Exchange-correlation errors at harmonic and anharmonic orders: the case of bulk Cu

As an aid towards improving the treatment of exchange and correlation effects in electronic structure calculations, it is desirable to have a clear picture of the errors introduced by currently popular approximate exchange-correlation functionals. We have performed ab initio density functional theory and density functional perturbation theory calculations to investigate the thermal properties of bulk Cu, using both the local density approximation (LDA) and the generalized gradient approximation (GGA). Thermal effects are treated within the quasiharmonic approximation. We find that the LDA and GGA errors for anharmonic quantities are an order of magnitude smaller than for harmonic quantities; we argue that this might be a general feature. We also obtain much closer agreement with experiment than earlier, more approximate calculations.     

Factors influencing feature usage in work-related communication

Two studies are presented. The first aimed to identify possible barriers to the uptake and use of commonly available telephony features and to determine whether greater knowledge of features/access codes and availability of user manuals could increase feature usage under certain conditions. Results showed that feature-usage patterns were not affected by any of the manipulations, but that they were determined by specific job demands. Using Constantine and Lockwood's (1999) conceptualization of user roles, a method to support feature bundling decisions for specific target markets was developed and tested in the second study. The method - Strategic User Needs Analysis (SUNA) - was shown to yield a useful balance between high- and low-level information about selected roles. SUNA provided sufficient information to distinguish between PDA feature usage patterns of two similar target user groups as well as to suggest additional features each of the two target groups would find useful. The development of SUNA and observational findings of actual PDA usage are reported.     

‘More power’ call sparks soft compact research

The 42-volt electrical system is to be introduced in automobiles to provide the extra power needed for various electromagnetic devices. This offers an opportunity for insulated iron powder to replace lamination steel in a variety of motors. Brushless motor design can probably benefit most from insulated iron powder compacts because of the design simplicity of powder metal parts and three-dimensional flux capability that is most beneficial in rotating devices says Sim Narasimhan…     

The MITRE E3 family of models structure and results

A family of energy/economic/environmental (E³) models is presented as a mechanism for analysing national policy issues. The family consists of discrete models which are designed to be run in an integrated manner. The outputs of certain models provide the inputs to the next. This structure allows the analyst to readily incorporate an understanding of regional factors such as local energy prices, concerns over air quality, water availability, or attitudes towards construction of new energy facilities, into national assessments of energy policies. This paper reviews the analytic framework within which energy policy issues are currently addressed. The initial family of E³ models is described with the emphasis on the data linkages and feedback which are provided when these models are run sequentially. The ongoing MITRE research programme with the E³ family of models is presented and plans and opportunities for future work are outlined.     

Model-Based Diagnosis of Hybrid Systems

Techniques for diagnosing faults in hybrid systems that combine digital (discrete) supervisory controllers with analog (continuous) plants need to be different from those used for discrete or continuous systems. This paper presents a methodology for online tracking and diagnosis of hybrid systems. We demonstrate the effectiveness of the approach with experiments conducted on the fuel-transfer system of fighter aircraft     

Potent and selective bicyclic lactam inhibitors of thrombin: Part 2: P1 modifications

The synthesis and antithrombotic activity of a series of nonpeptide bicyclic thrombin inhibitors is described. We have explored the SAR with modifications to the P1 site. The introduction of arginine mimetics at the P1 site led to potent and selective thrombin inhibitors.     

An investigation of the ordered DO19 phase formation in the Ti-Al system

For the Ti-rich, Ti-AI system, the- and- ₂ phase boundaries have been obtained through differential thermal analysis for alloy compositions ranging from 10.2 to 25.2 at% Al (6 to 16 wt% Al). It has been shown that in the above mentioned composition range, a metastable disordered-phase can be quenched in. This metastable then transforms to the ordered ₂(DO)₁₉ phase upon heating and/or isothermal ageing. It has also been observed that the kinetics of this ordering phenomenon is composition dependent.     

Physical properties of natural and modified cotton cellulose grafted with acrylate monomers

Natural, cyanoethylated, and formaldehyde-crosslinked cotton cellulose has been grafted with methyl, ethyl, and n-butyl acrylate and methyl methacrylate monomers. Various physical properties such as density, moisture regain, birefringence, and mechanical properties were studied. The results indicate that the density and moisture regain of the grafted fibers are less than those of natural cotton. The birefringence of grafted fibers is also less than that of natural cotton. The variation in birefringence with percent graft-on depends on the monomer. Parameters such as orientation factor, helix angle, and refractive power of fibers were calculated from the birefringence data and the results discussed. It was observed that due to grafting of both natural and crosslinked cotton, there is a decrease in tensile strength, increase in elongation at break, and decrease in the initial modulus. Attempts are made to understand these changes in the properties of cotton in terms of the changes occurring in the fine structure of the fiber.     

Practical and scalable evolution of digital circuits

This paper addresses the scalability problem prevalent in the evolutionary design of digital circuits and shows that Evolvable Hardware (EHW) can indeed be considered as a viable alternative design methodology for large and complex circuits. Despite the effort by the EHW community to overcome the scalability problems using both direct mapped techniques and developmental approaches, so far only small circuits have been evolved. This paper shows that, by partitioning a digital circuit and making use of a modular developmental approach, namely, the Modular Developmental Cartesian Genetic Programming (MDCGP) technique, it is indeed possible to evolve large circuits. As a proof of concept, a 5 × 5 multiplier is evolved for partition sizes of 32 and 64. It is shown that compared to the direct evolution technique, the MDCGP technique provides five times reduction in terms of evolution times, 6–56% reduction in area and improved fault tolerance. The technique is readily scalable and can be applied to even larger partition sizes, and also to sequential circuits, thus providing a promising path to evolve large and complex circuits.     

Removal of Cr(VI) using co-immobilized activated carbon and <Emphasis Type="Italic">Bacillus subtilis</Emphasis>: fixed-bed column study

Fixed-bed column studies were conducted to evaluate the potential of co-immobilized (activated carbon and Bacillus subtilis) (CI) beads for the removal of Cr(VI) from aqueous solution. The impact of various parameters such as initial Cr(VI) concentrations (100, 150, and 200 mg/L), flow rate (3, 9, and 15 mL/min), and bed depth (10, 15, and 20 cm) on Cr(VI) adsorption onto CI beads were investigated. The breakthrough time increased with a decrease in initial Cr(VI) concentration and flow rate, and an increase in bed height. The breakthrough data obtained for Cr(VI) removal was more adequately described by the Thomas model with high correlation coefficients (R ² = 0.982). The eluent, 0.1 M NaOH, provided high elution efficiencies (~90 %) in all the six cycles. Obtained results pointed out that CI beads could potentially be used for the removal of Cr(VI) from aqueous solution.