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Gross motor skills in children with hearing impairment in preschool age
Vrtišková, Eliška ; Komorná, Marie (advisor) ; Kotvová, Miroslava (referee)
The bachelor's thesis deals with the topic of gross motor skills in children with hearing impairment in preschool age. In order to understand the relationship between hearing impairment and gross motor skills, the first chapter describes the anatomy of the auditory organ. Hearing impairment, its division and compensation options are then defined. The second chapter characterizes motor skills and individual psychomotor development milestones with an emphasis on preschool age. The last chapter summarizes the findings of some foreign research dealing with this topic. The practical part provides data on the state of gross motor skills in children with hearing impairment. For this purpose, ten hearing-impaired probands underwent two different test batteries. The results of the first were compared with the expected age of task acquisition, and the results of the second were compared with the score of two control groups taken from two diploma theses. The obtained data showed a lower level of motor skills in children with hearing impairment compared to intact children. The findings are described in more detail in the discussion together with the answers to the research questions. KEYWORDS Gross motor skills, hearing impairment, balance, preschool age
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Differentiation of musculoskeletal disorders related to the nursing profession in inpatient and outpatient wards
Malinová, Lenka ; Nováková, Tereza (advisor) ; Maršáková, Kateřina (referee)
Title: Differentiation of work-related musculoskeletal disorders among nurses in inpatient and outpatient care units Objectives: The aim of this study was to determine a prevalence of work-related musculoskeletal disorders among nurses and compare localization of disorders among inpatient and outpatient care units nurses. Another goal of the study was to find a connection between WRMDs and occurring common factors. Methods: There was a questionnaire made to conduct this study. It was based on standardised Nordic musculoskeletal questionnaire (NMQ) and sent in both printed and electronic form to various healthcare facilities. The research group consisted of 146 respondents, mostly women, that work as a nurse. Results were processed from obtained data and the conclusions were determined. Results: In the last 12 months, 87 % of nurses suffered from work-related musculoskeletal disorders in at least one area of their body. The most commonly affected area was lower back and neck, both regions approximately 65 %. The biggest difference between nurses working in inpatient and outpatient care units was hand and wrist, where the results showed three times percentage of MS disorder occurence in the first group. Another difference was in lower back area, approximately 20 % less outpatient care units nurses...
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Role of tissue-specific expression of the ISWI protein Smarca5/Snf2h in murine hematopoiesis.
Turková, Tereza ; Stopka, Tomáš (advisor) ; Forejt, Jiří (referee) ; Mráz, Marek (referee)
The process of cell differentiation is dependent on the chromatin-remodeling activity of the ISWI ATPase SMARCA5 (SNF2H) and its complexes. A series of mouse models have been used to study the functions of this ATPase, starting with a model with constitutive deletion of the Smarca5 gene and followed by models with tissue-specific deletion of Smarca5 gene (especially at different stages of hematopoiesis). The severity of phenotypic manifestations in mouse models varies from early embryonic lethality in the constitutive deletion model, through fetal lethality associated with erythropoiesis failure (Vav1iCre model - deletion in the definitive hematopoietic progenitor) to lymphopoiesis defects that do not limit animal survival (hCD2iCre model - deletion in T and B lymphocytes) in conditional deletion models. This work builds on the observations obtained in the study of deletion models of this Smarca5 gene, i.e. that deletion leads to arrest of cell proliferation and their entry into apoptosis. Defects were observed already at the stem cell and hematopoietic progenitor stages, which were unable to enter the differentiation process in the absence of the SMARCA5 protein. In these models, it was not possible to study the progression of differentiation because of this reason. Therefore, we decided to create...
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Atomization of volatile germanium species in hydride generation atomic absorption spectrometry
Slota, Alexandra ; Kratzer, Jan (advisor) ; Štádlerová, Barbora (referee)
The aim of this thesis was to optimize the atomization conditions of volatile Ge species for hydride generation atomic absorption spectrometry (HG-AAS). The selected species were inorganic germanium (iGe) and its methyl-substituted forms: monomethylgermanium (MMGe) and dimethylgermanium (DMGe). The atomizers for which optimizations were performed included diffusion flame (DF), multi-atomizer (MMQTA), dielectric barrier discharge (DBD) either with sinusoidal modulation of the high voltage source and glued electrodes (REF-SIN) or sputtered electrodes with rectangular high voltage waveform modulation (SE-SW), and finally atmospheric pressure glow discharge (APGD). Under optimal atomization conditions, the highest sensitivity, around 10 ms/ng, was found in DBD atomizers. The advantage of the SE-SW configuration, compared to the REF- SIN arrangement, is better peak shape and repeatability of the measurements. Atomizers such as DF and MMQTA provided mutually comparable sensitivity, which was about 5 times lower than in DBD. The APGD atomizer was the only atomizer studied in which the sensitivity was not comparavle among Ge species. The sensitivity for both methylated species was about half that for iGe (3.0 ms/ng). As part of the mechanistic study, high Ge deposition rates in all types of atomizers,...
