metal surface by the inhibitor, forming a protective film. Further evidence comes from the surface characterization of the inhibited metal surface by contact angle measurement, SEM, EDAX spectra, and atomic force microscopic studies. DFT and Monte Carlo simulation studies showed a proper alignment with the experiment results. 2020 Elsevier B.V. -
Multimodal Emotion Recognition Using Deep Learning Techniques
Humans have the ability to perceive and depict a wide range of emotions. There are various models that can recognize seven primary emotions from facial expressions (joyful, gloomy, annoyed, dreadful, wonder, antipathy, and impartial). This can be accomplished by observing various activities such as facial muscle movements, speech, hand gestures, and so forth. Automatic emotion recognition is a significant issue that has been a hotly debated research topic in recent years. At the moment, several research people have taken a component in inheriting or extra multimodal for higher understanding. This paper indicates a method for emotion recognition that makes use of 3 modalities: facial images, audio indicators, and text detection from FER and CK+, RAVDESS, and Twitter tweets datasets, respectively. The CNN model achieved 66.67 percent on the FER-2013 dataset of labeled headshots while on the CK+ dataset, 98.4 percent accuracy was obtained. Finally, diverse fusion strategies had been approached, and each of those fusion techniques gave distinctive results. This project is a step towards the sense of interaction between human emotional aspects and the growing technology that is the future of development in today's world. 2022 IEEE. -
Synergetic Effect of Metal Nanoparticle Embedded Graphene Membrane : A Novel Approach for Antimicrobial Filtration
Water, the elixir of life, holds a profound significance that extends far beyond its essential utility. It's not just a resource; it pulsates as the life force of our existence, intricately woven into the very fabric of our daily lives. Water is the silent force that shapes our world, from nurturing our health and sustaining social structures to fueling economic development and fostering the environment. However, the adequacy of potable water quality confronts adverse impacts stemming from inadequate wastewater treatment, escalating domestic and industrial waste, and the microbial contamination of surface water sources. Furthermore, climate change emerges as a pivotal factor intensifying the depletion of water levels in natural resources due to diminished rainfall. Reports project that, by 2025, two-thirds of global population might contend with water scarcity. Given the persistence of current scenario, there exists a notable potential for significant conflicts among nations stemming from water scarcity. However, such a predicament can be mitigated through proactive measures, including the preservation of natural resources and the implementation of advanced technologies to recover fresh water from contaminated sources. Advanced technologies for the purification of contaminated water encompass sedimentation, precipitation, filtration, and ion exchange, which can effectively extract clean water from diverse impurities. Notably, membrane-based purification has gained prominence in recent years, owing to its cost- effectiveness and energy-saving attributes. Carbon-based nanomaterials, including carbon nanotubes,fullerenes and graphene have garnered considerable attention in recent research studies, particularly in the realm of membrane applications. Within this, membranes fabricated by carbon nanotubes (CNT) stand out, showcasing exceptional filtering properties attributed to their tubular carbon structure. However, the cost-effectiveness and ease of synthesis impediments pose significant challenges, acting as bottlenecks for their widespread application in water purification. Consequently, graphene-based membranes emerge as a promising alternative to CNT membranes, demonstrating selective separation of ions and molecules. Specifically, membranes derived from graphene oxide (GO) and reduced graphene oxide (rGO) exhibit superior filtering capabilities compared to ceramic and polymeric counterparts, owing to their layered structure featuring tunable nanochannels, hydrophilic or hydrophobic nature, and commendable mechanical resilience. Graphene oxide solution synthesis has been done using Hummer's method, followed by fabrication of high-quality membranes through vacuum filtration techniques. Current work emphasis on recognizing the pivotal influence of membrane thickness on both water flux and dye rejection, meticulous optimization of filtration properties by producing graphene oxide (GO) membranes at various concentrations. Furthermore, reduction of graphene oxide through the hydrothermal method, enabling a comprehensive comparative analysis of water flux and rejection between graphene oxide (GO) and reduced graphene oxide (rGO) membranes was carried out. In our investigation, the results unequivocally validate that the GO 500 sample exhibits optimized filtration properties. Furthermore, the reduced graphene oxide (rGO) variant surpasses graphene oxide (GO) in terms of filtration efficacy, demonstrating superior filtering properties. It