Co-simulation Based Finite State Machine for Telematic and Data Compression Microservices in IoT

Wireless Personal Communications - Despite the wide adoption of Internet of things (IoT) with several webs standards and cloud technologies; building of city wide IoT based smart city platform for...     

Multi-objective optimization of machining and micro-machining processes using non-dominated sorting teaching–learning-based optimization algorithm

Selection of optimum machining parameters is vital to the machining processes in order to ensure the quality of the product, reduce the machining cost, increasing the productivity and conserve resources for sustainability. Hence, in this work a posteriori multi-objective optimization algorithm named as Non-dominated Sorting Teaching–Learning-Based Optimization (NSTLBO) is applied to solve the multi-objective optimization problems of three machining processes namely, turning, wire-electric-discharge machining and laser cutting process and two micro-machining processes namely, focused ion beam micro-milling and micro wire-electric-discharge machining. The NSTLBO algorithm is incorporated with non-dominated sorting approach and crowding distance computation mechanism to maintain a diverse set of solutions in order to provide a Pareto-optimal set of solutions in a single simulation run. The results of the NSTLBO algorithm are compared with the results obtained using GA, NSGA-II, PSO, iterative search method and MOTLBO and are found to be competitive. The Pareto-optimal set of solutions for each optimization problem is obtained and reported. These Pareto-optimal set of solutions will help the decision maker in volatile scenarios and are useful for real production systems.     

A kinetic model for pyrolysis of Douglas fir bark

A kinetic study of catalysed and non-catalysed pyrolysis of Douglas fir bark was conducted using a DuPont 951 Thermogravimetric Analyzer. A kinetic model in which activation energy is assumed to be a linear function of the extent of reaction was used to describe the pyrolysis of bark. It was found that as conversion increases from 10 to 70% the apparent activation energy increases (as 101.7 + 142.7 X) to 201.8 kJ/mol for the non-catalysed bark and (as 102.6 + 86.2 X) to 162.8 kJ/mol for the catalysed bark. The order of reaction was found to be one for the non-catalysed and two for the catalysed bark. The model shows good agreement with the data reported by other investigators using a fluidized bed.     

Effect of heating and cooling rate on the kinetics of allotropic phase changes in uranium: A differential scanning calorimetry study

The kinetic aspects of allotropic phase changes in uranium are studied as a function of heating/cooling rate in the range 10⁰-10² K min⁻¹ by isochronal differential scanning calorimetry. The transformation arrest temperatures revealed a remarkable degree of sensitivity to variations of heating and cooling rate, and this is especially more so for the transformation finish (T_f) temperatures. The results obtained for the α → β and β → γ transformations during heating confirm to the standard Kolmogorov-Johnson-Mehl-Avrami (KJMA) model for a nucleation and growth mediated process. The apparent activation energy Q_eff for the overall transformation showed a mild increase with increasing heating rate. In fact, the heating rate normalised Arrhenius rate constant, k/β reveals a smooth power law decay with increasing heating rate (β). For the α → β phase change, the observed DSC peak profile for slower heating rates contained a distinct shoulder like feature, which however is absent in the corresponding profiles found for higher heating rates. The kinetics of γ → β phase change on the other hand, is best described by the two-parameter Koistinen-Marburger empirical relation for the martensitic transformation.     

Fabrication of Tuneable Thickness Silica Films on Solid Surfaces Using Amines and Proteins

We report an elegant and simple method to fabricate silica films with controlled thickness and roughness using protein coated solid surfaces as substrates. Bovine serum albumin (BSA) and lysozyme having different inherent charges have been used as model proteins (templates) to fabricate silica films. The formation of silica films was achieved by immobilization of BSA and lysozyme on amine (poly(allylamine) (PAH), poly(ethyleneimine) (PEI) and octadecyl amine (ODA)), coated surfaces, followed by treatment with silica precursors (tetramethoxysilane) under environmentally benign conditions of pH and temperature. BSA adsorbs strongly on hydrophilic surfaces (PAH and PEI coated) via electrostatic interaction, while lysozyme shows greater affinity towards hydrophobic surfaces (ODA coated) via largely hydrophobic interactions. The thickness (12–60 nm) and roughness of the films (1.30–3.75 nm) could be tuned by varying the amount of the adsorbed proteins on the amine-coated surfaces. This simple route to prepare silica films of controlled thickness could have potential application in membrane fabrication, biomedical devices, biosensors and next generation electronic components.     