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Measuring the retention curve of rocks: the example of sandstone from the Jizera formation
Fataciune, Sotir ; Slavík, Martin (advisor) ; Ondovčin, Tomáš (referee)
Retention curve describes the ability of an unsaturated porous medium to retain water at different suction pressures. It thus plays an important role in providing information on the movement and occurrence of water in the vadose zone. While the determination of the retention curve for soil is common, it is far less common in the case of rocks. The aim of this bachelor thesis is to determine the retention curve of sandstone from the Jestrebicka jehla in Kokorinsko using the tensiometer - weight method. A partial aim is to compare this curve with two previous measurements on the same sandstone: i) measurements by student A. Studencová, using the tensiometer - weight method, and ii) measurements made by the laboratory of Research Institute for Soil and Water Conservation, according to a slightly modified method of CSN ISO 11274. There were notable differences between the retention curves. The retention curve according to the CSN for a given suction pressure showed lower moisture values, which is probably due to insufficient saturation of the sample and air entrapment in the rock pores. Relatively large differences in the retention curve between two independent tensiometer - weight method measurements were also found, which are probably due to insufficient contact between the tensiometer and the porous...
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Mg-hydroxyapatite composite materials prepared by powder metallurgy
Řičánek, Adam ; Doskočil, Leoš (referee) ; Buchtík, Martin (advisor)
This bachelor thesis focuses on the preparation of magnesium-hydroxyapatite composite by powder metallurgy methods. The theoretical part of bachelor thesis deals with magnesium, magnesium alloys and magnesium materials. Furthermore, the theoretical part of the bachelor thesis deals with the basics of powder metallurgy, processing of materials prepared by powder metallurgy and metal matrix composites. In the experimental part of the bachelor thesis, two series of composites were made with different quantities of hydroxyapatite. Composites were made by mixing Mg with filler and by mixing and milling Mg with filler. Both series of composites were characterised by investigation of microstructure and element composition, hardness, compressive strength and corrosion resistance. Composites of mixed and milled series showed a highly homogenous structure. Hardness, compressive strength and corrosion resistance increased with increasing amounts of hydroxyapatite. Composites of mixed series showed heterogeneous structures. Hardness did not increase with increasing amount of hydroxyapatite. Corrosion resistance slightly increased with increasing amount of filler. Compression strength decreased with the increasing amount of filler due to lower cohesion and incompactness of the structure.
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Low energy cements based on clinker phases
Šmeral, Miloslav ; Koplík, Jan (referee) ; Bartoníčková, Eva (advisor)
This thesis deals with low-energy cements and the effect of dopants on their hydration, specifically copper and sulfur. The theoretical part summarizes the general information about clinker minerals, their low-energy/low-carbon alternatives and sustainability in the cement industry. Additionally, possible synthesis of clinker minerals are described. In the experimental part, methods for the preparation of doped tricalcium aluminate and the analysis of the synthesized products are presented. The sulfur doped tricalcium aluminate had the highest hydration heat. On the other hand, copper doped tricalcium aluminate and tricalcium aluminate in combination of these dopants exhibited lower hydration heat. The presence of the dopants also affected the composition of the hydration products.
