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Residual Service Lifetime of Furnaces in Petrochemical Industry
Horsák, Libor ; Vincour, Dušan (referee) ; Lukavský, Jiří (referee) ; Vejvoda, Stanislav (advisor)
The objectives of this work is residual lifetime of heaters in petrochemical industry. There is no comprehensive publication about this theme. This paper lists and describes the most of main phenomena that has to be taken into account in the process of determination of residual lifetime. This paper focuses on creep damage of a real heater based on deformation measurement. It describes some heater failures that could cause unplanned operation interruption however, appropriate intervention made possible safe heater operation until planned heater shutdown. No compact method is given how to determine heater residual lifetime, but a direction is given how a complex method of residual lifetime assessment of refinery heaters could be created.
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Flow Induced Vibration Fatigue Analysis of Tube Bundle
Buzík, Jiří ; Vincour, Dušan (referee) ; Lukavský, Jiří (referee) ; Vejvoda, Stanislav (advisor)
The aim of the dissertation thesis is the control of the tube bundle on the cyclic fatigue caused by the flow past tube bundle. Fatigue due to flow is caused by flow-induced vibrations. Examined vibrations are caused by the mutual interaction of two phases (solid and liquid). The present work is focused mainly on the interaction of tube bundles with fluid. The current level of knowledge in this field allows to predict mainly static respectively quazi-static loading. These predictions are based on methods of comparing key vibration variables such as frequencies, amplitudes or speeds (see TEMA [1]). In this way, it is possible to determine quickly and relatively precisely the occurrence of a vibrational phenomenon, but it is not possible to quantitatively assess the effect of these vibrations on the damage of to the tube beam and to predict its lifespan, which would require the determination of the temperature field and the distribution of forces from the fluid on the beam. The aim of the work is to evaluate the-state-of-the-art, to perform a numerical simulation of the flow of fluids in the area of shell side under the inlet nozzle. Current methods of numerical analyses very well solve this problem, but at the expense of computing time, devices and expensive licences. The benefit of this work is the use of user-defined function (UDF) as a method for simulating interaction with fluid and structure in ANSYS Fluent software. This work places great emphasis on using the current state of knowledge for verifying and validation. Verifying and validation of results include, for example, experimentally measured Reynolds and Strouhal numbers, the drag coefficients and for example magnitude of pressure coefficient around the tube. At the same time, it uses the finite element method as a tool for the stress-strain calculation of a key part on tube such as a pipe-tube joint. Another benefit of this work is the extension of the graphical design of heat exchanger according to Poddar and Polley by vibration damages control according to the method described in TEMA [1]. In this section, the author points out the enormous influence of flow velocity on both the tube side and the shell side for design of the heat exchanger to ensure faultless operation. As an etalon of damage, the author chose a heat exchanger designated 104 from the Heat Exchanger Tube Vibration Data Bank [3]. With this heat exchanger, vibrational damage has been proven to be due to cutting of the tubes over the baffles. The last part outlines the possibilities and limits of further work.
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Visual attention to faces in intersexual and intrasexual selection
Pátková, Žaneta ; Třebická Fialová, Jitka (advisor) ; Lukavský, Jiří (referee) ; Stirratt, Michael (referee)
This thesis focuses on visual attention towards faces in intersexual and intrasexual selection. It consists of two main parts. The first part begins with a brief overview of the intersexual and intrasexual selection mechanisms. Within the framework of intersexual selection, facial attractiveness is discussed, with its putative link to health and immune system function. Within the framework of intrasexual selection, the thesis focuses on perceived facial dominance and formidability and their connection to actual characteristics. Moreover, specific facial traits and morphological features connected with judgements of attractiveness, dominance, and formidability are described. Given the scarce evidence of direct visual attention towards facial features connected with judgements of facial attractiveness and dominance or formidability, we discuss the eye-tracking method, which can measure direct visual attention. A brief summary of eye-tracking studies focusing on visual attention to faces, especially during attractiveness and dominance assessments, is provided. Finally, the thesis focuses on how individual sensory modalities (visual, olfactory and vocal) relate to each other in the perception of individuals and the detection of cues to an individual's quality. The second part of this thesis includes...
