This master thesis deals with the vibration diagnostics of machine vibrations during unit tests in industrial company Siemens Electric Machines s.r.o Drásov. In the master thesis is elaborated a design of the diagnostic system which contains selected methods of vibration diagnostics, methology, procedure of measurement and evaluation of measured values. The part of master thesis is also a practical example of measurement on which the mentioned system is tested.

This master's thesis deals with vibrodiagnostics and its use for monitoring of the vibration transmission during grinding of large shafts at Siemens Electric Machines s.r.o. based in Drásov. Diagnostic system for machine tools testing was designed as well as a measurement methodology, which is used to detect the vibration transfer from the grinding spindle to the workpiece. Influences that affect the quality of the ground surface were determined, based on evaluation of measured data. The last part is dedicated to a proposal of a diagnostic and measuring system.

This thesis analyzes the economic situation of the company using the methods of financial and economic analysis, identify problem areas and finally proposes measures to achieve the targeted improvement of the company.

In this diploma thesis is elaborated design of diagnostic system for small jet engines. The aim is to describe the types of possible failures of jet engines, to determine important parameters characterizing the immediate state of engine and define methods for measurement of selected parameters. The first part is devoted to a description of selected types of small turbojet engines, followed by a summary of the most widely used diagnostic methods for assessing the health condition of the engine during operation. The next chapter contains calculation of the engine thermal cycle with characteristics of construction components. Then there is analysis of small jet engine failures with a description of their causes and possibilities of identification by diagnostic system. Thesis continues with a description of measurement methods and selection of the required sensors. Next chapter is focused on the proposed diagnostic system for condition monitoring of the engine. The last part is devoted to an excursion in laboratory for jet engine testing at the Technical University in Košice.

No description available.

