High purity pion beam at TRIUMF

An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay π⁺→e⁺ν is also described.     

An economical cognitive approach for bi-objective optimization using bliss points, visualization, and interaction

When an optimization problem encompasses multiple objectives, it is usually difficult to define a single optimal solution. The decision maker plays an important role when choosing the final single decision. Pareto-based evolutionary multiobjective optimization (EMO) methods are very informative for the decision making process since they provide the decision maker with a set of efficient solutions to choose from. Despite that the set of efficient solutions may not be the global efficient set, we show in this paper that the set can still be informative when used in an interactive session with the decision maker. We use a combination of EMO and single objective optimization methods to guide the decision maker in interactive sessions.     

Finite-Element Analysis of Hot Mix Asphalt Microstructure Using Effective Local Material Properties and Strain Gradient Elasticity

This paper presents the development of a methodology for microstructure analysis and modeling of hot mix asphalt (HMA). This methodology relies on using effective local material properties and strain gradient theory in the finite element analysis of HMA microstructure. The effective local properties are calculated using an analytical micromechanical model that captures the influence of percent of particles on the microscopic response of HMA. Strain gradient elasticity is used in order to account for the effect of particle size in the finite element analysis. The autocorrelation function and the moving window technique are used to determine the microstructure characteristic length scales that are used in strain gradient elasticity. A number of asphalt mixes with different aggregate types and size distributions are analyzed in this paper.     

Structure-Property Relationships in Dual-Phase Cu-Al Alloys: Part I . Individual Phases

Dual-phase (α + martensite) microstructures were produced in binary Cu-Al alloys by quenching from the (α + β) phase field. A wide range of martensite volume fraction V_M was obtained, depending on alloy composition and quench temperatureT. Linear dependence onT of V_M was established. Predefined values for V_M can thus be achieved by adjustment ofT and alloy composition. Furthermore, the size, shape, and distribution of component phases can be varied in a predetermined fashion by means of controlled cooling from the β range. The properties of α and martensite were tracedvia microhardness measurements. The microhardness of martensite increases with quench temperature in spite of the accompanying decrease of its solute content. This is in accord with previous work and emphasizes the dominating role of martensite ordered structure on strength. Such strength depends only on quench temperature irrespective of overall alloy composition or morphology. The α microhardness is not affected by alloy composition or quench temperature. The martensitic phase can be hardened by means of short time tempering due to order hardening or solute clustering effects. Depending on quench temperature, optimum use of such temper hardening can be achieved. Moreover, cold working of dual-phase structures followed by annealing at temperatures around 300 °C achieves substantial strengthening of both α and martensite. The strengthening of α is a consequence of anneal hardening. Although such high strength levels are accompanied by reduction of the ductility (as measured by thickness reduction achieved by cold rolling), the heat treatment schedule can be optimalized to achieve high strength while restoring ductility.     

Design optimisation of a solar-energy harnessing system for stimulating an irrigation pump

Water from below ground level is to be raised, for the irrigation of a desert area near Cairo, Egypt, by harnessing solar power. The solar-energy collector is an array of gravity-return heat pipes, each surrounded by a cylindrical high-vacuum enclosure. The prime mover, in the form of a multi-vane expander, operates in an organic Rankine-cycle using trichlorotrifluoroethane as the working fluid. For specified conditions, the performances and optimal output temperatures of the collector (so that maximum overall efficiency of the system can be achieved) are predicted.     

