Precombustion Cleaning of Coal By Triboelectric Separation of Minerals

In one method of electrostatic beneficiation, pulverized coal is tribocharged by contact with electrically grounded copper. Coal maceral and mineral particles charge with positive and negative polarities, respectively. The charged particles are passed through a separator consisting of two plate electrodes, across which a high voltage is applied, and the positively charged coal particles are separated from the negatively charged mineral particles. The efficiency of separation is dependent upon coal bulk and surface composition, and fineness of grind. Analyses of total sulfur and ash content of the charge-separated particles were used to evaluate beneficiation success of the Illinois No. 6 and Pittsburgh No. 8 coals studied. Two-stage beneficiation demonstrated improved separation. Exposing coal powders to chemical vapors of SO 2 , NH 3 , or acetone prior to beneficiation did not enhance beneficiation.     

Test-case generation with IOGen

The IOGen static-analysis tool for a subset of Ada addresses part of the problem of verification of software reliability. It uses a technique based on symbolic execution and produces a set of I/O pairs that represent execution paths through a program. The authors present IOGen's design and demonstrate how to use it to test programs and validate Ada software interfaces. Although IOGen is specific to an Ada subset, the same technique can be applied to any language with a grammar that uses a left-to-right scan with one look-ahead token producing a leftmost derivation (an LL(1) grammar)     

Photoelectrochemical characterisation of indium nitride and tin nitride in aqueous solution

Indium nitride (InN) and tin nitride (SnN_x) films were produced with reactive d.c. magnetron sputtering technique. The thin film semiconductors were optically and photoelectrochemically characterised and the energetic positions of the two semiconductors’ band edges were determined with respect to the normal hydrogen electrode. The sputtered InN thin film showed an indirect bandgap of 1.4 eV and a direct bandgap of 1.8 eV. The optical spectra of SnN_x indicated a bandgap energy of approximately 1.4 eV. All nitride films showed n-type photoresponse in KI (aq) electrolyte at an irradiation intensity of 1000 W/m². The photoelectrochemical characterisation indicated that InN and SnN_x with a bias of about 400 mV or less can be used for photo-oxidation of water.     

EVAC: a virtual environment for control of remote imaginginstrumentation

The objective of this project, called the Experimentalist's Virtual Acquisition Console (EVAC), was to demonstrate a prototype system for using virtual environments that would allow a researcher access the hardware in a remote experimental laboratory over high-speed networks, in order to control remote instrumentation. We wanted to give the researcher tools that would not only allow for complete control of the imaging system but also provide the potential for collaboration with researchers at distant sites. We targeted three imaging instruments, all located at the Beckman Institute for Advanced and Technology: a magnetic resonance imaging system, a transmission electron microscope and a scanning tunneling microscope. Our goal was not to control all three instruments simultaneously but rather to demonstrate that our unified virtual environment interface could be adapted to these widely different imaging devices. In building this demonstration, we faced many problems commonly encountered in developing a remote interface to a new instrument. These included the lack of any standard interface to the devices, the necessity of dealing with proprietary software, and the problem of developing a distributed model so that the instruments could be controlled over the network. The EVAC project has illustrated the potential of a virtual laboratory over a high-speed network     

A complete parameterization of all positive rational extensions ofa covariance sequence

In this paper we formalize the observation that filtering and interpolation induce complementary, or “dual,” decompositions of the space of positive real rational functions of degree less than or equal to n. From this basic result about the geometry of the space of positive real functions, we are able to deduce two complementary sets of conclusions about positive rational extensions of a given partial covariance sequence. On the one hand, by viewing a certain fast filtering algorithm as a nonlinear dynamical system defined on this space, we are able to develop estimates on the asymptotic behavior of the Schur parameters (1918) of positive rational extensions. On the other hand we are also able to provide a characterization of all positive rational extensions of a given partial covariance sequence. Indeed, motivated by its application to signal processing, speech processing, and stochastic realization theory, this characterization is in terms of a complete parameterization using familiar objects from systems theory and proves a conjecture made by Georgiou (1983, 1987). Our basic result, however, also enables us to analyze the robustness of this parameterization with respect to variations in the problem data. The methodology employed is a combination of complex analysis, geometry, linear systems, and nonlinear dynamics     

Atomic layer deposition (ALD): A versatile technique for plasmonics and nanobiotechnology

While atomic layer deposition (ALD) has been used for many years as an industrial manufacturing method for microprocessors and displays, this versatile technique is finding increased use in the emerging fields of plasmonics and nanobiotechnology. In particular, ALD coatings can modify metallic surfaces to tune their optical and plasmonic properties, to protect them against unwanted oxidation and contamination, or to create biocompatible surfaces. Furthermore, ALD is unique among thin-film deposition techniques in its ability to meet the processing demands for engineering nanoplasmonic devices, offering conformal deposition of dense and ultra-thin films on high-aspect-ratio nanostructures at temperatures below 100 °C. In this review, we present key features of ALD and describe how it could benefit future applications in plasmonics, nanosciences, and biotechnology.     

The electrochemical oxidation of aqueous sulfur dioxide: A critical review of work with respect to the hybrid sulfur cycle

Literature regarding the mechanism of the electrochemical oxidation of aqueous sulfur dioxide to sulfuric acid has been critically evaluated to provide a detailed understanding of the reaction under various applied conditions. This reaction is of high relevance to the hybrid sulfur cycle for large scale hydrogen production, as well as other industrial applications such as flue gas desulfurisation. Widespread disagreement in the literature and non-reproducible behaviour of the electrochemical oxidation reaction has been found in this review to often be a result of poorly defined electrode preconditioning procedures. It has also been found that the mechanistic pathway of the oxidation reaction is heavily influenced by the electrode material, solution pH and the applied anodic potential. These factors are thought to influence adsorption and the reductive formation of sulfur species at low potentials.     

Eyeblink conditioning during an interstimulus interval switch in rabbits (Oryctolagus cuniculus) using picrotoxin to disrupt cerebellar cortical input to the interpositus nucleus.

The role of the cerebellar cortex in eyeblink classical conditioning remains unclear. Experimental manipulations that disrupt the normal function impair learning to various degrees, and task parameters may be important factors in determining the severity of impairment. This study examined the role of cerebellar cortex in eyeblink conditioning under conditioned stimulus?unconditioned stimulus intervals known to be optimal or nonoptimal for learning. Using infusions of picrotoxin to the interpositus nucleus of the rabbit cerebellum, the authors pharmacologically disrupted input from the cerebellar cortex while training with an interstimulus interval (ISI)-switch procedure. One group of rabbits (Oryctolagus cuniculus) was 1st trained with a 250-ms ISI (optimal) and then switched to a 750-ms ISI (nonoptimal). A 2nd group was trained in the opposite order. The most striking effect was that picrotoxin-treated rabbits initially trained with a 250-ms ISI learned comparably to controls, but those initially trained with a 750-ms ISI were severely impaired. These results suggest that functional input from cerebellar cortex becomes increasingly important for the interpositus nucleus to learn delay eyeblink conditioning as the ISI departs from an optimal interval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensitivities of Band-Edge Selectivities

Many filters have a band-edge selectivity (BES) that is a function of parameters other than filter order. In these cases, the band-edge selectivity can be maximized without increasing the order of the filter. However, in increasing BES, we must keep track of the sensitivity of BES to the parameters. In this paper, we provide sensitivities of BES to filter parameters for a variety of classical filters, these being described by rational functions approximating the ideal filter magnitude response. The results are useful in the design of such filters.