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?-cyclodextrin functionalized graphitic carbon nitride as a promising electrocatalyst for the selective oxidation of Tetrahydrofurfuryl alcohol
Selective electrochemical conversion of Tetrahydrofurfuryl alcohol (THFA) was facilitated employing ??cyclodextrin (??CD) functionalized graphitic carbon nitride (GCN) based nanocomposite. The GCN bulk were obtained by subjecting melamine to pyrolysis and further the material was exfoliated to improve its optoelectronic properties. Non-covalent attachment of ??CD over GCN via ultrasonication creates reactive surface sites on the electrode (??CD/GCN/CFP) facilitating a better host-guest interaction. The cyclic voltammetry and chronoamperometry techniques were employed to investigate the reaction mechanism (qualitative) and kinetics (quantitative) respectively of 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) mediated electrochemical oxidation of THFA. Further, on subjecting the reaction mixture to bulk electrolysis, the desired product was isolated with yield of 78%. The enhanced efficacy, stability and repeatability of the developed heterogenous catalyst aims to surpass all other conventional synthesis of Tetrahydrofurfural (THFF). 2022 Elsevier Ltd -
Effect of salt fingers on heat transfer for different non-uniform concentration profiles in a micropolar liquid
This paper discusses the theoretical aspects of the effect of salt fingers on heat transfer for different non-uniform concentration profiles in a micropolar liquid layer kept between two parallel plates of infinite extent separated by a thin layer, heated and soluted from above. The onset of salt finger convection (convection due to the salt finger process) is studied through the linear stability analysis theory. The system of partial differential equations is solved numerically using the normal mode analysis method and the required solution is found by applying the Galerkin method. The effect of heat transfer and concentration of micropolar liquid is obtained for (i) freefree, (ii) rigidrigid, and (iii) rigidfree isothermal, permeable with no-spin boundary conditions. The effect of different micropolar parameters (i.e.,coupling parameter, micropolar heat conduction parameter, couple stress parameter, and inertia parameter) has been analyzed on the onset of stationary convection, and the results are depicted graphically. It is shown that different non-uniform concentration gradients, diffusivity ratio, coupling parameter, and solutal Rayleigh number influence the heat transfer in the system. The phase of concentration flow for different boundary conditions is compared and analyzed. 2022 Wiley Periodicals LLC. -
Fast and effective removal of textile dyes from the wastewater using reusable porous nano-carbons: a study on adsorptive parameters and isotherms
In the present study, recyclable porous nano-carbons (PNCs) were used to remove textile dyes (mainly methylene blue, methyl orange, and rhodamine B) from an aqueous environment. Due to their high surface area and mesoporous nature, PNCs exhibited extremely fast and efficient adsorption behavior. PNCs synthesized at an elevated temperature of 1000 C are used in batch experiments, as they showed maximum dye removal with high surface area. Batch mode was used to optimize operational parameters such as initial dye concentration, contact time, adsorbent dose and pH as a function of time. Within ~7 minutes of treatment, PNCs achieved a maximum removal efficacy of ~99 percent for methylene blue. The recyclability of PNCs was investigated, and it retained its efficiency even after seven cycles. The efficacy of PNCs in treating industrial water contaminated with methylene blue dye was assessed. Different adsorption isotherms were carried out to determine maximum amount of dye that can be adsorbed on to surface of PNCs. The maximum adsorption capacity attained using Langmuir isotherm for methylene blue was around 1216.54 mg g-1. Adsorption kinetics were applied on experimental data to identify the rate of adsorption. It was confirmed that novel onion peel-based porous PNCs were successful in removing methylene blue dye effectively with short duration in comparison with other dyes mainly rhodamine B and methyl orange. Graphical abstract: [Figure not available: see fulltext.] 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. -
Secure Image Transmission Scheme based on DNA Sequences
Cryptography and steganography are the most widely utilized and adopted fields of secure data communication. Data transfer can be secured using a combination of these methods. The data is transmitted from sender to receiver using cryptography, the most secure method. At the same time, steganography performs the information hiding in the form of video, image, or text within a cover image. The sensitive data is hidden, so it is not visible to the human eye. The data is stored and transferred more securely by adding DNA technology to the cryptography. It provides additional data security level and is most commonly employed to implement computation. This research developed a new method for combining cryptography with steganography. There are two phases to the proposed method: image encryption and hide phases and image extraction phases. Encryption is done by using the Signcryption algorithm. Four standard images were utilized as test material for the evaluation. Four factors are used to determine the performance of the proposed method as Peak signal-to-noise ratio (PSNR), Mean Square Error, Entropy, and Structural Similarity Index Measure (SSIM) for hiding and extracting the messages. The implementation is done in python. The proposed method achieves better performance when compared to the previously published works. 2022 Seventh Sense Research Group -
