27 research outputs found
Evaluation of the current state of aquatic ecosystems and the problems of the protection of biological resources during development of kruzenshternskoye gcf
The results of studies of the current state of freshwater ecosystems and their biotic components in the western part of the Yamal Peninsula are presented in the article. Based on the evaluation of the structure of communities of phytoplankton, zooplankton, benthos, and whitefishes, the range of problems related to the protection of biological resources during the development of the Kruzenshternskoye gas field is defined. The data on species composition and quantitative indicators of hydrobionts of different types of waterbodies and watercourses in the lower reaches of the Mordyyakha and Naduyyakha Rivers basins is the basis for environmental monitoring of water objects during development and exploitation of the Kruzenshternskoye gas field. Estimation of the fish fauna state and their food base in the territory of the Kruzenshternskoye GCF according to the monitoring program is present. The river delta zones are the most important feeding areas of the salmonid and whitefishes valuable fish species in the territory of Kruzenshternskoye GCF. In cases where water bodies and watercourses are not completely demolished for the construction of GCF facilities, changes of quantitative and qualitative characteristics of communities of hydrobionts after the end of operations are reversible. River ecosystems are restored within a shorter period of time in comparison to lacustrine ones. Proposals for the protection of fisheries resources and monitoring of aquatic ecosystems on the basis of comprehensive studies are reported. Recommendations on reducing the anthropogenic impact on aquatic ecosystems in the development period are present. The results of the investigation were used in the development of the environmental protection part of the Kruzenshternskoye deposit project. Anthropogenic disturbances present now on the gas deposit territory of Kruzenshternskoye does not influence the aquatic ecosystems.The article have been prepared within the Project of the Presidium of the Russian Academy of Sciences № 12-P-47-2013 and "The Arctic" Project of the Presidium of the Ural Branch of the Russian Academy of Sciences № 12-4-3-012
Principles of integrative modelling at studying of plasma and welding processes
The relevance of the problem subject to the research is conditioned by need for introduction of modern technologies into the educational process and insufficient adaptation of the higher school teachers to the applied information and automated procedures in education and science. The purpose of the publication consists in the analysis of automated procedures efficiency in engineering training and development of structurally functional model of information skills for students and teachers during their teaching in welding and allied technologies. The leading approach to research of this problem is the structurally functional method of the objects studying. This method based on representation of technological structure as hierarchical sequence of the interconnected devices and division of a matter into objects and means of influence that allows to allocate the processes providing functioning between means of influence. In the publication the structurally functional models of information skills formation for students and teachers in engineering and natural-science training are presented. The materials of the publication can be useful for students and teachers at studying of welding and allied technologies and development of scientifically-methodical maintenance for engineering and natural-science disciplines. © 2016 Anakhov et al
Integrated study of water Sr isotopes and carbonate Sr-C-O isotopes reveals long-lived fluid compartments in the Langfjellet oil discovery, Norwegian North Sea