is noteworthy to highlight that reduced graphene oxide (rGO) exhibits less antibacterial properties compared to graphene oxide (GO). The disinfection capability of the membrane is pivotal in ensuring the recovery of pure water. To bolster the antibacterial features of GO, we have undertaken an enhancement strategy by incorporating silver nanoparticles. Silver nanoparticle, showcases multifaceted properties including surface plasmon resonance and unique morphologies, which contribute significantly to the inactivation of bacteria. The conducted studies reveal that membranes incorporating graphene oxide with silver (GO-Ag) exhibit remarkable antibacterial properties against both gram-positive and gram-negative bacteria. Additionally, these membranes demonstrate appreciable filtration capabilities and exhibit effective antifouling properties, further emphasizing their potential for advanced applications in water purification systems. Fouling is a significant challenge in membrane technology, as the continuous passage of contaminants results in the formation of layers on membrane surface, thereby diminishing its filtration efficiency. Despite the antifouling properties exhibited by GO- Ag membranes, there exists further improvement in enhancing performance and extending the membrane's lifespan. To address this, we have undertaken a reduction of graphene oxide and incorporated silver nanoparticles, aiming to augment the antifouling properties and overall efficacy of membrane. The conclusive findings indicate that fine-tuned membrane exhibits remarkable antibacterial properties, superior filtration capabilities, and a minimal irreversible fouling ratio. These outcomes provide confirmation that the fabricated membranes stand as potential materials for water purification applications, showcasing a well-rounded set of properties essential for effective and sustainable water treatment. -
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Intelligent approach to automate a system for simulation of nanomaterials
Nanomaterial composites are generally found to have great thermal properties and hence have witnessed an increasing demand in the recent years for manufacturing of efficient miniature electronic devices. The process of finding the right composites that exhibit the desired properties is a rather tedious task involving a lot of trial and error in the current scenario. This paper proposes a methodology to digitize and automate this entire process by administering certain efficient practices of assessing the properties of nanomaterial like Coarse Grained Molecular Dynamics thus resulting in faster simulations. 2023 Author(s). -
SIGNIFICANT DIFFERENCE, CULTURAL DISTANCE, AND CULTURAL HUMILITY IN CHILDRENS MEDIA RESEARCH
The study of children, adolescents, and media (CAM) places a special emphasis on the welfare of young audiences and the media that socially, culturally, and historically constructs their identity, knowledge, and understanding of themselves and the world around them. CAM scholars form a legion of worriers and warriors focused on making the world a better place for children to live and learn (Jordan, 2021, p. 147). This legion spans the world, embodying the three traditional realms of media studies (audience, texts, and institutions) as a microcosm of media studies (Lemish, 2015, p. 1) and crosses disciplinary, theoretical, and empirical boundaries. As such, CAM scholarship can sometimes be difficult to find since it is often located in many different disciplinary journals and books as well as in proprietary industry reports. Lemish (2019) spoke of her journey in finding a home for her childrens media research and calls for the need for deeper internationalization of CAM that can account for the variance of childrens lives and the structural forces that shape the market and content of childrens media. This special issue contributes to this vision and highlights CAM research produced outside of a Western, educated, industrialized, rich and democratic (WEIRD) society (Jordan & Prendella, 2019). Moreover, it allows for a space to reflect on CAM scholarship as a whole and future directions for consideration. Lets explore some of the limitations in existing childrens media research and ways in which international collaboration can help to mediate some of these concerns. (2023). All Rights Reserved. -
Unveiling the Motivation Drivers in Start-Up Workspace
This article delves into the relationship between workplace happiness and productivity in startup settings. Its primary objective is to dissect the multifaceted factors impacting employee well-being, aiming to enhance overall efficiency by customizing the work environment in myriad ways. For this study, a descriptive causal methodology was employed to investigate the impact of workplace happiness on productivity within start-up companies. A carefully structured questionnaire was administered to 256 employees within well-established organisations in Bangalore, India. Participants were selected through a Judgement sampling process to ensure impartial and unbiased representation. Survey respondents preferred the pre-COVID working conditions, acknowledging their advantages. However, the increased autonomy and flexibility in work arrangements have led to enhanced productivity under the new hybrid model. Notably, when employees are entrusted with greater responsibility, their job satisfaction rises, resulting in increased work output. organizations are now tasked with offering additional incentives to remote employees, thereby elevating the satisfaction and job fulfilment experienced by these individuals. Effectively tackling challenges necessitates the alignment of learning and development objectives with the internal business processes that maximize each employee's abilities and potential. This involves meeting the criteria outlined in the balanced scorecard components. 2024, Iquz Galaxy Publisher. All rights reserved. -
