Mixing mechanism of three‐tip kneading block in twin screw extruders

In recent years, twin screw extruders have been applied to various kinds of polymer processing. It has been important to find their optimum geometrical configurations and operational processing conditions for the best performance of extrusions and products. Many engineers have been evolving numerical and the experimental methods to characterize the mixing performance for twin screw extruders. We have carried out three‐dimensional flow simulations of kneading blocks in intermeshing co‐rotating twin screw extruders by using the finite element method to quantify their ability in distributive and dispersive mixing. We discuss their performance in distributive mixing for three different type of kneading blocks in terms of the residence time distribution and the nearest distance between markers at various periods of time, by using the marker tracking method. Those numerical techniques and applications of mixing indices have enabled us to quantify and evaluate their abilities in distributive mixing of kneading blocks in twin screw extruders.     

Effect of the reaction bath temperature in a fixed-bed reactor for oxidation of oxylene over V2O5/TiO2 catalysts

The effects of the reaction variables in the operation of a fixed-bed reactor for oxidation ofo-xylene over V₂O₅/TiO₂ catalysts were studied experimentally using a bench reactor. Reaction temperature, feed flow rate and feed concentration ofo-xylene were found to have significant effects on the product distribution and the temperature profile in the reactor. Drastic enhancements ofo-xylene oxidation reaction were observed at some conditions, which was ascribed to the effect of heat accumulated in the bed and indicated a possible way to increase the productivity in the industrial condition. This paper was presented at the 8th APCChE (Asia Pacific Confederation of Chemical Engineering) Congress held at Seoul between August 16 and 19, 1999.     

Document image-processing system for name and address recognition

This article describes a real-time document image processing system. Its objective is to recognize names and addresses from scanned address block images extracted from various tax forms of the United States Internal Revenue Service. The Name and Address Block Reader (NABR) system accepts both machine- and hand-printed address block images as input. Salient aspects of the system are presented, including document analysis (connected component analysis, address block extraction, label detection, hand-print/machine-print discrimination) and document recognition. Document recognition is performed in two nonidentical streams for machine-and hand-print; key steps are address parsing, character recognition, word recognition, and postal data base lookup (ZIP+4 and city-state-ZIP files). System output is a packet containing the results of recognition together with data base access status file. Real-time throughput (8500 forms/h) is achieved by employing a loosely coupled multiprocessing architecture where successive input images are distributed to available address recognition processors. The functional architecture, software design, system architecture, and the hardware implementation are described. Performance evaluation on machine- and hand-written addresses are presented. © 1996 John Wiley & Sons, Inc.     

A hybrid actuator scheme for robust position control of a flexible single-link manipulator

This article presents a novel hybrid actuator scheme to actively and robustly control the endpoint position of a very flexible single-link manipulator. The control scheme consists of two actuators; a motor mounted at the beam hub and a piezoceramic bonded to the surface of the flexible link. The control torque of the motor, which produces a desired angular motion, is determined by employing the sliding mode control theory on the equation of motion of the rigid link having the same mass as that of the proposed flexible link. The torque is then applied to the flexible manipulator to activate the commanded motion. During the motion, the undesirable oscillation caused by the torque, based on the rigid link dynamics, is actively suppressed by applying a feedback control voltage to the piezoceramic actuator. Consequently, desired tip motion is achieved. Both regulating and tracking control responses are analyzed through experimental implementation to demonstrate high performance characteristics to be accrued from the proposed methodology. © 1996 John Wiley & Sons, Inc.     

