DETERMINATION OF INERTIAL EFFICIENCIES AND DUST FREE ZONES OF ELECTRICALLY ENHANCED COLLECTORS

ABSTRACT

The determination of particle trajectories when electrostatic forces are present is an important part of analyzing collection efficiency. For small Stokes numbers, an asymptotic expansion of the Fuchs trajectory equation yields a first order differential equation which depends only on spacial variables. Using this equation, trajectories of particles about collectors with an axis of symmetry parallel to the direction of air flow can then be determined by a single numericalintegration. The geometry of the direction field of this equation is analyzed to numerically determine the limiting trajectories which, in turn, yield the efficiency. The same kind of analysis of the saddle points of this direction field in combination with numerical integration can be used to determine those solution paths which bound the dust free zones about the collector.

These ideas are demonstrated by applications to the case of a spherical collector on which there is an electrostatic charge and which is subject to an external electrical field.     

Tooling constraints and shop floor scheduling: evaluating the impact of sequence dependency

In a previous study, we began the process of examining how finite tooling resources affect the operation of a simulated job shop. The paper extends this line of research by focusing on the problem of how to schedule a shop operating with both finite machine and tooling resources, and faced by varying levels of tooling-related sequence dependency in the setups. Four tool assignment rules and two dispatching procedures are evaluated. Findings show the importance of using tool assignment rules which consider not only tool-related information such as tool availability but also the priority of the jobs waiting to be processed. Specifically, as the level of sequence dependence increases and the availability of tooling decreases, the performance of the shop is greatly influenced by the tool assignment rule used to manage the flow of tooling to and from work centres     

On converting a dual graph into a block layout

One of the difficulties associated with the application of graph theory to the facilities layout problem is the conversion of the dual graph into a block layout. This paper presents a procedure to address this problem. The procedure exploits the similarities between the graph-theoretic approach and computerized layout-construction procedures, and also resolves some of their differences. It considers the faces of the dual graph one by one and places them in the block layout adjacent to each other in a manner consistent with the adjacencies specified by the dual graph, The procedure is independent.of the manner the maximal planar weighted graph is developed.     

Characteristics of California Navel Orange Juice and Pulpwasn

California navel orange juice, two-stage pulpwash and concentrated orange juice obtained from a commercial processing plant during the 1979–80 processing season were analyzed by chemical, physical and microbiological methods. Statistically significant differences (P < 0.01) were found between single-strength orange juice and pulpwash in the concentration of nitrate, sulfate, phenolics, carbohydrates, protein, pectin, UV/VIS absorption characteristics, minerals and carotenes. Seasonal variations were found in carbohydrates, organic acids, minerals, microbiological data, UV/VIS absorption characteristics, carotenoids, protein and phenolics. This report outlines methods of analysis, summarizes analytical results and discusses application of these findings to the detection of pulpwash adulteration of orange juice.     

需求低迷,模拟IC价格面临压力 --预计平均价格将保持下降趋势,直至2006年上半年

iSuppli公司日前对模拟IC市场的价格发展趋势进行了分析。     

Food Waste Management and Value-added Products

ABSTRACT: Optimization of thermal treatments has been proven to enhance the quality of food products, especially when operated together with a validation method that confirms the safety of the processing operations. Recent developments in the understanding and application of pasteurization treatments have allowed this area to grow at a rapid rate. UK and European consumers now have a wide variety of high-quality pasteurized foods to choose from in the retail and catering markets. Food producers have used this to their advantage by converting processing operations from severe treatments such as sterilization to milder ones that can be categorized under the pasteurization umbrella. This has increased food product quality and added value to existing products. Two examples will be given, both of which utilized a novel validation method based on time-temperature integrators to provide process safety data that were difficult to obtain by alternative methods. The first was in applying a novel processing technology, ohmic heating, to produce higher-quality fruit products when compared with traditional processing methods. The second was in the production of high-quality sous vide ready meals supplied chilled or frozen to the catering sector. These developments in technology and validation have been made possible by work at CCFRA that has taken the pasteurized foods sector forward. CCFRA has been active in pasteurization research for many years and has produced industry guideline documents on, for example, pasteurization treatments and sous vide processing. Microbiological research on the growth and death of target microorganisms has been linked with processing, hygiene, and validation research, which provided the underpinning science for these guidelines. Food manufacturers work closely with CCFRA to apply their pasteurization processes in order to produce high-quality value-added products.     

A simple and rapid antibody-capture ELISA for the detection of staphylococcal enterotoxin A in food including a simple extraction step

A sensitive and precise ELISA for the detection of staphylococcal enterotoxin A in food has been developed, using specific IgG anti-toxin antibodies purified from immunized rabbits. an antibody capture format was found to be the most useful following cross-reaction and sensitivity studies. the ELISA was used to investigate concentration of staphylococcal enterotoxin A from food samples by polyethylene glycol dialysis. the procedure was shown to be inefficient and highly variable, as well as time-consuming. Direct analysis of aqueous food extracts without a concentration step was found to be possible. With an assay time of 140 min, the ELISA detection limit was 12.5 pg of toxin (corresponding to a sensitivity of 0.5 ngg^-1 of food sample.     

Non-Invasive Determination of Freezing Effects in Blueberry Fruit Tissue by Magnetic Resonance Imaging

Water and sugar distribution in a single blueberry were mapped both before and after freeze/thaw using magnetic resonance imaging. Images were obtained using a slice selective spin echo pulse sequence which included a T₁ inversion recovery time period, allowing selection of either the water signal or the sugar signal. Freeze/thaw results in the rupture of water retaining membranes within discrete locations of the fruit tissue. This causes a change in the ratio of motion modified water (i.e., hydrogen bonded or chemically exchanged) to unmodified (i.e. mobile and not chemically exchanged) in those regions, as well as a concomitant change in sugar concentration, due to diffusion to other tissues.     

The Theory of Diffusional Phase Transformations and Microstructure

As an aid in the understanding of the development of microstructural features, the theories of diffusional phase transformations are reviewed with emphasis on the problems associated with precipitate growth from supersaturated solid solution. This paper is mainly concerned with those basic thermodynamic and kinetic aspects of transforming systems that influence the size and shape of precipitates. Grain boundary precipitation, Widmanstätten precipitation, and two-phase cooperative growth are considered, and the roles played in each by volume and interface diffusion, and by interface properties, are discussed.     

Flavor Modification by Sodium Chloride and Monosodium Glutamate

Five concentrations of sodium chloride or monosodium glutamate were added to pure taste or flavor substances. The five mixtures were ranked for pure taste or flavor intensity. No true potentiation was found. Suprathreshold sodium chloride or monosodium glutamate additions generally suppressed pure tastes and flavors. The extent of suppression depended upon the pure taste or flavor present. This differential sup pression may result in apparent potentiation in more complex mixtures (e.g., three or more components) due to an apparent (relative) increase in intensity of less-suppressed flavor components. Apparent potentiation may also be due to addition of flavor components of sodium chloride and monosodium glutamate.