О ДВУХСОЗВЕЗДНЫХ GBAS

The problem of accurate navigation support for landing systems is of great importance in our time in connection with the constantly increasing intensity of air traffic in major airports. At present, there is a trend towards a transition to navigational identification of aircraft by satellite radio navigation systems. Currently, two global navigation satellite systems, composed of navigational spacecraft – the Russian GLONASS system and the USA GPS system – operate in full. Moreover, to provide the necessary accuracy of positioning and data integrity the additional means are used – differential corrections. The article gives evidence of increasing the accuracy of positioning using the GBAS system. It is shown that the positioning with using GBAS ensures data integrity, corresponding to the category of «critical data» in accordance with ICAO requirements. The technical advantages of the Russian GBAS station are given. A comparative analysis of GBAS and the ILS landing system has been carried out. The article proves the urgency of the functional augmentation development of multi-frequency multi-system terrestrial systems. To calculate the characteristics of the maintenance continuity of the GBAS system, the complex technical systems effectiveness method of evaluation was used. Numerical data are presented on the probability of solving the navigation problem in the differential mode for the nominal mode. The calculation of the maintenance continuity characteristics of the GBAS system based on the complex technical systems effectiveness method of evaluation was carried out. The advantages of using the mobile version of the GBAS LKKS-A-2000 station are substantiated to provide the helicopters with an instrument approach for landing on unprepared sites. The figure shows the implementation of coordinates estimation errors in the differential mode in solving the navigation problem using 5 navigation satellites of the GPS system. The figure shows the implementation of estimation errors for the same record in using all visible and navigational satellites. The figure shows the number of visible navigation satellites.Проблема точного навигационного обеспечения систем посадки приобретает большое значение в наше время в связи с постоянно повышающейся интенсивностью воздушного движения в основных аэропортах. В настоящее время наметилась тенденция к переходу к навигационным определениям воздушных судов по спутниковым радионавигационным системам. В настоящее время в полном объеме функционируют две глобальные навигационные спутниковые системы, составленные из навигационных космических аппаратов – российская система ГЛОНАСС и американская система GPS. При этом для обеспечения необходимой точности позиционирования и целостности данных используются дополнительные средства – дифференциальные поправки. В статье приведены доказательства повышения точности позиционирования с использованием системы GBAS. Показано, что позиционирование с использованием GBAS обеспечивает целостность данных, соответствующую категории «критических данных» по требованиям ИКАО. Приведены технические преимущества российской станции GBAS. Проведен сравнительный анализ GBAS и cистемы посадки ILS. В статье обоснована актуальность разработки многочастотных многосистемных наземных систем функционального дополнения. Для расчета характеристик непрерывности обслуживания системы GBAS использован метод оценки эффективности сложных технических систем. Приведены численные данные по вероятности решения навигационной задачи в дифференциальном режиме для штатного режима. Проведен расчет характеристик непрерывности обслуживания системы GBAS на основе метода оценки эффективности сложных технических систем. Обоснованы преимущества использования мобильной версии станции GBAS ЛККС-А-2000 для обеспечения для вертолетов инструментального захода на посадку на неподготовленных площадках. Приведен рисунок, демонстрирующий реализацию ошибок оценивания координат в дифференциальном режиме при решении навигационной задачи по 5 навигационным спутникам системы GPS. Приведен рисунок, демонстрирующий реализацию ошибок оценивания для той же записи при использовании всех видимых и навигационных спутников. Приведен рисунок, демонстрирующий число видимых навигационных спутников.

Чрескожная высокочастотная селективная ризотомия в терапии тригеминальной невралгии при рассеянном склерозе

Trigeminal neuralgia is a rare symptom of multiple sclerosis affecting the disability. Multiple sclerosis related trigeminal neuralgia has been attributed to a demyelinating lesion in the pons. When the adequate pain drug-relieve therapy is not possible or when the patient becomes refractory to the treatment or can not continue pharmacological treatment because of the side effects, surgical intervention, including percutaneous radiofrequency rhizotomy is being discussed. Literature review and the data upon the efficiency and safety of this neurosurgical treatment in 16 patients with multiple sclerosis have been analyzed. Percutaneous radiofrequency rhizotomy has been proved to be a safe, reproducible and effective method of the symptomatic surgical treatment of trigeminal neuralgia in patients with multiple sclerosis in cases of the intolerance/inefficiency of the pharmacological therapy.Невралгия тройничного нерва (НТН) является относительно редким, но инвалидизирующим симптомом при рассеянном склерозе (РС). В качестве наиболее частой причины считается наличие очага демиелинизации в варолиевом мосту. При ограничении возможностей медикаментозной терапии НТН при РС в связи побочными эффектами рассматривается возможность различных методов хирургического лечения, в том числе проведение чрескожной высокочастотной селективной ризотомии (ЧВСР). Приведены литературные и собственные данные оценки эффективности и безопасности ЧВСР при НТН у 16 больных РС. Полученные результаты позволили заключить, что ЧВСР является безопасным, повторяемым и эффективным методом симптоматического хирургического лечения НТН при РС при неэффективности/непереносимости медикаментозной терапии

