About the productivity of shaft air heater located along the perimeter of pithead

In the existing shaft air heaters that heat the air for air suppliers in the cold season heater channel is used. Part of the air from heater goes to the channel, another one is sucked through pithead by general shaft pressure drawdown formed by main ventilation installation. Wherein, mix of two air flow leads to shaft heat regime violation that could break the pressurization of intertubular sealers. Moreover, heater channel design is associated with additional expenditures. Paper describes the air heater, located in the pithead. The location of a heater in one line along pithead perimeter is the key feature. In this case there is no need to design heater channel, thus, there is no problem with mix of cold and heated air flows. Air processing it the heater located on the perimeter of pithead and mix of cold and heated air flows in the supplier from the channel was modeled in the software Soldworks flow simulation. The comparative analysis of both types of heater proved efficiency of proposed design of installation, smooth propagation of heat field along the all cross-section of air supplier, decrease of consumption of electric power for air processing and installation operation by transformation negative natural common excavation traction to positive

Results of modelling of mine ventilation with air curtain installed into downcast and upcast shafts

Existing mine air heaters (MAH) that heat the air supplied into downcast shafts during the cold period are equipped with a heat channel. A part of the air from a MAH goes through a heat channel. Another part is sucked through a pit head by general depression created by a shaft main fan. That raises a problem of mixing of two air streams, which disturbs thermal regime in the shafts and could lead to violation of safety rules, in particular, create a breach of sealing of intertubular seals. Besides, there is a concern of energy saving during ventilation at underground mining enterprises. One of the reasons for energy efficiency reduce during air supply to a mine are external leaks appeared during ventilation by a suck method. The article presents proposed solution for both problems using air curtain. During air preparation in the cold period, it is proposed to place air curtain in an air downcast shafts above the junction of a heat channel and a shaft. That is done in order to prevent air infiltration (sucking) through a pit head. According to the paper air curtain should be used in the ventilation shaft to decrease outside air leakage in order to increase energy efficiency of a main fan performance. It is determined during mathematical modelling (in SolidWorks Flow Simulation software) of ventilation and air preparation that air curtain can increase efficiency of MAH and decrease energy consumption on ventilation

Towards effective indirect radioisotope energy converters with bright and radiation hard scintillators of (Gd,Y)3Al2Ga3O12 family

Ceramics of quaternary garnets (Gd,Y)3Al2Ga3O12 doped with Ce, Tb have been fabricated and evaluated as prospective materials for indirect energy converters of α-and β-voltaic. Samples were characterized at excitation with an X-ray source and an intense 150 keV electron beam and showed good temperature stability of their emission and tolerance to irradiation. The role of X-rays accompanied the α-particle emitting in the increase of the conversion efficiency is clarified. The garnet-type structure of the matrix in the developed materials allows the production of quality crystalline mass with a light yield exceeding that of the commonly used YAG: Ce scintillator by a factor of two times. © 2022 Korean Nuclear SocietyMinistry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2021-1353, FEUZ-2020-0060; Ministerstwo Edukacji i Nauki, MNiSW: 075-11-2021-070; Ministry of Science and Higher Education of the Russian FederationAuthors with affiliations b, d, e and f acknowledge support from Russian Ministry of Science and Education grant No. 075-15-2021-1353 . The scientific equipment provided by shared research facilities “Scientific Research Analytical Center of National Research Center “Kurchatov Institute” – IREA” was used, with financial support of Russian Federation, represented by the Ministry of Science and Higher Education, agreement No. 075-11-2021-070 dated August 19, 2021. The work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, project No. FEUZ-2020-0060 ) (authors with affiliation “c”).Authors with affiliations b, d, e and f acknowledge support from Russian Ministry of Science and Education grant No. 075-15-2021-1353. The scientific equipment provided by shared research facilities “Scientific Research Analytical Center of National Research Center “Kurchatov Institute” – IREA” was used, with financial support of Russian Federation, represented by the Ministry of Science and Higher Education, agreement No. 075-11-2021-070 dated August 19, 2021. The work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, project No. FEUZ-2020-0060) (authors with affiliation “c”)

Тонометрическое внутриглазное давление у взрослого населения: популяционное исследование

