DC static switch circuit with power saving feature

A main switch transistor is provided with a base drive circuit to vary the base drive current in accordance with load current to minimize power dissipation. Base drive may also be limited to a maximum for overload current limiting

Is simultaneous yy and ξ\xi--scaling in the quasi-elastic region accidental?

We study the $y$ and $\xi$--scaling of the nuclear response at large momentum transfer in order to understand how scaling based on very different descriptions of the elementary interaction can occur simultaneously. We find that the approximate validity of $\xi$-scaling at low energy loss arises from the coincidental behavior of the quasielastic and deep inelastic cross sections.Comment: 4 pages, 3 Postscript figure

Fluorescence-based analyser as a rapid tool for determining soluble protein content in dairy ingredients and infant milk formula

peer-reviewedAbstract: Milk protein, in particular native whey protein, is of interest to dairy manufacturers as a measure of functional and nutritional quality. However, quantification of soluble whey protein (SP) is time consuming; giving rise to the need to develop rapid, accurate, and portable at-line process analytical technology. In this study, the performance of a fluorescence-based analyser(F) (Amaltheys II, Spectralys Innovations, France) was evaluated for quantification of SPF and whey protein nitrogen index (WPNI)F in skim milk, whey protein concentrate and infant formula powders. Rehydration of powders prior to analysis was a key factor for ensuring repeatability and reproducibility. A comparison of the analyser with reference methods for SPF and WPNIF resulted in coefficient of determination (R2) > 0.993 for both SPKjeldahl method and WPNIGEA. The results show the fluorescence-based analyser to be rapid, compact, and accurate device, suited for providing reliable support to dairy ingredient and infant formula manufacturers. Industrial relevance: The fluorescence based analysis investigated in this article is suitable for application in the dairy industry where it can be used as a rapid, at-line PAT tool for both liquid and powder samples. The technology has the potential to replace well-established methods for measurement of soluble protein. The main benefit to industry is the ability to respond more rapidly to variations in soluble protein without compromising on the accuracy associated with more time consuming methods

The Application of On-line Sensors and Novel Control Technologies for Food Processing

End of Project ReportThe objective of this research was to apply on-line continuous sensors in food processing, in particular in cheese and milk powder manufacture, in order to improve process control, for example, by achieving higher quality, increased yields, reduced losses and less downgrading of product. This project focused on technologies for monitoring rheologyrelated parameters. The main conclusions were as follows: * Seven systems for monitoring curd formation in cheesemaking were evaluated in the laboratory. * Two on-line systems for monitoring curd firmness (hot-wire and NIR reflectance) have been deployed in a commercial cheese plant with promising results. * Experimental results demonstrated that NIR reflectance / transmission probes have a potential for on-line application in cheesemaking. Despite the difference in scale, the commercial sensors compared well with the cheesemaker s observation of curd firming and look promising as an objective means of predicting curd cut time in an industrial cheese plan. * A detailed knowledge of the rheological variation in cheese curd has been developed and a means of investigating factors which influence the rheology of cheese curd (e.g. effect of heat treatment or fortification of cheesemilk) has been determined. * Technologies available for monitoring concentrate viscosity changes in the production of milk powder have been assembled at pilot scale, and initial trials have been encouraging. Further evaluation of the MTL plant to assess on-line performance, ruggedness and cleanability are planned.Department of Agriculture, Food and the Marin