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51.
This paper analyses inter-organizational networks that link together firms operating in the food processing and distribution industry in the UK. In doing so, the paper draws on insights recently developed by Mark Casson that treat inter-firm networks as an institutional response to the changing costs and opportunities of information management. Detailed analysis of product innovation and supply-chain management issues within the industry, exemplified by the growth of chilled ready-meals, leads to the identification of two distinct but complementary inter-firm networks: a network of control and a network of innovation. In each case, the study finds that the critical information is derived from the retailers' interface with consumers and thus that these information-based networks are effectively controlled by the leading supermarket chains. The study's conclusions are considered in relation to the recent findings of the UK Competition Commission following its investigation into grocery retailing in Britain. 相似文献
52.
Paulo A. Santos Marcia A.S. Spinac Karen K.G. Fermoselli Marco-A. De Paoli 《Composites Part A》2007,38(12):2404-2411
The interest for the use of vegetal fibers as polymers reinforcement has recently increased because of their unique environmental and technological advantages. This work evaluated the use of Curauá fibers in polyamide-6 composites aiming at glass fiber replacement. Fiber content of 20, 30 or 40 wt% and fiber lengths of 0.1 or 10 mm were studied. Fibers were treated with N2 plasma or washed with NaOH solution, to improve their adhesion to PA-6. Samples with 20 wt% of short or long fibers, with or without pre-treatment, were compounded in two different co-rotating intermeshing twin-screw extruders. These samples were submitted to mechanical and thermal tests. In conclusion, non-dried raw materials improved fiber/matrix interfacial adhesion. Tensile and flexural properties of this composite are better than unfilled, but lower than glass fiber reinforced polyamide-6. However, its impact resistance and heat deflection temperature are similar to the glass fiber reinforced polyamide-6 and its lower density, enable it to replace this latter in specific non-critical applications. 相似文献
53.
M. J. Hendrickson R. P. Cox J. C. Konen 《Journal of the American Oil Chemists' Society》1948,25(3):73-77
Conclusions An alkaline-solution technique has been developed permitting the study of the drying and aging process of an oil film using
the ultraviolet spectrophotometer. This technique has been found to be a valuable tool for investigating some of the chemical
changes which occur as a vegetable oil film dries and ages.
The drying or autoxidation of an oil film has been shown to proceed along the general lines of a three-stage reaction with
the short initial stage being characterized by an accumulation of conjugated diene and triene structures which reaches a maximum
at the time the film has set up or becomes continuous. The second or curing stage was characterized by a slow decrease in
the measurable conjugated diene and triene structures. The third or deterioration stage was not investigated; however, this
method should be readily adaptable to studies involving film breakdown as represented by phenomena such as after-yellowing
since the development of absorption peaks characteristic of linolenic ketones, for example, would permit an early prediction
of yellowing long before the concentration of the chromophore groups became great enough for visual observation.
During the initial stage of drying there was also evidence for an increase in the alpha-keto structures capable of enolizing
in alkali to give absorption maxima characteristic of triene and tetraene conjugated systems. These enolizable structures
also decreased in amount during the film curing period and are not characterizable on the basis of observed absorption maxima
and published information.
The method of obtaining a spectral solution of a dry, infusible oil film through the medium of alcoholic KOH was applied to
investigations on the relationship existing between the light absorption of the film solution and the durability or weather
resistance of the straight oil film. The results obtained verified the principle previously reported that the quantity of
light absorbed by an oil film in the region of 320–400 mμ was indicative of the durability of the film upon exposure to accelerated
weathering conditions. 相似文献
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Schistosoma mansoni and S. japonicum infections in nude mice (nu/nu) were compared with infections in nu/+ heterozygotes or intact mice. Seven to 12 weeks after exposure to S. mansoni, the responses of Swiss NCR, C3H, BALB/c and C57B1/6 nude mice did not differ substantially. Nude mice of all these strains showed minute granulomas around eggs in the liver and minimal hepatic fibrosis. Microvesicular and necrotizing changes in hepatocytes were similar in all mouse strains, and S. mansoni infections were frequently lethal to nude, but not to intact mice between the seventh and ninth weeks of infection. Nude mice that survived the ninth week of infection generally lived until the 12th week. The number of eggs per mature worm pair in the tissues of S. mansoni-infected nude mice was similar to the number in intact mice, but nude mice passed fewer eggs in the feces. Nude mice that received serum from infected intact mice excreted eggs in the stool in numbers equivalent to intact mice, but continued to form minute granulomas around S. mansoni eggs. Reconstitution with fetal thymus or with splenocytes from normal or S. mansoni-infected mice partially or completely restored hepatic granuloma size, granuloma eosinophils, hepatic fibrosis, and excretion of eggs in the feces. In contrast to S. mansoni infection, S. japonicum infections in nude mice did not cause necrosis of hepatocytes or excessive mortality, and S. japonicum eggs were passed in the feces in numbers equivalent to those passed by infected intact mice. 相似文献
58.
Expanded on R. E. Fassinger's (see record 1990-21225-001) model of career choice in college women by testing 2 causal models of career choice and orientation with high school women. Ss were 409 adolescent women enrolled in their last year of high school in an all-female private liberal arts high school in a large Midwestern city. Structural equation modeling analyses suggested that the career orientation and career choice of adolescent women were predicted by ability, agentic characteristics, gender role attitudes, and relationship with mother. Young women who possessed liberal gender role attitudes, were instrumental and efficacious with regard to math and careers, and exhibited moderate degrees of attachment and independence from their mothers tended to value their career pursuits. Adolescent women who selected nontraditional and prestigious careers showed high ability and strong agentic characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
59.
An orderly design procedure that can save time and help prevent problems in the development of fuzzy logic systems is presented. The nature of fuzzy logic is examined, and the design of fuzzy control systems is discussed. The architecture of a simple fuzzy controller for a steam turbine is used as an example, to show how fuzzy control models work. A four-step methodology for fuzzy system design is described 相似文献
60.
Abstract. Regional scientists have had a long fascination with spatial economic interdependence, initially stimulated by the development of a suite of models in Isard (1960). In recent years there have been two major developments; first, a movement towards greater integration in model development not only with large-scale models, but also with careful attempts to make more components of the system endogenous. The second development has been the pursuit of greater integration than in earlier studies between theory and applied regional economic modelling, most notably in the area of trade and economic development. We explore some of the recent developments of this latter approach and provide an assessment of the current state-of-the art of some future opportunities. 相似文献