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Mechanical properties of entropy stabilized ceramic materials
Ronschak, Johana ; Mařák, Vojtěch (referee) ; Salamon, David (advisor)
This work focuses on the topic of the currently novel high entropy materials (HEM). The focus is put primarily on high entropy carbides (HEC) and the effect of carbon content in the matrix of a high entropy alloy (HEA) on its microstructure and hardness. Additionally, the effect of mechanical preparation, sintering temperatures and carbon diffusion from within the sintering die is observed on the samples. Several samples were sintered using the Spark Plasma Sintering (SPS) method under different temperatures. Density, phase and structure analyses were put in correlation to Vickers hardness tests, X-Ray Diffraction (XRD) analysis as well as on some samples to nanohardness tests and Energy Dispersive Spectroscopy (EDS) analysis. Powder milling has been implemented in order to reduce the final material’s porosity, which could negatively impact the accuracy of the hardness reading. Thus, a higher density of the HEA VNbTaMoW has been reached compared to literature by 7 %. Additionally, this result was obtained using lower sintering temperatures. The milled VNbTaMoW had a density of 100 % along with a hardness of 6,9 GPa. Two single-phase HEC materials VNbTaMoW-C0,8 and VNbTaMoW-C0,9 reached hardnesses of 20,46 GPa and 16,87 GPa respectively, whilst densities of 100 % and 97,9 % were observed. The heterogeneous material of VNbTaMoW-C0,5 showed an average hardness of 16,83 GPa. Within this material, nanohardness was measured of the lamellar areas as 20,4 GPa whilst the homogenous areas reached up to 29,3 GPa. The effect of the C diffusion was observed on all samples with the most significant being that of the VNbTaMoW and VNbTaMoW-C0,5 microstructures, where a heterogeneous and homogenous phase of the VNbTaMoW-C0,8 composition was created respectively. C has reached a depth of ~180 m within the VNbTaMoW through diffusion and ~200 m in VNbTaMoW C0,5, where an increase of hardness was observed from 18,4 GPa in the core material to 22,6 GPa on the surface. This work observed a positive impact of mechanical powder milling on the final microstructure and density. Additionally, the implementation of milling has resulted in a lower needed sintering temperature than reported in literature, whilst reaching higher densities. An increase of hardness has been observed in the HEC depending on the C content, with the highest being measured on the VNbTaMoW-C0,8. The material VNbTaMoW-C0,9 showed lower hardness, most likely due to its higher porosity, which lowers the effective hardness of the material. This points towards a possible direction of further studies in regard to the optimalization of HEC powder preparation and sintering temperatures with the goal of obtaining a full-density material with content of C > 80 mol %.
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High-speed shaft production design
Polesný, Pavel ; Jaroš, Aleš (referee) ; Kalivoda, Milan (advisor)
In the bachelor's thesis, a production process of the crankshaft of a single-cylinder two-stroke engine is designed. The flywheel has a diameter of 20.5 mm, the crank pin has a diameter 9 g6, the connecting rod pin has a diameter 4 g6, and the total length is 63.5 mm. Due to the production batch of 1000 pieces, the machining method was selected. The crankshaft will be produced as a monolith. Then the grooves at the ends of the ground surfaces 9 g6 and 4 g6 were addressed. Due to the wall thickness of 1.25 mm, the surfaces will be without grooves, and a radius or chamfer will be in the corners. The axial bearing and the connecting rod have an internal chamfer of 0.7x45°, thus grooves are unnecessary. The chosen material is 15.142 steel, tempered to a lower strength, supplied in 25x3000 mm bars by ZJP, s.r.o. The semifinished part will be manufactured on a Swiss-type lathe Manurhin K'MX EVO 732. After nitriding, the part will be ground on a Bernardo URS 500 N grinder. For the machining on the EVO 732, OPTIMA EXTREMECUT 46 mineral oil was chosen, and for grinding, a 2% concentration emulsion mixed from BITOL M petroleum emulsion oil was selected. Then the technological process was developed, and operational instructions were created. Calculations determined that 26 bars are needed for the production of the specified series. The entire series production will take just under 4 shifts.
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Preparation of layered double hydroxides on Mg-hydroxyapatite-based substrates
Knoflíček, Milan ; Doskočil, Leoš (referee) ; Buchtík, Martin (advisor)
The aim of this bachelor thesis was the preparation and characterization of coatings based on layered double hydroxides (LDH) on Mg composite substrates prepared by powder metalurgy. Hydroxyapatite (HAp) was used as a filler. The deposition of MgAl-LDH coatings on the surface of composites was carried out in a reaction mixture containing Al(NO3)3 at pH 10 and a temperature of 95 °C. The morphology and structure of the samples were characterized using scanning electron microscopy (SEM). The elemental composition of both composites themselves and the prepared coatings were characterized by energy dispersive spectroscopy (EDS). Analysis of the structure of Mg-HAp composites revealed that the frequency of HAp agglomerates increased with increasing reinforcement concentration. The highest frequency of agglomerates was detected in samples containing 20 and 50 wt. % HAp filler, where unlike the other samples, a significant deterioration of corrosion properties was also observed. In contrast, the best corrosion resistance was shown by the sample with 1 wt. % of filler. Other samples with filler contents from 0 to 10 wt. % were relatively similar in terms of corrosion resistance. Potentiodynamic tests demonstrated that coated samples exhibited significantly higher corrosion resistance compared to the uncoated samples. A uniform layer of LDH was observed in the coated samples with HAp content up to and including 10 wt. %. The presence of cracks related to the presence of bulky HAp agglomerates was detected on samples with higher reinforcement content, i.e. 20 and 50 wt. % HAp. Lower coating adhesion was also observed at these locations. It was found that to achieve high quality of LDH coatings, the optimum amount of HAp reinforcement of mixed and subsequently pressed Mg-HAp composites is up to 5 wt. % HAp. Higher HAp content in the samples generally led to the formation of defects and deterioration of corrosion properties.
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