Nonlinear longitudinal/transversal modal interactions in highly extensible suspended cables

Recent research literature mostly deals with nonlinear resonant dynamics of low-extensible cables involving transversal modes. Herein, we aim to investigate geometrically nonlinear longitudinal/transversal modal interactions in highly extensible suspended cables, whose material properties are assumed to be linearly elastic. Depending on cable elasto-geometric properties, the spectrum of low-order planar frequencies manifests primary and secondary frequency crossover phenomena of transversal/transversal and longitudinal/transversal modes, respectively. By focusing on 1:1 internal resonances, nonlinear equations of finite-amplitude, harmonically forced and damped, cable motion are considered, fully accounting for overall inertia and displacement coupling effects. Meaningful quadratic nonlinear contributions of non-resonant, higher-order, longitudinal modes are highlighted via a multimode-based, second-order multiple scales solution. Overall coupled/uncoupled dynamic responses, bifurcations, stability and space-time-varying displacements due to longitudinal/transversal (vs. transversal/transversal) modal interactions at secondary (vs. primary) crossovers are analytically and numerically evaluated, along with the resonant longitudinal mode-induced dynamic forces

Two-to-one resonant multi-modal dynamics of horizontal/inclined cables. Part II : internal resonance activation, reduced-order models and nonlinear normal modes

Resonant multi-modal dynamics due to planar 2:1 internal resonances in the nonlinear, finite-amplitude, free vibrations of horizontal/inclined cables are parametrically investigated based on the second-order multiple scales solution in Part I [1]. The already validated kinematically non-condensed cable model accounts for the effects of both non-linear dynamic extensibility and system asymmetry due to inclined sagged configurations. Actual activation of 2:1 resonances is discussed, enlightening on a remarkable qualitative difference of horizontal/inclined cables as regards non-linear orthogonality properties of normal modes. Based on the analysis of modal contribution and solution convergence of various resonant cables, hints are obtained on proper reduced-order model selections from the asymptotic solution accounting for higher-order effects of quadratic nonlinearities. The dependence of resonant dynamics on coupled vibration amplitudes, and the significant effects of cable sag, inclination and extensibility on system non-linear behavior are highlighted, along with meaningful contributions of longitudinal dynamics. The spatio-temporal variation of non-linear dynamic configurations and dynamic tensions associated with 2:1 resonant non-linear normal modes is illustrated. Overall, the analytical predictions are validated by finite difference-based numerical investigations of the original partial-differential equations of motion

Experimental and numerical studies of inclined cables: free and parametrically-forced vibrations

Because of few experimental studies in the inclined cable literature, this paper is aimed at experimental modelling and investigating the linear free and nonlinear forced vibrations of sagged inclined cables, by discussing the relevant outcomes in the background of theoretical and numerical achievements. Attention is paid to the identification of cable hybrid modes due to system asymmetry, which gives rise to an avoidance phenomenon in the natural frequency spectrum, and to the investigation of some typical 3-D nonlinear dynamics involving the simultaneous parametric/external excitation due to a harmonically time-varying support movement. Large-amplitude out-of-plane/in-plane multi-modal interactions due to non-planar/planar internal resonances are experimentally observed and complemented by space-time numerical simulation of the associated, geometrically nonlinear, partial-differential equations of parametrically-forced cable motion. Overall, the experimental and numerical results highlight the fundamental linear/nonlinear dynamic characteristics of inclined cables, and the crucial role played by the asymmetry induced by cable inclination, in addition to the significant effects of cable sag and dynamic extensibility

Two-to-one resonant multi-modal dynamics of horizontal/inclined cables. Part I : theoretical formulation and model validation

This paper is first of the two papers dealingwith analytical investigation of resonant multimodal dynamics due to 2:1 internal resonances in the finite-amplitude free vibrations of horizontal/inclined cables. Part I deals with theoretical formulation and validation of the general cable model. Approximate nonlinear partial differential equations of 3-D coupled motion of small sagged cables - which account for both spatio-temporal variation of nonlinear dynamic tension and system asymmetry due to inclined sagged configurations - are presented. A multidimensional Galerkin expansion of the solution ofnonplanar/planar motion is performed, yielding a complete set of system quadratic/cubic coefficients. With the aim of parametrically studying the behavior of horizontal/inclined cables in Part II [25], a second-order asymptotic analysis under planar 2:1 resonance is accomplished by the method of multiple scales. On accounting for higher-order effectsof quadratic/cubic nonlinearities, approximate closed form solutions of nonlinear amplitudes, frequencies and dynamic configurations of resonant nonlinear normal modes reveal the dependence of cable response on resonant/nonresonant modal contributions. Depending on simplifying kinematic modeling and assigned system parameters, approximate horizontal/inclined cable models are thoroughly validated by numerically evaluating statics and non-planar/planar linear/non-linear dynamics against those of the exact model. Moreover, the modal coupling role and contribution of system longitudinal dynamics are discussed for horizontal cables, showing some meaningful effects due to kinematic condensation

