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As a new type of spinning machine, the jet spinning machine absorbs the carding system of the rotating cup spinning series and the nozzle part of the jet spinning. This paper aims to intends to introduce the double carding structure currently studied by the rotating cup spinning into the jet spinning machine, and analyze the influence of the nozzle characteristic number on the flow field in the double carding structure to verify the advantages of the double carding structure.

The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field. The influence of the nozzle characteristic number on the flow pattern in the four models is compared. The advantages and disadvantages of a conventional single comb and a double comb with a bypass channel on the longer side of the transport channel as an additional air supply channel are also evaluated.

At present, the double comb technology of rotary cup spinning is being studied at home and abroad to improve the spinning quality and improve the difficult problem of mixed yarn with large difference in processing fiber properties. At present, the jet spinning machine combines the advantages of rotary cup spinning and jet spinning, absorbing the comb system of rotary cup spinning series and the nozzle part of jet spinning. Therefore, it is found that the introduction of the double-split structure into the wool jet spinning has research value to improve the spinning quality.

The purpose of this paper is to refer to the previous research on the double comb structure in rotary spinning, and to apply the double comb structure in the new jet spinning machine to improve the spinning quality. The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field.

The main aim of this paper is to build an equivalent circuit model of a comb drive microactuator, while the phenomenon of generating the electric fringing field at electrode edges is taken into consideration.

The approach to the comb drives design requires the “leakage capacitance” (appearing at electrode edges) to be introduced to the complex equivalent circuit model. Introducing these capacitances leads to defining the circuit model properly.

Such a complex approach by use of the equivalent circuits model could make it possible to reduce the discrepancy between the field and circuit models. These results were obtained after comparing both field and circuit models.

MEMS microdrives are in the area which is being developed very dynamically. Improvements in the mathematical models would permit more precise microdrive design, leading to optimal structure.

The contamination on SMT assemblies caused by a number of flux/cleaning variation has been investigated, with several analysis methods used to quantify the contamination. The results from analysis of test printed circuit boards (PCBs) using anion separation, conductivity, ionic contamination measurement, visual and SEM inspection, microsections and surface insulation resistance (SIR) methods were compared. The best cleaning result was observed with the combination of water soluble (WS) solder cream and water cleaning. The best measurement method for cleanliness of PCBs was considered to be SIR measurement. For WS fluxes, the iconic contamination test offers effective measurement of the amount of residues left on the PCBs.

The use of surface insulation resistance testing has been restricted to QC laboratory applications. The extension of this technique to modern electronics and, in particular, to contamination control of SMAs has forced the development of new methods of SIR measurement. These have revealed that existing standards are rapidly becoming obsolete because the premises on which they are founded are no longer valid. Even more alarming, it is revealed that we are rapidly reaching, not only the limit of our knowledge in the field, but also the technical limits of existing standard materials used in industry today. This paper is a warning against too much complacency, as the risk of running into real problems, at all process stages, will become very pertinent within a few years. The technical content of this paper is based on about three years' study of the subject resulting in the measurement of SIR at about 10 V, as opposed to the traditional values of 100 and 500 V, which have been proved to be of little value with conductor spacings such as are usual on SMAs.

The purpose of this study is to explore the franchise relationship in China, focusing on the relational constructs of power, control, support and conflict in this developing franchise environment. Agency theory has dominated franchise research. A more rounded theoretical interpretation of the franchising relationship is offered by employing both agency theory and institutional theory perspectives.

The study adopts an interpretive approach, employing in-depth interviews with franchisors and franchisees in nine franchise organisations operating in the retail sector in China. It contributes a fuller understanding of how to manage the research process in China.

The study reveals how the relational constructs of power, control, support and conflict are manifest in the franchise relationship in China. The explanatory power of agency theory is apparent when viewed in terms of the vertical agency problem. However, free-riding outside the franchise system, in the form of counterfeiting, mitigates against the occurrence of free-riding within it. With regard to institutional theory, we demonstrate that the regulatory institutional pillar is a crucial foundation for the franchise relationship.

The study offers insights for franchisors and franchisees considering franchise relationships in China.

For the first time in the literature, this study offers insights into key elements of the franchise relationship in China. Employing both agency and institutional theories facilitates a rounded explanation of the developing franchise environment in China.

Surface insulation, electrochemical migration and various other insulation resistances are terms which are often glibly used, sometimes even incorrectly. This paper categorises different types of insulation resistance and catalogues about twenty practical applications of insulation resistance measurement, each with its ideal general conditions of measurement (test voltage, bias voltage, bias polarity, test voltage period, test frequency, test duration, temperature, humidity, test pattern type, test pattern dimensions, voltage gradients, tolerances, etc.) This description is independent of any of the nearly forty known, often contradictory, standards, most of which no longer correspond to the practical printed circuit or assembly of today. Also discussed are the different technologies of insulation resistance measurement, starting with the original non‐electronic ‘Megger®’ types through to modern laboratory electrometers and, finally, instrumentation specific to the practical measurement of printed circuit insulation resistances, including static and dynamic types. The importance of automatic statistical analyses is emphasised, especially with production testing as well as qualification procedures. This paper is aimed not only at those wishing to learn what modern insulation resistance testing is all about, but also at experienced persons wanting to marshall their thoughts about the fundamental meanings of insulation testing for different applications and specifications.

This paper discusses the requirements of quality assurance of electronics assemblies with respect to the surface conditions, and more particularly the problems introduced by modern assembly techniques. Ionic contamination testing and surface insulation resistance measurement are dealt with as complementary techniques. Particular emphasis is laid on the fact that standards related to both QC methods are inadequate and do not reflect modern needs. Cleaning, as a corollary to contamination, is touched upon without detail, other than a table comparing methods as a function of purchasing and operating costs, technical performance, etc.

THE aerospace industry does use standard bearings, but there are also many circumstances where space restrictions, load carrying requirements or mass limitations dictate that the only practical solution is to develop a special bearing.

Anglair Ltd's Product Finishing Division Leicester has supplied the advanced paint plant that has recently come on stream at the Banbury plant of Caradon Rolinx for priming thermoplastics automotive bumper mouldings.

Engelhard have introduced a pure palladium electroplating process called ‘Palltronic’. The ‘Palltronic’ process produces deposits that are significantly more ductile than those from other pure palladium processes. It is specifically designed for high‐speed plating of connectors, contacts, printed circuit boards and other electronic components and can be used as a substitute for gold in nearly all of these applications.