Characterization of large area filtered arc deposition technology: part II — coating properties and applications

A dual-filtered cathodic arc deposition process was used to synthesize a variety of hard coatings on polished substrates, using large-area filtered-arc deposition (LAFAD) technology. The surface morphology showed that the coatings were free of macro defects or inclusions, and there was no degradation of the initial surface finish. Mechanical properties of the coatings deposited were measured by a nanoindentation technique. A duplex (heat treatment+deposition) process was used to deposit a unique multilayer hard coating on H-13 steel core pins used in aluminum die-casting application. Extensive characterization of the coated pins showed that the coating improved the erosion/corrosion resistance, as well as thermal cracking resistance, of the steel by nearly one order of magnitude over commercially used PVD coatings.     

An efficient cutset approach for evaluating communication-network reliability with heterogeneous link-capacities

This paper presents an efficient cutset approach to compute the reliability of a large communication network having heterogeneous link capacities. The reliability measure has been defined as capacity related reliability (CRR). The proposed method, subset cut technique (SCT), requires the cutset information of the network. For each minimal cut C/sub i/, and a given minimum bandwidth requirement W/sub min/, the method enumerates all nonredundant subset cut (SC), where each SC relates link capacities & minimum bandwidth requirements. Note that if all links in an SC fail, the capacity of the induced cut C/sub i/ will be less than W/sub min/. Given the failure probability of each link, and the nonredundant SC, any Boolean technique for generating mutually disjoint terms can be utilized to obtain a capacity related unreliability (CRU) of the network. Thus, the CRU for an (s,t) node pair is the probability that the network has a capacity of less than W/sub min/ for the given node pair. Note that CRR=1-CRU. Two SCT algorithms are proposed: Algorithm-1, and Algorithm-2; and the suitability of using either algorithm is also discussed. Examples are given to illustrate the techniques. The time complexity, and the proof of correctness for the proposed algorithms are also included. It is shown empirically that the time complexity of generating the nonredundant SC of a network is polynomial in the order of the number of cuts of the network. The proposed SCT algorithms have been implemented in C. We have utilized the SCT to generate the CRR of some large communication networks with various W/sub min/ values.     

Modeling of permeate flux of synthetic fruit juice and mosambi juice (Citrus sinensis (L.) Osbeck) in stirred continuous ultrafiltration

Ultrafiltration studies of synthetic sucrose and pectin mixture and enzymatically treated mosambi juice have been performed in a stirred continuous cell. A model based on gel layer theory is developed to predict the flux decline during filtration for both synthetic and actual juice. From the steady state flux data, the mass transfer coefficient is observed to vary with operating pressure only and a modified Sherwood number relationship is proposed for such a system. The permeate of the filtered juice contains almost all the nutritional values of the original juice with significant improvement in clarity.     

Interaction of fomblin® lubricant with surface nitrided and/or coated bearing (M50) steel

High‐temperature perfluoropolalkylether lubricants including Fomblin^® are susceptible to degradation and cause corrosion in the presence of ferrous metals such as M50 bearing steel. This paper describes the effect of surface treatment (nitriding), coating chemistry and architecture in preventing corrosion/oxidation of M50 steel and thermo‐oxidative degradation of Fomblin^® fluid. Specifically, Cr‐CrN multilayered coating architecture was used with and without a nitrided steel surface. The oxidation/corrosion tests were conducted by immersing the nitrided and/or coated M50 coupons in Fomblin^® fluid in an oxidative environment at 270°C for 24 h and compared with untreated/uncoated coupons. It is shown that a considerable lessening of the corrosion of the steel and degradation of the Fomblin^® fluid can be achieved by nitriding alone. Nitriding in combination with the multilayered Cr‐CrN coating exhibited the best protection. The results are discussed in relation to the literature data. Copyright © 2009 John Wiley and Sons, Ltd.