181 research outputs found
Turbine engines bladed disks’ with circular damping links forced vibration
Викладено методику досліджень вимушених коливань вінців робочих лопаток турбомашин з коловими демпферними зв’язками. З використанням методу кінцевих елементів розроблено удосконалену математичну модель секції «сектор диску - лопатка з демпферними зв’язками», що враховує конструктивну неоднорідність пера лопатки та диску. Наведено результати розрахунку амплітуд та частот вимушених коливань, викликаних дією змінної газодинамічної сили, для двох основних типів вінців робочих лопаток турбіни. Представлено залежність амплітуд вимушених коливань від змінної складової газодинамічної сили.The problem of turbine engines bladed disks with circular damping links forced vibration has been studied. All calculations have been provided for the two main disk’s types, used in the turbo machinery manufacturing. Purpose. The new adaptive mathematical model of turbine engine bladed disks with circular damping links forced vibration should be developed by means of finite elements method. Design/methodology/approach. Borrowed from the literature on finite elements method main mathematical models and some types of the finite elements can’t be used for the correct description of the foregoing problem. The matter is that turbine blades and disks have constructional non-homogeneity, which hardly ever could be correctly explained, using well-known finite elements and their mathematical dependences. On the other hand the variable aerodynamic force influence has also been taken into consideration. That is why the new model, which consists of sections, including disk’s sector, the whole blade and parts of damping links, has been developed. The finite elements methodology has been used for the forced vibration frequencies and amplitudes of this section calculation. Such approach gives an opportunity to describe the forced vibration of the whole bladed disk as the superposition of the developed sections. Findings. It is found that even non-homogeneous turbine engine’s bladed disks’ forced vibration problem could be correctly solved by means of finite elements model, using the newly developed mathematical model, which consists of bladed disk’s sections. Originality/ value. The developed mathematical model and main dependences could be used for the turbine’s and compressor’s bladed disks under non-stationary aerodynamic force vibration problem solution.Изложена методика исследования вынужденных колебаний венцов рабочих лопаток турбомашин с замкнутыми на круг демпферными связями. С использованием метода конечных элементов разработана уточненная математическая модель секции «сектор диска - лопатка с демпферными связями», учитывающая конструктивную неоднородность пера лопатки и диска. Приведены результаты расчета амплитуд и частот вынужденных колебаний, вызванных воздействием переменной газодинамической силы, для двух основных типов венцов рабочих лопаток турбины. Представлена зависимость амплитуд вынужденных колебаний от величины переменной составляющей газодинамической силы
Вплив психологічних аспектів інновацій на процеси реформування системи управління органів внутрішніх справ
Моргун, О. С. Вплив психологічних аспектів інновацій на процеси реформування системи управління органів внутрішніх справ / О. С. Моргун // Право і безпека. - 2009. - № 5 (32). - С. 198 -202.Проаналізовано сучасний стан проблеми інновацій, різноманітні підходи до розуміння психологічної
сутності інновацій. Вказано на необхідність вивчення проблеми інновацій у професійній діяльності співробітників правоохоронних органів в умовах реформування системи ОВС.Current state of the innovations’ problem, different approaches to understanding the psychological essence of
innovation is analyzed. It is pointed out on necessity to study the problem of innovation in the professional activity of law enforcement officers under circumstances of internal affairs agencies’ system reformation.Проанализированы современное состояние проблемы инноваций, различные подходы к пониманию психологической сущности инноваций. Указано на необходимость изучения проблемы инноваций в профессиональной деятельности сотрудников правоохранительных органов в условиях реформирования системы ОВД
Regulation of superoxide dismutase activity in soybean plants by inoculating seeds with rhizobia containing nanoparticles of metal carboxylates under conditions of different water supply
Soybean is one of the most profitable advanced crops in agricultural production in Ukraine and the world as a whole. Therefore, studies of means of regulation and increase in the adaptive capacity of soybeans in symbiosis with nodule bacteria under the action of unfavourable environmental factors are relevant and should be aimed at the use of complex bacterial compositions involving modern nanotechnological approaches. Nanocarboxylates of ferrum, molybdenum and germanium metals were used as components of rhizobia inoculation suspension for soybean seed treatment to study the effectiveness of their complex effect on the regulation of the activity of the key antioxidant enzyme superoxide dismutase in plants under drought. Various symbiotic systems were used, which included soybean plants and inoculation suspensions based on the active, virulent Tn5-mutant Bradyrhizobium japonicum B1-20 by adding nanoparticles of ferrum, germanium and molybdenum carboxylates to the culture medium in a ratio of 1: 1000. Citric acid was the chelator. A model drought lasting 14 days was created during the period of active fixation of atmospheric molecular nitrogen by root nodules of soybeans in the budding and flowering stages, by means of controlled watering of plants to 30% of the total moisture content. In the stage of bean formation, watering of plants was resumed to the optimal level – 60% of the total moisture content. The control was soybean plants, the seeds of which were inoculated with a suspension of rhizobia without the addition of chelated metals. The following research methods were used in the work – microbiological, physiological and biochemical. According to the results, it was found that when nanoparticles of carboxylates of ferrum, molybdenum and germanium were added to the inoculation suspension of rhizobia, there was an increase in superoxide dismutase activity in root nodules and a decrease in soybean leaves under optimal water supply conditions of plants. This indicates the initial changes in the activity of the antioxidant enzyme in these symbiotic systems, induced by the influence of chelated metals in combination with the rhizobia of the active Tn5-mutant B. japonicum B1-20. Prolonged drought induced an increase in the overall level of superoxide dismutase activity in soybean nodules and leaves, compared to plants grown under optimal watering conditions. The symbiotic system formed by soybeans and B. japonicum with molybdenum carboxylate nanoparticles was the most sensitive to long-term drought exposure, compared to two other soybean-rhizobial symbioses using ferrum and germanium nanocarboxylates. This was manifested in the unstable reaction of the enzyme to the action of drought – suppression or intensification of the level of its activity in the root nodules and leaves of soybeans inoculated with rhizobia containing molybdenum carboxylate nanoparticles. In symbiotic systems with the participation of germanium and ferrum nanocarboxylates, slight changes were revealed in superoxide dismutase activity in root nodules and leaves of plants during drought and restoration of enzyme activity to the level of plants with optimal watering after water stress. It is concluded that the addition to the culture medium of rhizobia Tn5-mutant B1-20 of nanocarboxylates of germanium or ferrum is an effective means of regulating the activity of the antioxidant enzyme superoxide dismutase in soybean root nodules and leaves, which can contribute to an increase in the protective properties and adaptation of plants to the action of dehydration
Targeting dsRNA-specific single-chain Fv antibody fragments to different cellular locations in Nicotiana tabacum L.
