捣固炼焦技术的经济效益

在评价捣固炼焦技术的经济效益时,必须考虑到两个极为重要的方面,一是焦炭质量能否达到现代高炉的要求,二是环境保护要求可达到什么程度。本文将从上述两个方面来论述捣固炼焦是极为经济而有生命力的技术。并通过实例从定性和经济效益来阐述此项技术的优点,以纠正对捣固炼焦技术的偏见。１现代高炉要求的焦炭质量１９９７年的钢铁年鉴上刊登的一篇有关捣固炼焦的论文中提出：“由于装炉煤质量问题,特别是高挥发分煤的配比较大,与高炉相关的诸如焦炭反应后强度和焦炭反应性等焦炭质量达不到要求”的观点。但作者通过下面几个实例得出了…     

A heuristic approach for the allocation of resources in large‐scale computing infrastructures

An increasing number of enterprise applications are intensive in their consumption of IT but are infrequently used. Consequently, either organizations host an oversized IT infrastructure or they are incapable of realizing the benefits of new applications. A solution to the challenge is provided by the large‐scale computing infrastructures of clouds and grids, which allow resources to be shared. A major challenge is the development of mechanisms that allow efficient sharing of IT resources. Market mechanisms are promising, but there is a lack of research in scalable market mechanisms. We extend the multi‐attribute combinatorial exchange mechanism with greedy heuristics to address the scalability challenge. The evaluation shows a trade‐off between efficiency and scalability. There is no statistical evidence for an influence on the incentive properties of the market mechanism. This is an encouraging result as theory predicts heuristics to ruin the mechanism's incentive properties. Copyright © 2015 John Wiley & Sons, Ltd.     

Durability of Fe-Co thin films on Ti-6Al-4V

The durability of Fe-Co thin films bonded on Ti-6Al-4V was studied as a function of layer thickness at ambient temperature. Interface toughness of the thin films was characterized by indentation and analyzed using an interface fracture model. The critical stresses for interface debonding and the fatigue life response of Ti-6Al-4V with and without Fe-Co thin films were evaluated by three-point bend fatigue at a stress ratio R of 0.1. The results indicated that the critical stress for interface debonding increased with decreasing layer thickness according to a critical energy release rate criterion. The Fe-Co thin films did not alter the fatigue life of the Ti-6Al-4V substrate. The presence of microcracks and interface debonds in the thin films did not affect the functionality of the sensor to detect strain via the inverse magneto-elastic effect. The overall durability of the films was in the range needed for practical application of the film as an embedded sensor.     

Traunbrücke Steyrermühl — Sprengungsüberwachung mit BRIMOS® Structural Health Monitoring

Die Traunbrücke Steyrermühl ist Teil der A1 Westautobahn und wurde in den Jahren 1959 und 1960 errichtet. Die 18‐feldrige Stahlbetonbrücke besteht aus zwei Richtungstragwerken und weist eine Gesamtlänge von 240,45 m auf. Im Hinblick auf die Gewährleistung der Tragsicherheit und Funktionsfähigkeit der Brücke wurden während der Sprengung des Richtungstragwerks Salzburg im August 2010 das unmittelbar benachbarte, zunächst bestehen bleibende Richtungstragwerk Wien überwacht und die Auswirkungen der Sprengung bewertet, wobei besonderes Augenmerk auf die primäre Tragstruktur (Bogen) gelegt wurde. Da am Tragwerk bereits im Jahr 2005 eine dynamische Referenzmessung mit BRIMOS® durchgeführt wurde, konnte die aktuelle Untersuchung (Messung 2010) dadurch entsprechend effizienter gestaltet werden. Mit Hilfe ausgewählter Einzelpunkte am Brückentragwerk (HOT SPOTS) konnten das maßgebliche Tragverhalten der Brücke und etwaige Veränderungen umfassend beschrieben und quantifiziert werden. Ein direkter Vergleich im Abstand von fünf Jahren zeigt den Verlauf der gemessenen Tragfähigkeit über die Zeit (Brückendeck unter dem Einfluss der Verkehrsbelastung bzw. der Sprengung). Blast of the Westbound Bridge Structure and Evaluation of its Affection on the remaining Eastbound Bridge Structure with BRIMOS® Structural Health Monitoring. The bridge object is part of the A1 highway and was constructed in 1959. It is composed of 18‐spans (reinforced concrete) and has a total length of 240,45 m. While the bridge structure — related with the driving direction Salzburg — was removed (blown) in August 2010, the remaining structure (driving direction Vienna) was monitored in order to evaluate the impact of the blasting with regard to its structural safety and operability. The investigation was focused on the primary load‐bearing structure (arch). Due to the fact that an initial dynamic measurement with BRIMOS® has been conducted already in 2005, the prevailing investigation (measurement 2010) could be configured more efficiently. Measurements at selected single bridge locations (HOT SPOTS) enabled a comprehensive documentation and quantification of the bridge’s decisive structural behaviour and possible changes respectively. A direct comparison after 5 years of structural service life shows the progression of the measured structural resistance over time (bridge deck under the influence of traffic load and the bridge blasting).     

Cascaded two-degree-of-freedom control of seeded batch crystallisations based on explicit system inversion

Simple structures and robustness against disturbances are important attributes of chemical productions controllers. The present contribution considers these aspects for seeded batch cooling crystallisations. A new cascaded control scheme is presented. It combines consistent feedforward control with classic feedback control of the main physical process variables, which are the crystalliser temperature, the supersaturation and the crystal mean size. The calculation of the feedforward trajectories uses an explicit inversion of the crystalliser model which is based on the Methods of Moments. A state observer is used to determine online the respective moments of the crystal size distribution. An additional observer is included to estimate unmeasurable heat disturbances and to update the temperature feedforward trajectories. The present contribution summarises the model derivation, system inversion, feedforward and feedback controller design and the design of the observers. Numerical simulations and experimental results from a laboratory plant at BASF Ludwigshafen prove the applicability of the proposed control concept.     

The surfactant addition effect in the elaboration of electrodepositated NiP-SiC composite coatings

In this work, NiP-SiC composite coatings were prepared by electrodeposition from a plating bath containing NiSO₄·6H₂O; NiCl₂·6H₂O; H₃PO₃; H₃PO₄; Na₂SO₄ and SiC particles (average diameter of 600 nm) in suspension. Anionic surfactant (SDS — sodium dodecyl sulfate, CH₃(CH₂)₁₁SO₄Na) or cationic surfactant (CTAHS — cetyltrimethylammonium hidrogensulfate, C₁₉H₄₃NO₄S) were also added to this suspension. The number of incorporated particles by area unit (α_np/A) was evaluated by image analysis of micrographs obtained by scanning electron microscopy (SEM). It was observed that organic additive addition influences the incorporated SiC particles rate on the metallic matrix. Addition of organic additives such as SDS or CTAHS modifies the characteristic of suspensions. Depending on particle size organic additive addition can change the number of incorporated particles in deposits during growth of the matrix. Decrease of the incorporated particle amount with the increase of particle size was verified. The selective incorporation process is associated to the presence of organic additive and it was not dependent on surfactant charge.