Routine measurements of reservoir pressure variation with depth can detect pressure discontinuities indicative of barriers to vertical fluid movement. This study investigates how pressure data can be augmented by detailed profiles of formation water 87Sr/86Sr ratio to determine the precise location and cause of such barriers, and by C–O–Sr isotope analysis of carbonate cements to determine the duration over which the barrier has persisted. The study focuses on the clastic Hugin Formation reservoir in the Langfjellet Oil Discovery (Norwegian North Sea). Here, pressure data indicated a barrier somewhere within a 25 m depth interval. Formation water 87Sr/86Sr was measured with high spatial resolution by extraction from core samples using the residual salt analysis (RSA) method. This revealed three homogeneous populations of water separated by a small step in 87Sr/86Sr over a 7 m interval containing coal and shale layers, and a very large step in 87Sr/86Sr over a 1.2 m interval corresponding to a thin coal and shale layer situated below a major flooding surface. The latter is the main candidate for the pressure barrier. Modelling confirmed that this inferred pressure barrier also greatly retards Sr diffusion. Carbonate cements occur disseminated throughout the reservoir and in several heavily-cemented zones. Oxygen isotope-derived temperatures indicate that these formed in two episodes: (1) Pre-compactional, precipitated shortly after deposition in the zone of bacterial methanogenesis (~30 °C, ~200 m depth, ~162 Ma); (2) Post-compactional incorporating thermal decarboxylation-derived carbon (~90 °C, ~2500 m depth, ~46 Ma). Carbonate 87Sr/86Sr data reveal the same compositional populations present in the current formation water to be present in both cement generations. The water compositional stratification must thus have been present when the early and late cements precipitated, down till today. The persistence of a compositional step for most of the geological history of the rocks confirms the presence of a major fluid communication barrier. The Sr RSA data show invariant water composition across the heavily carbonate cemented intervals, implying no barrier effect. The combination of pressure data (to identify pressure barriers), Sr RSA (to add spatial resolution) and Sr–C–O isotopes of carbonates of different ages (to add a time dimension) is useful for identifying major long-term fluid communication barriers and differentiating them from smaller, less effective or shorter-term features. The method has applications for identifying seals in exploitation of petroleum and water resources, and underground storage of CO2 and radioactive waste
Clostridium difficile infection - a new interdisciplinary problem
Background: То assess the prevalence and risk factors of the development of antibiotic-associated diarrhea related to Clostridium difficile infection in patients in a large multi-specialiry hospital. Materials and methods: a retrospective analysis was made of 131 patients, who were hospitalized in Municipal Autonomous Institution 'City Clinical Hospital №40' in Yekaterinburg in 2014, who had diarrhea developed on the background of antibacterial therapy. According to the results of the data obtained through studies of coprofiltrates on Clostridium difficile, the patients were divided into 2 groups: 71 patients with a positive result, and 60 patients with a negative result. Results: the prevalence of CD-infection in MAI «City Clinical Hospital № 40», according to the data of the 2014 year, amounted to 0.14% of the total number of the hospitalized patients. The predictors of the risk of the development of CD-infection in patients are age of patients older than 65 years old (OR = 3.43, 95% Cl 1.06 to11.08, p = 0,0409), Charlson comorbidity index of 2 points or more (OR = 2.92,95% Cl 1.33 to 6.44, p = 0,0114), the presence of anemia (OR = 4.35, Cl 1.98 to 9.54, p = 0,0003), hospitalization in the ICU lasting more than 1 day (OR = 10.59,95% Cl 2.35 to 47.69, p=0,0002) and hospitalization in the department of surgery (OR = 2.46,95% Cl 1.16 to 5.20, p = 0,0276), surgical intervention (OR = 3.06,95% Cl 1.33 to 7.04, p = 0,0120), the stay of patients in hospital more than 5 days (OR = 3.87; 95% Cl 1.87 to 8.01, р = 0,0004), chronic dialyzing of patients with chronic renal failure (OR = 8.56,95% Cl 1.05 to 69.69, p = 0,0210), installation of a urethral catheter (OR = 3.43,95% Cl 1.06 to 11.08, p = 0,0409), the use of PPI for more than 7 days (OR = 7.76,95% Cl 1.69 to 35.53, p = 0,0032), holding antibacterial therapy for more than 5 days (OR = 4.10,95% Cl 1.93 to 8.68, p = 0,0003), holding more than 1 course of antibiotic therapy (OR = 5.31.95% Cl 1.12 to 25.03, p = 0,0365), use of ceftriaxone (OR = 3.21; 95% Cl 1.51 to 6.82, p = 0,0036). Conclusions: risk factors for the development of CD-infection are age older than 65 years old and multiple comorbidities (Charlson index more than 2 points), chronic renal failure requiring hemodialysis, and anemia, hospitalization in the ICU and the departments of surgery, surgical treatment, holding more than 1 course of antibiotic therapy and fhe duration of antibacterial therapy for more than 5 days, the application of cephalosporins of the 3rd generation.