Enhancing neurocognitive skills for effective leadership and decision-making
In today's dynamic workplace, human resource development and management (HRDM) professionals face multifaceted challenges requiring advanced cognitive abilities. This book chapter explores the critical interplay between leadership skills, decision-making, and executive functions (EFs) in HRDM. It sheds light on their pivotal role in shaping workplace dynamics and organizational outcomes. Focusing on skills such as emotional intelligence, cognitive flexibility, and continuous learning, the chapter delves into their neurocognitive underpinnings, particularly within the prefrontal cortex. It discusses strategies for enhancing EFs, including reflective practice, empathy training, and mindfulness, and emphasizes the concept of neuroplasticity in fostering continuous learning and adaptation within HRDM. By integrating insights from neuroscience into HR practices, the chapter offers valuable guidance for HR professionals seeking to optimize organizational performance, enhance leadership qualities, and drive effective decision-making processes. 2024 by IGI Global. All rights reserved. -
Secure IBS Scheme for Vehicular Ad Hoc Networks
Vehicular Ad hoc Networks (VANET) havedrastically grown in recent years since they provide a better and more secure driving experience. Due to its characteristics, it is vulnerable to many security attacks. Even though many authentication schemes are proposed, their overheads are high. Hence, this study proposes a new Identity-Based Signature (IBS) for authentication with privacy-preservation. It supports secure communications with additional security features. It requires less overhead since it uses XOR operations and one-way hash functions for the signing and verification process. When the proposed schemes performance is compared to the recent schemes, it is observed that the proposed approach is more efficient in computation and communication. 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
A Secure Resilient Scheme for Autonomous Vehicles against External Attacks
Autonomous vehicular ad hoc networks are networks created with autonomous vehicles and other entities in the vehicular environment. Like traditional vehicular ad hoc networks, autonomous ad hoc networks are also prone to internal and external attacks. Many authentication schemes are proposed to overcome internal attacks, whereas external attacks are not focused on. Though the impact of external attacks is less when compared to that of internal attacks, external attackers observe and analyze the network traffic information, which will be helpful for the internal attackers to affect the performance of the network. Hence, this chapter proposes a secure identity-based authentication scheme without pairings against external attacks. It uses an elliptic curve cryptography-based identity-based signature to authenticate vehicles. The proposed authentication scheme ensures secure vehicular communications, including inter-vehicular communication, without RSUs during emergencies. Simulation results demonstrate its superior performance. 2024 River Publishers. All rights reserved. -
Secure Authentication Schemes for Vehicular Adhoc Networks: A Survey
Vehicular Adhoc Network (VANET) is based on theprinciples of Mobile Adhoc NETwork (MANET) where vehicles are considered as nodes and secure communication is established to provide asafe driving experience. Due to its unique characteristics, it has various issues and challenges. These issues can be resolved by ensuring security requirements like authentication, privacy preservation, message integrity, non-repudiation, linkability, availability etc. Authentication plays a vital role since it is the first step to establish secure communication in the vehicular network. It also distinguishes malicious vehicles from legitimate vehicles. Different authentication schemes have been proposed to establish secure vehicular communications. A survey of the existing authentication schemes is given in this paper. At first, the existing authentication schemes are broadly classified based on message signing and verification methods. Then, each category is clearly explained with its sub-categories. At last, the existing schemes in each category are compared based on security requirements, security attacks and performance parameters. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Secure Identity Based Authentication for Emergency Communications
