275 research outputs found
METHODOLOGICAL APPROACHES TO EVALUATING BEER AND NON-ALCOHOLIC PRODUCTS SHELF LIFE
The article discusses the relevance of developing methodological approaches to the beer and soft drinks accelerated aging method in the market. The controlled indicators selection principles, mainly affecting the quality of the finished product, and the basic equation describing the dependence of changes in indicators on the main temperature factor are given. Studies of the influence of various physical factors (temperatures in the range of 50–60 °C, UV-radiation), both individually and jointly, on the physicochemical and organoleptic characteristics of packaged water for various experimental versions did not show statistically significant changes in the normalized parameters of the basic salt and microelement composition investigated water during storage. The optimal mode of accelerated «aging» of packaged water at an elevated temperature (up to 60 °C) and UV-radiation was established. In the case of soft drinks, thermostating was used when changing the temperature regimes (heat 50 ± 2 °C / cold 6 ± 2 °C) at an exposure time of 30 days, which made it possible to observe a decrease in taste and aroma compared with the control, as well as a decrease in sweetness and the appearance of a slight plastic taste for non-carbonated drink. The influence a temperature regime change on brewing products, which cannot be estimated using the existing method due to the high turbidity, is shown.The article discusses the relevance of developing methodological approaches to the beer and soft drinks accelerated aging method in the market. The controlled indicators selection principles, mainly affecting the quality of the finished product, and the basic equation describing the dependence of changes in indicators on the main temperature factor are given. Studies of the influence of various physical factors (temperatures in the range of 50–60 °C, UV-radiation), both individually and jointly, on the physicochemical and organoleptic characteristics of packaged water for various experimental versions did not show statistically significant changes in the normalized parameters of the basic salt and microelement composition investigated water during storage. The optimal mode of accelerated «aging» of packaged water at an elevated temperature (up to 60 °C) and UV-radiation was established. In the case of soft drinks, thermostating was used when changing the temperature regimes (heat 50 ± 2 °C / cold 6 ± 2 °C) at an exposure time of 30 days, which made it possible to observe a decrease in taste and aroma compared with the control, as well as a decrease in sweetness and the appearance of a slight plastic taste for non-carbonated drink. The influence a temperature regime change on brewing products, which cannot be estimated using the existing method due to the high turbidity, is shown
Increasing the resistance of a NiCrBSi coating to heat wear by means of combined laser heat treatment
Testing of NiCrBSi coatings formed by gas-powder laser cladding and combined laser heat treatment, including laser cladding and high-temperature annealing, were conducted under conditions of sliding friction on the Kh12M steel according to the pin-on-disk scheme. The combined processing resulting in the formation of large carbides and chromium borides in the coatings is shown to increase their wear resistance by a factor of 1.8 at sliding velocities of 6.1 and 9.3 m/s, when there is significant frictional heating of the friction surfaces. © 2018 Author(s)
The KHOLOD Experiment: A Search for a New Population of Radio Sources
Published data from long-term observations of a strip of sky at declination
+5 degrees carried out at 7.6 cm on the RATAN-600 radio telescope are used to
estimate some statistical properties of radio sources. Limits on the
sensitivity of the survey due to noise imposed by background sources, which
dominates the radiometer sensitivity, are refined. The vast majority of noise
due to background sources is associated with known radio sources (for example,
from the NVSS with a detection threshold of 2.3 mJy) with normal steep spectra
({\alpha} = 0.7-0.8, S \propto {\nu}^{- \alpha}), which have also been detected
in new deep surveys at decimeter wavelengths. When all such objects are removed
from the observational data, this leaves another noise component that is
observed to be roughly identical in independent groups of observations. We
suggest this represents a new population of radio sources that are not present
in known catalogs at the 0.6 mJy level at 7.6 cm. The studied redshift
dependence of the number of steep-spectrum objects shows that the sensitivity
of our survey is sufficient to detect powerful FRII radio sources at any
redshift, right to the epoch of formation of the first galaxies. The inferred
new population is most likely associated with low-luminosity objects at
