|
Design of Experiment for Non-Stationary Processes of Production
Jadrná, Monika ; Macák, Tomáš (advisor)
The doctoral thesis is concerned with the services sector and the area of mass production. Particularly, the optimization of the product portfolio of the travel agency and the optimization of production rounds of ammunition.
The theoretical part deals with the current overview of discussed topic. Further, the terminology and methods of the decision-making process are defined to support decision making. The theoretical basis of research focused on the choice of appropriate input variables in the area of services, and on the choice of a particular material option in the production area and appropriate equipment for the production. The theoretical part forms the basis for the practical part of the thesis.
For the doctoral thesis was chosen an enterprise operating in the defined sector. Product portfolio for the services sector is optimised using Fuzzy logic and Fuzzy sets so that the enterprise can maintain its competitiveness in todays highly ambitious market. Product portfolio for manufacture is optimised for achieving desired properties of the product.
The main aim of the thesis is to propose a new methodological approach for the management of selected business processes in their nonstationary time course. The aim of the practical implementation is to verify the functionality of the proposed methodological approach, both in the area of services and in the field of mass production.
|
|
Properties of Aerosol, Produced by Laser Ablation of Standard Materials for ICP-MS Analysis.
Holá, M. ; Nováková, H. ; Ondráček, Jakub ; Vojtíšek, M. ; Kanický, V.
Laser ablation (LA), together with inductively coupled plasma mass spectrometry (ICP-MS) as a detection system, has become a routine method for the direct analysis of various solid samples. The product of laser ablation contains a mixture of vapour, droplets and solid particles. All components are finally transported to a plasma by a carrier gas as a dry aerosol including mainly agglomerates of primary nanoparticles. In general, characterisation of aerosols by their particle size distribution (PSD) represents indispensable tool for fundamental studies of the interaction of laser radiation with various materials. The particle size distribution of dry aerosol originating from laser ablation of standard material was monitored by two aerosol spectrometers – Fast Mobility Particle Sizer (EEPS) and Scanning Mobility Particle Sizer (SMPS) simultaneously with laser ablation - ICP-MS analysis.\n
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22016102412241 - PDF
|
|
FRACTURE MECHANICS ASSESSMENT OF CRACKED WELDED POLYOLEFIN PIPES
Mikula, Jakub ; Ševčík, Martin ; Hutař, Pavel ; Náhlík, Luboš
The aim of this paper is to present methodology for estimation of fracture mechanics parameters in polyolefin pipes with an axially oriented crack using three dimensional numerical analyses. Linear elastic fracture mechanics is used for description of fracture behavior. In the paper, three different variants of pipe weld with an internal axial semi-elliptical crack are studied. Numerical models correspond to a cracked pipe containing material nonhomogeneity in the welding area caused by welding process. A critical locations of the crack initiated along the pipe wall is found and the stress intensity factor for such cracks with real crack shape are numerically estimated in these critical locations. The methodology presented here can be used for estimation of residual lifetime of welded polymer pipes containing crack.
|
|
Time lapse tomography of fracture progress in silicate-based composite subjected to the loading a combination with acoustic emission scanning
Kumpová, Ivana ; Kytýř, Daniel ; Fíla, Tomáš ; Veselý, V. ; Trčka, T. ; Vopálenský, Michal ; Vavřík, Daniel
The initiation and propagation of a fracture in quasi-brittle materials (such as silicatebased composite) is an increasingly discussed topic for which various methods of research have been developed/applied. As the quasi-brittle silicate-based composite compounds are very non-homogenous, the mechanism of the crack initiation and propagation can be very different even for samples with the\nidentical geometry. One possible approach to study the fracture mechanism in quasi-brittle materials is to use several different experimental techniques in a single experiment and perform detail analysis to identify generally valid fracture process phenomena. In this work, a simultaneous monitoring of fracture\nprocess zone formation and propagation by three different methods is presented and discussed. A three point bending test was performed on a notched silicate composite specimen. During the loading process, a highly accurate force displacement dependence was recorded accompanied with X-ray radiography,\nX-ray computed tomogra-phy and acoustic emission scanning.