Expression of antibodies or antibody fragments in plants is a useful tool for producing active antibody
derivatives for diagnostic or pharmaceutical purposes as well as for immunomodulation. We investigated
the effect of cellular expression site on the stability and yield of double-stranded RNA (dsRNA)-specific
single-chain Fv-fragments (scFv) in transgenic tobacco. Two antibodies (J2 and P6) belonging to
the V23(J558) heavy chain variable gene family but differing in the light chain variable domain were
used. scFvs were targeted to the cytoplasm – with or without anchoring them in the plasma membrane –,
into the endoplasmic reticulum (ER) and to the apoplast. Although high mRNA concentrations were
detected in all cases, scFv proteins accumulated only when scFvs were made ER-resident by appropriate
signal sequences. When the ER retention signal was removed to allow scFv-secretion to the apoplast, no
scFv-proteins were detected. Despite the strong homology of the VH-sequences of J2 and P6 antibodies, only P6 provided a stable scFv scaffold for intracytoplasmic expression. J2-scFv could not be stabilised neither by adding a C-terminal stabilisation signal nor by anchoring the protein at the cytoplasmic side of the plasma membrane (PM). It was found that dsRNA-specific J2-scFvs are active in vivo and enhance Potato Virus Y induced symptoms in infected tobacco. This is the first report describing the expression and biological effect of RNA-specific antibodies in plants
Observation of subkelvin superconductivity in Cd₃As₂ thin films
We report an experimental observation of superconductivity in Cd3As2 thin films without application of external pressure. The films under study were synthesized by magnetron sputtering. Surface studies suggest that the observed transport characteristics are related to the polycrystalline continuous part of the investigated films with a homogeneous distribution of elements and the Cd-to-As ratio close to stoichiometric Cd3As
The Strategic Perspectives of Using GIS-Technologies for Creating of Integrative Antarctic Geo-base of Scientific Data
Strategic prospects use GIS technologies are presented in report for making integrated geodatabase of scientific data, designed on base of the lifelengths operating in the field of automations of the information handling in National antarctic scientific centre MES of Ukraine (NASC). It is shown, that given decision effectively, in good time, corresponds to the world standard of the collection, processing and presentation of scientific data.У доповіді подано стратегічні перспективи використання ГІС технології для створення інтегрованої геобази наукових даних, яка проектується на основі багаторічних напрацювань в галузі автоматизації обробки інформації в Національному антарктичному науковому центрі МОН України (НАНЦ). Показано, що дане рішення є ефективним та своєчасним, відповідає світовим стандартам збирання, обробки та презентації наукових даних.Ключові слова: ГІС-технологія, Геобаза, ArcGIS, Серверні технології.В докладе представлены стратегические перспективы использования ГИС технологии для создания интегрированной геобазы научных данных, проектируемой на основе многолетних наработок в области автоматизации обработки информации в Национальном антарктическом научном центре МОН Украины (НАНЦ). Показано, что данное решение эффективно, своевременно, соответствует мировым стандартам сбора, обработки и презентации научных данных
Joule Heating and Current-Induced Instabilities in Magnetic Nanocontacts
We consider the electrical current through a magnetic point contact in the
limit of a strong inelastic scattering of electrons. In this limit local Joule
heating of the contact region plays a decisive role in determining the
transport properties of the point contact. We show that if an applied constant
bias voltage exceeds a critical value, the stationary state of the system is
unstable, and that periodic, non-harmonic oscillations in time of both the
electrical current through the contact and the local temperature in the contact
region develop spontaneously. Our estimations show that the necessary
experimental conditions for observing such oscillations with characteristic
frequencies in the range Hz can easily be met. We also show a
possibility to manipulate upon the magnetization direction of a magnetic grain
coupled through a point contact to a bulk ferromagnetic by exciting the
above-mentioned thermal-electric oscillations.Comment: 9 pages, 6 figures, submitted to Physical Review
Transkingdom Networks: A Systems Biology Approach to Identify Causal Members of Host-Microbiota Interactions
Improvements in sequencing technologies and reduced experimental costs have
resulted in a vast number of studies generating high-throughput data. Although
the number of methods to analyze these "omics" data has also increased,
computational complexity and lack of documentation hinder researchers from
analyzing their high-throughput data to its true potential. In this chapter we
detail our data-driven, transkingdom network (TransNet) analysis protocol to
integrate and interrogate multi-omics data. This systems biology approach has
allowed us to successfully identify important causal relationships between
different taxonomic kingdoms (e.g. mammals and microbes) using diverse types of
data
Alteration of Neuron-Glia Interactions in Neurodegeneration: Molecular Biomarkers and Therapeutic Strategy
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