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Synergetic effects of cross-linking and incorporation of Fe-Al bimetallic combination on the properties of polyvinyl alcohol novel films
Polyvinyl alcohol films incorporated with Fe-Al bimetallic combination novel films were synthesized by sol-gel method in the presence of glutaraldehyde (GA). The results of FTIR spectra confirmed the cross-linking between PVA and GA, resulted in the formation of rigid molecular chains. The comparison of thermograms of pure PVA and Fe-Al PVA films cured with GA indicated the enhanced thermal stability of the cured films. The electrical properties of the pure PVA films and bimetallic PVA films cured with GA were studied in the frequency range 100 Hz to 100 kHz. The current study explains the effect of GA and incorporation of Fe-Al bimetallic combination towards the structural modification and dielectric properties like dielectric constant, dielectric loss, ac conductivity, polarization, and permittivity of the cured PVA films. The variation of the storage modulus of cured PVA films as a function of temperature has also been studied. 2023, Qatar University and Springer Nature Switzerland AG. -
Facile synthesis of aluminum oxyhydroxide-PVA films and its adsorptive evaluation for the removal of methylene blue dye from water: kinetics, optimization studies and mechanism
Aluminum oxyhydroxide-polyvinyl alcohol films were synthesized by the solgel method with varying metal-polymer ratios. The results of the characterization confirmed the formation of aluminum oxyhydroxideand the incorporation of metal into the polymer. The adsorption isotherms of the film exhibited type IV isotherms indicating the mesoporous nature with a non-uniform pore size distribution. The optical profilometric studies confirmed the surface roughness of the film. The adsorptive nature of the film was tested for the removal of methylene blue dye from the aqueous solution. Optimization studies were conducted to investigate the effect of various parameters on the adsorption process. The adsorption isotherms of methylene blue fit with the Langmuir isotherm model and follow a pseudo-second-order equation. A suitable reaction mechanism was proposed, which confirms the adsorptive nature of the film is due to the electrostatic attraction. The synergetic effect of the metal-polymer blend, surface roughness and pore size of the film, which ranges from 0.01 to 0.025nm,enhances the adsorption of methylene blue. The comparison of results obtained in the current study with earlier reports confirms that the aluminum oxyhydroxide-polyvinyl alcohol films can be considered an eco-friendly, cost-effective adsorbent for removing methylene blue. 2023, The Polymer Society, Taipei. -
Synergistic effect of metals and cross linkers on surface modification of iron aluminum oxyhydroxide-PVA polymer films for enhanced catalytic activity in transesterification reaction
Iron-incorporated aluminum oxyhydroxide polyvinyl alcohol films (Fe-Al-PVA) were synthesized using the solgel method. The influence of cross-linking agents on the aluminum oxyhydroxide films was investigated by incorporating glutaraldehyde into the synthesized films. Various characterization techniques were employed to understand the physico-chemical properties that affect the catalytic and adsorptive behavior of the self-supported films. The liquid phase transesterification of terpenes was used to test the catalytic activity of the films for the synthesis of industrially important terpene esters. The products were analyzed using GC, GCMS, and NMR techniques, and optimization studies were carried out under different experimental conditions. The reaction scope was expanded to a wider range of organic compounds, and a possible reaction mechanism was proposed. This study demonstrates the design and modification of efficient bimetallic polymer film catalyst for organic transformations. 2023 Wiley Periodicals LLC. -
Correlation of Surface Properties and Catalytic Activity of Metal Aluminophosphates
Alumina and its modified forms have gained significant interest in recent years as potential material for a wide variety of industrial applications. Aluminophosphates were reported as one of the promising catalytic materials in organic transformations. The catalytic activity of a material is always associated with the nature of active centers available on the surface of a catalyst. The incorporation of metal ions into aluminophosphates is of particular interest for the design of the novel catalysts. The post and pretreatment methods followed for the synthesis of the material determines the structural and textural properties of the material. The transition metal loading over aluminophosphates play a significant role in the generation of surface-active sites. This chapter deals with simple ecofriendly synthesis, physico-chemical characterization and catalytic activity of metal aluminophosphates. The chapter mainly explains the correlation of surface properties and catalytic activity of metal aluminophosphates in industrially important organic transformations. 2023 selection and editorial matter, Anitha Varghese and Gurumurthy Hegde; individual chapters, the contributors. -
