Stress, deformation and safety analysis of the recumbent bicycle frontal composite axle

Tato diplomová práce se zabývá vytvořením výpočtového modelu kompozitní nápravy lehokola – tříkolky firmy AZUB pro analýzu deformačně napěťových stavů. Diplomová práce se skládá ze čtyř částí. První část obsahuje seznámení s nabídkou celoodpružených tříkolek nejznámějších výrobců. Dále obsahuje pojednání o kompozitních materiálech, které tvoří hlavní prvek odpružení firmy AZUB a popis přední nápravy téže firmy. V druhé části je podrobně zpracován výpočtový model sloužící k analýze deformačně napěťových stavů pro tři zvolené zátěžné stavy. Je diskutován vliv některých parametrů materíálu a geometrie na chování nápravy s cílem vybrání vhodné varianty odpružení. Třetí část se zabývá výrobou prototypu přední nápravy a zkouškami, které slouží ke zjištění vstupních dat do numerického výpočtu a k verifikaci výsledků výpočtového modelu. Úpravy a změny vedoucí k výrobě druhého prototypu jsou obsahem poslední části. Na základě těchto zkušeností jsou pak formulována doporučení pro budoucí vývoj výpočtového modelu odpružené nápravy i samotného odpružení přední nápravy lehokola.This diploma thesis deals with creation of computational model of AZUB recumbent tricycle composite axle for stress strain analysis. The thesis consists of four main parts. The first part contains introduction to the offer of full suspended tricycles from the most known manufacturers. Furthermore it contains introduction to composite materials that makes the main element of AZUB´´s suspension, and the description of the AZUB´´s front axle. In the second part there is detailed compilation of computational model for purpose of stress strain analysis of three load states. The effect of specific material and geometry parameters on axle behavior is discussed with the aim of choosing the most appropriate variant. Third part deals with the manufacturing of the front axle prototype and with tests leading to input data for numerical model and verification of computational model. Modifications and changes that lead to manufacturing of the second prototype are content of the last part. Based on this experience some recommendations for future development of the numerical axle model and the front axle suspension itself are formulated.

Deformation, stress and safety analysis of the bicycle frame.

Cílem této práce bylo posouzení poddajnosti a bezpečnosti rámu jízdního kola pomocí přístupu prosté pružnosti, konkrétně pomocí výpočtové deformační a napjatostní analýzy. Po zjednodušení modelu byly zpracovány dvě varianty výpočtu, které se lišily způsobem zatížení rámu. Pro výpočet bylo využito matematického softwaru Maple 12.0, pomocné nákresy byly ztvárněny v programech Autodesk Inventor a AutoCAD. Pro kontrolu výsledků byl použit program ANSYS Workbench.The aim of this bachelor thesis is to assess complience and safety of the bicycle frame with basic elasticity approach, namely by deformation and stress analysis. After model simplyfying, two different cases were made. Difference between these two were in loads aplied on the frame. Maple 12.0 softwarre was used for calculation, Autodesk Inventor and AutoCAD were used for sketches. The results were checked with ANSYS Workbench.

GNSS for VFR flights. Supporting learning material for students and instructors

This publication addresses general aviation pilots of all age and experience to provide them essential information about Global Navigation Satellite Systems (GNSS). Its major aim is to enhance safety of VFR flight operations and to allow pilots to take use of the full potential of these systems. It provides a basic, yet sufficient level of knowledge about general principles of these systems and combines it with a set of tips and advises for their practical and safe use during VFR flights. This would be supported by new training syllabi, both for theoretical knowledge (TK) and practical skill (PS), that will provide pilots with a more advanced knowledge of these systems from their early training. Part A of this publication provides pilots with a level of theoretical GNSS knowledge, which is required by the new proposed theoretical syllabi for PPL(A), PPL(H) and LAPL. Part B of this publication is structured in accordance with the proposed changes and additions to the PPL(A), PPL(H) and LAPL theoretical knowledge syllabi, namely AMC1 to EASA rule FCL.210 and AMC1 to FCL.215 identified by the CaBilAvi project consortium. On the other hand, this part B is also incorporated into the e-learning application available for free use on CaBilAvi project webpage (http://cabilavi.gnss-centre.cz/web/elearning)

The level of business ethics of small and medium-sized enterprises in the Visegrad group