Potential, prospects, and problems of textile tourism in Kerala
Tourism in the textile industry has tremendous potential for future growth and development of local economies and rural communities, building upon the services provided by local governments. This study focuses on Khadi textile business operations, with a particular emphasis on textile-based businesses, and provides visitor perceptions of textile tourism. It discusses the possibilities and challenges in the local textile industry, including the dificulties faced by the weavers in marketing their goods to tourists and exporters. The questionnaire survey applied to 120 visitors from three different khadi shops in Kozhikode, Kerala. According to the study's findings, textile business centres require strategic promotional approaches to boost textile tourism. The major hurdle for weavers and independent producers is a lack of direct access to visitors, as well as access to information controlled by producers, commercial interests, and gallery owners. more in the future to expand the reach of this type of tourism. The potential role that the government and tourism authorities may play an important role in designing policies that may grant this form of tourism increased visibility. 2022, Universidade de Aveiro. All rights reserved. -
From maximum force to the field equations of general relativity and implications
There are at least two ways to deduce Einstein's field equations from the principle of maximum force c4/4G or from the equivalent principle of maximum power c5/4G. Tests in gravitational wave astronomy, cosmology, and numerical gravitation confirm the two principles. Apparent paradoxes about the limits can all be resolved. Several related bounds arise. The limits illuminate the beauty, consistency and simplicity of general relativity from an unusual perspective. 2022 World Scientific Publishing Company. -
IPWM Based IBMSC DC-AC Converter Using Solar Power for Wide Voltage Conversion System; [Convertisseur DC-AC IBMSC bassur l'IPWM et utilisant l'ergie solaire pour un syste de conversion large tension]
This article proposes isolated bidirectional micro dc-ac single phase controlled (IBMSC) converter based on in-phase-voltage pulsewidth modulation (IPWM). This resonant IPWM converter, ratio of voltage conversion can be controlled from 0 to ?. So, this converter is highly referred for huge range voltage conversion. However, voltage conversion ratio determines power transfer direction and duty ratio. Power flow direction and duty cycle value can be varying smoothly, so it is suitable for dc-ac bidirectional power conversion application. Inverter mode and also rectifier mode are possible from bidirectional operation, which is controlled by a unified current controller. The proposed solution can achieve smooth switching grid operation with high efficiency. Working principle, design procedure, control strategy, and characteristics of the proposed converter are implemented with a prototype model of power rating 500 W with a voltage range of 20-50 V to test the ability of withstanding. Performance, feasibility, and effectiveness of the proposed converter are tested with this hardware test-bench model. 2022 IEEE. -
An Adaptive Cluster based Vehicular Routing Protocol for Secure Communication
In todays scenario, Vehicular Ad-hoc Network (VANET) is one of the modern fields in vehicle communication; it includes a large number of nodes that can be changed arbitrarily with the ability to link or exit the system anytime. Moreover, it has various complexities because of the attacks model in the transmission and communication channel. Besides, most of the attacks are known as black hole attack and wormhole attack. The presence of these attacks causes large damage in the data broadcasting region that ends in data drops or collapses. To defeat these problems, a novel Clustered Vehicle Location protocol for Hybrid Krill Herd and Bat Optimization (CVL-HKH-BO) technique is proposed. Thus, the proposed mechanism of hybrid krill herd and bat optimization is to detect and prevent attacks based on the fitness function. Moreover, secure communication can be enhanced by the proposed technique. Consequently, the solution to energy consumption and packet delay issues are solved using the CVL protocol. The projected strategy is implemented in the Network simulator (Ns-2) platform, and the outcomes show the node energy, overload and delay are minimized by increasing the quantity of packets transmitted in the network. Sequentially, the proposed technique is compared with existing techniques in terms of throughput, packet loss, delay time and data broadcasting ratio. Therefore, the duration of the node can be enhanced and can attain high energy capable data transmission. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Biological Feature Selection and Classification Techniques for Intrusion Detection on BAT