|
|
Deformation characteristics of chopped fibre composites subjected to quasi-static tensile loading
Šleichrt, J. ; Adorna, M. ; Neühauserová, M. ; Fenclová, N. ; Petráňová, Veronika
This work presents deformation behaviour of cost effective chopped fiber composites. Use of chopped fibre is advantageous for manufacturing however complex shape parts production technology could be challenging. Batches of samples with different fibres composition were subjected to uni-axial tensile loading to obtain overall materials properties and inspection of proper manufacturing based on local deformation inhomogeneities. Both crossbeam displacement and optical strain measurement were used for elastic characteristics evaluation. Deformation response was derived from full-field optical strain measurements based on digital image correlation method. Relatively large variation of mechanical properties testing of samples was found.
|
|
Organization and management of production in selected enterprise
DRNOVÁ, Markéta
The topic of my dissertation is "Organization and management of production in selected enterprise". The main goal of this dissertation is mapping of selected enterprise in one year period and obtain sufficient amount of information for future analysis and suggest possible improvements. The identification data, characteristic, products and services and production planning of selected enterprise are provided in introduction of practical part of this dissertation. Analysis of present state with mapping of present state for individually semi-finished products is introduced in the next part of dissertation. For analysis of present state was calculated VA index and for each semi-finished product was created diagram of material movement in next chapter. The goal of analyses and diagram is the finding of narrow spaces in the material flow. The target map of future state was created in the next part. This map is based on present map. The future map presents critical factors that need to be improved. Finally it defines a new VA index, which should be approach to the current state. The penultimate section includes recommendations methods and elements of lean production to the new production hall which the company wants to build. Among the recommended methods are mainly the 5S method, visualization, standardization, SMED and Bottleneck. The last chapter contains a number of measures. For example employee motivation, continuous improvement, personal responsibility, introduction of EDI and ergonomics which would lead to the improvement of the business this enterprise.
|
|
Improving labour productivity: How to determine standard time for performing specific tasks in the selected organization
BARTOŠKOVÁ, Martina
This bachelor thesis focuses on the standard time needed for specific tasks in the selected organization, as well as on the appropriate methods for its determination. The findings serve as a basis for the formulation of measures which should be taken to improve labour productivity. The methods include the standardization of tasks, time study and computer-based data analysis (Microsoft Excel spreadsheets). The theoretical part of the paper discusses the nature of job production, the methods appropriate for the calculation of standard production time and the ways to ensure efficient work and time management in the given factory. Apart from these, a complete description (history, facility layout, pre-production and production stages, machines and materials) of the selected organization is provided to serve as a background for the case study presented in the practical part. This includes the list of production tasks, production time tables and time standards along with materials necessary to facilitate production. The aim of the thesis is to help the organization improve its labour productivity and provide it with the algorithm which can be used to determine production time for similar orders.
|
|
Doped DLC coatings for biomedical applications
Písařík, Petr
Nowadays there are materials having excellent properties for use in medicine (Diamond-like carbon, Hydroxyapatite, …). Diamond-like carbon (DLC) is a metastable form of amorphous carbon containing bonded carbon atoms of sp2 and sp3 hybridized orbital. DLC layers are semiconductors with high mechanical hardness, chemical inertness, low coefficient of friction, high thermal conductivity, good electrical and optical properties, biocompatibility and no cytotoxicity. All properties of the films are not always ideal, so it is necessary to modify the layer. One example of how to modify the properties of thin layers are dopations. The incorporation of dopants in films may lead to greater multifunctionality and much improved properties. Most modifications were made to modify contact angle and surface energy, to reduce internal stresses, to decrease surface roughness, coefficient of friction or wear....
