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There are various system techniques or models which are used for access control by performing cryptographic operations and characterizing to provide an efficient cloud and in Internet of Things (IoT) access control. Particularly in cloud computing environment, there is a large-scale distribution of these traditional symmetric cryptographic techniques. These symmetric cryptographic techniques use the same key for encryption and decryption processes. However, during the execution of these phases, they are under the problems of key distribution and management. The purpose of this study is to provide efficient key management and key distribution in cloud computing environment.

This paper uses the Cipher text-Policy Attribute-Based Encryption (CP-ABE) technique with proper access control policy which is used to provide the data owner’s control and share the data through encryption process in Cloud and IoT environment. The data are shared with the the help of cloud storage, even in presence of authorized users. The main method used in this research is Enhanced CP-ABE Serialization (E-CP-ABES) approach.

The results are measured by means of encryption, completion and decryption time that showed better results when compared with the existing CP-ABE technique. The comparative analysis has showed that the proposed E-CP-ABES has obtained better results of 2373 ms for completion time for 256 key lengths, whereas the existing CP-ABE has obtained 3129 ms of completion time. In addition to this, the existing Advanced Encryption Standard (AES) scheme showed 3449 ms of completion time.

The proposed research work uses an E-CP-ABES access control technique that verifies the hidden attributes having a very sensitive dataset constraint and provides solution to the key management problem and access control mechanism existing in IOT and cloud computing environment. The novelty of the research is that the proposed E-CP-ABES incorporates extensible, partially hidden constraint policy by using a process known as serialization procedure and it serializes to a byte stream. Redundant residue number system is considered to remove errors that occur during the processing of bits or data obtained from the serialization. The data stream is recovered using the Deserialization process.

The purpose of this study is to conduct a numerical computation to analyse the thermal attribute and heat transfer phenomenon of a fully wetted porous fin of a longitudinal profile. The fin considered is that of a functionally graded material (FGM). Based on the spatial dependency of thermal conductivity, three cases such as linear, quadratic and exponential FGMs are analysed.

The governing equations are nondimensionalised and solved by applying Runge-Kutta-Fehlberg fourth-fifth order technique.

The parametric investigation is executed to access the significance of the pertinent parameters on the thermal feature of the fin and heat transmit rate. The outcomes are portrayed in a graphical form.

No such study has yet been published in the literature.

The influence of radiation on nanoliquid flow through a vertical microchannel in the presence of heat source is examined. This study aims to investigate the efficiency of multi-walled carbon nanotube (MWCNT) considering water and engine oil as base fluid.

Nondimensional variables are used to obtain the dimensionless physical model. The solutions are computed numerically via Runge–Kutta–Fehlberg integration scheme.

It is established that (k_nf/k_f)_Lamina > (k_nf/k_f)_Column > (k_nf/k_f)_Tetrahedron > (k_nf/k_f)_Hexahedron > (k_nf/k_f)_Sphere.

Thermal conductivity of MWCNT is analyzed using different models. Also, it is remarked that Xue model exhibits higher thermal conductivity for MWCNT compared to Maxwell model, Yu-Choi model and Hamilton-Crosser model.

This paper aims to study the temperature performance with natural convection and radiation effect on a porous fin in fully wet condition.

The finite element method (FEM) is applied to generate numerical solution of the obtained non-dimensional ordinary differential equation containing highly nonlinear terms. The parameters which impact on the heat transfer of fin have been scrutinized by means of plotted graphs.

The porous fin is taken for the analysis in radial profile moving with constant velocity. Here, the thermal conductivity is considered to be temperature dependent. The Darcy’s model has been implemented to study the heat transfer analysis.

The paper is genuine in its type, and there are hardly any works on fins as per the authors’ knowledge.

The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been scrutinised along with the simultaneous variation of surface emissivity, heat transfer coefficient and thermal conductivity with temperature. The emissivity of the surface and the thermal conductivity are considered as linear functions of the local temperature between fin and the ambient. Darcy’s model was considered to formulate the heat transfer equation. According to this, the porous fin permits the flow to penetrate through it and solid–fluid interaction occurs.

Runge–Kutta–Fehlberg fourth–fifth-order method has been used to solve the reduced non-dimensionalized ordinary differential equation involving highly nonlinear terms.

The impact of pertinent parameters, such as convective parameter, radiative parameter, conductivity parameter, emissivity parameter, wet porous parameter, etc., on the temperature profiles were elaborated mathematically with the plotted graphs. The heat transfer from the fin enhances with the rise in convective parameter.

The wet nature of the fin enhances heat transfer and in many practical applications the parameters, such as thermal conductivity, heat transfer coefficient as well as surface emissivity, vary with temperature. Hence, the main objective of the current study is to depict the significance of simultaneous variation in surface emissivity, heat transfer coefficient and thermal conductivity with respect to temperature under natural convection and radiation condition in a totally wetted longitudinal porous fin.

This study aims to portray the systematic study of hybrid nanofluid with particle shape effect on significant heat transfer enhancement. The steady flow of hybrid nanoliquid in a microchannel with the aid of porous medium has been considered. The dispersion of copper and Al₂O₃ in water is taken as hybrid mixture. The impact of thermal radiation, slip length and convective conditions on flow and thermal features are examined numerically.