Introdução: A apneia obstrutiva do sono (AOS) é caracterizada por episódios repetidos de colapso parcial ou completo das vias aéreas superiores durante o sono, resultando em eventos respiratórios caracterizados por hipopneias ou apneias, respectivamente. Os eventos respiratórios podem resultar em fragmentação do sono, hipoxemia recorrente e geração de pressão intratorácica negativa. Todos esses mecanismos são potencialmente deletérios ao sistema cardiovascular. A AOS é comum entre pacientes com doença cardiovascular, porém ainda é pouco reconhecida. O padrão ouro para o diagnóstico da AOS é a Polissonografia (PSG) completa. O acesso a PSG completa é limitado, contribuindo para o subdiagnóstico da AOS. A poligrafia noturna de variáveis respiratórias (PGR) é um método simplificado, sendo uma alternativa promissora para o diagnóstico da AOS. No entanto, estudos de validação de PGR incluíram somente populações pré-selecionadas ou referidas para laboratórios de sono e excluíram pacientes com comorbidades significativas. Atualmente a Academia Americana de Medicina do sono reconhece o uso da PGR para o diagnóstico da AOS em pacientes com alta probabilidade pré-teste de AOS moderada a grave e em pacientes sem comorbidades significativas. Objetivo: Validar a PGR para o diagnóstico de AOS entre pacientes consecutivos avaliados para cirurgia de revascularização miocárdica, portanto, com Doença Arterial Coronariana (DAC). Avaliar a prevalência da AOS e a utilidade dos sintomas clínicos para o diagnóstico da AOS entre os pacientes com DAC. Métodos: Pacientes com indicação de revascularização do miocárdio foram avaliados através de exames clínicos e laboratoriais de rotina, escala de sonolência diurna (Epworth) e risco clínico de apneia do sono (questionário de Berlin), ecocardiograma, PSG e PGR. A PGR utilizada é classificada como tipo 3, com os seguintes canais: fluxo de ar, esforço respiratório, oximetria de pulso, frequência de pulso, ronco e sensor de posição, (Stardust II ®). Resultados: Foram estudados 70 pacientes consecutivos (76% do sexo masculino); idade (média DP) = 58 ± 7 anos, índice de massa corpórea (IMC) [mediana (25-75%)] = 27,6 (25,8-31,1) kg/m2. Vinte pacientes (29%) apresentaram fração de ejeção do ventrículo esquerdo (FEVE) 45%. A PSG da população revelou índice de apneia e hipopneia (IAH)= 2320 eventos/h. A prevalência de AOS com um IAH 5, 15 e 30 eventos/h foi de 87%, 54% e 27%, respectivamente. A sonolência diurna medida pela escala de Epworth e o risco clínico de AOS verificado pelo questionário de Berlin foram pobres preditores de AOS. A sensibilidade / especificidade da PGR para detectar AOS (IAH 5 eventos/h) e AOS grave (IAH 30 eventos/h) foram 0,92/0,67% e 0,42/0,92%, respectivamente. A média da diferença do IAH entre os dois métodos diagnósticos apresentada no Bland-Altman foi de + 5,3, indicando que os valores do IAH da PGR foram em média inferiores aos da PSG. O desvio padrão da diferença foi de 14,6 eventos/hora, apresentando uma considerável concordância entre o IAH da PSG e da PGR. Conclusão: Este estudo valida o uso da PGR para o diagnóstico da AOS em uma população de pacientes consecutivos, avaliados para revascularização do miocárdio, em quem a doença cardíaca é significativa. A prevalência de AOS entre pacientes com DAC é alta atingindo mais de 50% dessa população. No entanto, os sintomas clínicos, nessa população, não são preditores adequados de AOS. Em função da alta prevalência de AOS e baixa especificidade de sintomas clínicos, nossos dados sugerem que a PGR é um instrumento promissor para a avaliação de pacientes com DAC avaliados para cirurgia de revascularização do micárdio / Introduction: Obstructive sleep apnea (OSA) is characterized by repeated episodes of partial or complete collapse of the upper airway during sleep, resulting in respiratory events characterized by hypopnea or apnea, respectively. Respiratory events may result in sleep fragmentation, hypoxemia and recurrent generation of negative intrathoracic pressure. All these mechanisms are potentially harmful to the cardiovascular system. OSA is common among patients with cardiovascular disease, but is still poorly recognized. The gold standard for diagnosis of OSA is polysomnography (PSG). Access to full PSG is limited, contributing to the under diagnosis of OSA. The polygraph nocturnal of respiratory variables (PGR) is a simplified method, being a promising alternative for the diagnosis of OSA. However, validation studies of PGR only included populations pre-selected or referred to sleep laboratories and excluded patients with significant comorbidities. Currently the American Academy of Sleep Medicine recognizes the use of PGR for the diagnosis of OSA in patients with high pretest probability of moderate to severe OSA and in patients without significant comorbidities. Objective: Validate the PGR for the diagnosis of OSA among consecutive patients evaluated for coronary artery bypass grafting (CABG), therefore with Coronary Artery Disease (CAD). To assess the prevalence of OSA and to evaluate the usefulness of clinical symptoms for diagnosis of OSA among patients with CAD. Methods: Patients with indication of CABG were evaluated by clinical examination and routine laboratory, the scale of daytime sleepiness (Epworth) and clinical risk of sleep apnea (Berlin questionnaire), echocardiogram, PSG and PGR. The PGR use is classified as type 3, with the following channels: airflow, respiratory effort, pulse oximetry, pulse rate, snoring and position sensor, (Stardust II ®). Results: We studied 70 consecutive patients (76% male); age (mean SD) = 58 ± 7 years; body mass index (BMI), [median (25-75%)] = 27,6 (25,8 to 31,1) kg/m2. Twenty patients (29%) had left ventricular ejection fraction (LVEF) 45%. The PSG of population showed apnea-hypopnea index (AHI) = 23 20 events / h. The prevalence of OSA with an AHI 5, 15 and 30 events / h was 87%, 54% and 27%, respectively. Daytime sleepiness measured by Epworth Sleepiness Scale and the clinical risk of OSA verified by the Berlin questionnaire were poor predictors of OSA. The sensitivity and specificity to detect OSA (AHI 5 events / h) and severe OSA (AHI 30 / events) of the PGR were 0,92/0,67% and 0,42/0,92%, respectively. The average difference in AHI between the two diagnostic methods presented in Bland-Altman was + 5,3, indicating that the values of the AHI of the PGR were on average lower than the PSG. The standard deviation of the difference was 14,6 events / hour, presenting a considerable agreement between the AHI of PSG and the PGR. Conclusion: This study validates the use of PGR for the diagnosis of OSA in a population of consecutive patients evaluated for CABG, in whom heart disease is significant. The prevalence of OSA among patients with CAD is high reaching over 50% of this population. However, the clinical symptoms are not adequate predictors of OSA in this population. Due to the high prevalence of OSA and low specificity of clinical symptoms, our data suggest that the PGR is a promising tool for the assessment of CAD patients evaluated for surgery for the CABG

