Method of calculating variable section shafts shear deformations

This article considered method to measure low-frequency angular oscillations of rotors of electric machines and solved the problem of assess shear deformations of rotating shafts in transient conditions. Method of calculating torsional torques is considered by the example of electric generator shaft of diesel generator unit. This method allows taking into account the angular deformations of the rotating shafts, and reducing vibration overloads, and increasing in both resource and reliability

Метод структурно-параметрического синтеза конфигураций многорежимного объекта

Сложность современных объектов с перестраиваемой структурой приводит к необходимости учета различных факторов взаимодействия их с окружающей средой и связана с увеличением числа входящих в их состав элементов и подсистем, а также, соответственно, стремительным ростом числа внутренних связей, и проявляется в таких аспектах, как структурная сложность, сложность функционирования, сложность выбора поведения, сложность моделирования и сложность развития. Данные системы функционируют в условиях существенной неопределённости, связанной с изменением содержания целей и задач, стоящих перед объектом, воздействием возмущающих факторов со стороны внешней среды и имеющих целенаправленный и/или нецеленаправленный характер. Указанные аспекты сложности системы связаны не только с неопределенными воздействиями внешней среды, но и с множеством различных режимов (видов) функционирования, соответствующих множественности решаемых задач и множественности показателей качества их решения. Как правило, системы с фиксированной структурой, настраиваемые обычно на установившийся (какой-то заданный) режим, не обеспечивают наилучшего качества управления в других режимах. Поэтому многорежимность и неопределенность условий функционирования обуславливают необходимость решения проблемы анализа и синтеза конфигурации и реконфигурации рассматриваемых объектов, основанных на интеллектуальных подходах. При этом на этапах создания и проектирования объектов с перестраиваемой структурой должны быть синтезированы такие взаимосвязанные множества режимов функционирования и структур, а также, возможно, внесён такой уровень избыточности в указанные множества с учетом пространственно-временных, технических и технологических ограничений, при которых на этапе их применения по целевому назначению имелась бы возможность гибко реагировать на все расчётные и нерасчётные нештатные ситуации, вызывающие структурные изменения объекта. С формальной точки зрения, решение указанных задач возможно в рамках такого важнейшего класса современных научно-технических задач, как задачи многокритериального структурно-функционального синтеза конфигураций многорежимных объектов на различных этапах их жизненного цикла. В настоящей статье приведен метод решения указанных задач, основанный на предложенной авторами концепции параметрического генома сложных многорежимных объектов. Применение данной концепции позволяет в концентрированном виде хранить явные и неявные знания экспертов о взаимодействии элементов и подсистем объекта при выполнении различных вариантов реализации режимов функционирования, а также осуществлять оперативное вычисление значений оптимистических и пессимистических оценок показателей структурно-функциональной надежности однородных/неоднородных, монотонных/немонотонных, равноценных/неравноценных многорежимных объектов. Для решения задачи многокритериального выбора требуемого количества недоминируемых вариантов конфигураций многорежимного объекта, равномерно расположенных в множестве эффективных (паретовских) альтернатив, была предложена комбинация метода интервального лексикографического упорядочения (последовательных уступок) и операторного решающего правила. При этом для проведения детального анализа возможности реализации объектом совместного или раздельного задействования режимов функционирования с равноценной или неравноценной интенсивностью их применения было предложено нечетко-возможностное представление обобщенного показателя структурно-функциональной надежности в виде трапециевидного числа и определения его центра тяжести. Эффективность использования разработанного метода структурно-параметрического синтеза конфигураций многорежимного объекта с перестраиваемой структурой проиллюстрирована на примере решения задачи структурно-параметрического синтеза конфигураций системы управления движением малого космического аппарата «Аист-2Д»

Torque sensors calibration of electromechanical complexes shafts

Noncontacting torquemeters calibration is one of the acute tasks currently. Such sensors are widely used in measuring torques and torsional oscillations of elastic shafts of industrial plants and electromechanical systems. Noncontacting torquemeters must be properly calibrated before they are used to measure torque and torsional oscillations of rotating shafts. The paper describes a new approach to solving the task of calibration of noncontacting torquemeters and torsional oscillations meters of elastic shafts. The approach is based on the finite elements method as well as realized in the measuring device – torquemeter. The torquemeter allows to measure little torques and torsional oscillations of elastic shafts of electromechanical complexes