ABOUT TWO-STAR GBAS

The problem of accurate navigation support for landing systems is of great importance in our time in connection with the constantly increasing intensity of air traffic in major airports. At present, there is a trend towards a transition to navigational identification of aircraft by satellite radio navigation systems. Currently, two global navigation satellite systems, composed of navigational spacecraft – the Russian GLONASS system and the USA GPS system – operate in full. Moreover, to provide the necessary accuracy of positioning and data integrity the additional means are used – differential corrections. The article gives evidence of increasing the accuracy of positioning using the GBAS system. It is shown that the positioning with using GBAS ensures data integrity, corresponding to the category of «critical data» in accordance with ICAO requirements. The technical advantages of the Russian GBAS station are given. A comparative analysis of GBAS and the ILS landing system has been carried out. The article proves the urgency of the functional augmentation development of multi-frequency multi-system terrestrial systems. To calculate the characteristics of the maintenance continuity of the GBAS system, the complex technical systems effectiveness method of evaluation was used. Numerical data are presented on the probability of solving the navigation problem in the differential mode for the nominal mode. The calculation of the maintenance continuity characteristics of the GBAS system based on the complex technical systems effectiveness method of evaluation was carried out. The advantages of using the mobile version of the GBAS LKKS-A-2000 station are substantiated to provide the helicopters with an instrument approach for landing on unprepared sites. The figure shows the implementation of coordinates estimation errors in the differential mode in solving the navigation problem using 5 navigation satellites of the GPS system. The figure shows the implementation of estimation errors for the same record in using all visible and navigational satellites. The figure shows the number of visible navigation satellites

Zapiski dekabrista D. I. Zavalishina.

Mode of access: Internet

Spatial structure, thermodynamics and kinetics of formation of hydrazones derived from pyridoxal 5′-phosphate and 2-furoic, thiophene-2-carboxylic hydrazides in solution

© 2019 Elsevier B.V. The spatial structure of pyridoxal 5′-phosphate hydrazones of 2-furoic hydrazide; thiophene-2-carboxylic hydrazide in aqueous solution was studied by means of quantum chemical calculations and NOE experiment. The hydrazones could exist as a mixture of different conformers; however, the specific ones could be suggested from experimental and calculated data. The stability constants of hydrazones at pH of 1.9; 6.6; 7.0; 7.4 were determined using UV–Vis spectroscopy. Rate constants of the hydrazone formation and hydrolysis reaction within the range of 6.6–7.4 pH were obtained. Isothermal calorimetric titration was performed in order to determine the change in the free Gibbs energy, enthalpy and entropy of hydrazones formation at pH of 6.6. Hydrazones were synthesized and characterized by means of 1 H, 13 C, 31 P NMR, IR, UV–Vis, fluorescent, MS-spectroscopy as well as DSC and elemental analysis

Spatial structure, thermodynamics and kinetics of formation of hydrazones derived from pyridoxal 5′-phosphate and 2-furoic, thiophene-2-carboxylic hydrazides in solution

© 2019 Elsevier B.V. The spatial structure of pyridoxal 5′-phosphate hydrazones of 2-furoic hydrazide; thiophene-2-carboxylic hydrazide in aqueous solution was studied by means of quantum chemical calculations and NOE experiment. The hydrazones could exist as a mixture of different conformers; however, the specific ones could be suggested from experimental and calculated data. The stability constants of hydrazones at pH of 1.9; 6.6; 7.0; 7.4 were determined using UV–Vis spectroscopy. Rate constants of the hydrazone formation and hydrolysis reaction within the range of 6.6–7.4 pH were obtained. Isothermal calorimetric titration was performed in order to determine the change in the free Gibbs energy, enthalpy and entropy of hydrazones formation at pH of 6.6. Hydrazones were synthesized and characterized by means of 1 H, 13 C, 31 P NMR, IR, UV–Vis, fluorescent, MS-spectroscopy as well as DSC and elemental analysis