The aim of the paper is to define and compare the significant attributes in the field of business ethics according to the size of the firm, gender and education of entrepreneurs in the SME segment in sum in the V4 countries. The empirical research, which was aimed at identifying the attitudes of small and medium-sized firms, was conducted in June 2022 in the Visegrad Four countries (Czech Republic, Slovakia, Poland and Hungary). The data collection was carried out by the external firm. Statistical hypotheses were tested through descriptive statistics, chi-square and Z-score at α = 5% significance level. The attitudes of SMEs towards the following statements were examined: ST1: I consider ethics in business important; ST2: I consider the ethical implications of my decisions when managing my business; ST3: I feel good when I behave ethically in business; and ST4: Our company enforces rules of ethical conduct in business. We find that the level of agreement with these statements is high. We did not find statistically significant differences in responses based on defined demographic characteristics

GNSS for IFR flights. Learning material for students and instructors

Pilots flying IFR (Instrument Flight Rules) nowadays are expected to come across with GNSS usage. The main reason behind this is that the RNAV 5 (alias Basic RNAV) navigation specification is mandatory above FL095 in almost the whole European airspace. Today’s knowledge for IFR flying is insufficient for safe and trouble-free flying in the PBN environment. As the EASA’s new regulation (EU 2016/539) is resolving this issue with the requirement of a PBN clause to Instrument Rating, it will be in effect from 25 August 2018. The first section (part A) of this publication was designed to guide General Aviation (GA) pilots towards basic principles of PBN. The GNSS receiver is almost an exclusive navigation device used in GA which enables PBN operations. Therefore, the publication is GNSS-orientated. The second section (part B) provides Learning Objectives identified by the CaBilAvi project consortium, as they are relevant and important for PBN flying and missing from the required theoretical knowledge of pilots. The proposed Learning Objectives are explained throughout part “B”, and they are relevant to every Instrument Rated pilot and beyond. Due to the structure of the proposed Learning Objectives, some of the content of this Part may be duplicate to part A. On the other hand, part B is also incorporated into the e-learning application available for free use on CaBilAvi project webpage (http://cabilavi.gnss-centre.cz/web/elearning)

GNSS in civil aviation. Learning material for "winter training"

The main purpose of this publication is to increase the awareness of pilots in the use of GNSS. The Winter Training Brochure is oriented towards a brief and clear explanation of the basic principles and requirements for the correct and safe use of GNSS devices during the flight, with regard to the target group, pilots and instructors, different age, experience and skill categories. The Winter Training Brochure is divided into three main parts, Part 1 addresses the basic theoretical bases and GNSS principles common for VFR and IFR flights, Part 2 deals with the principles of GNSS use for VFR flights, Part 3 deals with the principles of GNSS use for IFR flights

Effect of pirfenidone on lung function decline and survival: 5-yr experience from a real-life IPF cohort from the Czech EMPIRE registry

Abstract Introduction Pirfenidone, an antifibrotic drug, slows-down the disease progression in idiopathic pulmonary fibrosis (IPF) over 12 months, however limited data on the decline of lung function and overall survival (OS) in real-world cohorts on longer follow-up exists. Patients/methods Of the enrolled Czech IPF patients (n = 841) from an EMPIRE registry, 383 (45.5%) received pirfenidone, 218 (25.9%) no-antifibrotic treatment and 240 (28.5%) were excluded (missing data, nintedanib treatment). The 2- and 5-yrs OS and forced vital capacity (FVC) and diffusing lung capacity for carbon monoxide (DLCO) were investigated at treatment initiation and 6, 12, 18 and 24 months’ follow-up. Results During a 2-yr follow-up, less than a quarter of the patients progressed on pirfenidone as assessed by the decline of ≥10% FVC (17.0%) and ≥ 15% DLCO (14.3%). On pirfenidone, the DLCO (≥10%) declines at 6, 12, 18 and 24 months’ and DLCO (≥15%) declines at 6, 18 and 24 months’ follow-up were associated with increased mortality. The DLCO decline showed higher predictive value for mortality than FVC decline. In patients with no-antifibrotics, FVC and DLCO declines were not predictive for mortality. Pirfenidone increased 5-yrs OS over no-antifibrotic treatment (55.9% vs 31.5% alive, P = 0.002). Conclusion Our study observed the 2-yrs sustained effect of pirfenidone on the decline of lung function and survival in the real-world patient’s IPF cohort. DLCO decline of ≥10% shows a potential as a mortality predictor in IPF patients on pirfenidone, and should be routinely evaluated during follow-up examinations