|
|
Nutritional care about immobile patient on standard department of internal type
AMBLEROVÁ, Michaela
Nutritional care for immobile clients at a standard department of internal type becomes still more important, because nutritional care is important for maintaining good health and supporting quality of life. Nutritional status of immobile clients is very important to diagnose as early as possible in order to avoid all risks of potential complications. Adequate nutrition is also very important to maintain good mental health. The central objective of this work was to explore the specifics of nursing care in the field of nutritional care for immobile client at a standard department of internal type. Following this goal, three research questions were set up: How is the nutritional status of patients at a standard department of internal type assessed? What are the possibilities of application of nutrition for immobile client at a standard department of internal type? What are the specifics of nursing care in the fields of nutrition of immobile client at a standard department of internal type? The empirical part of the thesis was processed using qualitative research, which was realized through semi-structured interview technique. The interview contained 3134 questions, which focused on nutrition care for immobile clients on standard unit of internal type. The research sample consisted of nurses working in the standard department of internal type in the České Budějovice Hospital, a.s. Overall, this study leads to two findings, both positive and negative. Within the positive findings we can say that nurses provide adequate care in the application of nutrition per os. Negative findings relates to the fact that the interviewed nurses provide only basic care in case of the introduction of enteral and parenteral nutrition. They do not know more detailed specifics of enteral and parenteral nutrition. Based on this finding, we think it would be useful to organize regular seminars and trainings for nurses to expand their knowledge about this type of care, or at least remind it. This thesis can serve as an informational material for nurses in practice or students of other health professions. This work can serve also as a basis for further research.
|
|
Specifics of nursing care in patients after transapical aortic valve implantation.
VOTRUBOVÁ, Nataliya
Transcatheter aortic valve implantation (TAVI) is a new and an attractive method in cardiology and as well as in cardiac surgery. It is constantly evolving method which has been developed as an alternative to standard open surgery, especially in patients with severe symptomatic aortic stenosis with unacceptably high perioperative risk or patients who are not suitable for conventional open heart surgery because of age and comorbidities.A teamwork is very importantfor this new method and approach. The choice for TAVI is discussed by the institutional multidisciplinary heart team, typically consisting of interventional cardiologists, imaging-specialists, cardiac surgeons and anaesthesiologists. The first implant in a human being was performed by Cribierin 2002. In Czech Republic this method was first used in 2008. Transcatheter aortic valve implantation (TAVI) was accepted as a minimally invasive alternative to open surgery. This method does not require the use of cardiopulmonary bypass, and cardiac arrest. Other several benefits includinglower risks of bleeding and stroke events, better wound healing, less pain, as well as more rapid early recovery due to preservation of continuity of the sternumthat result in shorter durations of stay in the hospital, earlier rehabilitation and faster returns to normal life. In the presented work was used a combination of qualitative-quantitative methods of investigation. The data was obtained by using the quantitative research. The main technique was using the questionnaires designed for nurses working at the Department of Cardiac Surgery, Hospital Czech Budejovice, a. s. These results were backed up by the implementation of qualitative research, which investigated the patients and physicians view on monitored issues. Questioning method using a semi structured interview technique was used for qualitative research. The results of the survey were processed using descriptive statistics charts in LibreOffice Calc and using diagrams created in LibreOffice Writer. Qualitative results of the research were transcribed from audio recordings and coded, and the base code was created nine categories of interviews with clients/patients and three categories of interviews with doctors. The aim of this work was to explore the specific problem of nursing care about the clients / patients after transapical aortic valve implantation. On the base of our obtained data it is evident, that the client/patient after TAVI may be positioned sideways, the use of surgical drains are less frequently, so the care about the surgical wounds is simpler, patients report less pain in the surgical wound and postoperative rehabilitation and recovery is shorter. H1 - The nurses take care about the clients/patients after transapical aortic valve implantation in the same way as about the clients/patients after open aortic valve replacement, without realizing the differences between the patients treated with different approaches, was not confirmed. The nurses'sees/reported major differences in invasiveness and extent of providing care, rehabilitation, convalescent, in the duration of the hospitalization and better cosmetic effect. The results of the research can serve as a basis for creating the standards of nursing care or educational material for clients/patients. It is also possible to present the results of this work at a specialized seminar for non medical healthcare workers and results can also increase the quality of nursing care about the clients/patients after transapical aortic valve implantation.
|
guest ::