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Anxiety in Parkinson's Disease and Its Measurement
Netík, Jan ; Lukavský, Jiří (advisor) ; Horáková, Hana (referee)
This thesis introduces anxiety as one of the most common and important neuropsychiatric symptoms of Parkinson's disease (PD). It places anxiety in the context of other motor and non-motor symptoms and describes the circumstances of its onset and its potential role in early recognition of PD even before a clinical diagnosis is established and before the onset of characteristic motor symptoms. The thesis also touches on the difculties in measuring anxiety in PD and discusses selected models of anxiety and psychodiagnostic methods for its measurement, building in particular on Spielberger's concept of state and trait anxiety, which represents the basis for the State-Trait Anxiety Inventory (STAI), for which we construct the frst Czech norms in the empirical part of the work and verify some psychometric properties of the method on a population of healthy respondents. In the second study, the thesis examines the validity of measuring anxiety in a sample of previously untreated patients with idiopathic PD, who, according to the literature, have an early measurable increase in anxiety. We test whether the STAI can capture the diference between the normative sample and patients with newly diagnosed PD. The results show that the STAI can detect increased anxiety in these patients, although the...
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Frequency of pareidolias as sensory illusions in REM sleep behavior disorder
Radostová, Tereza ; Bezdíček, Ondřej (advisor) ; Lukavský, Jiří (referee)
This thesis focuses on pareidolias as sensory illusions in patients with an idiopathic form of REM sleep behavior disorder (iRBD). The literature review presents iRBD as a prodromal stage of neurodegenerative diseases from the range of alpha-synucleinopathies. Then, the phenomenon of pareidolia as a potentially clinically useful measure of progressive neurodegeneration in iRBD is explored. The empirical part of this thesis aims to test the discriminative potential of the Noise Pareidolia Test (TŠP) in a Czech population of iRBD patients (n = 17) and cognitively healthy volunteers (n = 54). Another aim was to map the neuropsychological context of pareidolia occurrence in both groups and finally to compare the frequency of pareidolia responses in iRBD patients with mild cognitive impairment (iRBD- MCI) versus iRBD without cognitive impairment (iRBD-NC). Subjects were assessed with the TŠP and other neuropsychological tests. Results of the analyses showed that TŠP demonstrated poor intergroup discrimination ability. A significant association was found between a measure of global cognitive function and the ability to correctly recognize faces in the TŠP in iRBD patients. Patients with iRBD-MCI showed a higher number of pareidolia responses compared to iRBD-NC. These findings provide a valuable...
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Facial Recognition in Intercultural Context: An Other-Ethnicity Effect Meta-Analysis
Kroufek, Marek ; Boukalová, Hedvika (advisor) ; Lukavský, Jiří (referee)
This thesis focuses on primarily on other-race effect as a particular psychological phenomenon intercepting face recognition process. In its theoretical part, it subsequently compiles main theoretical models and approaches that attempts to explain other-race effect. A peculiar focus is given to its developmental perspective. The empirical part consists of a meta- analytical study observing other-race effect in children. First it compiles previous meta-analyses concerning other-race effect and after that a proper meta-analysis is conducted. The current meta-analysis contains data from 22 articles (72 samples, n = 3784) and tests following hypotheses: (a) existence of other-race effect in children; (b) increase in bias following age; (c) indication of the critical period in face recognition; (d) relationship between other-race effect and belonging to an ethnic majority within population; (e) global trend in other-race effect over the time. The meta-analysis confirms size effect of middle range and fits results into the theoretical framework. Key words: other-race effect, face recognition, meta-analysis, children
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Phenomenology of 5-MeO-DMT and connection with aspects of mental health
Živnůstka, Miroslav ; Lukavský, Jiří (advisor) ; Pešout, Ondřej (referee)
Given the increasing knowledge of psychedelic compounds in the field of mental health care provided by scientific research in recent decades, the aftereffects of 5-MeO-DMT on aspects of mental health are relatively unexplored. Its unique acute subjective effects can be observed within phenomenology. Studies to date suggest that the experience of ego dissolution and mystical experience are significantly related to improvements in mental health. This work has two objectives. The first intention is to explore the immediate experience with this substance. The second intention is to map the connection between the effect of this substance and aspects of mental health in the period after the use of the substance. In the theoretical part, mental health, psychedelics and 5-MeO-DMT are defined. It primarily presents current findings on the phenomenology of 5-MeO-DMT and empirical work focused on the connection between that substance and mental health. The empirical part describes the research, which included the semi-structured interviews with healthy users of 5-MeO-DMT, processed by thematic analysis. The phenomenology of 5-MeO-DMT was shown to consist of a death experience and an essence of being experience in this research. Finally, I identified the following positive aspects of mental health related to...