Privacy is a significant problem in communications networks. As a factor, trustworthy knowledge sharing in computer networks is essential. Intrusion Detection Systems consist of security tools frequently used in communication networks to monitor, detect, and effectively respond to abnormal network activity. We integrate current technologies in this paper to develop an anomaly-based Intrusion Detection System. Machine Learning methods have progressively featured to enhance intelligent Anomaly Detection Systems capable of identifying new attacks. Thus, this evidence demonstrates a novel approach for intrusion detection introduced by training an artificial neural network with an optimized Bat algorithm. An essential task of an Intrusion Detection System is to maintain the highest quality and eliminate irrelevant characteristics from the attack. The recommended BAT algorithm is used to select the 41 best features to address this problem. Machine Learning based SVM classifier is used for identifying the False Detection Rate. The design is being verified using the KDD99 dataset benchmark. Our solution optimizes the standard SVM classifier. We attain optimal measures for abnormal behavior, including 97.2 %, the attack detection rate is 97.40 %, and a false-positive rate of 0.029 %. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Low temperature performance evaluation of asphalt binders and mastics based on relaxation characteristics
Low temperature cracking is one of the main distresses of asphalt pavement in cold regions. Stress relaxation characteristics is critical for cracking resistance of asphalt materials, especially at low temperatures, but there are few studies on the relaxation characteristic of asphalt mastics. To evaluate the effects of relaxation characteristics of asphalt binders and mastics on its low temperature performance, beam bending relaxation test was carried out through dynamic thermomechanical analyzer at low temperatures. Relaxation rate and relaxation time were proposed to illustrate the relaxation characteristics of asphalt binders and mastics. Then, the low-temperature performance of asphalt binders and mastics was evaluated by bending beam rheometer (BBR), glass transition temperature (Tg), and single edge notch beam bending test. Finally, the correlation of relaxation characteristics with low-temperature properties was analyzed based on Pearsons correlation coefficient and Spearman rank correlation coefficient. The results show that the elasticity of asphalt mastics increases with incorporation of mineral fillers and thus the viscous deformation potential is reduced, which affects the stress relaxation capability. The low-temperature cracking performance of asphalt mastics is indeed compromised as compared with asphalt binders, and the asphalt mastics prepared with fly ash performs the worst since it presents a stronger hardening effect. Fracture energy is determined not to be suitable for evaluating the low-temperature performance of asphalt mastics since its results contradict the BBR and Tg tests. The maximum displacement at fracture can better characterize the brittleness of asphalt materials at low temperatures. The relaxation characteristic index has the strongest correlation with Tg of asphalt binders and mastics, followed by maximum displacement at fracture and comprehensive compliance parameter (Jc). The correlation coefficients are almost larger than 0.5, suggesting that relaxation time and relaxation rate can characterize the low-temperature properties of asphalt binders and mastics. 2022, RILEM. -
Influence of perceived equity, job enrichment, and burnout among educators in Indian private universities on job satisfaction and the desire to quit
The desire to quit converts into actual attrition if left unaddressed. Additionally, employees job satisfaction strongly influences their desire to stay or leave. Several individual and organizational factors affect job satisfaction levels, all of which must be thoroughly analyzed to curb both the desire to quit and attrition. The current study tests a model associating perceived equity, job enrichment, and burnout with job satisfaction and the desire to quit of educators employed in private universities in India. Data were collected from 272 university faculty members using five scales, namely, job enrichment, perceived equity, employee burnout, job satisfaction, and intention to leave, and were analyzed using AMOS 17. The initial fitness results failed to support the hypothesized framework, but a revised framework yielded a good fit for the data. Results show that perceived equity has a positive influence on job satisfaction (Hypothesis 2), job enrichment positively affects job satisfaction (Hypothesis 3), burnout negatively influences job satisfaction (Hypothesis 4), and job satisfaction negatively affects the desire to leave (Hypothesis 1). Perceived equity, burnout, and job satisfaction were found to mediate the association between job enrichment and the desire to leave. The results indicate that private universities must focus on job satisfaction to reduce employees desire to quit, thereby reducing the attrition level, which is currently a severe problem with both financial and non-financial consequences to universities. From the results, it can be seen that job enrichment has acted as a mediator to influence employees job satisfaction. Future research can explore HR practices contributing to high job enrichment, and this study would have considerable practical implications. Copyright 2022 Annamalai. -
Enhanced radial basis function neural network for tomato plant disease leaf image segmentation
