Low-Frequency Acoustic Signals Propagation in Buried Pipelines

The article deals with the issues concerning acoustic signals propagation in the large-diameter oil pipelines caused by mechanical action on the pipe body. Various mechanisms of signals attenuation are discussed. It is shown that the calculation of the attenuation caused only by internal energy loss, i.e, the presence of viscosity, thermal conductivity and liquid pipeline wall friction lead to low results. The results of experimental studies, carried out using the existing pipeline with a diameter of 1200 mm. are shown. It is experimentally proved that the main mechanism of signal attenuation is the energy emission into the environment. The numerical values of attenuation coefficients that are 0,14- 0.18 dB/m for the pipeline of 1200 mm in diameter, in the frequency range from 50 Hz to 500 Hz, are determined

Archaeological Studies of St Petersburg by the Institute for the History of Material Culture of the Russian Academy of Sciences

During recent years, researchers from the Institute for the History of Material Culture (IHMC) RAS conducted a series of large-scale archaeological investigations in St Petersburg, Russia. The volume and character of these investigations varied from archaeological supervision of earthworks to large excavations. They have yielded valuable information on the presence, situation, and type of cultural layers within the area of the city and Leningrad oblast, as well as on the tragic fate of the first builders of St Petersburg. These studies, in addition, provided more exact historical data on town planning in the city. The archaeological investigations were conducted at about 100 points within the territory of St Petersburg and its surroundings. This short paper presents an account of some of the most importantinvestigations

Soft Skills of Future Specialists in Creative Areas of Training

Рассмотрены актуальность и важность воспитательной деятельности вуза в формировании конкурентоспособного специалиста через формирование навыков будущего. Опрошено 33 респондента, из них 15 работодателей и 18 самозанятых студентов, и приведены результаты по определению навыков будущего, способствующих повышению конкурентоспособности.The relevance and importance of educational activities of the university in the formation of a competitive specialist through the formation of skills of the future are considered. 33 respondents were interviewed, including 15 employers and 18 self-employed students, and the results on determining the skills of the future that contribute to improving competitiveness are presented

The experience of using the hackathon format for the formation of flexible skills on the example of the Creative hackathon “Graffiti”

Рассмотрена базовая структура проведения хакатонов, проведен анализ данного формата как формы проведения культурно-массового мероприятия на предмет формирования навыков будущего у участников. Проведен анализ опыта реализации мероприятия в формате хакатона на примере «Творческого хакатона “Граффито”».The basic structure of hackathons is considered, the analysis of this format as a form of holding a cultural event for the formation of future skills among participants is carried out. The analysis of the experience of implementing the event in the hackathon format is carried out on the example of the Creative hackathon “Graffiti”

Обработка пропусков в рыночных данных на примере задачи оценки кривой доходностей облигаций

Missing observations in market data is a frequent problem in financial studies. The problem of missing data is often overlooked in practice. Missing data is mostly treated using ad hoc methods or just ignored. Our goal is to develop practical recommendations for treatment of missing observations in financial data. We illustrate the issue with an example of yield curve estimation on Russian bond market. We compare three methods of missing data imputation — last observation carried forward, Kalman filtering and EM–algorithm — with a simple strategy of ignoring missing observations. We conclude that the impact of data imputation on the quality of yield curve estimation depends on model sensitivity to the market data. For non-sensitive models, such as Nelson-Siegel yield curve model, final effect is insignificant. For more sensitive models, such as bootstrapping, missing data imputation allows to increase the quality of yield curve estimation. However, the result does not depend on the chosen data imputation method. Both simple last observation carried forward method and more advanced EM–algorithm lead to similar final results. Therefore, when estimating yield curves on the illiquid markets with missing market data, we recommend to use either simple non-sensitive to the data parametric models of yield curve or to impute missing data before using more advanced and sensitive yield curve models.Пропуски в рыночных данных — частая проблема в финансовых исследованиях, которой уделяется относительно мало внимания на практике. Обработка пропусков, как правило, выполняется эвристически и является лишь вспомогательным шагом исследований. Целью нашей работы является разработка практических рекомендаций по работе с пропусками в рыночных данных. Проблема иллюстрируется на примере задачи оценки временной структуры процентных ставок на российском рынке государственных облигаций. Мы сравниваем три различных метода заполнения пропусков в данных — заполнение последним значением, фильтр Калмана и EM-алгоритм — с простой стратегией удаления пропусков. Мы приходим к выводу, что эффект от заполнения пропусков на качество оценки кривой зависит от чувствительности модели кривой доходностей к рыночным данным. Для слабо чувствительных к данным моделей, например для модели кривой доходностей Нельсона-Зигеля, эффект от заполнения пропусков минимален. Для более чувствительных моделей кривой, таких как бутстрэп, за счет заполнения пропусков удается достичь статистически значимого улучшения качества оценки срочной структуры процентных ставок. При этом данный результат не зависит от способа заполнения пропусков. И простой метод заполнения последним значением, и более сложный EM-алгоритм дают схожие результаты. Рекомендация исследования состоит том, что на практике при оценке кривой доходностей в условиях неполных данных необходимо либо использовать слабо чувствительные к данным параметрические модели кривой доходностей, либо заполнять пропуски в данных перед использованием чувствительных моделей

