Effect of deformation temperature on precipitation,microstructural evolution,mechanical and corrosion behavior of 6082 Al alloy

The influence of cryorolling (CR), room temperature rolling (RTR) and post annealing on precipitation, microstructural evolution (recovery, recrystallisation and grain growth), mechanical and corrosion behavior, was investigated in the present work. The precipitation kinetics and microstructural morphology of CR, RTR, and post annealed samples were investigated by differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and electron back scattered diffraction (EBSD) to elucidate the observed mechanical properties. After annealing at 200 °C, UTS and hardness of CR samples (345 MPa and HV 127) were improved as compared to RTR samples (320 MPa and HV 115). The increase in hardness and UTS of CR samples after annealing at 200 °C was due to precipitation of β″ from Al matrix, which imparted higher Zener drag effect as compared to RTR samples. The improvement in corrosion and pitting potentials was observed for CR samples (?1.321 V and ?700 mV) as compared to RTR samples (?1.335 V and ?710 mV). In CR samples, heavy dislocation density and dissolution of Mg₄Al₃Si₄-precipitates in the Al matrix have improved corrosion resistance of the alloy through formation of protective passive layer and suppression of galvanic cell, respectively.     

Effect of laser flux density on ZnCdS thin films

Effect of laser flux density on the structural quality and optical properties of Zn_0.6Cd_0.4S thin films synthesized by ultraviolet pulsed laser deposition have been studied. The stoichiometric composition of this alloy was estimated using lattice constant calculated via XRD data. Surface morphology of the samples was examined using AFM. Optical properties were studied at room temperature by transmittance, absorbance, and photoluminescence measurements. Studies revealed that there is an improvement in the structural quality with increasing the laser flux density in some range. However, too high laser flux density could lead to the degradation in structural quality of thin film. It was observed from the PL data that with increase in laser flux density there is a decrease in the band gap. Transmission data shows a transmittance of more than 70% in the visible region. TEM investigation of the samples reveals that the particles are spherical in shape with average diameter of 15 nm.     

Comparative survival and evaluation of functional probiotic properties of spray-dried lactic acid bacteria

The effect of spray drying on the viability and retention of key probiotic properties like acid and bile tolerance and cholesterol assimilation of three probiotic lactic acid bacteria (LAB) ( Lactobacillus plantarum CFR 2191, Lactobacillus salivarius CFR 2158 and Pediococcus acidilactici CFR 2193) has been studied. More than 97% survival was exhibited by the three LAB (1% cell suspension) spray dried with maltodextrin and nonfat skimmed (NFSM) as carriers. LAB cultures spray dried with maltodextrin showed significantly greater ( P ≤  0.05) retention of functional properties than those with NFSM. The results highlight a cost-effective way of producing large quantities of selected probiotic cultures with functional properties for neutraceutical application.     

DNACDS: Cloud IoE big data security and accessing scheme based on DNA cryptography

The Internet of Everything (IoE) based cloud computing is one of the most prominent areas in the digital big data world. This approach allows efficient infrastructure to store and access big real-time data and smart IoE services from the cloud. The IoE-based cloud computing services are located at remote locations without the control of the data owner. The data owners mostly depend on the untrusted Cloud Service Provider (CSP) and do not know the implemented security capabilities. The lack of knowledge about security capabilities and control over data raises several security issues. Deoxyribonucleic Acid (DNA) computing is a biological concept that can improve the security of IoE big data. The IoE big data security scheme consists of the Station-to-Station Key Agreement Protocol (StS KAP) and Feistel cipher algorithms. This paper proposed a DNA-based cryptographic scheme and access control model (DNACDS) to solve IoE big data security and access issues. The experimental results illustrated that DNACDS performs better than other DNA-based security schemes. The theoretical security analysis of the DNACDS shows better resistance capabilities.     

Synthesis of Benzenesulfonamide Derivatives via Ring Opening of Aziridines in the Presence of Magnetically Retrievable Graphene Based (CoFe@rGO) Nanohybrid

Graphene based magnetic nanohybrids have engrossed considerable research curiosity because of their exceptional properties and diverse applications associated with green chemistry. In this regard, a practical, facile and regioselective preparation of 1,2-diamines from N-tosylaziridine/(S)-(+)-2-Benzyl-1-(p-tolylsulfonyl)aziridine and aryl amines in the presence of magnetically separable graphene based nanohybrid (CoFe@rGO) has been proposed under mild and solvent free conditions. The FT-IR, FE-SEM, XPS, XRD and TEM spectroscopic analysis confirmed the formation of the CoFe@rGO nanohybrids. For unsymmetrical aziridine, nucleophilic attack of aryl amines was observed to take place selectively at the more substituted carbon atom of aziridine ring. Environmentally benign, efficient, shorter reaction time, solvent-free conditions, low catalyst loading, excellent reaction yields and reusability of the catalyst for six consecutive runs without significant loss in its activity are the key advantages of this protocol.

Graphical Abstract