Primary crop losses in agriculture are due to leaf diseases, which farmers cannot identify early. If the diseases are not detected early and correctly, then the farmer will have to undergo huge losses. Therefore, in the field of agriculture, the detection of leaf diseases in tomato crops plays a vital role. Recent advances in computer vision and deep learning techniques have made disease prediction easy in agriculture. Tomato crop front side leaf images are considered for research due to their high exposure to diseases. The image segmentation process assumes a significant role in identifying disease affected areas on tomato leaf images. Therefore, this paper develops an efficient tomato crop leaf disease segmentation model using an enhanced radial basis function neural network (ERBFNN). The proposed ERBFNN is enhanced using the modified sunflower optimization (MSFO) algorithm. Initially, the noise present in the images is removed by a Gaussian filter followed by CLAHE (contrast-limited adaptive histogram equalization) based on contrast enhancement and un-sharp masking. Then, color features are extracted from each leaf image and given to the segmentation stage to segment the disease portion of the input image. The performance of the proposed ERBFNN approach is estimated using different metrics such as accuracy, Jaccard coefficient (JC), Dice's coefficient (DC), precision, recall, F-Measure, sensitivity, specificity, and mean intersection over union (MIoU) and are compared with existing state-of-the-art methods of radial basis function (RBF), fuzzy c-means (FCM), and region growing (RG). The experimental results show that the proposed ERBFNN segmentation model outperformed with an accuracy of 98.92% compared to existing state-of-the-art methods like RBFNN, FCM, and RG, as well as previous research work. 2022 Elsevier B.V. -
Design Optimization of Electrical Connector Assembly using FEA
Due to the increasing number of devices and systems connected to an electric system, the need for reliable and high-quality electrical connectors has become more prevalent. This project aims to optimize the design of an electrical connector during its two most critical stages: insertion and retention of housing using FEA. A structural analysis is performed during the insertion and retention stages of housing. This process involves calculating the dimensional deformations and maximum strains developed during the steps mentioned above to determine the reliable functioning of electrical contacts. The input geometry is fed to the finite element analysis. The forces applied on the connectors latch on their respective connection are ensured to be under the limit. The analysis and simulation results are reflected to validate the safe forces in the connector assembly and a proper justification for an experimental set up in the laboratory. 2022, Books and Journals Private Ltd.. All rights reserved. -
Numerical Modelling and Experimental Validation of Novel Para Winglet Tape for Heat Transfer Enhancement
Heat exchangers are predominantly used in the industries of production, manufacturing, power, oil and gas, petroleum, and cooling solutions. The competence of the heat exchanger is optimized through active and passive augmented techniques. The current study revolves around the performance evaluation of Novel Para winglet tape for flow and friction characteristics. Turbulence flow properties from Re of 30,000-to-6000 were explored for three different inclinations and pitches, respectively. Experimental and numerical solutions are derived to showcase the flow behavior over Para winglet tape inserts in the double pipe heat exchanger. Appreciable results were obtained in enhancing the Nusselt number (Nup) for a better heat transfer enforcement through the DEX. All case studies also increased when compared to the smooth pipe. Experimentally, the maximum Nu and Nusselt number ratio was observed to be 398.23 and 5.05 times over the plain tube. Similarly, the maximum friction factor and its ratio were observed to be near 0.33 and 8.89 times over the plain tube. Finally, the maximum POI of 2.68 to 2.37 was achieved with 20 inclinations. The experimental and numerical outcomes of Para winglet tape with the higher inclination and shorter pitch were found to be best out of the others. 2022 by the authors. -
Proficient randomized response model based on blank card strategy to estimate the sensitive parameter under negative binomial distribution
This paper has great potential for estimating population proportion who possess stigmatized character by using Negative binomial distribution as a randomization device. The properties of the proposed estimation procedure have been examined. Measure of privacy protection for the proposed randomization device has been also quantified. Empirical studies are performed to support the theoretical results, which show the dominance of the proposed estimator over its competitors. Results are analysed and suitable recommendations are put forward for survey practitioners whenever they deal with sensitive characteristics. 2021 -
Breast Cancer Detection in Mammography Images Using Deep Convolutional Neural Networks and Fuzzy Ensemble Modeling Techniques