Introdução: A apneia obstrutiva do sono (AOS) é caracterizada por episódios repetidos de colapso parcial ou completo das vias aéreas superiores durante o sono, resultando em eventos respiratórios caracterizados por hipopneias ou apneias, respectivamente. Os eventos respiratórios podem resultar em fragmentação do sono, hipoxemia recorrente e geração de pressão intratorácica negativa. Todos esses mecanismos são potencialmente deletérios ao sistema cardiovascular. A AOS é comum entre pacientes com doença cardiovascular, porém ainda é pouco reconhecida. O padrão ouro para o diagnóstico da AOS é a Polissonografia (PSG) completa. O acesso a PSG completa é limitado, contribuindo para o subdiagnóstico da AOS. A poligrafia noturna de variáveis respiratórias (PGR) é um método simplificado, sendo uma alternativa promissora para o diagnóstico da AOS. No entanto, estudos de validação de PGR incluíram somente populações pré-selecionadas ou referidas para laboratórios de sono e excluíram pacientes com comorbidades significativas. Atualmente a Academia Americana de Medicina do sono reconhece o uso da PGR para o diagnóstico da AOS em pacientes com alta probabilidade pré-teste de AOS moderada a grave e em pacientes sem comorbidades significativas. Objetivo: Validar a PGR para o diagnóstico de AOS entre pacientes consecutivos avaliados para cirurgia de revascularização miocárdica, portanto, com Doença Arterial Coronariana (DAC). Avaliar a prevalência da AOS e a utilidade dos sintomas clínicos para o diagnóstico da AOS entre os pacientes com DAC. Métodos: Pacientes com indicação de revascularização do miocárdio foram avaliados através de exames clínicos e laboratoriais de rotina, escala de sonolência diurna (Epworth) e risco clínico de apneia do sono (questionário de Berlin), ecocardiograma, PSG e PGR. A PGR utilizada é classificada como tipo 3, com os seguintes canais: fluxo de ar, esforço respiratório, oximetria de pulso, frequência de pulso, ronco e sensor de posição, (Stardust II ®). Resultados: Foram estudados 70 pacientes consecutivos (76% do sexo masculino); idade (média DP) = 58 ± 7 anos, índice de massa corpórea (IMC) [mediana (25-75%)] = 27,6 (25,8-31,1) kg/m2. Vinte pacientes (29%) apresentaram fração de ejeção do ventrículo esquerdo (FEVE) 45%. A PSG da população revelou índice de apneia e hipopneia (IAH)= 2320 eventos/h. A prevalência de AOS com um IAH 5, 15 e 30 eventos/h foi de 87%, 54% e 27%, respectivamente. A sonolência diurna medida pela escala de Epworth e o risco clínico de AOS verificado pelo questionário de Berlin foram pobres preditores de AOS. A sensibilidade / especificidade da PGR para detectar AOS (IAH 5 eventos/h) e AOS grave (IAH 30 eventos/h) foram 0,92/0,67% e 0,42/0,92%, respectivamente. A média da diferença do IAH entre os dois métodos diagnósticos apresentada no Bland-Altman foi de + 5,3, indicando que os valores do IAH da PGR foram em média inferiores aos da PSG. O desvio padrão da diferença foi de 14,6 eventos/hora, apresentando uma considerável concordância entre o IAH da PSG e da PGR. Conclusão: Este estudo valida o uso da PGR para o diagnóstico da AOS em uma população de pacientes consecutivos, avaliados para revascularização do miocárdio, em quem a doença cardíaca é significativa. A prevalência de AOS entre pacientes com DAC é alta atingindo mais de 50% dessa população. No entanto, os sintomas clínicos, nessa população, não são preditores adequados de AOS. Em função da alta prevalência de AOS e baixa especificidade de sintomas clínicos, nossos dados sugerem que a PGR é um instrumento promissor para a avaliação de pacientes com DAC avaliados para cirurgia de revascularização do micárdio / Introduction: Obstructive sleep apnea (OSA) is characterized by repeated episodes of partial or complete collapse of the upper airway during sleep, resulting in respiratory events characterized by hypopnea or apnea, respectively. Respiratory events may result in sleep fragmentation, hypoxemia and recurrent generation of negative intrathoracic pressure. All these mechanisms are potentially harmful to the cardiovascular system. OSA is common among patients with cardiovascular disease, but is still poorly recognized. The gold standard for diagnosis of OSA is polysomnography (PSG). Access to full PSG is limited, contributing to the under diagnosis of OSA. The polygraph nocturnal of respiratory variables (PGR) is a simplified method, being a promising alternative for the diagnosis of OSA. However, validation studies of PGR only included populations pre-selected or referred to sleep laboratories and excluded patients with significant comorbidities. Currently the American Academy of Sleep Medicine recognizes the use of PGR for the diagnosis of OSA in patients with high pretest probability of moderate to severe OSA and in patients without significant comorbidities. Objective: Validate the PGR for the diagnosis of OSA among consecutive patients evaluated for coronary artery bypass grafting (CABG), therefore with Coronary Artery Disease (CAD). To assess the prevalence of OSA and to evaluate the usefulness of clinical symptoms for diagnosis of OSA among patients with CAD. Methods: Patients with indication of CABG were evaluated by clinical examination and routine laboratory, the scale of daytime sleepiness (Epworth) and clinical risk of sleep apnea (Berlin questionnaire), echocardiogram, PSG and PGR. The PGR use is classified as type 3, with the following channels: airflow, respiratory effort, pulse oximetry, pulse rate, snoring and position sensor, (Stardust II ®). Results: We studied 70 consecutive patients (76% male); age (mean SD) = 58 ± 7 years; body mass index (BMI), [median (25-75%)] = 27,6 (25,8 to 31,1) kg/m2. Twenty patients (29%) had left ventricular ejection fraction (LVEF) 45%. The PSG of population showed apnea-hypopnea index (AHI) = 23 20 events / h. The prevalence of OSA with an AHI 5, 15 and 30 events / h was 87%, 54% and 27%, respectively. Daytime sleepiness measured by Epworth Sleepiness Scale and the clinical risk of OSA verified by the Berlin questionnaire were poor predictors of OSA. The sensitivity and specificity to detect OSA (AHI 5 events / h) and severe OSA (AHI 30 / events) of the PGR were 0,92/0,67% and 0,42/0,92%, respectively. The average difference in AHI between the two diagnostic methods presented in Bland-Altman was + 5,3, indicating that the values of the AHI of the PGR were on average lower than the PSG. The standard deviation of the difference was 14,6 events / hour, presenting a considerable agreement between the AHI of PSG and the PGR. Conclusion: This study validates the use of PGR for the diagnosis of OSA in a population of consecutive patients evaluated for CABG, in whom heart disease is significant. The prevalence of OSA among patients with CAD is high reaching over 50% of this population. However, the clinical symptoms are not adequate predictors of OSA in this population. Due to the high prevalence of OSA and low specificity of clinical symptoms, our data suggest that the PGR is a promising tool for the assessment of CAD patients evaluated for surgery for the CABG

