Basic-Composition Mixture for the Consumable Lining of Intermediate Ladles

Thermomechanical and chemical-ceramic properties of the PTMS basic-composition mixture for the consumable refractory lining of intermediate ladles in service at the Kombinat Magnezit Joint-Stock Co. are considered and some details of the fabrication technique are discussed. Results for the mixture tested for performance at various metallurgical plants are given. Advantages of the mixture for practical application, its microstructural characteristics in pre- and post-service conditions, and the wear behavior are discussed.     

Environmental stress and recovery: the geochemical record of human disturbance in New Bedford Harbor and Apponagansett Bay,Massachusetts (USA)

Sediments record the history of contamination to estuaries. Analysis of the concentrations of toxic organic compounds, contaminant and crustal metals, organic carbon content and isotopic composition in sediment cores from two estuarine systems in Buzzards Bay allowed reconstruction of human impacts over 350 years. Vertical distributions of the contaminants correlate with changes in the nature of watershed/estuarine activities. All contaminants were highly enriched (tens to hundreds times background) in modern New Bedford Harbor sediments. Enrichment began around the turn of the 20th century for all but PCBs, which were first synthesized in the 1930s. An increase in organic carbon content and a shift of carbon isotopes toward a more terrestrial signature illustrates increasing anthropogenic impact in New Bedford as population grew along with the industrial base. Institution of environmental protection measures in the late 20th century was reflected in decreased, although still substantially elevated, concentrations of contaminants. A lack of industrial development in Apponagansett Bay resulted in much lower concentrations of the same indicators, although specific contaminants related to the early whaling industry increased significantly above background as early as the late 18th century. The similarity of indicators in older portions of cores from NBH and unimpacted Apponagansett Bay demonstrates that cores can be used to establish reference conditions as successfully as using separate sites judged a priori to represent the reference state. The historical reconstruction approach provides the basis for establishing relationships between environmental stressors and factors that drive the stressors, as well as a framework for the assessment of ecological response(s) to environmental stressors over a range of time and/or exposure scales.     

Selecting gunning materials for the working lining of intermediate ladles at the MMK corporation

Production has been organized of new grades of gunning materials at the Magnesite Gunning Material Corporation (previously the Magnesite Intokast Satka Corporation), which is part of the Magnesite Group holding, and these materials are used to form the working layer of lining in intermediate MNLZ ladles. Effective use has been made of a novel special technology for preparing the gunning materials. The method implies organizing the relation between the refractory maker and the users as regards modifying the quality of the gunning materials in accordance with changes in the production parameters and the amount of steel. The new materials completely match the technological specifications of MNLZ Corporation at MMK and provide a considerable reduction in the costs of preparing the intermediate ladles.     

Spectral sensitivity of the YΦ-4 photographic film in the 0.27–3-keV range

The sensitometric characteristics of a YΦ-4 photographic film were measured in the 0.27–3 keV spectral region. It was ascertained that, as the photon energy decreased from 3.2 to 1.2 keV, the YΦ-4 photographic-film sensitivity remained virtually constant and the abruptly fell. Comparison of the YΦ-4, YΦ-2T and YΦ-P films showed that their sensitivities are functions of the photon energy.     

Method of convolution in multicriteria problems with uncertainty

The problem of optimizing complex systems under incomplete information when there are several criteria for the system’s efficiency (optimization goals) is considered. The properties of different types of the convolution of these criteria, as well as the method of successive concessions for formalizing the concept of the solution of multicriteria (MC) problems with uncertainty, are analyzed. We show that there is a difference between the solutions obtained with different convolutions and method modifications. The advantages of the inverse logical convolution are demonstrated.