Numerical Simulation and Validation of Ozone Concentration Profile in Green Gram (Vigna radiate) Bulks

The new fumigant ozone offers an alternative to contact insecticides such as phosphine and methyl bromide as a grain fumigant. This study was carried out to test the flow characteristics of ozone from points of release to the available concentration of ozone to kill pests at other areas along the storage bin. A mass transfer model which predicts ozone concentration as a function of time was applied along with continuity equation to simulate the ozone transfer in a storage bin. Ozone exchange rate based on grain bed thickness was taken into account and evaluated using the correlation developed during the experiment. The relative error between the experimental and predicted ozone concentration values for the entire bin geometry was less than 25.7%. Overall, the general trends of measured ozone concentration were compatible with the simulated ones.     

Effect of imbibed moisture on monotonic and low-velocity impact behavior of injection over-molded short/continuous fiber reinforced polypropylene composites

Design of automotive components with over-molded short/continuous fiber reinforced thermoplastic composites necessitates understanding of their behavior under extreme outdoor conditions. The short, quasi-isotropic and over-molded short/continuous glass fiber reinforced polypropylene (PP) composite specimens were prepared as per standard and immersed in water until equilibration to study their relative moisture absorption characteristics and consequent mechanical behavior. As the absorbed moisture mostly occupied the interface between fiber and matrix in laminated composite inserts and moisture absorption of short fiber composite core is insignificant, the moisture absorption of over-molded composites is just above 50% of that of laminated composites. The flexural, interlaminar shear and impact behavior of equilibrated composites is primarily governed by the quantum of imbibed moisture of composite materials. Optical analysis of failed moisture equilibrated over-molded specimens showed a marginal delamination between plies of the inserts without any perceptible damage within the short fiber composite similar to dry as molded specimens.     

Effect of Fiber Bridging Stress on the Fracture Resistance of Silicon-Carbide-Fiber/Zircon Composites

The room-temperature fracture-resistance behavior ( R -curve) of unidirectional silicon-carbide-fiber-reinforced zircon-matrix composites has been studied experimentally and numerically. The composites showed strong rising R -curve behavior from experimental results that used in situ crack-length measurements taken via optical microscopy as well as the compliance method. A numerical calculation, based on the available models, then was performed to determine the bridging-stress function from the experimental R -curve. In addition, the effect of the residual stress and constituent properties on the bridging-stress function also has been considered in the numerical calculations. These results have indicated that the bridging-stress function, which controls the fracture resistance of ceramic composites, can be obtained from the carefully measured R -curve.     

Continuous cooling deformation testing of steels

In the processing of steel, the design of any kind of heat treatment and/or thermomechanical processing schedule, to obtain a given microstructure, is greatly facilitated by the knowledge of the austenite-to-ferrite transformation characteristics. In the past, isothermal and continuous cooling tests were used in the laboratory to create time-temperature-transformation and continuous cooling transformation diagrams, respectively, which then served as the source of transformation data. The problem with such information is that it is only truly applicable to one particular microstructure, usually one resulting from a simple reheating cycle in the austenite region. Most industrial steel processing operations additionally involve several stages of high-temperature deformation leading to changes in the microstructure emerging from the final pass. To account for this situation, a novel laboratory method for the determination of the transformation characteristics, based on continuous cooling deformation testing, was developed. A major attraction of this test technique is that the specific microstructure, for which the transformation characteristics are required, can be generated by hot deformation and then immediately evaluated by continuous cooling deformation. In this article, the basic continuous cooling deformation test technique and general methods of data analysis are illustrated, using results from several different grades of steel. Formerly with the Department of Mining and Metallurgical Engineering, McGill University     

Dynamic provisioning of availability-constrained optical circuits in the presence of optical node failures

This paper investigates what impact optical node failures may have on wavelength-division-multiplexed networks, in which reliable end-to-end optical circuits are provisioned dynamically. At the node level, the optical cross-connect (OXC) equipment availability measure is estimated using proven component level availability models. At the network level, end-to-end optical circuits are provisioned only when the level of connection availability required by the application can be guaranteed. With the objective of yielding efficient utilization of the network resources, i.e., fibers and OXCs, circuit redundancy is achieved by means of shared path protection (SPP) switching, in combination with differentiated reliability (DiR). The resulting optimal routing and wavelength assignment problem is proven to be NP-complete. To produce suboptimal solutions in polynomial time, a heuristic technique is presented, which makes use of a time-efficient method to estimate the end-to-end circuit availability in the presence of multiple (link and node) failures. Using the proposed heuristic, a selection of representative OXC architectures and optical switching technologies is examined to assess the influence of the node equipment choice on the overall network performance.     

Bacterial foraging optimisation: Nelder?Mead hybrid algorithm for economic load dispatch

A novel stochastic optimisation approach to solve constrained economic load dispatch problem using hybrid bacterial foraging (BF) technique is presented. in order to explore the search space for finding the local minima of the current location, the simplex algorithm called nelder-mead is used along with BF algorithm. the proposed methodology easily takes care of solving non-convex economic dispatch problems along with different constraints such as transmission losses, dynamic operation constraints (ramp rate limits) and prohibited zones. simulations were performed over various standard test systems with different number of generating units and comparisons are performed with other existing relevant approaches. the findings affirmed the robustness and proficiency of proposed methodology over other existing techniques.     

Editorial: Big Data Innovation for Sustainable Cognitive Computing

Mobile Networks and Applications -     

Thermal stress and probability of failure analyses of functionally graded solid oxide fuel cells

Thermal stresses and probability of failure of a functionally graded solid oxide fuel cell (SOFC) are investigated using graded finite elements. Two types of anode-supported SOFCs with different cathode materials are considered: NiO-YSZ/YSZ/LSM and NiO-YSZ/YSZ/GDC-LSCF. Thermal stresses are significantly reduced in a functionally graded SOFC as compared with a conventional layered SOFC when they are subject to spatially uniform and non-uniform temperature loads. Stress discontinuities are observed across the interfaces between the electrodes and the electrolyte for the layered SOFC due to material discontinuity. The total probability of failure is also computed using the Weibull analysis. For the regions of graded electrodes, we considered the gradation of mechanical properties (such as Young’s modulus, the Poisson’s ratio, the thermal expansion coefficient) and Weibull parameters (such as the characteristic strength and the Weibull modulus). A functionally graded SOFC showed the least probability of failure based on the continuum mechanics approach used herein.     

基于AMESim的取样装置动态仿真与试验研究

以新型物料粒度在线检测系统中的取样装置为研究对象,介绍了该装置的结构和工作原理.利用AMESim软件和试验相结合的方法,分析了该装置的速度-负载特性,分析结果表明,该装置性能良好,能够满足取样要求.