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.     

A survey of dynamic bandwidth allocation algorithms for Ethernet Passive Optical Networks

Ethernet Passive Optical Network (EPON) has been widely considered as a promising technology for implementing the FTTx solutions to the “last mile” bandwidth bottleneck problem. Bandwidth allocation is one of the critical issues in the design of EPON systems. In an EPON system, multiple optical network units (ONUs) share a common upstream channel for data transmission. To efficiently utilize the limited bandwidth of the upstream channel, an EPON system must dynamically allocate the upstream bandwidth among multiple ONUs based on the instantaneous bandwidth demands and quality of service requirements of end users. This paper introduces the fundamental concepts on EPONs, discusses the major issues related to bandwidth allocation in EPON systems, and presents a survey of the state-of-the-art dynamic bandwidth allocation (DBA) algorithms for EPONs.     

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...     

Effects of forage level and canola seed supplementation on site and extent of digestion of organic matter, carbohydrates, and energy by steers

The objective of this study was to determine the effects of fat supplementation from canola seed (CS) on ruminal fermentation and postruminal digestion of OM, carbohydrates, and energy of diets containing different levels of forage. Six ruminally and duodenally cannulated beef steers (354 kg +/- 18) were given ad libitum access to six isonitrogenous diets that were offered twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage levels (70 vs 30% of dietary DM as corn silage) and three forms of CS supplementation including no CS or CS added at 10% of dietary DM as whole CS treated with alkaline hydrogen peroxide or untreated crushed CS. Fat from CS provided 5% of dietary DM. The remaining dietary ingredients were corn, canola meal, molasses, and urea. No interactions (P > .05) between dietary forage level and CS supplementation were observed for ruminal characteristics or digestion of OM, carbohydrates, and energy in the rumen, postruminally, or in the total tract. Fat supplementation from CS did not affect (P > .05) DMI. With few exceptions, fat supplementation did not affect (P > .05) ruminal, postruminal, or total tract digestibilities of OM, structural and nonstructural carbohydrates, and GE. Ruminal disappearance of GE was decreased (P < .05) when diets were supplemented with fat from whole treated CS, and total tract digestibilities of OM and GE were decreased (P < .05) when diets were supplemented with fat from CS in either form. Ruminal pH, concentrations of NH3 N and total VFA, and molar proportions of acetate, propionate, and butyrate were not affected (P > .05) by fat supplementation. Results suggest that fat supplementation from CS (at 5% of dietary DM) as whole treated or untreated crushed had no negative effects on ruminal fermentation of OM, carbohydrates, or energy when steers were given ad libitum access to diets containing high or low forage.     

STABILITY AND RHEOLOGY OF HEAVY CRUDE OIL-IN-WATER EMULSION STABILIZED BY AN ANIONIC- NONIONIC SURFACTANT MIXTURE

The stability and rheology of an Egyptian Heavy crude oil-in-water emulsions stabilized by an anionic (TDS) and a nonionic (NPE) surfactants individually or in a mixture have been studied. The study reveals that, the viscosity of the crude oil decreases when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration and speed of mixing of the emulsion increases. Fresh water and synthetic formation water have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in synthetic formation water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing fresh water is always less than that containing formation water, these findings have been correlated with the crude oil/water interracial tension (IFT) measurements The decreased IFT value results in a decrease in the average particle size of the dispersed crude oil leading