Synthesis and characterization of Poly-Vinyl Alcohol-Alumina composite film: An efficient adsorbent for the removal of Chromium (VI) from water
Composite poly vinyl alcohol-alumina films were synthesized by a novel eco-friendly route in the absence of template. The physico-chemical nature of the synthesized film was studied using different characterization techniques. The poly vinyl alcohol-alumina composite film was found to be an efficient adsorbent for the removal of Chromium (VI) at higher concentrations from water. The preparation conditions were optimized to synthesize an efficient adsorbent film for the removal of chromium. The surface properties, chemical composition and amorphous nature of the film confirmed by different characterisation techniques attributes to the chromium removal efficiency of the film. Poly vinyl alcohol-alumina films are economically cheap, easy to prepare, efficient adsorbent for removal of chromium (VI) eco-friendly in nature and reusable with effortless regeneration methods. 2022 -
Synthesis, Adsorptive Properties and Applications of Modified Aluminum Oxyhydroxide-PVA Films
Over the past few years, there has been an increasing interest in polymer films and newlinemetal-incorporated polymer films because of their distinctive characteristics and newlinepotential applications. The effectiveness of alumina or modified alumina polymer films newlineas adsorbents or catalysts is greatly influenced by their surface properties, texture, chemical composition, and thermal stability. This thesis describes the synthesis of aluminum oxyhydroxide - polyvinyl alcohol composite films by sol-gel method. The synthesized films were modified by incorporating transition metals and cross-linking agents depending on the desired application as a catalyst or adsorbent. The synthesized films were characterized using different techniques, like powder X-ray diffraction studies (pXRD), Fourier transform infrared spectra (FTIR), Raman spectra, BrunauerEmmett-Teller surface area (BET), Barrett-Joyner-Halenda (BJH) isotherm, atomic newlineforce microscopy, optical profilometry, thermogravimetric analysis, Scanning electron newlinemicroscopy (S.E.M), and X-ray photoelectron spectroscopy (XPS) to determine the newlinestructural and textural properties. The films were deployed as adsorbents for the removal of heavy metals and dyes from water as well as catalysts for industrially important organic transformations. The results of the characterization studies were used to correlate the surface characteristics and adsorptive capacities of the fabricated films. The films were found to have tuneable surface properties and enhanced adsorptive newlinebehaviour, which could be modified as per the application. Transition metalincorporated films exhibited remarkable adsorption properties for the elimination of heavy metals and organic dyes from aqueous solution. The adsorption reaction kinetics newlinewere investigated to ascertain the rate and mechanism of the reaction to improve the newlineefficiency, economic efficiency and environmental sustainability of the reaction. -
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Distributed DoS Detection in IoT Networks Using Intelligent Machine Learning Algorithms
The threat of a Distributed Denial of Service (DDoS) attack on web-based services and applications is grave. It only takes a few minutes for one of these attacks to cripple these services, making them unavailable to anyone. The problem has further persisted with the widespread adoption of insecure Internet of Things (IoT) devices across the Internet. In addition, many currently used rule-based detection systems are weak points for attackers. We conducted a comparative analysis of ML algorithms to detect and classify DDoS attacks in this paper. These classifiers compare Nave Bayes with J48 and Random Forest with ZeroR ML as well as other machine learning algorithms. It was found that using the PCA method, the optimal number of features could be found. ML has been implemented with the help of the WEKA tool. 2021 IEEE. -
Preparation for parenthood programme: Experiences form Southern India /
Internatinoal Review of Psychiatry, Vol.26, Issue 4, pp.423-429, ISSN No: 0954-0261. -
Integrated skills for parenting the adolescents (ISPA): An intervention to strengthen parent- adolescent relationship /
Review of Neuropsiquiatrica, Vol.76, Issue 4, pp.413-422, ISSN No: 1609-7394. -
RNA-seq DE genes on Glioblastoma using non linear SVM and pathway analysis of NOG and ASCL5
Differentially Expressed genes related to Glioblastoma Multiforme as an output of RNASeq studies were further studied to conclude new research insights. Glioma is a type of intracranial tumor (within the skull), which can grow rapidly in its malignant stages. Gene expression in Grade II, III and IV Gliomas is analysed using non linear SVM models. The enriched GO terms were identified GOrilla. Pathways related to NOG and ASCL5 gene were studied using Reactome. 2020, Springer Nature Switzerland AG. -
Financial Market Forecasting using Macro-Economic Variables and RNN