Breast cancer has evolved as the most lethal illness impacting women all over the globe. Breast cancer may be detected early, which reduces mortality and increases the chances of a full recovery. Researchers all around the world are working on breast cancer screening tools based on medical imaging. Deep learning approaches have piqued the attention of many in the medical imaging field due to their rapid growth. In this research, mammography pictures were utilized to detect breast cancer. We have used four mammography imaging datasets with a similar number of 1145 normal, benign, and malignant pictures using various deep CNN (Inception V4, ResNet-164, VGG-11, and DenseNet121) models as base classifiers. The proposed technique employs an ensemble approach in which the Gompertz function is used to build fuzzy rankings of the base classification techniques, and the decision scores of the base models are adaptively combined to construct final predictions. The proposed fuzzy ensemble techniques outperform each individual transfer learning methodology as well as multiple advanced ensemble strategies (Weighted Average, Sugeno Integral) with reference to prediction and accuracy. The suggested Inception V4 ensemble model with fuzzy rank based Gompertz function has a 99.32% accuracy rate. We believe that the suggested approach will be of tremendous value to healthcare practitioners in identifying breast cancer patients early on, perhaps leading to an immediate diagnosis. 2022 by the authors. -
Trigonometric Cosine, Square, Sawtooth and Triangular Waveforms of Internal Heating Modulations for Three-Component Convection in a Couple Stress Liquid: A Detailed Analysis
In this paper, the main focus is to study the effect of internal heating modulations of sinusoidal and non-sinusoidal waveforms on a three-component convection in a couple stress liquid. This three-component layer is heated from below and salted with two solutes at the bottom. In order to facilitate a solution to the problem, linear case is formulated using the Venezian approach for modulations while the non-linear case is modeled using 7-mode generalized Lorenz equations. With the aim of quantifying the heat and mass transfer, average Nusselt and average Sherwood numbers are computed. The investigation reveals that, internal heating modulations show a stabilizing or destabilizing trend that precisely depends on the modulated frequency and appropriate waveforms. The effect of heat source and sink is recorded on different convection processes. The effect of the pertinent parameters and waveforms on the stability of the system and on heat and mass transfer have been captured via graphs. The results confirm that the heat and mass transfer escalates to its maximum due to the square waveform. In this research paper, six problems involving three types of convection in two different liquids are solved as limiting cases of the problem. 2022, The Author(s), under exclusive licence to Springer Nature India Private Limited. -
A Cross-Sectional Study on Mental Health of School Students during the COVID-19 Pandemic in India
The broad objective of the present study is to assess the levels of anxiety and depression of school students during the COVID-19 lockdown phase and their association with students background, stress, concerns and social support. In this regard, the present study follows a novel two stage approach. In the first phase, an empirical survey was carried out, based on multivariate statistical analysis, wherein a group of 273 school students participated in the study voluntarily. In the second phase, a novel Picture Fuzzy FFA (PF-FFA) method was applied for understanding the dynamics of facilitating and prohibiting factors for three categories of focus groups (FG), formulated on the basis of attendance in online classes. Findings revealed a significant impact of anxiety and depression on mental health. Further, PF-FFA examinedthe impact of the driving forces that steered children to attend class as contrasted to the the impact of the restricting forces. 2022 by the authors. -
Semilinear fractional elliptic equations with combined nonlinearities and measure data
This study focuses on semilinear fractional elliptic problems with concave-convex type nonlinearities and measures as data. Suitable iteration techniques and embedding results are employed to ensure the existence and multiplicity of solutions. 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG. -
Modelling, Temperature Analysis, and Mechanical Properties of Friction Stir Welding of Al-Cu Joints with Hardened OHNS Steel Tools
Friction stir welding (FSW) is a nearly modern welding method with vital advantages over the conventional welding process, such as lower distortion, enhanced mechanical properties, and eco-friendly. In FSW, the joint characteristics mainly depend on heat development during the joining process due to its solid-state joining method. The basic principles of thermomechanical methods during FSW are unknown since it is a new metal joining method. In this investigation, the 2D and 3D models of the tools with different pin forms were designed using SOLIDWORKS. The ANSYS software was used to investigate the temperature distributions near the weld zones. The fixture was designed and made according to the machine conditions. The base plates used were AA6101 and C11000; the tool material used was the Hardened OHNS steel tool with square and circular pin form. The temperature values were measured in each trial while joining of Al-Cu base plates along the weld line. The results reveal that in the joint area, a trial with high temperature leads to high ultimate tensile strength (UTS) and Charpy impact strength (CIS). Made at tool rotation speed 1200 rpm and feed velocity 20 mm/min of Hardened OHNS steel tool with circular pin form. The obtained UTS value at joints was less than that of Al and Cu base plates. The microhardness value detected at the joint area was higher than the Al and Cu base plates, providing high strength, and irregularly dispersed. 2022, Books and Journals Private Ltd.. All rights reserved.