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Negative electrodes for sodium ion batteries
Šátek, Dominik ; Libich, Jiří (referee) ; Máca, Josef (advisor)
This bachelor thesis deals with sodium-ion accumulators with focus on negative electrode, introduces basic terms in the field of secondary cells and describes production of accumulators. The result of this work are tested electrodes based on natural carbon and sodium metatitanate. These electrodes are then compared with each other and evaluated.
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Salt in nutrition of older aged school children
KALETOVÁ, Nikol
This bachelor thesis, which is focused on the topic of salt consumed by older school age children, it is divided into two parts. The first part is devoted to mapping how much the older children take salt, and the second part focuses directly on food, of which the older children receive salt the most. In the theoretical part I focused on how much salt should contain the recommended daily amount for the children and on the use of salt in the human body. Then I mention what can cause excessive consumption of salt from early childhood. As we read in many publications, children nowadays using salt as excessively as their life. It is from their parents that children bring the most eating habits to their life. In the last part I focused on individual nutrients that children should consume in the right amount. In the Czech Republic, according to the World Health Organization, salt is used two to three times more than recommended daily amount. In the practical part I worked with 30 respondents for five weekends. During this time, their parents recorded their children´s meals, which included breakfast, snacks, lunch, afternoon snacks, and dinners. For the second part of the research, I used a questinainnaire to find out which types of food the children intake the highest amount salt. Afterwards I recorded all the diet data into Nutriservis Professional, which then evaluated the amount of sodium in milligrams. I transferred the calculations into Excel, where I calculated the amount in grams and then converted to the amount of salt per day using the formula * 2,5. Only then, I could evaluate the total amount of salt and the average of all five weekends for each respondent separately. From the resulting values I processed and evaluated, I found that 53.3% of children in the home environment consumed over 5 grams of salt per day over five weekends. This only confirms the fact, that older school-age children consume more salt than the recommended daily amount, as several authors claim in their printed publications.
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Simulation of processes in cellular membranes
Melcr, Josef ; Jungwirth, Pavel (advisor) ; Otyepka, Michal (referee) ; Tarek, Mounir (referee)
Simulation of processes in cellular membranes Abstract Many important processes in cells involve ions, e.g., fusion of synaptic vesi- cles with neuronal cell membranes is controlled by a divalent cation Ca2+ ; and the exchange of Na+ and K+ drives the the fast electrical signal transmis- sion in neurons. We have investigated model phospholipid membranes and their interactions with these biologically relevant ions. Using state-of-the-art molecular dynamics simulations, we accurately quantified their respective affinites towards neutral and negatively charged phospholipid bilayers. In order to achieve that, we developed a new model of phospholipids termed ECC-lipids, which accounts for the electronic polarization via the electronic continuum correction implemented as charge rescaling. Our simulations with this new force field reach for the first time a quantitative agreement with the experimental lipid electrometer concept for POPC as well as for POPS with all the studied cations. We have also examined the effects of transmembrane voltage on phospholipid bilayers. The electric field induced by the voltage exists exclusively in the hydrophobic region of the membrane, where it has an almost constant strength. This field affects the structure of nearby water molecules highlighting its importance in electroporation. 1
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Salt intake in infants
KRÁLOVÁ, Veronika
This bachelor's thesis deals with salt intake for infants. This is a current topic as there are lots of discussions about excessive salt intake nowadays. Taste for salt is developed in childhood and it influences its subsequent perception. Long-term excessive salt intake in food can cause a risk of hypertension. According to professor Janda, recommended daily amount of salt for an infant should not be more than 1 g. The aim of this bachelor's thesis is to find out the intake of salt for infants. There were two research questions formulated: "What is the intake of salt in food for infants?" and "What is the difference between salt intake for infants being only breast-fed, infants being fed by complementary milk food and those being fed by non-milk complementary food. The thesis is divided into two parts, theoretical and practical. The theoretical one describes the issue of salt intake, the practical one contains qualitative research. The focus group was comprised of 12 infants who were divided into 3 groups of 4. Infants up to 4 months old were in the first group, infants between 4-8 months old were in the second group and infants between 8-12 months were in the third group. Every fourth infant was chosen from the database of supervisor's patients. Three-days diet records were received from the mothers of the infants. Based on these records the amount of salt was further calculated in the Nutriservis program. The results of the survey are presented in charts and in word evaluation. The research shows that, from the point of view of salt intake, mother's milk is ideal infant food. The recommended amount of salt was not exceeded for neither of the chosen infants. The infants being fed only with mother's milk had the lowest salt intake, whereas the infants being fed with non-milk complementary food had the highest salt intake. This bachelor's thesis can serve as a source of information for students of nutritional therapy as well as for mothers of infants.