PURPOSE: To study the distribution of intraocular pressure (IOP) obtained by Maklakov tonometry in different age groups.METHODS: The study evaluated Caucasians without glaucoma aged 45-75. The participants underwent Maklakov tonometry with a 10 g tonometer at 09:00-12:00 with subsequent imprint evaluation by means of NesterovEgorov scale, measurements of central corneal thickness (CCT) and visual acuity. All the participants were divided into 3 groups by age: Group 1 consisted of participants aged 45-55, Group 2 comprised the ones aged 56-65, Group 3 included patients aged 66-75.RESULTS: In total 791 person were enrolled; 1 429 of 1 499 eyes (95.3%) were accepted into the study. IOP in Group I was 16.1±3.3 mmHg in Group 1; 16.3±3.3 in Group 2; 16.2±3.5 mmHg in Group 3. CCT in Group 1 was 545.7±14.6 μm; 545.3±15.4 μm in Group 2; 544.7±14.6 μm in Group 3. Visual acuity was 0.93±0.13 in Group 1; 0.89±0.15 in Group 2; 0.81±0.18 in Group 3. Average IOP in men was 16.4±3.3 mmHg, in women 16.5±3.3 mmHg. Age, vision acuity, CCT and IOP were within the normal distribution; IOP and CCT had no significant differences between the age groups. The measured parameters showed no significant intercorrelation. We found no significant difference between IOP in men and women.CONCLUSION: In a healthy population CCT and IOP values fall within a normal distribution and do not change significantly with age. IOP does not depend on sex. Average IOP in the studied population is 16.2±3.4 mmHg, average CCT is 545.3±15.1 μm.ЦЕЛЬ. Исследовать возрастные нормы внутриглазного давления (ВГД) при использовании тонометрии по Маклакову.МЕТОДЫ. Обследовали лиц европеоидной расы без глаукомы в возрасте 45-75 лет. Исследуемым измеряли ВГД тонометром Маклакова весом 10 грамм в период с 9:00 до 12:00 с последующей оценкой отпечатка по линейке Нестерова - Егорова, измеряли центральную толщину роговицы (ЦТР) и проверяли остроту зрения. Всех исследуемых разделили на три группы по возрасту: группа 1 — 45-55 лет, группа 2 — 56-65 лет, группа 3 — 66-75 лет.РЕЗУЛЬТАТЫ. Обследован 791 человек; из 1 499 глаз приняты 1 429 (95,3%). ВГД составило в группе 1 — 16,1±3,3 мм рт.ст.; в группе 2 — 16,3±3,3 мм рт.ст.; в группе 3 — 16,2±3,5 мм рт.ст. ЦТР составило в группе 1 — 545,7±14,6 мкм; в группе 2 — 545,3±15,4 мкм; в группе 3 — 544,7±14,6 мкм. Острота зрения составила в группе 1 — 0,93±0,13; в группе 2 — 0,89±0,15; в группе 3 — 0,81±0,18. Среднее ВГД у мужчин — 16,4±3,3 мм рт.ст., у женщин — 16,5±3,3 мм рт.ст. Возраст, острота зрения, ЦТР и ВГД имеют нормальное распределение; ВГД и ЦТР в разных группах достоверно не различаются. Наблюдаемые параметры ни в одном случае значимо не коррелируют друг с другом. Не выявлено разницы в ВГД у мужчин и женщин.ВЫВОДЫ. В здоровой взрослой популяции ЦТР и ВГД имеют нормальное распределение и не претерпевают значимых изменений с возрастом. ВГД не зависит от пола. Среднее ВГД в исследуемой популяции составляет 16,2±3,4 мм рт.ст., средняя ЦТР — 545,3±15,1 мкм

Analysis of the Polymer Two-Layer Protective Coating Impact on Panda-Type Optical Fiber under Bending

The article discusses the effects of thermal-force on the Panda-type optical fiber. The studies used a wide temperature range. The research used two thermal cycles with exposures to temperatures of 23, 60 and −60 °C. The field of residual stresses in the fiber formed during the drawing process was determined and applied. Panda was considered taking into account a two-layer viscoelastic polymer coating under conditions of tension winding on an aluminum coil in the framework of a contact problem. The paper investigated three variants of coil radius to analyze the effect of bending on fiber behavior. The effect of the coating thickness ratio on the system deformation and optical characteristics was analyzed. Qualitative and quantitative patterns of the effect of temperature, bending, thickness of individual polymer coating layers and relaxation transitions of their materials on the Panda optical fiber deformation and optical characteristics were established. Assessment of approaches to the calculation of optical characteristics (values of the refractive indices and fiber birefringence) are given in the framework of the study. The patterns of deformation and optical behavior of the Panda-type fiber with a protective coating, taking into account the nonlinear behavior of the system materials, were original results