Stock market forecasting is widely recognized as one of the most important and difficult business challenges in time series forecasting. This is mainly due to its noise. The use of RNN algorithms for funding has attracted interest from traders and scientists. The best technique for learning long-term memory sequences is to use long and short networks. Based on the literature, it is acknowledged that LSTM neural networks outperform all other models. Macroeconomics is a discipline of economics that studies the behavior of the economy as a whole. Macroeconomic factors are economic, natural, geopolitical, or other variables that influence the economy of a country. This study studies and test several macroeconomic variables and their significance on stock market forecasting. In macroeconomics, we have series that are updated once a month or even once a quarter, with data that is rarely more than a few hundred characters long. The amount of data given can sometimes be insufficient for algorithms to uncover hidden patterns and generate meaningful results. Depending on the prediction needs, we proposed a feasible LSTM design and training algorithm. According to the findings of this study, the inclusion of macroeconomic variable has a significant impact on stock price prediction. 2022 IEEE. -
A secure bio-hash-based multiparty mutual authentication protocol for remote health monitoring applications
Remote health monitoring can benefit a large number of stake holders in healthcare industry, and it has the potential to make healthcare facilities available to a large number of masses at a reduced cost. Wireless Body Area networks (WBAN) comprising of sensors, capable of capturing and transferring physiological parameters of patients, provide an efficient and cost-effective solution for remote health monitoring. Data security is one among the major concerns preventing the widespread adoption of this technology by patients and healthcare sector. This chapter on remote health monitoring, presents a biometric-based authentication protocol. The work also proposes a multiparty mutual authentication protocol for authenticating the entities, such as users, sensors, personal devices, and medical gateway, participating in a WBAN. In the proposed protocol, a verifier table is not required to store the password of users. Formal security analysis and verification of the discussed protocols are performed using Scyther tool, and the results reveal that the protocols are resistant to privileged-administrator resilience attack, man-in-the-middle attack, replay attack, and impersonation attack. The Author(s), under exclusive license to Springer Nature Switzerland AG 2021. -
Key management solutions for database as a service: A selective survey
In todays scenario, efficient data processing is a fundamental and vital issue for almost every scientific, academic, or business organization. To tackle this issue, organizations end up installing and managing database systems to satisfy different processing needs. In case of adopting a traditional solution, the organization needs to purchase the necessary hardware, deploy database products, establish network connectivity, and hire professional people who run the system. But this solution is getting impractical and expensive as the database systems and problems become larger and complicated (El-Khoury et al., 2009). Again, traditional solution entails different costs from the perspective of the investments involved. These concerns are handled efficiently to a great extent by the fast developing technology that goes by the name, cloud computing.. 2014 by Taylor & Francis Group, LLC. -
A Survey of Traditional and Cloud Specific Security Issues
The emerging technology popularly referred to as Cloud computing offers dynamically scalable computing resources on a pay per use basis over the Internet. Companies avail hardware and software resources as service from the cloud service provider as opposed to obtaining physical assets. Cloud computing has the potential for significant cost reduction and increased operating efficiency in computing. To achieve these benefits, however, there are still some challenges to be solved. Security is one of the prime concerns in adopting Cloud computing, since the user's data has to be released from the protection sphere of the data owner to the premises of cloud service provider. As more Cloud based applications keep evolving, the associated security threats are also growing. In this paper an attempt has been made to identify and categorize the security threats applicable to Cloud environment. Threats are classified into Cloud specific security issues and traditional security attacks on various service delivery models of Cloud. The work also briefly discusses the virtualization and authentication related issues in Cloud and tries to consolidate the various security threats in a classified manner. Springer-Verlag Berlin Heidelberg 2013. -
A Signature-Based Mutual Authentication Protocol for Remote Health Monitoring
