Influence of the composition and structure of the glass-crystalline shell of cenospheres on helium permeability

We studied the interrelation between the composition, morphology, and helium permeability of the shell of narrow fractions of nonmagnetic nonperforated cenospheres extracted from cenosphere concentrates of fly ash of the sialic type with the use of technological stages of hydrodynamic, magnetic separation, sizing, and aerodynamic classification. For the interval of variation of Al₂O₃ content from 20 to 38 wt %, the regression equation [SiO₂]/[Al₂O₃] = 5.06 − 0.1[Al₂O₃] is established, with the correlation coefficient equal to −0.98. It is found that, together with the growth in the concentration of Al₂O₃ in the indicated interval, the content of the originally mullite phase increases from 1.3 to 42.4 wt %, and this is accompanied by the growth of the helium permeability of the glass-crystalline shell of the cenospheres.     

卤代烃的制备工艺

介绍了一种液相法生产分子式为ＣＡＲ＾１Ｒ＾２ＣＢＲ＾３Ｒ＾４（此外的Ｒ＾１,Ｒ＾２、Ｒ＾３和Ｒ＾４指代意义如专项说明中所定义）的卤代烷加成物的工艺,是将相应的卤代烷烃（ＡＢ）与相应的烃（ＣＲ＾１Ｒ＾２＝ＣＲ＾３Ｒ＾３）在催化的存在下于溶剂中进行反应,所用的催化剂组成：（１）至少有一种含一价铜;（２）至少有一种为离子促进剂,选自卤代铵、吡啶或卤代吡啶及（ＭＱ４）Ｙ型的四价盐（Ｍ是元素周期表中ＶＡ族元素,如Ｎ、Ｐ、Ａｓ、Ｓｂ或Ｂｉ,Ｑ为Ｃ１－Ｃ１８烷烃、Ｙ为氯、溴或碘）。还介绍了用上述工艺制得的加成产物与ＨＦ反应制备一些氢氟烃的工艺,该工艺是在二晴或环化碳酸酯溶剂中进行,使反应混合物分成两相。     

Refractories for the slide gates of the steel-teeming ladles of the electric melt shop of belorussian metallurgical plant

Conclusions The imported refractories and design of the slide gate were analyzed. Experience in their use, which may be used in domestic practice for increasing refractory life and improving the designs of refractories and gates and the method of teeming steel through slide gates, was obtained.At Belorussian Metallurgical Plant a set of domestic refractories has been introduced in the Interstop slide gate in place of the imported ones. The life of the domestic refractories is equal to or exceeds that of the imported analogs.Translated from Ogneupory, No. 6, pp. 51–55, June, 1989.     

RHEOLOGICAL BEHAVIOR OF CONCENTRATED INULIN SOLUTION: INFLUENCE OF SOLUBLE SOLIDS CONCENTRATION AND TEMPERATURE

Inulin is a storage polysaccharide present in more than 30,000 vegetable products, including chicory roots, that are considered suitable for industrial application. The objective of this work was to evaluate the influence of temperature and the soluble solids concentration on the rheological behavior of a concentrated inulin solution obtained from a centrifugation process from chicory roots, after freezing at − 24C. For all the evaluated soluble solids concentrations, inulin solutions showed a rheological behavior of a highly pseudoplastic fluid, with high resistance to flow at low strain rates followed by a breakdown of the structure when the shear rate increased. The effect of temperature on the apparent viscosity of inulin solutions can be represented by the Arrhenius equation. The rheological behavior of inulin solutions can be represented by the Herschel–Bulkley, Casson, Cross and Power Law equations, where the consistency index increases as temperature rises and the soluble solids concentration as well.

PRACTICAL APPLICATIONS

The main objective of this work was to analyze the rheological behavior of a concentrated inulin solution obtained from chicory roots, to check the possibility of its application to obtain powder inulin.
The concentrated inulin solution was obtained by diffusion in hot water, followed by concentration by evaporation and phase separation conducted by lowering the temperature (−24C) and centrifugation at a velocity of 10,000 rpm for a time interval of 15 min. However, this solution is still going to be processed. Therefore, it is important to know its rheological behavior.
The influence of temperature and the soluble solids concentration on the rheological behavior of the concentrated inulin solution was also studied.     

Structure,morphology, and transport characteristics of profiled bilayer membranes

A procedure for the fabrication of profiled cation-exchange bilayer membranes with the homogenized surface based on the commercial membrane MK-40 has been developed. The surface morphology and membrane microstructure have been studied by atomic-force microscopy, electron microscopy, and standard contact porosimetry. The concentration dependences of the electrical conductivity and diffusion permeability of the profiled and bilayer profiled membranes have been studied. It has been shown that the application of an MF-4SK film on the surface of the profiled membrane results in a decrease in its diffusion permeability and some increase in specific conductivity. Based on the data obtained, the transport and structure parameters have been calculated in terms of the microheterogeneous model to assess the influence of the modification on the properties of the support membrane. The current–voltage characteristics of the membranes have been measured in sodium chloride solutions, and it has been shown that profiling leads to an increase in the limiting current by 40%. The investigation of mass transfer of ions in the channels formed by the support and modified membranes has shown that under intense current regimes, the mass transfer coefficient through the profiled bilayer membrane is one and a half times that through the initial profiled membrane.     

CALCOFLUOR AS A FLUORESCENT PROBE TO DETECT BIOFILMS OF FOODBORNE PATHOGENS

Biofilms enable foodborne pathogens to resist removal from surfaces, survive disinfection and elude detection. This study evaluated the use of Calcofluor, which binds to polysaccharides containing β-D-glucans, to detect biofilms produced by Salmonella enterica serovar Berta and Salmonella enterica serovar Typhimurium DT104 (St DT104), Escherichia coli, Aeromonas hydrophila, Vibrio cholerae O139 and Hyphomonas adhaerens. Biofilms produced by St DT104, S. berta and V. cholerae on five types of surfaces (glass, polypropylene, Teflon™, stainless steel and aluminum) were detected by Calcofluor. Results suggest the potential use of Calcofluor as probes of foodborne pathogens in biofilms.     

Airborne high‐resolution images for grape classification: changes in correlation between technological and late maturity in a Sangiovese vineyard in Central Italy

Background and Aims: The goal of this study was to investigate the relationships between NDVI values at different phenological stages and measurements of grape parameters at two different harvest dates. Methods and Results: The research was done on a Sangiovese vineyard in Central Italy. Over four seasons, airborne NDVI measurements acquired between June and August were related to grape parameters (yield per vine, pH, °Brix, anthocyanins and polyphenols) at technological harvest (H1) and two weeks later (H2). Correlations were higher at H1 and decreased at H2 with a different rate depending on the parameter. °Brix and pH correlations showed a moderate rate of variation between H1 and H2; bigger differences and a different inter‐annual dynamic were observed in anthocyanins and polyphenols between H1 and H2. Conclusions: The ability of NDVI to discriminate different grape classes was confirmed, but its efficacy substantially varies depending on the harvest date. These results suggest the existence, within the same vineyard, of different grape populations having specific timing and shape of ripening curve; as a consequence, distinct vigour zones of the vineyard show a different evolution of the content of grape parameters between the two harvests thus influencing the degree of correlation between grape quality and NDVI measurements. Significance of the Study: This is the first study in which harvest date has been considered for its influence on the predictive skill of RS. It therefore highlights not only the importance of spatial variation within the single vineyard, but also the importance of ripening dynamics.