|
| |
|
|
Design of Dosimeter
Navrátilová, Sára ; Sládek, Josef (referee) ; Fridrichová, Eva (advisor)
The task of this bachelor thesis is to create a design of dosimeter. This work deals with analysing the current state of the market. The goal is to create a design which will comply with technical, ergonomic and aesthetic requirements of the task.
|
|
|
Printed ozone dosimeter
Védlová, Petra ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis deals with ozone measurement methods, especially focusing on opto-chemical methods, when the color change of the sample is examined. Moreover it deals with dyes that are sensitive to ozone and their degradation kinetics. In the experimental part kinetics of dyes Orange I, Orange II and Indigo carmine is examined, These dyes are prepared in the form of ink of different composition. These inks are applied to diverse substrate materials by the material printing method, further by using a Baker film aplicator and in the end by the screen printing method. The properties of the samples are evaluated as well as factors affecting their degradation.
|
|
|
Methods of radioactive radiation measurement
Šugra, Marián ; Sekora, Jiří (referee) ; Chmelař, Milan (advisor)
This thesis includes a survey of radiation measurement. It describes principle of methodes for it´s measuring with their principle together. Fixates at methods uses on medical workstations. A general nucleus of this thesis is proposition quantimeter with Geiger Muller´s tube. Contains terms at single quires of quantimeter. This equipment is powered by battery and it is assigned for some medical premises. This device will be signalized overrun beforehand adjusted value.
|
|
|
Effect of a nuclear power plant in terms of radiatin burden
Vániš, Jiří ; Procházka, Zdeněk (referee) ; Belatka, Martin (advisor)
This text deals with ionizing radiation affecting nuclear power plant personnel and surrounding population. Irradiation limits of radiological industry personnel are also mentioned along with ways of protecting them and checks on absorbed ionizing radiation dose. In conclusion, a nuclear power plant, as a source of ionizing radiation, and its effects on contamination of water sources and gas vents are evaluated. The next part be engaged problematical of storage nuclear waste from the time, when is removed the nuclear waste from nuclear reactor, trough permanent storage.
|
|
|
Evaluation of patient dose in mammography
Polášková, Markéta ; Sekora, Jiří (referee) ; Kolářová, Jana (advisor)
Breast cancer presents serious epidemiological problem, in result of which die more than 2 000 czech women every year. Screening mammography is one of the most expanded and most effective examinations for early detection of this desease but one has to take into account an inconsiderable risk connected with the procedure based on X-ray ionizing radiation. This diploma thesis deals with evaluation of the dose absorbed by the tissue. It contains the description of evaluation of the average dose in glandular tissue on PMMA phantom, as well as results of the measurements on conventional and digital mammograph. A data file with exposure parameters from mammography screening is included and interpreted. Also the Monte Carlo method was used for the dose evaluation, the thesis contains the brief description of the method, concept of analysis model in mammography and results of simulations.
|
|
| |
|
|
Measurement of patients´ personal doses in radiotherapy outside the central beam of ionizing radiation using the electronic personal dosimeter
CHYLÍKOVÁ, Renáta
The introductory part of the diploma thesis primarily focuses on the history of radiotherapy, i.e. what it emerged from and how it developed, as it is one of the most important fields in medicine, especially because thousands of people are irradiated every day due to different tumour and non-tumour diseases. Another reason why ionizing radiation is described is the fact that it is a necessary part of tumour disease irradiation. Ionizing radiation is also connected with radiation protection. This section presents a historical overview of radiation protection, as well as principles and quantities of this field. Furthermore, it focuses on Czech acts, decrees, and government regulations which define various measures governing this issue. Radiation protection forms the basis of patient, workplace, and personnel monitoring. All this is connected with the measurement and evaluation of received personal doses. This brings the thesis to the field of dosimetry, therefore various dosimeters used in practice are described. The aim of this diploma thesis is the measurement of patients? personal doses in head and neck irradiation using the electronic personal dosimeter at the radiotherapy centre of Nemocnice České Budějovice, a. s. The thesis is based on the question of whether irradiation doses that patients with head and neck tumours receive outside the primary radiation beam are negligible. The theoretical part of the thesis uses all available resources from both foreign and Czech literature. The practical part is based on numerical statistics, i.e. a quantitative method. The research was carried out at the radiotherapy centre of Nemocnice České Budějovice, a. s. Irradiation of patients with head and neck tumours was performed on a linear accelerator. Each patient had a mask to which an electronic personal dosimeter was attached during irradiation. Using this dosimeter, it was possible to measure doses received outside the central radiation beam. The measured values were then used to carry out assessment using formulas. Patients who undergo cancer treatment receive relatively high doses of radiation, so my main goal was to measure personal dose equivalents at the reference point. When comparing the percentage of the number of examinations with the web portal Epidemiology of Malignant Tumours in the Czech Republic, it was found that irradiation of the neck is more frequent than irradiation of the head. The total values of personal dose equivalents are relatively high in each patient, but because it is medical treatment, these values are not subject to radiation exposure limits. The comparison of the irradiated areas shows that irradiation of the neck has small values of personal dose equivalents to 1Gy compared to irradiation of the head.