Studies of heterocyclic polymers. V. poly (1, 3′-benzobis (iminopyrrolenones))

The synthesis of dimethyl-2, 5-dicyanoterephthalate from 2,5-dibromo-p-xylene and its conversion to 1,3′-benzobis (iminopyrrolenone) are reported. 1,3 -Benzobis (N-phenyliminopyrrolenone) was prepared by reaction of 1,3′-benzobis (iminopyrrolenone) with aniline. The product was a bright yellow crystalline solid which was also formed when dimethyl-2,5-dicyanoterephthalate was condensed with aniline under suitable conditions. Poly (1,3′-benzobis (iminopyrrolenones)) were synthesised by the condensation of 1,3′ -benzobis (iminopyrrolenone) with aromatic diamines and with 1,6-diaminohexane at high temperatures in dimethyl sulphoxide. The degrees of polymerisation of the polymers obtained were low, as judged by the completeness of the condensation reaction. Thermogravimetric analyses of these polymers in air showed that they have 10% weight-loss temperatures in the range 420 to 520°C, for the polymers prepared from aromatic diamines, and of 350°C for the polymer derived from 1,6-diaminohexane. The insoluble, intractable nature of these polymers precluded a thorough study of their structure.     

Structure-Property Relationships in Dual-Phase Cu-Al Alloys: Part II. Alloy Behavior

The mechanical behavior of dual-phase Cu-Al alloys was investigated and properties were correlated to the relevant parameters: martensite volume fraction, martensite strength, and dual-phase morphology. The yield strength is markedly influenced by all parameters, being an increasing function of both martensite fraction and strength. With respect to component phases it is established that such function does not follow the law of mixtures. On the other hand, ultimate tensile strength exhibits linear dependence on volume fraction of martensite. On comparing theory with experiment, good agreement was established between true uniform strains calculated according to Mileiko's theory of composites and experimental results. High ductility levels are reachable over a rather broad range of martensite volume fraction. Depending on quench temperature, enhancement of ductility occursvia stress-induced phase transformation of martensite to fcc structure. Macrohardness measurements carried out on dual-phase structures showed linear dependence on martensite volume fraction. The data indicate that macrohardness could be predictedvia linear combination of microhardness of component phases and their volume fractions. Strengthening of dual-phase alloys could be achieved, at practically no loss of ductility, by means of short time annealing. Moreover, remarkable strengthening is attainablevia combinations of cold work and annealing while maintaining useful levels of ductility.     

Portfolio and investment risk analysis on global grids

The financial services industry today produces and consumes huge amounts of data and the processes involved in analysing these data have large and complex resource requirements. The need to analyse the data using such processes and get meaningful results in time, can be met only up to a certain extent by current computer systems. Most service providers attempt to increase efficiency and quality of their service offerings by stacking up more hardware and employing better algorithms for data processing. However, there is a limit to the gains achieved by using such an approach. One viable alternative would be to use emerging technologies such as the Grid. Grid computing and its application to various domains have been actively studied by many groups for more than a decade now. In this paper we explore the use of the Grid in the financial services domain; an area which we believe has not been adequately looked into.     

Secure and robust multipath routings for advanced metering infrastructure

A Smart Grid is the modernization of the electricity grid using communication technology with the prime goals of reducing energy consumption as well as cost increasing reliability and creating new services for all participants. It comprises key components such as the Advanced Metering Infrastructure (AMI), which includes Neighborhood area network (NAN). When multi-hopping is considered in wireless communication, especially in WiFi and ZigBee, the range of the communication can be extended to communicate with the gateway collector in AMI network. Wireless mesh AMI network may have smart meters, a NAN gateway, and fixed as well as mobile repeaters. Though many techniques have been developed to secure on-demand routing protocols in wireless multi-hop ad-hoc networks, these protocols have shortcomings. In this paper, we propose two robust and secure multipath routing protocols for wireless mesh AMI networks. We have analyzed their robustness to various attacks. The simulation results show that the proposed protocols are better than existing secure routing protocols.     

Composite Nanoarchitectonics with Polythiophene,MWCNTs-G,CuO and Chitosan as a Voltammetric Sensor for Detection of Cd(II) Ions

Journal of Inorganic and Organometallic Polymers and Materials - In this study, we describe an electrochemical method for detecting Cd(II) ions, utilizing a glassy carbon electrode (GCE) modified...