Rapid and sensitive detection of Salmonella Typhimurium on eggshells by using wireless biosensors

This article presents rapid, sensitive, direct detection of Salmonella Typhimurium on eggshells by using wireless magnetoelastic (ME) biosensors. The biosensor consists of a freestanding, strip-shaped ME resonator as the signal transducer and the E2 phage as the biomolecular recognition element that selectively binds with Salmonella Typhimurium. This ME biosensor is a type of mass-sensitive biosensor that can be wirelessly actuated into mechanical resonance by an externally applied timevarying magnetic field. When the biosensor binds with Salmonella Typhimurium, the mass of the sensor increases, resulting in a decrease in the sensor's resonant frequency. Multiple E2 phage-coated biosensors (measurement sensors) were placed on eggshells spiked with Salmonella Typhimurium of various concentrations (1.6 to 1.6 × 10(7) CFU/cm(2)). Control sensors without phage were also used to compensate for environmental effects and nonspecific binding. After 20 min in a humidity-controlled chamber (95%) to allow binding of the bacteria to the sensors to occur, the resonant frequency of the sensors was wirelessly measured and compared with their initial resonant frequency. The resonant frequency change of the measurement sensors was found to be statistically different from that of the control sensors down to 1.6 × 10(2) CFU/cm(2), the detection limit for this work. In addition, scanning electron microscopy imaging verified that the measured resonant frequency changes were directly related to the number of bound cells on the sensor surface. The total assay time of the presented methodology was approximately 30 min, facilitating rapid detection of Salmonella Typhimurium without any preceding sampling procedures.     

Effects of Bi2O3 and Na2O on the Thermal and Dielectric Properties of Zinc Borosilicate Glass for Plasma Display Panels

An approach to select appropriate network modifiers to tailor the thermal and dielectric properties of zinc borosilicate (ZBS) glass has been explored to apply the glass composition to a dielectric layer of plasma display panels. Based on ionic field strength of the modifiers and the ionic polarizability of the corresponding crystalline form, Bi₂O₃ and Na₂O modifiers have been selected to modify the thermal and dielectric properties of the glass toward the required properties for the application (440< T _g<460°C, 7.5 × 10⁻⁶−6/K, and 10< K <15). Bi₂O₃ addition to ZBS could meet all the required properties simultaneously at a given addition range (8.5–14 mol%), while the addition of Na₂O could not meet all the properties at a single composition range.     

Sn self-doped α-Fe2O3 nanobranch arrays supported on a transparent,conductive SnO2 trunk to improve photoelectrochemical water oxidation

We produced hierarchically branched Fe₂O₃ nanorods on a Sb:SnO₂ transparent conducting oxide (TCO) nanobelt structure as photoanodes for photoelectrochemical water splitting. Single-crystalline SnO₂ nanobelts (NBs) surrounded by Fe₂O₃ nanorods (NRs) were synthesized by thermal evaporation, then underwent chemical bath deposition and annealing. When Fe₂O₃ was crystallized by annealing, Sn was diffused from SnO₂ NBs and incorporated to Fe₂O₃ NRs, which was confirmed through Energy dispersive spectroscopy. Unlike previous high temperature sintering (∼800 °C), Sn doped hematite NRs were obtained at a low temperature (∼650 °C). This occurred since SnO₂ NBs directly connected to Fe₂O₃ NRs are an abundant source of Sn dopant. The 3D hematite NRs on SnO₂ NBs annealed at 650 °C produce a photocurrent density of 0.88 mA/cm² at 1.23 V vs. RHE, which is 3 times higher than that of hematite NRs on a fluorine doped tin oxide (FTO) glass substrate annealed at the same temperature. The enhanced photocurrent is attributed to the improved electrical conductivity of Fe₂O₃ NRs by Sn doping, the efficient electron transport pathway by TCO nanowire and the increased surface area by hierarchically branched structure.     

Combined effects of Diospyros lotus leaf and grape stalk extract in high-fat-diet-induced obesity in mice

Food Science and Biotechnology - The aim of this study was to investigate the combined effects of Diospyros lotus leaves extracts (DLE) and Muscat Bailey A grape stalk extracts (MGSE) in obesity...     

Development of a freshness indicator for monitoring the quality of beef during storage

Food Science and Biotechnology - Quality of beef and detect changes in freshness during storage was evaluated using freshness indicator. The freshness indicator can indicate spoilage or freshness...     

Generalizing Hamming+k data hiding by overlapped pixels

Multimedia Tools and Applications - Matrix coding based data hiding (MCDH) using linear codes (syndrome coding) is an efficient coding method for steganographic schemes to improve their embedding...