Screening of microorganisms producing biosurfactants from renewable substrates

Biosurfactants are one of the promising biotechnological products applied in agriculture. Their use, however, is currently far from economically viable, due to the expensive feedstock for the growth of microorganisms. The solution to this problem can be to reduce the cost of production by using organic waste as a nutrient substrate. In this study, oil-containing wastes were considered as substrates - waste frying sunflower oil and petroleum-contaminated soil. At the first stage of research, we screened native waste microorganisms capable of synthesizing biosurfactants. As a result of the study, strains with the ability to form biosurfactants were isolated. Six strains (A, B, C, D, E, F) were isolated from waste frying sunflower oil, two strains (A1, B1) were isolated from petroleum-contaminated soil. The highest yield of biosurfactants is typical for strains A and A1 - 0.429 and 0.502 mg ml-1, while the best ratio of biosurfactant mass to cell biomass is typical for strains A1 and E - 0.9 and 0.6. The most effective producer of biosurfactants turned out to be strain E with an emulsifying activity of E24 equal to 80% and a surface tension of the culture liquid of 27.1 mN m-1

SARS-CoV-2 Wastewater Genomic Surveillance: Approaches, Challenges, and Opportunities

During the SARS-CoV-2 pandemic, wastewater-based genomic surveillance (WWGS) emerged as an efficient viral surveillance tool that takes into account asymptomatic cases and can identify known and novel mutations and offers the opportunity to assign known virus lineages based on the detected mutations profiles. WWGS can also hint towards novel or cryptic lineages, but it is difficult to clearly identify and define novel lineages from wastewater (WW) alone. While WWGS has significant advantages in monitoring SARS-CoV-2 viral spread, technical challenges remain, including poor sequencing coverage and quality due to viral RNA degradation. As a result, the viral RNAs in wastewater have low concentrations and are often fragmented, making sequencing difficult. WWGS analysis requires advanced computational tools that are yet to be developed and benchmarked. The existing bioinformatics tools used to analyze wastewater sequencing data are often based on previously developed methods for quantifying the expression of transcripts or viral diversity. Those methods were not developed for wastewater sequencing data specifically, and are not optimized to address unique challenges associated with wastewater. While specialized tools for analysis of wastewater sequencing data have also been developed recently, it remains to be seen how they will perform given the ongoing evolution of SARS-CoV-2 and the decline in testing and patient-based genomic surveillance. Here, we discuss opportunities and challenges associated with WWGS, including sample preparation, sequencing technology, and bioinformatics methods.Comment: V Munteanu and M Saldana contributed equally to this work A Smith and S Mangul jointly supervised this work For correspondence: [email protected]

A nearly complete database on the records and ecology of the rarest boreal tiger moth from 1840s to 2020

Global environmental changes may cause dramatic insect declines but over century-long time series of certain species’ records are rarely available for scientific research. The Menetries’ Tiger Moth (Arctia menetriesii) appears to be the most enigmatic example among boreal insects. Although it occurs throughout the entire Eurasian taiga biome, it is so rare that less than 100 specimens were recorded since its original description in 1846. Here, we present the database, which contains nearly all available information on the species’ records collected from 1840s to 2020. The data on A. menetriesii records (N = 78) through geographic regions, environments, and different timeframes are compiled and unified. The database may serve as the basis for a wide array of future research such as the distribution modeling and predictions of range shifts under climate changes. It represents a unique example of a more than century-long dataset of distributional, ecological, and phenological data designed for an exceptionally rare but widespread boreal insect, which primarily occurs in hard-to-reach, uninhabited areas of Eurasia.Peer reviewe

Seasonal and annual fluxes of nutrients and organic matter from large rivers to the Arctic Ocean and surrounding seas

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 35 (2012): 369-382, doi:10.1007/s12237-011-9386-6.River inputs of nutrients and organic matter impact the biogeochemistry of arctic estuaries and the Arctic Ocean as a whole, yet there is considerable uncertainty about the magnitude of fluvial fluxes at the pan-arctic scale. Samples from the six largest arctic rivers, with a combined watershed area of 11.3 x 106 km2, have revealed strong seasonal variations in constituent concentrations and fluxes within rivers as well as large differences among the rivers. Specifically, we investigate fluxes of dissolved organic carbon, dissolved organic nitrogen, total dissolved phosphorus, dissolved inorganic nitrogen, nitrate, and silica. This is the first time that seasonal and annual constituent fluxes have been determined using consistent sampling and analytical methods at the pan arctic scale, and consequently provide the best available estimates for constituent flux from land to the Arctic Ocean and surrounding seas. Given the large inputs of river water to the relatively small Arctic Ocean, and the dramatic impacts that climate change is having in the Arctic, it is particularly urgent that we establish the contemporary river fluxes so that we will be able to detect future changes and evaluate the impact of the changes on the biogeochemistry of the receiving coastal and ocean systems.This work was supported by the National Science Foundation through grants OPP-0229302, OPP-0519840, OPP-0732522, and OPP-0732944. Additional support was provided by the U. S. Geological Survey (Yukon River) and the Department of Indian and Northern Affairs (Mackenzie River)

Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial

Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D

Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049