Цель: Оценить распространённость и факторы риска развития антибиотико-ассоциированной диареи, связанной с Clostridium difficile инфекцией, у пациентов в крупном многопрофильном стационаре. Материалы и методы: проведен ретроспективный анализ 131 истории болезни пациентов, находившихся на стационарном лечении в МАУ ГКБ № 40 в 2014 году, у которых на фоне проведения антибактериальной терапии развилась диарея. По результатам данных, полученных при исследовании копрофильтрата на Clostridium difficile, пациенты были разделены на 2 группы: 71 пациент с положительным результатом и 60 пациентов с отрицательным результатом. Результаты: распространенность CD-инфекции в МАУ ГКБ № 40, по данным за 2014 год, составила 0,14% от общего числа госпитализированных пациентов. Предикторами риска развития CD-инфекции у пациентов являются: возраст пациентов старше 65 лет (0Ш = 3,43,95% ДИ 1,06-11,08, р = 0,0409), индекс коморбидности Charlson более 2 баллов (ОШ = 2,92,95% ДИ1,33 - 6,44, р=0,0114), наличие анемии (ОШ = 4,35, ДИ 1,98 - 9,54, р = 0,0003), госпитализация в ОРИТ длительностью более 1 суток (ОШ = 10,59,95% ДИ 2,35 - 47,69, р = 0,0002) и в отделения хирургического профиля (ОШ = 2,46,95% ДИ 1,16 - 5,20, р = 0,0276), проведение оперативного вмешательства (ОШ = 3,06,95% ДИ 1,33-7,04, р = 0,0120), пребывание пациентов в стационаре более 5 суток (ОШ = 3,87,95% ДИ 1,87 - 8,01, р = 0,0004), проведение хронического диализа у пациентов с ХПН (ОШ = 8,56,95% ДИ 1,05 - 69,69, р = 0,0210), установка уретрального катетера (ОШ = 3,43,95% ДИ 1,06 -11,08, р = 0,0409), применение ИПП более 7 суток (ОШ = 7,76,95% ДИ 1,69 - 35,53, р = 0,0032), проведение антибактериальной терапии более 5 суток (ОШ = 4,10,95% ДИ 1,93 - 8,68, р = 0,0003), проведения более чем 1 курса антибактериальной терапии (ОШ = 5,31,95% ДИ 1,12 - 25,03, р = 0,0365), применение цефтриаксона (ОШ = 3,21,95% ДИ 1,51 - 6,82, р = 0,0036). Заключение: факторами риска для развития CD-инфекции являются: возраст старше 65 лет, наличие нескольких сопутствующих заболеваний (индекс Charlson более 2 баллов), хроническая почечная недостаточность, требующая проведения гемодиализа, и анемия, госпитализация в ОРИТ и отделения хирургического профиля, оперативное лечение, проведение более чем одного курса антибиотикотерапии, и длительность антибактериальной терапии более 5 суток, применение цефалоспоринов 3-й генерации
Risk Factors for diarrhea associated with Clostridium difficile in patients at a clinical hospital
Coupled Basin and Hydro-Mechanical Modeling of Gas Chimney Formation: The SW Barents Sea
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The Mechanical Response of a Magma Chamber With Poroviscoelastic Crystal Mush
Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 126(4), (2021): e2020JB019395, https://doi.org/10.1029/2020JB019395.Improved understanding of the impact of crystal mush rheology on the response of magma chambers to magmatic events is critical for better understanding crustal igneous systems with abundant crystals. In this study, we extend an earlier model by Liao et al. (2018); https://doi.org/10.1029/2018jb015985 which considers the mechanical response of a magma chamber with poroelastic crystal mush, by including poroviscoelastic rheology of crystal mush. We find that the coexistence of the two mechanisms of poroelastic diffusion and viscoelastic relaxation causes the magma chamber to react to a magma injection event with more complex time-dependent behaviors. Specifically, we find that the system’s short-term evolution is dominated by the poroelastic diffusion process, while its long-term evolution is dominated by the viscoelastic relaxation process. We identify two post-injection timescales that represent these two stages and examine their relation to the material properties of the system. We find that better constraints on the poroelastic diffusion time are more important for the potential interpretation of surface deformation using the model
Clostridium difficile-associated disease in versatile hospital patient population and risk factors for its development
