The effects of presenting functionally abstracted information in fault diagnosis tasks

With respect to the design of visual information display (VID) for process control, this study experimentally evaluated the effectiveness of functionally abstracted information in the task of fault diagnosis. The benefits of functional properties of work domain have been emphasized by ecological interface design (EID), a relatively new design framework for human–machine interfaces. According to the concept of EID, multilevel information representation based on abstraction hierarchy of work domain is expected to be advantageous for supporting the operator's problem solving. To investigate the advantage of EID application, an experiment was conducted using a computer-based simulation of the secondary cooling system of nuclear power plants. Three interfaces were compared: the first representing only the physical properties of the process, the second representing purpose-related generalized functions (GFs) in addition to the physical properties, and the third representing abstract functions (AFs) governing the GFs in addition to the physical properties. The results showed that the diagnostic performance was improved by displaying functionally abstracted information at both levels, and that the usefulness of the abstract information was dependent on the complexity of the diagnosis problems.     

Factors controlling ammonia loss from trash covered sugarcane fields fertilized with urea

Ammonia losses following surface applications of urea to trash covered sugar cane fields were investigated in four climatic zones of tropical Queensland. Volatilization of ammonia and evaporation of water were determined by micrometeorological techniques. The results showed that the pattern, rate and extent of ammonia loss were controlled by the availability of water in the trash and its evaporation. Water added by dewfall, rainfall or condensation of evaporated soil moisture dissolved some of the urea and allowed it to be hydrolyzed to ammonia by the urease enzyme in the sugarcane residues; when the water evaporated, ammonia was lost to the atmosphere.In the dry climatic zone, where no rain or dew fell, water addition to the trash by condensation of evaporated soil moisture was not sufficient to dissolve much urea so very little ammonia was lost. In the cool and warm moist zones, small additions of water to the trash from dew, light rain and condensation maintained a slow but steady pattern of ammonia loss over a period of six weeks and resulted in losses of 32% and 39% of the applied nitrogen. At the site in the wet zone, heavy rainfall apparently washed the urea from the trash layer into the soil and limited ammonia loss to 17% of the applied nitrogen.Substitution of ammonium sulfate for urea reduced ammonia loss to less than 1.8% of the applied nitrogen.     

Semi‐Empirical Equations for the Residence Time Distributions in Disperse Systems – Part 1: Continuous Phase

Residence time distributions (RTD) are often described on the basis of the dispersion or the tanks in series models, whereby the fitting is not always good. In addition, the underlying ideas of these models only roughly characterize the real existing processes. Two semi‐empirical equations are presented based on characteristic parameters (mean, minimum, maximum residence time) and on an empirical exponent to permit better fitting. The determination of the parameters and their influence on the RTD are discussed. The usefulness of the models is shown in this first part for single‐phase systems and for the continuous phase of multiphase systems using data from literature for laminar and turbulent flows in different apparatuses. A comparison with the results of other models is also done.     

Direct Transfer Printing with Metal Oxide Layers for Fabricating Flexible Nanowire Devices

A direct printing method for fabricating devices by using metal oxide transfer layers instead of conventional transfer media such as polydimethylsiloxane is presented. Metal oxides are not damaged by organic solvents; therefore, electrodes with gaps less than 2 μm can be defined on a metal oxide transfer layer through photolithography. In order to determine a suitable metal oxide for use as transfer layer, the surface energies of various metal oxides are measured, and Au layers deposited on these oxides are transferred onto polyvinylphenol (PVP). To verify the feasibility of our approach, Au source–drain electrodes on transfer layers and Si nanowires (NWs) addressed by the dielectrophoretic (DEP) alignment process are transferred onto rigid and flexible PVP‐coated substrates. Based on transfer test and DEP process, Al₂O₃ is determined to be the best transfer layer. Finally, Si NWs field effect transistors (FETs) are fabricated on a rigid Si substrate and a flexible polyimide film. As the channel length decreases from 3.442 to 1.767 μm, the mobility of FET on the Si substrate increases from 127.61 ± 37.64 to 181.60 ± 23.73 cm² V^?1 s^?1. Furthermore, the flexible Si NWs FETs fabricated through this process show enhanced electrical properties with an increasing number of bending cycles.     

Annealing-induced enhancement of ferromagnetism in SnO2-core/Cu-shell coaxial nanowires

In this study, we have coated tin oxide (SnO₂) nanowires with a Cu shell layer via the sputtering method and subsequently investigated the effects of thermal annealing. The annealing-induced changes in morphologies, microstructures, and compositions of the resulting core-shell nanowires were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and energydispersive X-ray spectroscopy (EDX). The Cu shell layers were agglomerated to form clusters, which were mainly comprised of the Cu₂O phase. For the first time, a hysteresis loop indicating weak ferromagnetism was observed from the pure SnO₂ nanowires. Both the coercivity and the retentivity in the hysteresis loop were slightly increased by Cu-sputtering, indicating a very slight enhancement of ferromagnetism. Also, the ferromagnetic behavior was significantly enhanced by thermal annealing. We discuss the possible mechanisms of annealing-induced enhancement of ferromagnetism in the SiO₂/Cu core-shell nanowires, which include the generation of Cu₂O phase, Cu-doping into the SnO₂ lattice, and the generation of oxygen vacancies in SnO₂ core nanowires.     

A high-frequency annular-array transducer using an interdigital bonded 1-3 composite

This paper reports the design, fabrication, and characterization of a 1-3 composite annular-array transducer. An interdigital bonded (IB) 1-3 composite was prepared using two IB operations on a fine-grain piezoelectric ceramic. The final composite had 19-μm-wide posts separated by 6-μm-wide polymer kerfs. A novel method to remove metal electrodes from polymer portions of the 1-3 composite was established to eliminate the need for patterning and aligning the electrode on the composite to the electrodes on a flexible circuit. Unloaded epoxy was used for both the matching and backing layers and a flexible circuit was used for interconnect. A prototype array was successfully fabricated and tested. The results were in reasonable agreement with those predicted by a circuit-analogous model. The average center frequency estimated from the measured pulse-echo responses of array elements was 33.5 MHz and the -6-dB fractional bandwidth was 57%. The average insertion loss recorded was 14.3 dB, and the maximum crosstalk between the nearest-neighbor elements was less than -37 dB. Images of a wire phantom and excised porcine eye were obtained to show the capabilities of the array for high-frequency ultrasound imaging.