Modification of the surface of sheet glass (A Review)

The paper contains an analysis of the literature data on modification of the surface of sheet glass in order to impart heat-shielding, conducting, hydrophobic, x-ray-shielding, decorative, and other properties to glass. Various industrial and scientific entities engaged in production and development of modifying coatings are described. A classification of film coatings is offered, and the main production methods are considered. The effect of various factors on film coatings is analyzed. Translated from Steklo i Keramika, No. 4, pp. 3–7, April, 2000.     

Improvement of Aglycone π-Stacking Yields Nanomolar to Sub-nanomolar FimH Antagonists

Antimicrobial resistance has become a serious concern for the treatment of urinary tract infections. In this context, an anti-adhesive approach targeting FimH, a bacterial lectin enabling the attachment of E. coli to host cells, has attracted considerable interest. FimH can adopt a low/medium-affinity state in the absence and a high-affinity state in the presence of shear forces. Until recently, mostly the high-affinity state has been investigated, despite the fact that a therapeutic antagonist should bind predominantly to the low-affinity state. In this communication, we demonstrate that fluorination of biphenyl α-d -mannosides leads to compounds with perfect π–π stacking interactions with the tyrosine gate of FimH, yielding low nanomolar to sub-nanomolar K_D values for the low- and high-affinity states, respectively. The face-to-face alignment of the perfluorinated biphenyl group of FimH ligands and Tyr48 was confirmed by crystal structures as well as ¹H,¹⁵N-HSQC NMR analysis. Finally, fluorination improves pharmacokinetic parameters predictive for oral availability.     

Construction materials based on cullet

The results of the development of decorative, heat-insulating and soundproof construction materials based on glass cullet are discussed. The service parameters of the samples are determined and the optimum technological production schemes are developed. Translated from Steklo i Keramika, No. 1, pp. 4–6, January, 1999.     

Identification of local compactions in ceramics

Fractures of non-fired samples and samples heat-treated in the temperature range 900–1200°C made of a mixture of tinted granules molded at various pressure levels and non-tinted powder are investigated. It is demonstrated that a crack propagates along the boundaries of the granules simulating local compaction areas, and after firing at 1050 – 1100°C, the fracture becomes more level. At the same time, the system (the sample) passes to an unstable state which has the properties of a bifurcation. An increase in the heating rate from 2.5 to 6.5°C/min produces a shift in the transition from an uneven to a level fracture depending on the initial granule density (granule molding pressure). The identification and elimination of the principal bifurcations in a technological process opens up the possibility of developing ceramics with reproducible structure and properties.     

Effect of nitrogen and vanadium on austenite grain growth kinetics of a low alloy steel

Austenite grain growth kinetics in a steel containing 0.4% C, 1.8% Cr with different nitrogen contents (in the range 0.0038–0.0412%) and a micralloying addition of 0.078% V were investigated. The investigations were carried out in an austenitising temperature range of 840–1200 °C for 30 min. The results of investigations showed that N promotes the grain growth of austenite. The microalloying addition of vanadium protects the austenite grain growth because of carbonitride V(C,N) precipitation and the grain boundary pinning effect of undissolved particles of V(C,N). Using a thermodynamic model, the carbonitride V(C,N) content, undissolved at the austenitising temperature was calculated. At temperatures when a coarsening and dissolution of carbonitride occurs, the austenite grains start to growth. The effect of nitrogen on the type of chord length distribution of austenite grains was analysed.     

Variation in fatty acid composition of ewes' milk during continuous transition from dry winter to natural pasture diet

The profile variations of approximately 70 fatty acids (FAs) in milk of ewes consuming total mixed rations (TMR) and grazing natural pasture were determined. Milk of ewes grazing pasture in May and September in the Slovak Republic contained 3-times more conjugated linoleic acid (CLA) (P < 0.001) and trans-vaccenic acid (TVA) (P < 0.001), and 2-times more α-linolenic acid (ALA) (P < 0.001) than that of ewes fed TMR. A doubling of the CLA and TVA contents of milk of ewes fed with TMR was achieved by changing to meadow hay containing a higher ALA content. Less availability of vegetation and lower ALA pasture content in summer (P < 0.001) caused a 2-fold decrease (P < 0.001) of CLA and TVA contents when compared with data obtained in May. With grass re-growth and an increase in pasture ALA content in September, the CLA and TVA contents rose to values similar to those obtained in May (P > 0.05). No significant differences in the FA composition in milk of ewes grazing on summer pasture at higher altitude were observed.     

Influence of solvent and temperature on extraction of phenolic compounds from grape seed,antioxidant activity and colour of extract

This study was aimed to investigate the influence of solvent (water and ethanol in concentration: 50%, 70% and 96%) and extraction temperature (25–80) °C on polyphenols extraction of grape seed (Vitis vinifera L. cv. “Frankovka”) cultivated in Eastern Croatia. The best results were reached using 50% ethanol at 80 °C. The most abundant individual polyphenolic compound was catechin which makes the average of 45.11% of the total phenolic content followed by epicatechin (34.45%), procyanidin B₂ (12.90%), gallic acid (5.34%), gallocatechin (1.58%), epicatechin gallate (1.01%). The antioxidant activity of extracts was determined by DPPH‐method and it was highly dependent on extraction solvent and temperature. The total extractable proanthocyanidins content of extract had the highest positive correlation (r = 0.994) with antioxidant activity, which indicated that these compounds might be the most important antioxidant in examined grape seed extracts. Relationship between phenolic content and colour of extracts was observed.     

Growth of large Ti:Sapphire crystals by horizontal directional solidification in argon atmosphere

We report the growth of large (110 × 200 × 50 mm) titanium-doped sapphire crystals by horizontal directional solidification in a protective atmosphere and their lasing characteristics. The crystals are shown to be suitable for the fabrication of lasing elements with a figure of merit above 150 and wavefront distortion within λ/6.     

Information systems for geomechanical monitoring in underground structures

Results of the development of a monitoring system for underground structures, which makes it possible to unite and utilize data bases intended for various purposes (geographic, geologic, ecologic), and also results of numerical modeling of the interaction between a structure and rock mass, and data derived from field measurements within the framework of the design of the geographic information system (GIS), are cited for a specific entity. Utilizing the GIS, fixing of the structure in space will make it possible to assess more graphically and informatively the condition of the structure, and the degree of its safety, as well as the influence that it exerts on the adjacent setting and surrounding geologic medium during its construction and service. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 2–5, November–December, 2008.