АНАЛІЗ РИЗИКУ РОЗВИТКУ СИНДРОМУ ЕМОЦІЙНОГО ВИГОРАННЯ У МЕДИЧНИХ СЕСТЕР ГЕМАТОЛОГІЧНОГО ВІДДІЛЕННЯ КОМУНАЛЬНОГО ЗАКЛАДУ ТЕРНОПІЛЬСЬКОЇ ОБЛАСНОЇ РАДИ «ТЕРНОПІЛЬСЬКА УНІВЕРСИТЕТСЬКА ЛІКАРНЯ»

This article presents the results of investigation, aimed to find out the risks of  “emotional burnout” syndrome  development in nurses providing palliative care to incurable patients of hematological department of a municipal institution of Ternopil regional council “TernopilUniversityHospital.” The ways of prevention and correction of the “emotional burnout” syndrome are proposed.В статті наведені результати дослідження ризику розвитку синдрому «емоційного вигорання» у медсестер, що надають паліативну допомогу інкурабельним пацієнтам гематологічного відділення комунального закладу Тернопільської обласної ради «Тернопільська університетська лікарня». Запропоновані шляхи профілактики та корекції синдрому «емоційного вигорання»

АНАЛІЗ ЯКОСТІ НАВЧАННЯ МЕДИЧНИХ СЕСТЕР ЗАКАРПАТСЬКОГО БАЗОВОГО МЕДИЧНОГО КОЛЕДЖУ ЗА РЕЗУЛЬТАТАМИ СТАНДАРТИЗОВАНОГО ТЕСТОВОГО ДЕРЖАВНОГО ІСПИТУ «КРОК М»

The article analyzes the results of a standardized test public examination KROK"M" in graduates of Zarkarpatskyy medical college (2011-2014 yy.) and proposes modern methods to improve the quality of teaching in higher educational medical institutions.У статті проаналізовано результати стандартизованого тестового державного іспиту «Крок М» у випускників Закарпатського базового медичного коледжу за 2011‒2014 рр. та запропоновано сучасні методи покращення якості навчання у вищих навчальних медичних закладах.

ПРОБЛЕМИ І ПЕРСПЕКТИВИ ВИКЛАДАННЯ «ОСНОВ МЕДСЕСТРИНСТВА» В ЧЕРКАСЬКОМУ БАЗОВОМУ ДЕРЖАВНОМУ МЕДИЧНОМУ КОЛЕДЖІ

The article presents the analysis of level of knowledges on the subject «Fundamentals of Nursing» based on the results of the testing of students of different courses and postgraduates of the Cherkassy Basic State Medical College. The aim of  investigation is to assess the quality of students education and develop further recommendations for improving teaching effectiveness of subject «Fundamentals of Nursing».У статті проаналізовано рівень знань з предмета «Основи медсестринства» за результатами тестування студентів різних курсів та випускників Черкаського базового державного медичного коледжу з метою оцінки якості їх навчання та розробки подальших рекомендацій для підвищення ефективності викладання предмета «Основи медсестринства»

Reinforcing the pulmonary artery autograft in the aortic position with a textile mesh: a histological evaluation

OBJECTIVES The Ross procedure involves replacing a patient’s diseased aortic valve with their own pulmonary valve. The most common failure mode is dilatation of the autograft. Various strategies to reinforce the autograft have been proposed. Personalized external aortic root support has been shown to be effective in stabilizing the aortic root in Marfan patients. In this study, the use of a similar external mesh to support a pulmonary artery autograft was evaluated. METHODS The pulmonary artery was translocated as an interposition autograft in the descending thoracic aortas of 10 sheep. The autograft was reinforced with a polyethylene terephthalate mesh (n = 7) or left unreinforced (n = 3). After 6 months, a computed tomography scan was taken, and the descending aorta was excised and histologically examined using the haematoxylin–eosin and Elastica van Gieson stains. RESULTS The autograft/aortic diameter ratio was 1.59 in the unreinforced group but much less in the reinforced group (1.11) (P < 0.05). A fibrotic sheet, variable in thickness and containing fibroblasts, neovessels and foreign body giant cells, was incorporated in the mesh. Histological examination of the reinforced autograft and the adjacent aorta revealed thinning of the vessel wall due to atrophy of the smooth muscle cells. Potential spaces between the vessel wall and the mesh were filled with oedema. CONCLUSIONS Reinforcing an interposition pulmonary autograft in the descending aorta with a macroporous mesh showed promising results in limiting autograft dilatation in this sheep model. Histological evaluation revealed atrophy of the smooth muscle cell and consequently thinning of the vessel wall within the mesh support