Doping Induced Tailoring in the Morphology,Band-Gap and Ferromagnetic Properties of Biocompatible ZnO Nanowires,Nanorods and Nanoparticles

Nano-Micro Letters - The modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. Single phase Fe doped ZnO...     

A framework for an integrated unified modeling language

The unified modeling language (UML) is one of the most commonly used modeling languages in the software industry. It simplifies the complex process of design by providing a set of graphical notations, which helps express the objectoriented analysis and design of software projects. Although UML is applicable to different types of systems, domains, methods, and processes, it cannot express certain problem domain needs. Therefore, many extensions to UML have been proposed. In this paper, we propose a framework for integrating the UML extensions and then use the framework to propose an integrated unified modeling language-graphical (iUML-g) form. iUML-g integrates the existing UML extensions into one integrated form. This includes an integrated diagram for UML class, sequence, and use case diagrams. The proposed approach is evaluated using a case study. The proposed iUML-g is capable of modeling systems that use different domains.     

BSS: block-based sharing scheme for secure data storage services in mobile cloud environment

For the last few years, academia and research organizations are continuously investigating and resolving the security and privacy issues of mobile cloud computing environment. The additional consideration in designing security services for mobile cloud computing environment should be the resource-constrained mobile devices. The execution of computationally intensive security services on mobile device consumes battery’s charging quickly. In this regard, the study presents a novel energy-efficient block-based sharing scheme that provides confidentiality and integrity services for mobile users in the cloud environment. The block-based sharing scheme is compared with the existing schemes on the basis of energy consumption, CPU utilization, memory utilization, encryption time, decryption time, and turnaround time. The experimental results show that the block-based sharing scheme consumes less energy, reduces the resources utilization, improves response time, and provides better security services to the mobile users in the presence of fully untrusted cloud server(s) as compared to the existing security schemes.     

Neighbor Selection Game in Wireless Ad Hoc Networks

In wireless ad hoc networks, there is no infrastructure to enforce cooperation between nodes. As a result, nodes may act selfishly when running network protocols to conserve their energy resources as much as possible. In this paper, we consider the “neighbor selection” game in which each individual node tries to selfishly choose its neighborhood such that its own energy consumption is optimized. We first focus on a simplified version of this game where nodes know their transmission power before participating in the game. After analyzing the problem, we propose a couple of distributed algorithms to find stable topologies using two kinds of global and local connectivity information. We then take into account the general case where the transmission powers are unknown variables and should be determined during the game. Finally, we evaluate the performance of the proposed algorithms through simulations.     

Peel Effects on Phenolic Composition,Antioxidant Activity,and Making of Pomegranate Juice and Wine

Pomegranate peel was used in juicing to find out its effects on the juice products’ (storable juice and wine) sensory property, polyphenols composition, and antioxidant ability. Macroporous resin was used to purify the polyphenols, and 6 different in vitro assays were used to comprehensively determine the antioxidant activity of each. The results showed that juicing with peel made the juice bitter and astringent, but contributed better sensory quality to wine. Peel contributed higher total polyphenols and flavonoids, but lower anthocyanins to the juice products, and caused the phenolics content to fluctuate more dramatically during making wine than the storable juice. Polyphenols purified from the juice products containing peel showed higher total reducing ability and 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid radical elimination abilities, but their clearance activity of hydroxyl radicals was not positive, and their superoxide anion radical elimination ability showed no significant difference when compared to polyphenols purified from juice products without peel.     

Emulsified jet fuel flame characterization with image processing

This work describes a RGB digital image processing approach of emulsified jet fuel flame, which allows the characterization of the combustion phenomenon in the case of new fuels through color chemiluminiscence measurements. By applying RGB techniques, the image processing of the flame reveals useful parameters in an effective and cost-efficient technique for the determination of relevant chemical species, such as CH* and C₂*, equivalence ratio, and temperature estimation.Second generation emulsified aviation fuels containing water-jet fuel have been a challenge for simultaneous thrust augmentation and pollution diminution, with subsequent cost reduction and fossil fuel dependence. Testing new fuels would normally require expensive equipment and reliable investigation techniques, while image processing proved to be a reliable method for the estimation of combustion chemical species and temperature in the case of classic fuels.For the combustion behavior of emulsified jet fuel, a co-annular spray burner was used, allowing the complex investigation with UV-VIS spectrometer and flame photography. RGB image processing techniques showed good agreement with more complicated diagnosis tools, such as spectrometers.     

