216 research outputs found
A Volume-Force Synthetic Disturbance Approach for High-Fidelity of Unsteady Fluid Structure Interactions
The purpose of this dissertation is to analyze the momentum source model, for generating synthetic vortical disturbance field in numerical simulations of unsteady fluid-structure interactions, access limitations of this approach, to find requirements for the computational domain, space and time resolution, and apply this model to investigate selected physical problems. For this reason a comprehensive parametric study of volume-force based method of generating spectral synthetic turbulence inside the computational domain is conducted first. The method is then extended to synthesize turbulence with arbitrary energy spectrum. The synthetic turbulence is generated through momentum source terms in Navier-Stokes equations, and the developed numerical procedure is shown to reproduce any desired energy spectrum. Additionally, the approach is extended to be applicable to boundary layer type of flows. Then, selected applications of the momentum source model are considered including: gust-airfoil unsteady interactions, turbulence-airfoil unsteady interactions, Analysis of the turbulence effect on acoustic radiation of a novel airfoil design with an embedded cross-ow fan, the effect of turbulence intensity on wake vortex evolution.
In particular the effects of oblique vortical gust modes on airfoil unsteady aerodynamic and acoustic responses due to its interaction with an impinging 3D time-harmonic gust and turbulence are addressed first. Several analytical gust-airfoil interaction models are reviewed and extended to address 3D inviscid gust responses. The results of numerical simulations performed using ANSYS Fluent software are compared against analytical solutions. Additionally, the turbulence-airfoil aerodynamic and aeroacoustic response is analyzed. Next, noise signature of a wing with an embedded Cross-Flow Fan (CFF) in turbulent air is investigated. Comparative large-scale 2D simulations are performed for 4 cases including a baseline NACA 65(3)-221 airfoil with the Fowler flap, and the same airfoils with embedded stationary and rotating CFF, as well as, rotating CFF in turbulent air.
Lastly, the uniform ow momentum source model is implemented in OpenFOAM and simulation process is specified in order to obtain stationary decaying turbulence. Effect of turbulence intensity on wake vortex evolution is studied with the use of the momentum source model
ХХІІІ Международная научная конференция "Актуальные научные исследования в современном мире"
An analysis of modern approaches to the organization of physical education sessions for students is carried out. Pedagogical innovations in the practice of sports department of higher educational institution are characterized. The analysis of the main problems and prospects of the use of volleyball in the organization of the sessions for students is presented. The necessity is grounded of considering the indicators of physical state when student groups of sports department are formed.Проведен анализ современных подходов к организации занятий по физическому воспитанию студентов. Дана характеристика педагогических инноваций в практике работы спортивного отделения высшего учебного заведения. Представлен анализ основных проблем и перспектив использования волейбола в организации занятий со студентами. Обоснована необходимость комплектования групп спортивного отделения на основе учета показателей физического состояния
Research Competencies Condition Assessment of Pupils from Humanitarian-oriented Classes of Comprehensive School
The description of process and results of research competencies condition assessment of pupils from humanitarian subjects-oriented classes of comprehensive school is presented in the article. The interpretation of the obtained empirical data is given. The appeal to a problem of formation of research competence at pupils of comprehensive school is connected with the changing requirements of modern education to the organization and design of educational process, as well as formation of key competences at comprehensive school graduates. The transfer of the senior stage of comprehensive school to the profile training significantly expands opportunities for the research activity of pupils that is one of productive ways of their research competence formation
Teaching Model of Pupils’ Research Competence Formation in the Context of Humanitarian Subject-oriented Classes of General Education School: Functional and Organizational Characteristics
Functional and organizational characteristics of teaching model of pupils’ research competence formation in the context of humanitarian subject-oriented classes of general education schools are taken into consideration. The research activity aimed at increasing the educational process quality in general education school is one of the productive ways of pupils’ research competence formation. The functional and organizational characteristics of proposed teaching model include the conditions of research and development environment organization (such as system of methods, stages and forms of research activity organization, interconnection of school and higher education institution, integration of both curriculum and extra curriculum forms of education, pedagogic personnel work at formation of research competence of pupils of humanitarian subjects-oriented classes and research competence of teaching and researching staff), functioning of research and development environment, levels of research competence formation of pupils of humanitarian subjects-oriented classes (low, average, high)
Panicum virgatum microbial community and soil chemistry responses to conservation agriculture management
Master of ScienceDepartment of BiologyAri M. JumpponenThe holobiont concept of plants treats plants with their associated microbiomes that mostly consist of the fungi and bacteria as a single unit. Previous studies have shown the central role of microbiomes for plant health and performance, while also highlighting that the dynamic nature of the microbiomes can be affected by various biotic and abiotic factors that can rapidly change microbiome functionality. In the past two decades, development of novel technologies has substantially advanced research methods used to study plant and microbiome interactions – thus allowing for better identification of factors that shape microbiomes. Although effects of agricultural and production management on the plant, plant microbiomes and plant-associated soils are relatively well understood, effects of practical tools commonly employed in conservation agriculture remain largely unknown. Conservation agriculture management aims to achieve sustainable plant growth and productivity while minimizing active management such as fertilization, tillage, and soil movement. As a result of this lack of active management, conservation agriculture regimes promote the use of practical tools such as variety and planting density choices to achieve sustainable conservation goals The research described in this thesis aims to evaluate effects of conservation agriculture management on bacterial and fungal communities associated with soil and roots of four varieties of the native warm-season perennial grass Panicum virgatum L. (a.k.a. switchgass) initially planted at two different densities and growing under conservation agriculture conditions in southeastern Mississippi. To also assess the temporal dynamics, we repeatedly sampled switchgrass roots and associated soils approximating a log2 time series for a total of six times during one growing season, starting from within a week from the first leaf emergence in early spring to pre-frost in late fall. A small-scale pilot study comparing DNA isolation kits (Phire Plant Direct PCR vs. PowerSoil DNA Isolation kits)