Aim of investigation. To estimate proportion of patients with Clostridium difficile-associated disease in the spectrum of patients of versatile hospital and reveal its risk factors. Material and methods. Retrospective analysis of 131 case records of the in-patients of Yekaterinburg City Hospital No. 40 for the year 2014 who developed diarrhea during antibacterial therapy was carried out. According to fecal filtrate test for Clostridium difficile (CD), patients were divided into two groups: 71 patients had positive test, 60 - negative. Results. Proportion of patients with C. difficile-associated disease in Yekaterinburg City Hospital No. 40 for the year 2014 was 0,14% of total in-patient number. Predictors of C. difficile-associated diarrhea risk were following: the age over 65 years (OR=3.43; 95%CI 1.06-11.08; р=0.0409), Charlson comorbidity index over 2 points (OR=2,92, 95%CI 1.33-6.44; р=0.0114), presence of anemia (OR=4,35, 95%CI 1.98-9.54; р=0.0003), admission to intensive care unit with staying for more than 1 day (OR=10.59; 95%CI 2.35-47.69; р=0.0002) and in surgical departments (OR=2.46; 95%CI 1.16-5.20; р=0.0276), surgical intervention (OR=3.06; 95%CI 1.33-7.04; р=0.0120), hospital stay for 5 days (OR=3.87; 95%CI 1.87-8.01; р=0.0004), chronic dialysis at chronic renal failure (OR=8.56; 95% of CI 1,05-69,69; р=0,0210), installation of an urethral catheter (OR=3,43; 95% of CI 1.06-11.08; р=0.0409), proton pump inhibitors (PPI) therapy for over 7 days (OR=7.76; 95% CI 1.69-35.53; р=0.0032), antibacterial therapy for over 5 days (OR=4.10; 95%CI 1.93-8.68; р=0.0003), more than one course} of antibacterial treatment (OR=5.31; 95% CI 1.12-25.03; р=0.0365), ceftriaxone therapy (OR=3.21; 95%CI 1.51-6.82; р=0.0036). Conclusions. Following risk factors for C. difficile-associated diarrhea were determined: age over 65 years, presence of several associated diseases (Charlson score >2), chronic renal failure that require hemodialysis, anemia, admission to intensive care unit and surgical departments, surgical treatment, PPI administration for over 7 days, more than one course of antibiotic treatment and duration of antibacterial therapy for more than 5 days, administration of 3rd generation cephalosporins
The Longyearbyen CO2 Lab: Fluid communication in reservoir and caprock
The Longyearbyen CO2 Lab of Svalbard, Norway was established to estimate the potential for geological carbon sequestration at Spitsbergen. Several monitoring wells were drilled in and around the planned CO2 injection site. These revealed a Triassic to Cretaceous stratigraphy consisting of (from top to bottom) a zone of permafrost, the aquifer, the caprock shale, and the upper, middle and lower reservoir. This paper uses two tools to investigate fluid communication within and between these entities: 87Sr/86Sr of formation waters extracted from cores using the residual salt analysis (RSA) method, and the δ13C of gases, principally methane and CO2, degassed from core samples. The Sr RSA data reveal that the upper reservoir rocks have very constant formation water 87Sr/86Sr (0.7130) in wells several kilometres apart, suggesting good lateral communication on a geological timescale. However, there is a distinct barrier to vertical communication within the middle reservoir, indicated by a step change in 87Sr/86Sr (0.7130–0.7112), corresponding to thin but presumably laterally extensive (>1.5 km) lagoonal mudrocks. The aquifer, which shows a gradient in 87Sr/86Sr, is also interpreted to have some degree of vertical internal communication on a geological time scale. The caprock shale shows large-scale (over 350 m) smooth vertical gradient in 87Sr/86Sr (0.7200-0.7130). This is indicative of an ongoing mixing process between high- 87Sr/86Sr waters within the caprock and lower- 87Sr/86Sr waters in the underlying reservoir. Diffusion and flow modelling of the Sr data suggest that at some time in the past, shale fluid transport properties were enhanced by the formation of temporary pressure escape features (fractures or chimneys) during deep burial and uplift, or cycles of glaciation. Nevertheless, the smooth compositional gradient in the caprock indicates that fluid mixing has subsequently taken place slowly, dominated by diffusion. This interpretation is supported by the gas isotope data, where systematic variations in gas δ13C (-50‰ to −32‰) values also indicate slow and incomplete diffusional fluid mixing. These are positive indicators for caprock effectiveness during a CO2 injection project
Coupled Basin and Hydro-Mechanical Modeling of Gas Chimney Formation: The SW Barents Sea
publishedVersio