The reliability of modern gas turbine engines is largely due to careful damage tolerant design a method of structural design based on the assumption that flaws (cracks) exist in any structure and will continue to grow with usage. With proper monitoring, largely in the form of periodic inspections at conservative intervals reliability and safety is maintained. These methods while reliable can lead to the early retirement of some components and unforeseen failure if design assumptions fail to reflect reality. With improvements to sensor and computing technology there is a growing interest in a system that could continuously monitor the health of structural aircraft as well as forecast future damage accumulation in real-time. Through the use of two-dimensional and three-dimensional numerical modeling the initial goals and findings for this continued work include: (a) establishing measurable parameters directly linked to the health of the blade and (b) the feasibility of detecting accumulated damage to the structural material and thermal barrier coating as well as the onset of damage causing structural failure.

The reliability of modern gas turbine engines is largely due to careful damage tolerant design a method of structural design based on the assumption that flaws (cracks) exist in any structure and will continue to grow with usage. With proper monitoring, largely in the form of periodic inspections at conservative intervals reliability and safety is maintained. These methods while reliable can lead to the early retirement of some components and unforeseen failure if design assumptions fail to reflect reality. With improvements to sensor and computing technology there is a growing interest in a system that could continuously monitor the health of structural aircraft as well as forecast future damage accumulation in real-time. Through the use of two-dimensional and three-dimensional numerical modeling the initial goals and findings for this continued work include: (a) establishing measurable parameters directly linked to the health of the blade and (b) the feasibility of detecting accumulated damage to the structural material and thermal barrier coating as well as the onset of damage causing structural failure.

The reliability of modern gas turbine engines is largely due to careful damage tolerant design a method of structural design based on the assumption that flaws (cracks) exist in any structure and will continue to grow with usage. With proper monitoring, largely in the form of periodic inspections at conservative intervals reliability and safety is maintained. These methods while reliable can lead to the early retirement of some components and unforeseen failure if design assumptions fail to reflect reality. With improvements to sensor and computing technology there is a growing interest in a system that could continuously monitor the health of structural aircraft as well as forecast future damage accumulation in real-time. Through the use of two-dimensional and three-dimensional numerical modeling the initial goals and findings for this continued work include: (a) establishing measurable parameters directly linked to the health of the blade and (b) the feasibility of detecting accumulated damage to the structural material and thermal barrier coating as well as the onset of damage causing structural failure.