The modelled equations are made dimensionless by means of nondimensional entities. The solutions are computed numerically by the implementation of Runge–Kutta-based shooting technique. The results depict that the shape of hybrid mixtures plays a significant role in convective heat transfer. Relevant results on flow velocity, temperature, Nusselt number and friction factor for various physical constraints have been perused. The obtained outcomes are displayed graphically.

The acquired results depict that Nusselt number augments with Eckert number and solid volume fraction of hybrid nanoparticles, which has a vibrant role in enriching the heat transfer coefficient. Also, it is emphasized that the Nusselt number is larger for blade-shaped nanoparticle compared to other shapes.

The analysis of individual effect of thermal radiation, Joule heating, viscous dissipation and magnetic field on the flow of Cu and Al₂O₃ hybrid nanofluid through microchannel has vivacious role in augmenting heat transmission. Along with this, the impact of porous medium, shape factor, slip and convective peripheral conditions are also emphasized.

In heat transfer, fluids and nanoparticles can provide new innovative technologies with potential to adapt the heat transfer fluid’s thermal properties through control over particle size, shape and others. This paper aims to examine the effects of spherical and non-spherical (cylinder, disk, platelets, etc.) shapes of silver (Ag) nanoparticles on heat transfer enhancement and inherent irreversibility in hydromagnetic water base nanoliquid flow over a convectively heated stretching sheet with heat generation/absorption.

Applying suitable similarity constraints, the model partial differential equations are transformed into a set of nonlinear ordinary differential equations. Solutions are obtained analytically via optimal homotopy asymptotic method (OHAM) and numerically via shooting technique coupled with the Runge-Kutta-Fehlberg (RK-F) method.

The impact of Ag nanoparticle’s shape along with other germane factors, such as Biot number, magnetic field, solid volume fraction and heat source/sink on velocity and thermal profiles, Nusselt number, skin friction coefficient, heat transfer enhancement, rate of entropy generation and irreversibility ratio, are scrutinized via graphical simulations and discussed. This study revealed that cylindrical shape Ag nanoparticles generate high entropy and fluid friction irreversibility, whereas disk shape Ag nanoparticles exhibit high transfer enhancement rate. Moreover, a boost in magnetic field intensity, volume-fraction parameter and Biot number enhances the thermal boundary layer thickness.

The main objective of this work is to examine the different Ag nanoparticles shape effects on the heat transfer enhancement and inherent irreversibility owing to hydromagnetic nanoliquid flow past a convectively heated stretching sheet with heat source/sink, which has not been yet studied. It is hope that this study will bridge the gap in the present literature and serve as impetus to scholars, engineers and industries for more exploration in this direction. The intrinsic nonlinearity of the model equations precludes its exact solution; hence, OHAM and shooting technique coupled with the RK-F method have been used to numerically tackle the problem. Pertinent results are discussed quantitatively and displayed graphically and in tabular form.

The purpose of this paper is to study the thermal behaviour of radial porous fin wetted with nanofluid containing different shaped nanoparticles in the presence of natural convection and radiation. Here, the nanofluid suspended with molybdenum disulfide nanoparticle with base fluid as water is considered. The influence of non-spherical nanoparticles such as platelet, cylinder, brick and blade shapes is also investigated.

The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme.

The flow natures of the pertinent parameter are represented graphically and discussed their physical significance. From the validation of obtained outcome, it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.

The present paper deals with an analysis of the flow of molybdenum disulfide nanoparticles suspended in water over a porous fin of a radial profile. The effect of differently shaped nanoparticles on the heat transfer enhancement through the radial porous fin is investigated for the first time. The natural convection and radiation effects are also considered. The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. The effect of pertinent parameters on temperature field is examined. From the validation of obtained outcome it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.

This report offers the detailed investigation of Couette–Poiseuille flow of nanoliquid with varying viscosity. The analysis is carried out by considering flow between two parallel plates in a rotating permeable channel with the aid of nonlinear thermal radiation and Hall effect. The predominant equations governing the physical phenomenon are demonstrated using the Buongiorno model.

Numerical computation for the demonstrated physical problem is achieved through the implementation of the Runge–Kutta–Fehlberg fourth–fifth-order method along with shooting technique.

The theoretical view of Brownian motion, nonlinear radiation, Hall effect and thermophoresis parameter is presented graphically.

It is revealed that flow velocity increases with the upper wall motion parameter and magnetic field. Also, it is established that an increase in the Nusselt number is achieved for increasing values of nonlinear radiation parameter.

The study examines the cross-sectional and asymmetric relationship of investor sentiment with the stock returns and volatility in India.

The investor sentiment is captured using a market-based measure Market Mood Index (MMI) and a survey-based measure Consumer Sentiment Index (CSI). The asymmetric effect of the relationship is examined using quantile causality approach and cross-sectional effect is examined by considering indices such as the BSE Sensex, and the various size indices such as BSE Large cap, BSE Mid cap and BSE Small cap.

The result of the study found that investor sentiment (MMI) cause stock returns at extreme quantiles. Lower sentiment induces fear-induced selling, thereby lowers the returns and high sentiment is followed by lower future returns as market reverts to fundamentals. On the other hand, bullish shifts in sentiment lower the volatility. There exists a positive feedback effect of stock return and volatility in the formation of investor sentiment.

The study captures both asymmetric and cross-sectional relationship of investor sentiment and stock market in an emerging economy, India. The study uses a novel data set (i.e.) MMI which captures the sentiment based on market indicators and are widely disseminated to the public.