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Salt intake in women over 60 years and impact of food on their blood pressure
KLOUZKOVÁ, Barbora
Worldwide reported about salt intake is higher than the recommended amount. Actually literature reported amount by 5 - 7 g of NaCl per day. Czech Republic has same recommended number of NaCl. My bachelor thesis is about to find out how is the salt intake for selected respondents over 60 years old and how this quantity have effect to their blood pressure. I chose a qualitative research method, where I tracked salt intake, urine waste and blood pressure values. I didn´t use any nutritional databases, when I got the amount of salt I received. I checked the packages of foods that reported the amount of salt. Thanks to EU Regulation 1169/2011, it is now the duty of the manufacturer write quantity of NaCl on the packages of product. I also weighed all the salt we added to the foods. On the basis of these calculations, I determined the intake of NaCl per day and total of four days. I chose those foods, which salt intake was on the packages and I knew exactly amount. I measured the blood pressure, at the same time. The values from the morning, at noon and in the evening I wrote. Eventually, I collected urine, which was subsequently examined for mineral waste on the last day. As a check to see if the waste corresponds to intake, serve test results from laboratory. On the basis of the research, we found out that the recommended personal daily intake of NaCl was not exceeded, in this age category. The blood pressure values did not correspond to hypertension, and the results from the laboratory, correspond to the amount of salt received.
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XRD characterization of electrodes and electrode materials for electrochemical power sources
Klvač, Ondřej ; Chladil, Ladislav (referee) ; Čech, Ondřej (advisor)
The thesis describes available choices of methods for research of electrochemical power source electrode strcture by x-ray diffraction spectroscopy. At first there is a theoretical computation of difractogram. Then there are discussed possibilities of in-situ and ex-situ techniques as background research. Practical part of thesis compares theoretical assumptions to measurements of lithium and sodium cells, including analyze of crystallographic phases and lattice constants. As a conclusion, there are discussed possibilities of subsequent research.
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The salt intake in school children´s diet
MIČULKOVÁ, Barbora
It is generally known that the intake of salt in civilized countries has been currently multiple times exceeding the recommended amount that was set by the World Health Organization to less than 5 grams per a day. In Czech Republic this dose has been exceeded up to three times. The aim of this bachelor thesis is to evaluate the amount of the salt in lunches at school cafeterias in regards to the current nutritional recommendations. The thesis is divided into two parts, theoretical and practical. The theoretical part is about importance of sodium and salt in human diet, recommended amount of salt for adults and children, and complications related to its excessive intake. Furthermore it focuses on the occurrence of salt in food, the reduction of the salt in the diet and the nutrition of children. In the practical part I worked with five school canteens in České Budějovice, that provided me with weekly menus along with the list of raw materials and the quantity of salt used in individual lunches. The sodium content was evaluated by the Nutriservis Professional application, in which I inserted the raw materials the lunches were cooked from. According to the equation, I converted the amount of sodium to the amount of salt, added the amount of salt contained in average portion served at school canteens and compared the total amount to 1,7 grams, which is supposed to be in one portion. Based on the results of the verbal evaluation tables, all the school canteens of the research group exceeded the recommended salt limit in all the observed days. Groups of foods that have greatly influenced their high salt content include bakery products, cheeses and meat products. More attention needs to be paid to this subject, on the part of parents, and school canteens.
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Application of Atomic Absorption Spectrometry for Determination of Selected Elements from Potential Ecological Burden Area
Juránková, Lada ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This work is focused on the determination of selected (chemical) elements (Fe, Mn, Zn, Cr, Na, K, Mg a Ca) in a potential ecological burden area using flame atomic absorption spectrometry as a detection technique. A potential ecological burden is represented by tires which are used as a construction material or as an environment surrounding for growing decorative and consumable plants. Analytes were determined in plant origin samples. Firstly, the samples were dried in a laboratory electric dryer. The weighted amount of a dried sample (approximately 0.2 g) was digested inside a microwave decomposition device with an addition of nitric acid and hydrogen peroxide. An optimization of experimental parameters was done for each of the elements before sample measuring. A burner height was optimized and 8 mm height was chosen as a optimum for most elements. Under the optimum condition basic characteristics were measured for each element separately. These characteristics included limits of detection that were: 0.05; 0.01; 0.08; 0.21; 0.02; 0.01; 0.01; 0.01 mg L-1 for the following elements: Fe, Mn, Zn, Cr, K, Ca, Mg and Na, respectively. The limits of quantification, sensitivity and repeatability were determined for each element as well. A significant attention was paid to the content of zinc in the studied...
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Determination of selected elements in plant extracts by atomic absorption spectrometry
Rydlová, Lenka ; Hraníček, Jakub (advisor) ; Kratzer, Jan (referee)
The aim of this bachelor thesis was to determine selected elements (Na, Mg, K, Ca, Zn, Se) in plant extracts and juices by atomic absorption spectrometry using different types of atomization. Each method has been optimized for determination of the mentioned elements. For flame atomization it has been used optimization of height of the primary radiation from the hollow cathode lamp over the edge of the burner. The height was generally between 6.0 and 8.0 mm. Then there have been optimized flow of each component of the flame (acetylene, air, nitrous oxide) and it has been set location of the hollow cathode lamp and the flame. Under the optimized conditions basic characteristics describing the method of the determination of mentioned elements have been measured (LOD for sodium 2.13 µg L-1 , for magnesium 2.44 µg L-1 , for potassium 11.3 µg L-1 , for calcium 15.6 µg L-1 , for zinc 6.04 µg L-1 , for selenium 0.34 µg L-1 ). In the next part of the thesis the optimized methods have been used for measuring concentration of all elements in real samples. After the preparation of the samples including dilution, addition of various reagents etc., they have been atomized by flame in an atomic absorption spectrometer (Na, Mg, K, Ca, Zn) and determined, or converted to a volatile compound (Se) and determined by...
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