The Vehicular Ad Hoc Network (VANET) offers secure data transmission between vehicles with the support of reliable authorities and RSUs. RSUs are fully damaged in emergency scenarios like natural catastrophes and are unable to provide the needed services. Vehicles in this scenario must communicate safely without RSUs. Hence, this study suggests a secure and reliable identity-based authentication technique for emergency scenarios. To provide secure vehicle-to-vehicle communication without RSUs, ECC-based IBS is utilized. Additionally, it offers security features like message integrity, privacy protection, and authentication. It is also resistant to attacks depending on authentication and privacy. The proposed technique performs efficiently with less communication and computing cost when its performance is compared with recent schemes. The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024. -
Identity-based message authentication scheme using proxy vehicles for vehicular ad hoc networks
Message authentication verifies the identity of the sender vehicle, ensuring it in between vehicles and Road Side Units (RSU) is an essential part of Vehicular Adhoc Networks. Signature verification in RSUs will be troublesome if a large number of vehicles enters in its region at the same time. In such cases the efficiency of the RSUs will be affected due to high computational overhead. To address this issue, proxy vehicle based message authentication scheme (ID-MAP) is proposed by Asaar et al. (ITVT 67: 5409, 2018). It uses proxy vehicles to reduce the overheads of the RSU by verifying multiple messages at the same time. Even though it deals with the efficiency issues of RSU, the computational cost of signature generation is high. Since the ability of a vehicle to act as a proxy vehicle is based on the number of signed messages, it has a major impact. It also cannot guarantee privacy preservation and hence it is insecure against attacks based on privacy preservation. It also has other drawbacks like storage issues and high overheads. Hence, a new identity based message authentication using proxy vehicles is proposed in this paper. Elliptic Curve Cryptography based scheme is used without pairings for message authentication. Proxy vehicles will verify multiple messages from vehicles through batch verification and send the result to the RSU. The identity of multiple proxy vehicles will be verified by RSU, it can also cross check the correctness of the received result. Thereby RSUs can verify a large number of messages at the same time with the help of proxy vehicles. Security analysis shows that if each proxy vehicle verifies 300 messages of its neighbor vehicles, then with the help of proxy vehicles an RSU can verify 226,244 messages per second which is 40% less than that of ID-MAP scheme. It also shows that the computational cost to generate a signature in the proposed scheme is 50% less than that of ID-MAP scheme. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Antiferromagnetism of CoO-NiO bilayers studied by XMLD spectroscopy
CoO-NiO epitaxial bilayer system grown on MgO(001) substrate is investigated using x-ray magnetic linear dichroism (XMLD) spectroscopy with varying CoO overlayer thickness. An analysis of the Ni L 2 edge XMLD spectra using anisotropic XMLD formulation within a two-domain model reveals that the Ni moments undergo a spin reorientation with increasing CoO thickness. Such a spin reorientation is attributed to the competing magnetic interactions at both the NiO film interfaces, suggesting the existence of a sharp horizontal domain wall separating the in-plane and out-of-plane NiO domains. Our study also demonstrates a possible way to investigate the spin-structure along the thickness within the same chemical structure using a model-based approach, in a noninvasive manner. 2021 IOP Publishing Ltd. -
Magnetic coupling across the antiferromagnetic-antiferromagnetic interface
We investigate the magnetic coupling across the antiferromagnetic-antiferromagnetic (AFM-AFM) interface for the prototypical CoO-NiO bilayer system where the bulk Nl temperature (T N ) of NiO is higher than that of CoO. Using the temperature-dependent exchange-scattered electron intensities from the surface AFM lattice, the surface T N of CoO was estimated as a function of the CoO/NiO film thicknesses. Our results show that the surface T N of CoO layers is enhanced significantly from its bulk T N value and approaching the T N of the NiO layers, as the thickness of the CoO layers is reduced to the monolayer limit. Thus, thinner CoO layers are found to have higher T N than thicker layers on NiO, contrasting with the expected finite-size behavior. In addition to the short-range magnetic exchange coupling at the CoO-NiO interface, we observe the existence of a longer-range magnetic coupling across the interface, mediated by the magnetic correlations. Thus, the magnetic proximity effect is attributed to a combination of a short-range and a weaker long-range magnetic coupling, explaining the long AFM order propagation length in AFM-AFM superlattices and bilayers. Further, our results indicate a new approach to tune the AFM Nl temperature by varying the individual layer thickness of the bilayer system through the magnetic proximity effect. 2021 IOP Publishing Ltd. -
