Biosorption of copper(II) on prunus amygdalus shell: Characterization,biosorbent size analysis,kinetic, equilibrium and mechanistic studies

Deletion of Cu(II) from synthetic solution was investigated using ground Prunus Amygdalus shell (GPAS). FTIR revealed the probable functional groups for the binding of Cu(II). XRD revealed amorphous nature of the GPAS. SEM analysis furnished microscopic details of GPAS. GPAS size analysis was done using seven ASTM screens and three mean diameters, namely mass mean, volume mean and volume surface mean diameters. Kinetic study consisted of pseudo-first and pseudo-second order kinetics. Langmuir and Freundlich isotherms were used to elucidate the isotherm study of uptake of Cu(II) onto GPAS. Trend of Scatchard was used to verify the applicability of the Freundlich model, while D-R model helped to determine the nature of biosorption. A detailed analysis for rate controlling step was made. Various mean diameters were used to estimate the diffusion coefficient for the biosorption of Cu(II) onto GPAS.     

Combination of PDMS microfilters and micromixers based on flexible thermoplastic films for size sorting and mixing of microparticles

We present a study for the development of flexible microfilters based on sealing microstructured poly(dimethylsiloxane) (PDMS) to different functionalized thermoplastic films [polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET)]. The microfilter was manufactured by soft‐lithography and replica molding and then combined with plasma activation and chemical treatment using 3‐(aminopropyl)triethoxysilane (APTES). To demonstrate the functionality of the PDMS microfilters, poly(lactic‐co‐glycolic acid) (PLGA) microparticles (MPS) were filtered through the microfluidic device based on the three thermoplastic films. Subsequently, the mixing capabilities of a passive PDMS micromixer was observed with the injection of polymeric MPS (fluorescent and nonfluorescent) as fluidic mixers are not generally effective at mixing particles. On mixing nonfluorescent MPS (～<10–30 µm in diameter) a mixing performance of 13.3% at 5 mm was observed. Therefore, a PDMS microfiltering device was integrated with a PDMS micromixer using a simple and cost effective home‐made polymeric connector for filtration at a size sorting of 11 µm. The results exhibit that the combination of the two microfluidic devices can be achieved with size sorting and mixing of MPS with an improved mixing performance of 62.5% at 3 mm. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42088.     

Design of carbon/glass/epoxy‐based radar absorbing composites: Microwaves attenuation properties

Due to high specific strength, fatigue resistance, and stiffness, reinforced plastic composites have great deal of relevance in aerospace applications such as electromagnetic interference shielding, radar absorption, etc. These radar absorption structures offer good mechanical properties, absorption characteristics, and less interference with external profile making them viable for aerospace structure design. Present venture trades the investigation concerning the attenuation of electrical component (electromagnetic waves) through the inclusion of different carbon‐based absorbers in glass/epoxy. Short carbon fibers like carbon black and multi‐walled carbon nanotubes were utilized as the lossy components. The samples were manufactured via vacuum assisted resin infusion technique which gave uniform thickness and minimum void content. Particles were mixed in resin and infused in the glass preform. The effects of changing the absorber materials, number of layers of glass fiber mat and glass fiber itself were analyzed. Sandwiched absorbing structures with aramid honeycomb were also fabricated. The samples were tested via free space measurement technique. Two charts of results were obtained i.e. one with dielectric parameters and other with the reflection loss. Short carbon fibers showed the best fallouts in this study. Moreover, thickness with 16 layers of glass fiber was also evidenced as optimum for the structure. POLYM. ENG. SCI., 54:2508–2514, 2014. © 2013 Society of Plastics Engineers     

Lattice-Based Authentication Scheme to Prevent Quantum Attack in Public Cloud Environment

Public cloud computing provides a variety of services to consumers via high-speed internet. The consumer can access these services anytime and anywhere on a balanced service cost. Many traditional authentication protocols are proposed to secure public cloud computing. However, the rapid development of high-speed internet and organizations’ race to develop quantum computers is a nightmare for existing authentication schemes. These traditional authentication protocols are based on factorization or discrete logarithm problems. As a result, traditional authentication protocols are vulnerable in the quantum computing era. Therefore, in this article, we have proposed an authentication protocol based on the lattice technique for public cloud computing to resist quantum attacks and prevent all known traditional security attacks. The proposed lattice-based authentication protocol is provably secure under the Real-Or-Random (ROR) model. At the same time, the result obtained during the experiments proved that our protocol is lightweight compared to the existing lattice-based authentication protocols, as listed in the performance analysis section. The comparative analysis shows that the protocol is suitable for practical implementation in a quantum-based environment.     

Text Encryption Using Pell Sequence and Elliptic Curves with Provable Security

The demand for data security schemes has increased with the significant advancement in the field of computation and communication networks. We propose a novel three-step text encryption scheme that has provable security against computation attacks such as key attack and statistical attack. The proposed scheme is based on the Pell sequence and elliptic curves, where at the first step the plain text is diffused to get a meaningless plain text by applying a cyclic shift on the symbol set. In the second step, we hide the elements of the diffused plain text from the attackers. For this purpose, we use the Pell sequence, a weight function, and a binary sequence to encode each element of the diffused plain text into real numbers. The encoded diffused plain text is then confused by generating permutations over elliptic curves in the third step. We show that the proposed scheme has provable security against key sensitivity attack and statistical attacks. Furthermore, the proposed scheme is secure against key spacing attack, ciphertext only attack, and known-plaintext attack. Compared to some of the existing text encryption schemes, the proposed scheme is highly secure against modern cryptanalysis.     