redshifts z < 1. In spite of the appearance of new means of carrying out direct
studies of distant galaxies, searches for objects with very high redshifts
among steep and ultra-steep spectrum radio sources remains an effective method
for studying the early Universe.Comment: 13 pages, 10 figure
Segmentation of microscopic images of sputum stained by Ziehl - Nielsen using wavelet transform Mexican Hat
Background. Currently at bacterioscopic diagnosis of tuberculosis there is a large number of errors that is associated with a number of problems that can be solved by automated analysis of microscopic images of sputum. Automated image analysis usually consists of several stages: image segmentation and identification or recognition of objects in the image. The article examines the first of these stages - segmentation. The aim of the study was to investigate the possibility of segmenting a digital image of a microscopic preparation sputum, stained by the method of Ziehl - Nielsen, using wavelet transform Mexican Hat. Materials and methods. As research material we used 830 digital images obtained by microscopy of sputum smears stained by the method of Ziehl - Nielsen. For the automated segmentation of images we used two-dimensional wavelet transform of Mexican Hat Wavelet. Results. During the study we defined the optimal value of the a parameter, which is the only varying parameter of a wavelet Mexican Hat, and carried out the run-time evaluation of the wavelet transform digital microscopic images of sputum stained by the method of Ziehl - Nielsen. Conclusions. The conclusion is made about possibility of using two-dimensional wavelet transform Mexican Hat digital microscopic images of sputum stained by the method of Ziehl - Nielsen, for segmentation of these images
Modern possibilities of optical reconstructive surgery in patients after removal of the iridociliary zone tumor
Choroid neoplasms account for two-thirds of all intraocular tumors, of which 23% are tumors of the iris and ciliary body, and the rest are choroidal tumors. After removing the tumor of the iridociliary zone (ICZ) it is necessary to perform optical reconstructive surgery to reduce light aberrations and increase visual functions.Purpose. To identify key features of the complex rehabilitation of patients after removal of the ICZ tumor.Material and methods. The clinical and functional results of the complex rehabilitation of 12 patients (12 eyes) aged from 35 to 84 years (average 66 years) were studied at least 1 year after removal of the ICZ tumor. The area of the iris defect before the reconstructive surgery ranged from 15 to 55%. Preoperative uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were 0.26±0.19 (from 0.01 to 0.6) and 0.46±0.22 (from 0.1 to 0.8) respectively. All patients underwent phacoemulsification of cataract and implantation of the irislens diaphragm.Results. After the reconstructive surgery, UCVA and BCVA increased: 0.5±0.17 (from 0.2 to 0.7) and 0.61±0.27 (from 0.3 to 0.9) respectively. Undesirable optical effects were decreased, and patients were satisfied with the cosmetic result.Conclusion. The presented algorithm of optical reconstructive surgery after removal of the ICZ tumor creates necessary conditions for increasing postoperative functional results and improving the quality of life of these patients
RATAN-600 7.6-cm Deep Sky Strip Surveys at the Declination of the SS433 Source During the 1980-1999 Period. Data Reduction and the Catalog of Radio Sources in the Right-Ascension Interval 7h < R.A. < 17h
We use two independent methods to reduce the data of the surveys made with
RATAN-600 radio telescope at 7.6 cm in 1988-1999 at the declination of the
SS433 source. We also reprocess the data of the "Cold" survey (1980-1981). The
resulting RCR (RATAN COLD REFINED) catalog contains the right ascensions and
fluxes of objects identified with those of the NVSS catalog in the
right-ascension interval 7h < R.A. < 17h. We obtain the spectra of the radio
sources and determine their spectral indices at 3.94 and 0.5 GHz. The spectra
are based on the data from all known catalogs available from the CATS, Vizier,
and NED databases, and the flux estimates inferred from the maps of the VLSS
and GB6 surveys. For 245 of the 550 objects of the RCR catalog the fluxes are
known at two frequencies only: 3.94 GHz (RCR) and 1.4 GHz (NVSS). These are
mostly sources with fluxes smaller than 30 mJy. About 65% of these sources have
flat or inverse spectra (alpha > -0.5). We analyze the reliability of the
results obtained for the entire list of objects and construct the histograms of
the spectral indices and fluxes of the sources. Our main conclusion is that all
10-15 mJy objects found in the considered right-ascension interval were already
included in the decimeter-wave catalogs.Comment: 26 pages, 18 figure
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