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Framing Effects: A Review of Contemporary Findings
Vintr, Jáchym ; Lukavský, Jiří (referee)
This rigorous thesis reviews contemporary findings on the framing effect. It is an important psychological effect embedded in the field of social cognition. The thesis includes a theoretical and an empirical part. The theoretical part of the thesis reviews contemporary theoretical explanations of the framing effect. The main theoretical discussion concerns Prospect Theory, Dual-Process Theory, and its extension in the form of the tripartite model, as well as Fuzzy-Trace Theory. In the theoretical part, the thesis further discusses the typology of framing effects and provides a review of the most important replications and meta-analyses. Furthermore, the thesis discusses studies conducted during the covid-19 pandemic with emphasis on the practical application of framing effects in public health communication. The theoretical part further focuses on individual differences in susceptibility to framing effects. The thesis describes major individual predictors in detail, with focus on cognitive abilities, cognitive styles, numeracy, personality traits, and developmental factors. In the empirical part of this thesis, a pre-registered quantitative online study is conducted on a convenience sample selected from the Czech adult population (N = 584) to test whether numeracy predicts resistance to framing...
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Pupillometry as a measure of cognitive effort
Šútorová, Katarína ; Lukavský, Jiří (advisor) ; Novák, Ondřej (referee)
With the growing popularity of the study of eye movements, the availability of data regarding pupil size has also increased. The size of the pupil is influenced by several factors such as lighting conditions, the distance of the observed object, or psychosensory load. This work is focused on changes in pupil size in response to cognitive load. It is a literature review systemizing research on pupillary reactions. The first part of the thesis describes the neural pathways of pupillary reactions. The second part of the thesis presents particular factors causing changes in pupil size and their function. The third part focuses on different approaches in the methodology of cognitive-pupillometry experiments, which are currently not unified. In the empirical section, the use of pupillometry is demonstrated by performing a short experiment monitoring pupil dilation under different cognitive loads, specifically when calculating arithmetic problems. Key words pupil, pupillary reaction, cognitive load, pupillometry
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A Systematic Review: Financial Reward and Behaviour of Participants in Experiments on Confirmation Bias
Kunc, Benjamín ; Lukavský, Jiří (advisor) ; Vranka, Marek (referee)
This thesis studies the impact of financial rewards on the behavior of participants in behavioral experiments studying confirmation bias. Firstly, it describes theories on cognitive biases with emphasis on the confirmation bias and introduces theoretical approaches towards this bias and also the results of existing empirical studies. Furthermore, the thesis shows pitfalls of potential metaanalysis studying the impact of financial rewards on confirmation bias via a systematic review of experimental studies. Then, the thesis introduces a proposal of such metaanalysis with the intention to draft potential solutions for the issues of the experimental studies, which were described in the review. Within the proposal, a calculation of power-analysis is made and it shows the impact of a high heterogeneity of the experiments studying confirmation bias. Keywords Literature review; Confirmation bias; Incentives; Experiment; Methodology; Metaanalysi
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