Flower Pollination Heuristics for Nonlinear Active Noise Control Systems

Abstract In this paper, a novel design of the flower pollination algorithm is presented for model identification problems in nonlinear active noise control systems. The recently introduced flower pollination based heuristics is implemented to minimize the mean squared error based merit/cost function representing the scenarios of active noise control system with linear/nonlinear and primary/secondary paths based on the sinusoidal signal, random and complex random signals as noise interferences. The flower pollination heuristics based active noise controllers are formulated through exploitation of nonlinear filtering with Volterra series. The comparative study on statistical observations in terms of accuracy, convergence and complexity measures demonstrates that the proposed meta-heuristic of flower pollination algorithm is reliable, accurate, stable as well as robust for active noise control system. The accuracy of the proposed nature inspired computing of flower pollination is in good agreement with the state of the art counterpart solvers based on variants of genetic algorithms, particle swarm optimization, backtracking search optimization algorithm, fireworks optimization algorithm along with their memetic combination with local search methodologies. Moreover, the central tendency and variation based statistical indices further validate the consistency and reliability of the proposed scheme mimic the mathematical model for the process of flower pollination systems.     

Optimality of Solution with Numerical Investigation for Coronavirus Epidemic Model

The novel coronavirus disease, coined as COVID-19, is a murderous and infectious disease initiated from Wuhan, China. This killer disease has taken a large number of lives around the world and its dynamics could not be controlled so far. In this article, the spatio-temporal compartmental epidemic model of the novel disease with advection and diffusion process is projected and analyzed. To counteract these types of diseases or restrict their spread, mankind depends upon mathematical modeling and medicine to reduce, alleviate, and anticipate the behavior of disease dynamics. The existence and uniqueness of the solution for the proposed system are investigated. Also, the solution to the considered system is made possible in a well-known functions space. For this purpose, a Banach space of function is chosen and the solutions are optimized in the closed and convex subset of the space. The essential explicit estimates for the solutions are investigated for the associated auxiliary data. The numerical solution and its analysis are the crux of this study. Moreover, the consistency, stability, and positivity are the indispensable and core properties of the compartmental models that a numerical design must possess. To this end, a nonstandard finite difference numerical scheme is developed to find the numerical solutions which preserve the structural properties of the continuous system. The M-matrix theory is applied to prove the positivity of the design. The results for the consistency and stability of the design are also presented in this study. The plausibility of the projected scheme is indicated by an appropriate example. Computer simulations are also exhibited to conclude the results.     

Hot Hydrocarbon-Solvent Slot-Die Coating Enables High-Efficiency Organic Solar Cells with Temperature-Dependent Aggregation Behavior

Organic solar cells (OSCs) have made rapid progress in terms of their development as a sustainable energy source. However, record-breaking devices have not shown compatibility with large-scale production via solution processing in particular due to the use of halogenated environment-threatening solvents. Here, slot-die fabrication with processing involving hydrocarbon-based solvents is used to realize highly efficient and environmentally friendly OSCs. Highly compatible slot-die coating with roll-to-roll processing using halogenated (chlorobenzene (CB)) and hydrocarbon solvents (1,2,4-trimethylbenzene (TMB) and ortho-xylene (o-XY)) is used to fabricate photoactive films. Controlled solution and substrate temperatures enable similar aggregation states in the solution and similar kinetics processes during film formation. The optimized blend film nanostructures for different solvents in the highly efficient PM6:Y6 blend is adopted to show a similar morphology, which results in device efficiencies of 15.2%, 15.4%, and 15.6% for CB, TMB, and o-XY solvents. This approach is successfully extended to other donor–acceptor combinations to demonstrate the excellent universality of this method. The results combine a method to optimize the aggregation state and film formation kinetics with the fabrication of OSCs with environmentally friendly solvents by slot-die coating, which is a critical finding for the future development of OSCs in terms of their scalable production and high-performance.     

Dynamical Behavior and Sensitivity Analysis of a Delayed Coronavirus Epidemic Model

Mathematical delay modelling has a significant role in the different disciplines such as behavioural, social, physical, biological engineering, and bio-mathematical sciences. The present work describes mathematical formulation for the transmission mechanism of a novel coronavirus (COVID-19). Due to the unavailability of vaccines for the coronavirus worldwide, delay factors such as social distance, quarantine, travel restrictions, extended holidays, hospitalization, and isolation have contributed to controlling the coronavirus epidemic. We have analysed the reproduction number and its sensitivity to parameters. If,     

Open architecture dynamic manipulator design philosophy (DMD)

This paper presents a generic and universal architecture design for robotic manipulators. A flexible approach is taken to develop the design philosophy throughout, resulting in a hardware architecture that is portable, can be integrated and enables the implementation of advanced control methods. A software kernel of management, supervision and control was developed in order to obtain an easy user interface to the robotic researcher. The application of many such controls has, traditionally, often been severely restricted in partial commercial robotic systems because of limitations associated with their controllers; rather than the arms themselves.