Модернизация подшипникового узла ведущего вала компрессора 6ВВ32/7

Произведен расчет и подбор элементов подшипникового узла ведущего вала компрессора 6ВВ32/7.Calculation and selection of elements of bearing knot of the leading shaft of the compressor 6BB32/7 is made

A Direct Measurement of Atmospheric Dispersion in N-band Spectra: Implications for Mid-IR Systems on ELTs

Adaptive optics will almost completely remove the effects of atmospheric turbulence at 10 microns on the Extremely Large Telescope (ELT) generation of telescopes. In this paper, we observationally confirm that the next most important limitation to image quality is atmospheric dispersion, rather than telescope diffraction. By using the 6.5 meter MMT with its unique mid-IR adaptive optics system, we measure atmospheric dispersion in the N-band with the newly commissioned spectroscopic mode on MIRAC4-BLINC. Our results indicate that atmospheric dispersion is generally linear in the N-band, although there is some residual curvature. We compare our measurements to theory, and make predictions for ELT Strehls and image FHWM with and without an atmospheric dispersion corrector (ADC). We find that for many mid-IR applications, an ADC will be necessary on ELTs.Comment: 22 pages, 8 figures, accepted to PAS

Results from Two Inter-laboratory Comparison Tests Organized in Germany and at the EU Level for the Analysis of Acrylamide in Food

After the publication of high levels of acrylamide (AA) in food, many research activities started all over the world in order to determine the occurrence and the concentration of this substance in various types of food. As no validated methods were available at that time, interlaboratory studies on the determination of AA in food were of the highest priority. Under the boundary conditions of applying well – established evaluation schemes, the results of 2 studies conducted by the Federal Institute for Risk Assessment (BfR) in Germany and by the European Commission’s Directorate General Joint Research Centre (JRC) exhibited an overall acceptable performance of the participants in these studies. Nevertheless, many laboratories showed problems in determining AA in food with a complex matrix such as cocoa. The results of analysis also showed a broader variation of AA for samples with low AA concentration and indicated a bias of the results obtained by gas chromatography – mass spectrometry without derivatization. Improvements of the performance of some laboratories appeared to be necessaryJRC.D.8-Food safety and qualit

Assessment of various post systems' Fracture resistance after endodontic treatment

Objectives: The study's objective is to evaluate the fracture resistance of a tooth that has had endodontic treatment and has been rebuilt using various post and core systems. Materials and Methods: Thirty-six extracted premolar teeth of similar sizes were picked, and at random, they were separated into three groups: group A received stainless-steel posts, group B received zirconia fiber posts, and group C received glass fiber posts. Dual-cured resin cement was used to cement each post. The acrylic resin blocks have samples imbedded in them. Additionally, fracture loads were measured while a compressive force was given to the tooth at a crosshead speed of 1 mm/minute. The one-way analysis of variance F-test and post hoc Tukey's test were then used to analyze the results. Results: When the mean values and standard deviation were compared, it was found that glass fiber posts had the highest fracture resistance, followed by posts made of zirconia fiber, while stainless-steel posts had the lowest fracture resistance. Conclusion: When compared to zirconia posts and stainless-steel posts, glass fiber posts had the highest level of fracture resistance