19 research outputs found
Chemical Stabilization Features Of Ladle Furnace Slag In Ferrous Metallurgy
Nowadays due to the application expansion of secondary steel processing methods, which provide high-degree metal desulfurization, a problem of the ladle furnace slag (or high-calcium refining slag) stabilization arose in the ferrous metallurgy. This slag cannot be stabilized because of its self-disintegrating properties.
Keywords: ladle furnace slag, secondary alumina production wastes, slag stabilization, belite, mayenit
Cognitive Development and Adaptive Skills of Children in Institutions of Russian Federation
In present study we examine cognitive development and adaptive skills of children raised in institutions (called Baby Homes) in Russian Federation. Previously it was shown that children in institutions leg behind their age peers in physical and motor development, show deficits in cognitive and language development. However, during the last few years important changes have been introduced in the institutional care system in Russian Federation and there is a dearth of research on cognitive development of children in Baby Homes after the changes have been implemented. The purpose of the current study was to examine cognitive development and adaptive skills of children residing in modern baby homes. We examined 59 children in the age range from 35 to 59 months: 38 children living in baby homes (M = 45,42, SD = 7.04; 17 girls, 21 boys) and 21 children living in biological families (M = 44,90, SD = 7,76; 13 girls, 8 boys). To evaluate cognitive development of children we used three non-verbal scales of the Mullen Scales of Early Learning and the Vineland Behavior Adaptive Scales to obtain information about children’s adaptive skills. Results show that children in baby homes show significantly lower scores on all the scales of cognitive development and adaptive skills in comparison with children in biological families. These results demonstrate the necessity of future changes in the institutional care system in order to improve the environment for children in institutions, nurturing their development
Limestone Addition Effect on Phase Composition of Red Mud Reduction Roasting Products
There are millions of tons of solid waste residues accumulated in present-day alumina industry. Those solid waste residues contain red mud and belit mud. The creation of sludge depository, its keeping and taking environmental protection measures cost up to $8-12 million a year. However, red mud is a valuable raw material. The extraction of some useful elements from red mud makes it possible to obtain such valuable products as pig iron, iron-bearing concentrate, rare-earth elements, alumina concrete, constructional materials, etc.
Keywords: red mud, pig iron, cement clinker, gelenite slag, phase composition, chemical compositio
CT study of products from non-metallic composites reinforced by carbon fibers
Computerized tomography is used to study products from non-metallic composites reinforced by carbon fibers. It is demonstrated that samples do not rotate during the analysis process and can have diameter not exceeding the gantry hole (75 cm) of the unit. The weight of samples can be up to 200 kg, and the length during one-time testing does not exceed 150 cm. The results of spatial calibration of the technology are shown using a set of copper wires with diameters from 0.56 to 0.05 mm. The paper presents the results of defects detecting in products in the form of gas pores and metal inclusions.Комп’ютерна томографія використовується для дослідження виробів з неметалевих композитів, армованих вуглецевими волокнами. Показано, що в процесі аналізу зразки не обертаються і можуть мати діаметр, що не перевищує портальний отвір (75 см) установки. Вага зразків може бути до 200 кг, а довжина при одноразовому випробуванні не перевищує 150 см. Наведено результати просторового калібрування технології за допомогою набору мідних дротів діаметром від 0,56 до 0,05 мм. У роботі представлено результати виявлення дефектів у виробах у вигляді газових пір та металевих включень.Компьютерная томография применяется для исследования изделий из неметаллических композитов, армированных углеродными волокнами. Показано, что образцы не вращаются в процессе анализа и могут иметь диаметр, не превышающий портального отверстия (75 см) установки. Вес образцов может быть до 200 кг, а длина при разовых испытаниях не превышает 150 см. Показаны результаты пространственной калибровки технологии с использованием набора медных проводов диаметром от 0,56 до 0,05 мм. В работе представлены результаты обнаружения в изделиях дефектов в виде газовых пор и металлических включений
Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'
The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved
Staphylococcus aureus adherence to Candida albicans hyphae is mediated by the hyphal adhesin Als3p
The bacterium Staphylococcus (St.) aureus and the opportunistic fungus Candida albicans are currently among the leading nosocomial pathogens, often co-infecting critically ill patients, with high morbidity and mortality. Previous investigations have demonstrated preferential adherence of St. aureus to C. albicans hyphae during mixed biofilm growth. In this study, we aimed to characterize the mechanism behind this observed interaction. C. albicans adhesin-deficient mutant strains were screened by microscopy to identify the specific receptor on C. albicans hyphae recognized by St. aureus. Furthermore, an immunoassay was developed to validate and quantify staphylococcal binding to fungal biofilms. The findings from these experiments implicated the C. albicans adhesin agglutinin-like sequence 3 (Als3p) in playing a major role in the adherence process. This association was quantitatively established using atomic force microscopy, in which the adhesion force between single cells of the two species was significantly reduced for a C. albicans mutant strain lacking als3. Confocal microscopy further confirmed these observations, as St. aureus overlaid with a purified recombinant Als3 N-terminal domain fragment (rAls3p) exhibited robust binding. Importantly, a strain of Saccharomyces cerevisiae heterologously expressing Als3p was utilized to further confirm this adhesin as a receptor for St. aureus. Although the parental strain does not bind bacteria, expression of Als3p on the cell surface conferred upon the yeast the ability to strongly bind St. aureus. To elucidate the implications of these in vitro findings in a clinically relevant setting, an ex vivo murine model of co-infection was designed using murine tongue explants. Fluorescent microscopic images revealed extensive hyphal penetration of the epithelium typical of C. albicans mucosal infection. Interestingly, St. aureus bacterial cells were only seen within the epithelial tissue when associated with the invasive hyphae. This differed from tongues infected with St. aureus alone or in conjunction with the als3 mutant strain of C. albicans, where bacterial presence was limited to the outer layers of the oral tissue. Collectively, the findings generated from this study identified a key role for C. albicans Als3p in mediating this clinically relevant fungal-bacterial interaction