|
|
|
Measurement of urine absorbance with indicator Mn2+
KONEČNÝ, Jan
Measurement of urine absorbance which has been irradiate by a dose of ionising radiation with addition of Mn2+ should serve to find the dose of radiation. This method could work quickly and reliably for homogeneous irradiation of person or as a rough estimate of the dose which the person received during a radiation accident. This method should serve for quick classification of the person. The target of this thesis is to find out if the irradiated urine with the addition of a solution of manganese chloride will change absorbance according to radiation dose. And if urine can be used as a biological dosimeter. In the theoretical part I describe the basic areas related to the topic and target of my thesis. This part is divided to seven subchapters: ionising radiation, radiation protection, radiotherapy, particle accelerators, spectrophotometry, excretion and urine, and dosimetry and its methods. Methods of this thesis are not clear. I tried different procedures during experiments with different results. First, I always prepared samples of urine in tubes and irradiated it in a linear accelerator Clinac 2100C/D in České Budějovice, a.s. hospital with doses from 1 to 25 Gy. Before each measurement I had two sets of tubes with these doses: 0, 1, 2, 3, 5, 7, 10, 15, 20 and 25 Gy. The following procedure was different in each experiment. Sometimes I tried adding a solution of manganese chloride to all tubes at once. Sometimes I tried to adding a solution of manganese chloride to each tube separately. I added the solution to irradiated urine at various concentrations of solution (from 1 do 5 mols) and different amounts (from 1 to 3 ml). Another difference was the use of centrifuges. A centrifuge was use in about half of experiments. Other measurements were made without centrifugation.In discussion I propose recommended methods. I recommend measuring only without centrifuges. Each cell should be measured as soon as possible after irradiation and simultaneously as soon as possible after adding the solution of manganese chloride. Results of the thesis are not clear. Only some experiments which were measuring with centrifuge were clear. I can say that this method does not work when a centrifuge is used at any tested concentration of solution of manganese chloride. The absorbance of single doses of ionising radiation does not change and the values were the same when using 1M, 3M and 5M solutions of MnCl2. The resulting graphs from all experiments have a constant absorbance value of all measured doses. (subchapter 3.1).In the remaining experiments measured without the centrifuge the results were much more interesting. In some experiments the measured absorbance really changed with the dose of ionising radiation so the hypothesis of this study was confirmed. But the differences were too small for this method to be used for measuring radiation doses (subchapter 3.2).The results were compared with the results of the thesis ?Measurement of urine extinction in depending on ionising radiation? from author Š. Radová. She performed a similar experiment, but with a different indicator - FeSO4. 7 H20. It was found that the indicator FeSO4. 7 H20 is preferable to measuring doses of ionising radiation in urine. In conclusion I can say that the hypothesis of this study was confirmed, but the method could not be used in practice and irradiated urine with added MnCl2 indicator does not function as a biological dosimeter.
|
|
|
Ionizing radiation in material testing
VLNA, Zdeněk
It this bachelor thesis deals with the use of ionizing radiation in engineering practice. Analyzes various options for screening, depending on technical parameters and the isotope used. It contains a description of special types of X-ray equipment, X-ray lamp and isotopes used in practice and we can find a detailed procedure for gammamat and X-ray lamp. The protection against ionizing radiation is mentioned at the end and ionizing radiation sensor used in the field are listed.
|
guest ::