Remote health monitoring can offer a lot of advantage to all the players in healthcare industry and it can contribute to reduced healthcare expenses. Wireless medical sensor networks capable of accumulating and transferring vital parameters of patients play a crucial role in remote health monitoring. Security and privacy are major concerns preventing the patients from adopting this technology with an open mind. This paper presents a signature-based authentication protocol for remote health monitoring. The work also discusses an authentication protocol for the mutual authentication of users and medical server. The protocol does not require the server to maintain a password table. The proposed algorithms are resistant to various attacks such as replay attack, stolen verifier attack, and privileged insider attack. The work includes the informal and formal security analysis of the proposed protocols. Scyther tool is used for formal security analysis and the results show that the protocol is resistant to various common and automated attacks. 2019, Springer Nature Singapore Pte Ltd. -
A mobile based remote user authentication scheme without verifier table for cloud based services
The emerging Cloud computing technology, offering computing resources as a service is gaining increasing attention of both the public and private sector. For the whole hearted adoption of Cloud, the service providers need to ensure that only valid users gain access to the services and data residing within the provider's premises. Ensuring secure access to sensitive resources within the Cloud requires a strong user authentication mechanism using multiple authentication factors. The mechanisms should also consider the increasing needs of Internet access through smart phones and other mobile devices and facilitate access through a variety of devices. Traditionally, a user needs to maintain separate user accounts for each Service Provider whose service he/she desires to use and this may cause inconvenience to users. Single Sign on (SSO) addresses this issue by permitting users to create one login credential and access multiple services hosted in different domains. In this scenario, a compromise of the single credential can result in account take over at many other sites. This points out to the requirement of strengthening the authentication mechanism by using more than one factor. This paper proposes a SSO based remote user authentication scheme for a Cloud environment. The proposed protocol uses password and mobile token and does not require the server to maintain a verifier table. The protocol is verified using automated security Protocol verification tool, Scyther and the results prove that the protocol provides protection against man-in-the-middle attack, replay attack and secrecy of the user's credentials. 2015 ACM. -
A Single Sign on based secure remote user authentication scheme for Multi-Server Environments
A Multi-Server Architecture comprises of a server environment having many different servers which provides the user the flexibility of accessing resources from multiple Service Providing Servers using the same credential. The primary objective of a Multi Server Environment (MSE) is to provide services of different Service Providers (SPs) without repeating registration at each SP server, and to get a unique single credential for all the servers in MSE. However, the conventional MSEs, proposed by various researchers, proposes the individual authentication service by each SP on their respective server using the credential issued by the Registration Authority of MSE. The mechanism requires the user to access each SP by keying the same credentials for every SP separately. Single Sign On (SSO) is an authentication mechanism that enables a user to sign-on once and access the services of various SPs in the same session. SAML is generally used as a Single Sign-On protocol. This work analyzes the smart card based authentication scheme for Multi-Server Environment proposed by Li et al.'s and discuss various security attacks on the said scheme. The paper also proposes a Secure Dynamic-ID based scheme using smart cards or crypto cards which do not require a verifier table and implements Single Sign On feature using SAML protocol, thus allowing the user to enjoy all the features of an MSE along with SSO. 2014 IEEE. -
A proof of concept implementation of a mobile based authentication scheme without password table for cloud environment
Cloud computing is a fast growing technology offering a wide range of software and infrastructure services on a pay-per-use basis. Many small and medium businesses (SMB's) have adopted this utility based Computing Model as it contributes to reduced operational and capital expenditure. Though the resource sharing feature adopted by Cloud service providers (CSP's) enables the organizations to invest less on infrastructure, it also raises concerns about the security of data stored at CSP's premises. The fact that data is prone to get accessed by the insiders or by other customers sharing the storage space is a matter of concern. Regulating access to protected resources requires reliable and secure authentication mechanism, which assures that only authorized users are provided access to the services and resources offered by CSP. This paper proposes a strong two-factor authentication mechanism using password and mobile token. The proposed model provides Single Sign-on (SSO) functionality and does not require a password table. Besides introducing the authentication scheme, the proof of concept implementation is also provided. 2015 IEEE.