Effect of annealing time on solute carbon in ultralow-carbon Ti-V and Ti-Nb steels

The influence of annealing temperature and time on solute carbon levels was investigated in four ultralow-carbon (ULC) bake-hardenable steels; two Ti-V ULC steels with different V/C levels and two Ti-Nb ULC steels with different Nb/C levels. Internal-friction and scanning transmission electron microscopy (STEM) techniques were used to understand the precipitation/dissolution behavior in the various steels. An effect of annealing time on the carbon Snoek-peak height was observed in both Ti-V steels and in the Ti-Nb steel having a lower Nb/C ratio. Despite differences between these steels resulting from their composition (and, thus, carbide solubility) differences, after cold rolling and annealing at different temperatures, the maximum Snoek-peak height was achieved after annealing for shorter times in each instance, on the order of 1 minute. The highly stabilized Ti-Nb ULC steel with a higher Nb/C ratio did not show the effect because of the absence of solute carbon. For the Ti-V steels, most of the precipitates examined using STEM contained both Ti and V. The energy-dispersive X-ray (EDX) analysis indicated that both the Ti-V steels annealed at 845 °C for 1 minute have greater Ti/V ratios compared to their corresponding Ti-V steels in the as-received (hot-rolled) condition. This behavior is consistent with dissolution of carbides causing the carbon in solution to increase, as indicated by a greater carbon Snoek-peak height for both Ti-V steels in the annealed condition. The reduction in Snoek-peak height at longer annealing times is believed to be associated with segregation to lower-energy defect sites.     

Information technology at the National Computing Centre

An outline is given of the information services used in the National Computing Centre. An update is provided of a previous paper describing the local area network implemented in 1981. Three IT landmarks are highlighted, these include the introduction of word processing, the local area network and a digital PABX. The implications and subsequent developments are described. The facilities available on the local area network are discussed. The use of three electronic mail services are also considered, along with the use of facsimile.     

From visionary ideas to products

This paper presents the rationale for the creation of the Microelectronics and Computer Research Corporation (MCC), to be a cooperative research organization funded by a number of U.S. computer and electronics companies.

Factors inhibiting investment in fundamental research by individual companies today are presented and analyzed, and the benefits of the consortium approach for cooperatively performing basic research and early exploratory development work are described.

The present research activities of MCC in the areas of Advanced Computer Architectures, Computer Aided Design, Software Technology, and Packaging and Interconnect technology are presented. This is followed by a discussion of future directions for research in the field of computer science.     

Ergonomics of technology transfer

It is beyond doubt that high technology has elevated the standards of living of mankind. The modern technology created and developed to a great extent by Western or developed societies is now in great demand in Eastern and developing societies who are trying to leap-frog towards advancement. But unfortunately, in the transfer of technology, both the giver and the receiver seem to make many mistakes. A technology transferred without considering the ethnic variables in the societies and differences in the climates, has found to cause problems to the acquirer. Due to the basic human factor differences such as sizes of people, physical environment, physical capacities and organizational and cultural differences, a technology which is unadapted has found to be inappropriate, harmful, hazardous and unsuccessful. In the areas of health, working conditions, production and finance, undesirable effects have resulted through haphazard technology transfer, For a successful transfer, it is therefore stressed that technology has to be adapted or modified taking into consideration the technological, anthropological and socio-economic factors of the acquiring population.     

Slicing Software for Model Construction

Applying finite-state verification techniques (e.g., model checking) to software requires that program source code be translated to a finite-state transition system that safely models program behavior. Automatically checking such a transition system for a correctness property is typically very costly, thus it is necessary to reduce the size of the transition system as much as possible. In fact, it is often the case that much of a program's source code is irrelevant for verifying a given correctness property.In this paper, we apply program slicing techniques to remove automatically such irrelevant code and thus reduce the size of the corresponding transition system models. We give a simple extension of the classical slicing definition, and prove its safety with respect to model checking of linear temporal logic (LTL) formulae. We discuss how this slicing strategy fits into a general methodology for deriving effective software models using abstraction-based program specialization.     

汽车塑料标牌的表面处理工艺

汽车标牌不仅要求造型美观、字迹图案流畅,而且表面应具有金属的装饰感,同时其耐蚀性和耐候性也必须符合汽车外饰装饰件的要求,如中国第一汽车集团公司汽车外饰件需符合ＴＬ－ＶＷ５２８／Ｂ标准。目前绝大多数汽车标牌都采用塑料立体标牌,其制造工艺流程大体为：注塑...     

DEPP functionally graded piezoceramics via micro-fabrication by co-extrusion

This paper introduces the Dual Electro/Piezo Property (DEPP) gradient technique via Micro-Fabrication through Co-eXtrusion (MFCX) which pairs a high displacement lead zirconate titanate (PZT) piezoceramic with a high permittivity barium titanate (BT) dielectric. By grading with this material combination spatially across an actuator, the electric field is concentrated in the more active region for improved efficiency, higher displacements, and complex motions. To aid in synthesis and analysis of any gradient profile, compositional maps are provided for key material properties (density, stiffness, permittivity, and piezoelectric coefficients). The DEPP technique was validated, independent of the MFCX process, by powder pressing a conventional bimodal gradient beam which demonstrated through experiments high displacement capabilities at lower driving potentials than comparable functionally graded piezoceramic actuators. For more complex gradients, the MFCX process was adapted to the DEPP gradient technique and illustrated by the fabrication of a linearly graded prototype whose monolithic nature and gradual material variation significantly reduces internal stresses, improves reliability, and extends service lifetime.     

Struktur und Eigenschaften gepfropfter Kartoffelstärke. III. Mikrostruktur und Bindungsverhältnisse in der Pfropf-co-polymer-Phase

Structure and Properties of Grafted Potatoe Starch. III. Microstructure and Interchain Bonds in the Graft-Copolymer-Phase Graft copolymers of polyacrylic acid and polymethacrylic acid, grafted according to the Scott-xanthation process were investigated. By combining different optical methods information could be obtained about interchain bonds in the copolymer phase. From frequency, shape and intensity of different infra-red absorption bands it could be concluded that there are hydrogen bridges from the carboxylic groups of the side chain polymer to the hydroxyl groups of the backbone-polysaccharid. These bonds lead to a crystalline copolymer phase which is different from starch and have an influence on the configuration of the polysaccharid chains in solution.