Diamond grinding wheels production study with the use of the finite element method

AbstractResearch results on 3D modeling of the diamond grain and its bearing layer when sintering diamond grinding wheels are provided in this paper. The influence of the main characteristics of the wheel materials and the wheel production process, namely the quantity of metallic phase within diamond grain, coefficient of thermal expansion of the metallic phase, the modulus of elasticity of bond material and sintering temperature, on the internal stresses arising in grains is investigated. The results indicate that the stresses in the grains are higher in the areas around the metallic phase. Additionally, sintering temperature has the greatest impact on the stresses of the grain-metallic phase-bond system regardless of the type of the bond. Furthermore, by employing factorial design for the carried out finite element model, a mathematical model that reflects the impact of these factors on the deflected mode of the diamond grain-metallic phase-bond material system is obtained. The results of the analysis allow for the identification of optimal conditions for the efficient production of improved diamond grinding wheels. More specifically, the smallest stresses are observed when using the metal bond with modulus of elasticity 204GPa, the quantity of metallic phase in diamond grain of not higher than 7% and coefficient of thermal expansion of 1.32×10−51/K or lower. The results obtained from the proposed 3D model can lead to the increase in the diamond grains utilization and improve the overall efficiency of diamond grinding

Virtualization of museums

The article discusses the comparison of virtual museums with real museums, presented the basic principles of virtualization. Examples of implementation of virtual tours in Yekaterinburg, Novouralsk, Pervouralsk. Showed educational potential of virtual excursions and toursВ статье рассматривается сравнение виртуальных музеев с реальными музеями, представлены основные принципы виртуализации. Приведены примеры внедрения виртуальных туров в Екатеринбурге, Новоуральске, Первоуральске. Показан образовательный потенциал виртуальных экскурсий и туро

A Five-year Spectroscopic and Photometric Campaign on the Prototypical alpha Cygni Variable and A-type Supergiant Star Deneb

Deneb is often considered the prototypical A-type supergiant, and is one of the visually most luminous stars in the Galaxy. A-type supergiants are potential extragalactic distance indicators, but the variability of these stars needs to be better characterized before this technique can be considered reliable. We analyzed 339 high resolution echelle spectra of Deneb obtained over the five-year span of 1997 through 2001 as well as 370 Stromgren photometric measurements obtained during the same time frame. Our spectroscopic analysis included dynamical spectra of the H-alpha profile, H-alpha equivalent widths, and radial velocities measured from Si II 6347, 6371. Time-series analysis reveals no obvious cyclic behavior that proceeds through multiple observing seasons, although we found a suspected 40 day period in two, non-consecutive observing seasons. Some correlations are found between photometric and radial velocity data sets, and suggest radial pulsations at two epochs. No correlation is found between the variability of the H-alpha profiles and that of the radial velocities or the photometry. Lucy (1976) found evidence that Deneb was a long period single-lined spectroscopic binary star, but our data set shows no evidence for radial velocity variations caused by a binary companion.Comment: 49 pages, 9 figures, 5 tables, accepted for publication in the Astronomical Journa

Resistance of the microorganisms isolated from surgical hospital environment to disinfectants

The article presents the results of the study of resistance of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Aspergillus fungi to disinfectants. The microorganisms were isolated from the surgical ward environment of Central District Hospital of Neryungri. All strains were sensitive to Lysoformin 3000. Most of the microorganisms were sensitive to Ecocide and Septodor (85,7 % and 71,4 % respectively). Only E. coli was resistant to these disinfectants. The microorganisms showed the highest resistance to Javelion. S. aureus and E. coli were resistant to Javelion. The most effective disinfectants against Aspergillus were 1% solution of Septabic, 0,2% solution of Vegasept, 0,4% solution of Septodor, 0,5% solution of Lysoformin 3000. The other disinfectants (Chlor-sept, Hypocloride and Alfadez forte) had lower fungicidal activity against Aspergillus