Metodologia para melhorar a qualidade na organização do processo educacional através da implementação de software

The article deals with the issues of information exchange between teachers, pupils and educational organization departments. They analyzed the advantages and the disadvantages of traditional approaches: e-mail, communication via phones, social networks. They considered the issues of information placement intended for a large number of users. They revealed the need to address the problems associated with the publication of events - major administrative announcements of educational organizations, which are visible to all users and set to a certain date. The approach to publication of events is proposed within the framework of a system separate module. They considered the mechanism of mass mailings which allows users to transmit information to two or more recipients and ensures the exchange of information available only to recipients, unlike the "wall". An approach is proposed to increase the quality of the educational process organization, which allows a rapid exchange. The issues of information placement are considered on the website of the educational organization using the example of the training schedule. The advantages and the disadvantages of the traditional approach are analyzed. The issues of schedule planning among part-timer teachers are considered. They propose the approach to increase the quality the educational process quality organization, which allows you to place and make changes to the curriculum quickly using the example of the "Electronic Schedule" system.El artículo trata sobre los temas de intercambio de información entre profesores, alumnos y departamentos de organizaciones educativas. Analizaron las ventajas y desventajas de los enfoques tradicionales: correo electrónico, comunicación a través de teléfonos, redes sociales. Consideraron los problemas de la colocación de información destinados a un gran número de usuarios. Revelaron la necesidad de abordar los problemas asociados con la publicación de eventos: los principales anuncios administrativos de las organizaciones educativas, que son visibles para todos los usuarios y se establecen en una fecha determinada. El enfoque para la publicación de eventos se propone en el marco de un módulo separado del sistema. Consideraron el mecanismo de correo masivo que permite a los usuarios transmitir información a dos o más destinatarios y garantiza el intercambio de información disponible solo para los destinatarios, a diferencia del "muro". Se propone un enfoque para aumentar la calidad de la organización del proceso educativo, lo que permite un intercambio rápido. Los problemas de colocación de información se consideran en el sitio web de la organización educativa utilizando el ejemplo del programa de capacitación. Se analizan las ventajas y desventajas del enfoque tradicional. Se consideran los problemas de planificación de horarios entre los maestros a tiempo parcial. Proponen el enfoque para aumentar la calidad de la organización de la calidad del proceso educativo, lo que le permite ubicar y realizar cambios en el plan de estudios rápidamente utilizando el ejemplo del sistema "Programación electrónica".O artigo trata das questões de troca de informações entre professores, alunos e departamentos de organização educacional. Eles analisaram as vantagens e desvantagens das abordagens tradicionais: e-mail, comunicação via telefones, redes sociais. Eles consideraram os problemas de colocação de informações destinados a um grande número de usuários. Eles revelaram a necessidade de abordar os problemas associados à publicação de eventos - grandes anúncios administrativos de organizações educacionais, que são visíveis para todos os usuários e definidos para uma determinada data. A abordagem para publicação de eventos é proposta no âmbito de um módulo separado do sistema. Eles consideraram o mecanismo de envios em massa que permite aos usuários transmitir informações a dois ou mais destinatários e garante a troca de informações disponíveis apenas para os destinatários, ao contrário do "muro". Uma abordagem é proposta para aumentar a qualidade da organização do processo educacional, o que permite uma troca rápida. As questões de colocação de informações são consideradas no site da organização educacional usando o exemplo do cronograma de treinamento. As vantagens e desvantagens da abordagem tradicional são analisadas. As questões do planejamento do cronograma entre os professores temporários são consideradas. Eles propõem a abordagem para aumentar a qualidade da organização da qualidade do processo educacional, que permite colocar e fazer mudanças no currículo rapidamente usando o exemplo do sistema "Programação Eletrônica"