confirmed that, although the direct extraction and amplification kits provide a cost-effective and expedient alternative to the more commonly used PowerSoil kits, the direct kits do not produce comparable community views from all plant tissues. Our studies of switchgrass microbiomes highlight that, while bacterial and fungal communities in roots and soils are temporally dynamic and shift compositionally during the growing season, planting densities have no strong overall effect on microbiome richness, diversity, or composition, and that if microbiomes associated with four switchgrass varieties differed among switchgrass varieties, they did so only in the beginning of the growing season. Indicator taxon analyses identified many bacterial and fungal taxa in soil and roots that represent potential variety specific taxa in the early season and temporally dynamic taxa. Similar to the biotic attributes, the soil chemistry was minimally affected by switchgrass variety choice or planting density, although some temporal dynamics were observed. These findings indicate that in the hierarchy of tested factors, seasonal dynamics are the strongest driver of switchgrass microbiomes and soil chemistry. The seasonal dynamics overwhelm the effects of conservation agriculture management choices, as shown here for choice of switchgrass variety and planting density. Notwithstanding and based on our indicator taxon analyses that identified putative plant symbionts and pathogens or soil-inhabiting nitrogen fixing taxa, careful variety choices can potentially facilitate mindful microbiome manipulations to support the sustainable switchgrass productivity
Спортивно-ориентированные технологии в физическом воспитании студенческой молодежи (на примере занятий волейболом)
У статті обґрунтовано необхідність впровадження спортивно-орієнтованої технології з пріоритетним використанням волейболу у фізичному вихованні, спрямовану на підвищення ефективності процесу фізичного виховання у вищому навчальному закладі, залучення студентів до фізкультурно-спортивних занять, підвищення їх рухової активності, розкриття рухового потенціалу молоді в студентські роки, підвищення спортивної та фізичної підготовленості. Використано такі методи дослідження теоретичний аналіз та узагальнення даних спеціальної літератури та документальних матеріалів; соціологічні методи дослідження; педагогічні методи дослідження; метод експертної оцінки, методи математичної статистики. Дослідження проводилися на базі Національного технічного університету України «КПІ». У дослідженнях брали участь студенти першого курсу, у якості експертів долучалися викладачі фізичного виховання вищих навчальних закладів. Визначено ставлення студентів до використання волейболу у заняттях фізичним вихованням. На основі експертної оцінки виявлено переваги занять з використанням засобів волейболу. Сформульовані основні принципи спортивно-орієнтованого фізичного виховання студентів на основі пріоритетного застосування спортивних ігор (на прикладі волейболу), що покладені в основу розробки технології. Спортивно-орієнтована технологія включає такі компоненти: мету, завдання, принципи, педагогічні умови, програму, критерії ефективності.The paper substantiates the need for the introduction of a sports-oriented technology with the priority use of volleyball in physical education, aimed at improving the efficiency of the physical education process in higher educational institutions, attracting students to physical culture and sports classes, increasing their physical activity, fulfilling of their physical potential in the student years, and enhancing sports and physical preparedness. The following methods were used in the study: theoretical analysis and generalization of special literature data and documentary materials; sociological methods of research; pedagogical methods of research; the expert judgement method, and the methods of mathematical statistics. The study was carried out on the basis of the National technical university of Ukraine "KPI". The study involved first-year students; in addition, instructors of physical education of higher educational institutions were engaged as experts. The attitude of students toward the use of volleyball in physical education classes was determined. On the basis of expert evaluation, the advantages of the use of volleyball in physical education were identified. The main principles of the sports-oriented physical education of students on the basis of priority use of team sports (with an example of volleyball) were summarized that formed the basis for the development of technology. The sports-oriented technology includes the following components: the aim, objectives, principles, pedagogical conditions, program, and criteria of effectiveness.В статье обоснована необходимость внедрения спортивно-ориентированной технологии с приоритетным использованием волейбола в физическом воспитании, направленная на повышение эффективности процесса физического воспитания в высшем учебном заведении, привлечение студентов к физкультурно-спортивным занятиям, повышение их двигательной активности, улучшение двигательного потенциала молодежи в студенческие годы, повышение спортивной и физической подготовленности. Использованы следующие методы исследования теоретический анализ и обобщение данных специальной литературы и документальных материалов; социологические методы исследования; педагогические методы исследования; метод экспертной оценки, методы математической статистики. Исследования проводились на базе Национального технического университета Украины «КПИ». В исследованиях принимали участие студенты первого курса, в качестве экспертов привлекались преподаватели физического воспитания высших учебных заведений. Определено отношение студентов к использованию волейболу в занятиях физическим воспитанием. На основе экспертной оценки выявлены преимущества занятий с использованием средств волейбола. Сформулированы основные принципы спортивно-ориентированного физического воспитания студентов на основе применения приоритетности спортивных игр (на примере волейбола), положенные в основу разработки технологии. Спортивно-ориентированная технология включает следующие компоненты: цель, задачи, принципы, педагогические условия, программу, критерии эффективности
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