Loimologically significant pinniped helminths in Chukotka

The purpose of the research is study of pinniped helminth fauna in Chukotka, and the analysis of the fish of the main commercial families infected with pathogens of helminthozoonoses based on modern literature.Materials and methods. The helminths were collected in autumn of 2019 from pinnipeds caught in the Mechigmenskaya Guba of the Bering Sea in the Chukotka Autonomous Okrug by the method of partial helminthological dissection per Skryabin (gastrointestinal tract). Samples were examined from 6 walruses and 26 seals (13 spotted seals and 13 ringed seals). The helminths found were fixed in 70% alcohol. The helminth species were identified at the Department of Parasitology and Veterinary and Sanitary Examination of the MVA named after K. I. Skryabin using reference literature.Results and discussion. All pinnipeds were infected with nematodes of the family Anisakidae. Mature Pseudoterranova desipiens were found in the walrus (Infection Prevalence = 16.7% with Infection Intensity = 3 specimens/animal), mature Ps. desipiens, as well as Contracoecum osculatum and Anisakis simplex larvae (IP = 30.8% with II from 5 to 57 specimens) were found in the spotted seal, and Ps. desipiens larvae and mature Ps. desipiens were found in the ringed seal (IP = 15.4% with II from 1 to 4 specimens). Thus, only Ps. desipiens were represented by mature stages (females and males), and two other species of anisakids, C. osculatum and A. simplex, were found in the seals in the larval stage

STAPHYLOCOCCUS, STIMULATORS OF GROWTH FOR RAPID DIAGNOSIS OF HEALTHCARE-ASSOCIATED INFECTIONS

The possibility of using biologically active proton (2-hydroxyethyl) ammonium, ionic liquids of the general formula HN+RiR2(CH2CH2OH)3_n.•OOCCH,X(Ind)Ai; R = H, Me, X = O, S, SO; n = 0-2 as stimulators of growth S. aureus shows in the article. 24 strains isolated from patients with purulent-septic complications from the surgical department studied. There are shown a significant acceleration, of growth of S. aureus in a agar nutrient containing yolk-salt agar, the addition of stimulants tested at concentrations 4.10-6.10 wt. %. Proposed use of stimulants for the development of improved methods of rapid diagnosis of healthcare-associated infections caused by S. aureus, which will greatly reduce the time of issue analysis and. prescribe adequate treatment promptly sick

Comparative indicators of morphology and seed productivity in rare <i>Iris</i> L. spp. within their natural habitats and under cultivation in the Southern Urals

Background. Wild irises are promising for cultivation and use in breeding practice. Many of them are included in Red Lists, as they disappear under the impact of anthropogenic factors. It is biologically important to study their morphometric and reproductive parameters, so that the most stable and highly ornamental species could be recommended for expanding the range of flower plants.Materials and methods. Biological features of four Iris L. species rarely occurring in the Southern Urals: I. pseudacorus L., I. pumila L., I. scariosa Wild. ex Link, and I. humilis Georgi, were studied in 2012–2017 in 23 natural and 4 introduced cenopopulations. Individual parameters were compared for 25 medium-age plants from each cenopopulation in their mass-flowering and fruiting phase according to 11 biometric parameters using conventional methods. Statistical significance of the differences was assessed using Student’s t-test.Results. Comparison of morphometric parameters of four rare Iris spp. naturally occurring and introduced in Bashkortostan during six years of research showed significant differences between cenopopulations at a 5% significance level for most traits of I. pumila and I. pseudacorus. As for I. scariosa and I. humilis, differences were mostly insignificant (at tfact&lt; 2.064). Mean values of most reproductive parameters for I. scariosa, I. humilis and I. pseudacorus were significantly lower under introduction conditions than in natural populations. Under cultivation, seed productivity of I. pumila increased. Variability of most morphometric features of the studied irises was within normal response limits for the studied species. When cultivated in the environments of the Bashkir Cis-Urals, they bloom and bear fruit every year, except for I. humilis.Conclusion. Of the four rare Iris spp., I. pumila is recommended for landscaping settlements in the South Urals as the most stable species

Project approach to the development of rural tourism

The authors of the article provide an overview of scientific approaches to the definition of the essence and role of event and gastronomic tourism against the backdrop of the rural tourism promotion currently carried out. The interrelation between all the aforementioned types of tourism and the expediency of their joint development are substantiated. The necessity of holding events in order to smooth out the seasonality of rural tourism and attract tourists interested not only in standard services of rural guest houses but also in entertainment events is proved. Special emphasis is placed on the application of the project approach to the process of creating events. A description of the festivals held in the Vologda region is provided. The main problems of the implementation of project management at the municipal level are identified. The possibility of holding gastronomic festivals within the clusters operating in the region is considered. The example of the «SyrFest» gastronomic festival is used to demonstrate a possible project structure designed for such event