Influence of intravenous ferric carboxymaltose on non-invasive parameters of left ventricular myocardial work in patients with heart failure with reduced ejection fraction

Aim. To assess non-invasive parameters of left ventricular (LV) myocardial work in patients with heart failure with reduced ejection fraction (CHrEF) and iron deficiency (ID) after ferric carboxymaltose (FCM) therapy.Material and methods. There were following inclusion criteria: LV ejection fraction (EF) ≤40%; body >70 kg, receiving best medical therapy (BMT) in recommended doses in accordance with the guidelines of the European Society of Cardiology and the Russian Society of Cardiology. Median age was 67±11,7 years (men, 83%), while median LVEF and N-terminal pro-brain natriuretic peptide was 29% and 315 ng/ml, respectively. Patients were randomized by the envelope method. The first group consisted of 19 patients who received therapy with intravenous FCM 1500 mg in 2 injections with an interval of one week between injections in addition to BMT. The control group consisted of 16 patients who received BMT without FCM. All patients underwent a standard echocardiography, and non-invasive LV myocardial work was assessed immediately before inclusion in the study and after 3 months.Results. In the first group of patients receiving FCM therapy, an increase in LVEF (29,1±10,3 vs 35,4±11,1; p=0,001), mitral annular plane systolic excursion (1,2 (1;1,6 ) vs 1,5 (1,3;1,9), p=0,001), LV global longitudinal strain (-7 (-5;-8) vs -8 (-6;-11), p=0,007) and non-invasive indicators of myocardial work (global work index (826±314 vs 1041±354), p=0,0001; global constructive work (1173±388 vs 1435±405), p=0,0001; global work efficiency (85 (82;87) vs 86 (82;88), p=0,017)). There were no significant changes in the studied parameters in the BMT group.Conclusion. Patients with HFrEF and ID treated with FCM showed a significant increase in LV systolic function, including non-invasive myocardial work parameters, compared with the control group

Proinflammatory cytokines VEGFA, IL-6, IL-8 as markers of hepatotoxicity after COVID-19

The mechanism of hepatocellular liver damage after COVID-19 is a multifactorial process. The most widely discussed causes are cytolytic liver damage due to the inflammatory response after COVID-19, drug-induced hepatotoxicity and direct cytotoxic effect of the virus. There are observations that SARSCoV-2 infection causes hepatitis B virus reactivation, but little has been described about the interaction between hepatitis C virus and SARS-CoV-2. The course of coronavirus infection is associated with marked expression of proinflammatory cytokines, participants in the multisystem inflammatory response, IL-1β, IL-6, IL-8, IL-18, MCP-1, TNFα, which contribute significantly to the observed early and late liver function impairment. The aim of the study was to evaluate the role of proinflammatory cytokines (VEGFA, IL-8, IL-6, MCP-1, TNFα, IL-18) as additional markers of hepatotoxicity after COVID-19. The study was performed between March and August 2022. Patients were divided into 2 groups: Group 1 – with increased aminotransferases against the background of treatment from COVID-19 and/or in the following 3-6 months after the disease without viral liver damage (n = 42), Group 2 – patients with co-infection (chronic viral hepatitis C (HCV) and COVID-19 (n = 26). The levels of cytokines – VEGF-A, IL-6, IL-8, MCP-1, IL-18, TNFα in blood serum were estimated by enzyme immunoassay method. Statistical analysis was performed using StatTech v. 3.1.4. The results of the study revealed a comparable increase in the level of transaminases and C-reactive protein in both groups, significantly different from the reference values. Direct correlations of moderate strength (linear Spearman correlation) were found between the following cytokines: TNFα-MCP-1 (R = 0.559; p = 0.001), TNFα-VEGFA (R = 0.400; p = 0.002), TNFα-IL-6 (R = 0.503; p = 0.001). We diagnosed a significant increase in serum VEGFA levels in group 1 patients (hepatotoxicity after COVID-19) (Me (Q0.25-Q0.75): 522 (250 to 1002), p = 0.001) and in group 2 patients (HCV + COVID-19) (Me 1196, Q0.25-Q0.75: (73 to 432). Similar trend with the level of IL-6, IL-8, exceeding the values of cytokines in healthy donors and significantly higher than in group 2 patients. Identified correlations between inflammatory cytokines prove unidirectional changes in the functioning of the regulatory network controlling immune virus-induced reactions