Bayesian inference and uncertainty quantification for hydrogen-enriched and lean-premixed combustion systems

Development of probabilistic modelling tools to perform Bayesian inference and uncertainty quantification (UQ) is a challenging task for practical hydrogen-enriched and low-emission combustion systems due to the need to take into account simultaneously simulated fluid dynamics and detailed combustion chemistry. A large number of evaluations is required to calibrate models and estimate parameters using experimental data within the framework of Bayesian inference. This task is computationally prohibitive in high-fidelity and deterministic approaches such as large eddy simulation (LES) to design and optimize combustion systems. Therefore, there is a need to develop methods that: (a) are suitable for Bayesian inference studies and (b) characterize a range of solutions based on the uncertainty of modelling parameters and input conditions. This paper aims to develop a computationally-efficient toolchain to address these issues for probabilistic modelling of NOx emission in hydrogen-enriched and lean-premixed combustion systems. A novel method is implemented into the toolchain using a chemical reactor network (CRN) model, non-intrusive polynomial chaos expansion based on the point collocation method (NIPCE-PCM), and the Markov Chain Monte Carlo (MCMC) method. First, a CRN model is generated for a combustion system burning hydrogen-enriched methane/air mixtures at high-pressure lean-premixed conditions to compute NOx emission. A set of metamodels is then developed using NIPCE-PCM as a computationally efficient alternative to the physics-based CRN model. These surrogate models and experimental data are then implemented in the MCMC method to perform a two-step Bayesian calibration to maximize the agreement between model predictions and measurements. The average standard deviations for the prediction of exit temperature and NOx emission are reduced by almost 90% using this method. The calibrated model then used with confidence for global sensitivity and reliability analysis studies, which show that the volume of the main-flame zone is the most important parameter for NOx emission. The results show satisfactory performance for the developed toolchain to perform Bayesian inference and UQ studies, enabling a robust and consistent process for designing and optimising low-emission combustion systems.     

Thermoelastic vibration of doubly-curved nano-composite shells reinforced by graphene nanoplatelets

Abstract

The thermo-mechanical vibration characteristics of doubly-curved nano-composite shells reinforced by graphene nanoplatelets are investigated by considering a uniform distribution of graphene and a first-order shear deformation theory. The mechanical properties of the nano-composite shells are estimated by using the modified Halpin–Tsai model. The governing equations are first derived by a variational formulation using Hamilton’s principle and are solved using the Galerkin technique. Numerical results are presented for various shell curvatures and compared with those available in the archival literature. Furthermore, parametric studies are offered to highlight the significant influence of graphene nanoplatelets’ weight fraction, dimensions of graphene nanoplatelets, and temperature variation, on the free vibration of the nano-composite shells.     

Quantification and Compositional Diversity of Fatty Acid Methyl Esters Profile in Nigella sativa L. Germplasm

Nigella sativa L. is an annual underutilized crop of enormous significance, it contains more than 100 bioactive constituents having both pharmaceutical and industrial applications. Nigella sativa L. germplasm consisting of 32 genotypes was quantified for palmitic acid, stearic acid, oleic acid, linoleic and linolenic acid and results obtained varied in percentage. Lipid extracted by chloroform methanol 2:1 (24–37 %) was higher compared to n-hexane (18–35 %) and chloroform methanol 1:3 (18–34 %). Extraction with solvent chloroform methanol 2:1 yielded a higher quantity of oil contents, hence recommended. The polyunsaturated fatty acids were higher than monounsaturated fatty acids. Stearic and palmitic acids were positively correlated as were stearic and linoleic acids. It is inferred that breeding for increased stearic acid, linolenic acid and reduced palmitic acid can be achieved through modern breeding methods. The genotypes rich in oil and oleic-linoleic acid, viz., Pk-020545, Pk-020576, Pk-020609, Pk-020620, Pk-020654, Pk-020699, Pk-020720, Pk-020780, Pk-020874 and Pk-020878, have been suggested for crop improvement programs and could augment the supply of edible oil as well as a biofuel substitute with large scale cultivation.