THE STUDY OF THE ONSET OF RAYLEIGH B??NARD CONVECTION IN A COUPLE-STRESS DIELECTRIC LIQUID
The linear analysis of Rayleigh-Benard convection in dielectric couple stress fluid are studied using the Galerkin technique. The effects of six basic non-uniform temperature gradients on the onset of convection are analsysied. The eigenvalue is obtained for free - free velocity boundary combinations with isothermal and adiabatic boundaries. A linear stability analysis is performed. The influence of various parameters on the onset of convection has been analyzed. Six different non-uniform temperature profiles are considered and their comparative influence on onset is discussed. The problem suggests an elegant method of external control of internal convection. -
Influence of Planting Methods on Growth, Yield and Storage of Onion (Allium cepa L.) var. Bhima Shakti
Background: Successful crop production in any crop depends on the good agronomic practices. Being a commercial crop, onion needs good attention during the crop growth stages, most of the times, in onion cultivation farmers follow broadcasting method which leads to the wastage of seeds, seedling mortality and poor germination and it will affect the total yield and productivity. Methods: To identify the best planting method an investigation on performance of seed drill versus transplanted onion was conducted at University of Agricultural Sciences, Main Agriculture Research Station, Dharwad. Result: Results indicated that, T3- (Transplanting) performed superior for all the vegetative and yield parameters studied. Plant height 55.57 cm, leaf number (7.86, 8.29 and 8.08 in pooled), Leaf width (1.03 cm, 0.99 cm pooled 1.01 cm). Total yield: (21.97 t/ha, 22.05 t/ha and 22.01 t/ha), marketable yield (20.74 t/ha 20.95 t/ha and 20.85 t/ha), bulb weight (64.00 g, 53.00 g and 53.90 g in pooled, analysis). From this, it can be concluded that transplanting of onion was better compared to other methods. (2024), (Agricultural Research Communication Centre). All rights reserved. -
Broadband near infrared emission in Cr3+: Cs2AgBiCl6 double perovskite halides
Near Infra-red phosphors with broad emission band, high thermal stability and excellent efficiency are required in various bioimaging applications. In this study, we report the design and chemical reflux synthesis of a new family of Cr3+: Cs2AgBiCl6 double perovskites. In detail this article focuses on the impact of Cr3+ doping on the crystal structure, optical and vibrational properties of Cs2AgBiCl6 double perovskites. Different concentrations of Cr3+ doped Cs2AgBiCl6 double perovskites were analyzed using UVVisible, Raman, Photoluminescence (PL), PL excitation, time resolved PL, X-ray photoelectron spectroscopy. Morphological analyses were carried out using scanning and transmission electron microscopies. XRD spectra reveals that the cubic symmetry remains unaltered upon Cr3+ doping. Raman and Rietveld analysis show that the BiCl bond decreases upon Cr3+ incorporation. Optical absorption studies reveal a decrease in bandgap from 2.76 to 2.66 eV upon Cr3+ doping. PL spectroscopy of Cr 3+:Cs2AgBiCl6 exhibits a broad near infrared (NIR) emission band at 973 nm with an FWHM of 186 nm at 355 nm excitation. This demonstrates the promising prospects for NIR light emitting diode and bioimaging applications of Cr3+:Cs2AgBiCl6 double perovskites. 2023 Elsevier B.V. -
Extrinsic electronic states to tune the luminescence and bonding nature of Cs2NaInCl6 double perovskite
Halide double perovskites have been extensively investigated in recent years as more stable and environmentally friendly materials with significant optoelectronic properties. Herein, we introduce Mn2+ ions in the Cs2NaInCl6 lattice to impart new electronic pathways to the otherwise weak optically active double perovskite for tuning its luminescent behaviour. X-ray diffraction, Raman, UVvisible, Photoluminescence (PL), and timeresolved PL (TRPL) spectroscopy are used to investigate the effect of Mn 2+ feed ratio on structural, vibrational, and optical properties. The chemical environment and surface morphology of the Mn2+ ions doped Cs2NaInCl6 double perovskite were investigated using X-ray photoelectron (XPS), energy dispersive X-ray (EDS) spectroscopies, and scanning electron microscopy. Results of the Rietveld refinement and Raman spectra divulge a decrease in In-Cl and Na-Cl bond length upon Mn2+ incorporation. The microstructure of the Cs2NaInCl6 double perovskite system was also studied using HRTEM analysis. UVvisible studies demonstrated a tremendous increase in absorption and a slight increase in band gap upon Mn2+ doping. PL and TRPL measurements of Mn2+: Cs2NaInCl6 discloses its red luminescence at 614 nm corresponding to the d-d atomic transition of Mn2+ with a long lifetime of 2.1 ms. Electron density investigations using maximum entropy method (MEM) demonstrate clear evolution of In-Cl and Na-Cl bonds from a highly ionic nature in pure Cs2NaInCl6 to strong covalent nature in Mn2+: Cs2NaInCl6 double perovskites. This affirms the simultaneous replacement of In, Na ions by Mn2+ to maintain charge neutrality in the compound and tune the electronic states of the Cs2NaInCl6 system. 2023 Elsevier B.V.