|
|
Knowledge of substitutes of salt in food
Vaňková, Marie ; Váchová, Alena (advisor) ; Hanušová, Jaroslava (referee)
The diploma thesis deals with the issue of salt and possibility of its replacement in food. The chosen is topical because healthy nutrition is one of current modern trends. Table salt is an entire part of a diet of every person. As the compound of two biogenic elements - sodium and chlorine - it has unsubstitutable function in human body. However, an increased intake of sodium can be associated with health risks, especially hypertension. The World Health Organization recommends a maximum daily intake of salt 5 g. According to current statistics, nevertheless the salt intake in the Czech republic is up to three times higher. Therefore, it is appropriate to reduce the consumption of salt and attempt to its replacement without cutting down the taste of food. One of the goals of this thesis was find out possibilities of replacing the salt and what is their availability. The practical part deals with the results of survey, within these was examined the awareness of salt and the posibility of its replacement among different group of our population (students, pedagogical workers, heads of school canteens). In terms of established facts there was suggested a project called The salt is beneficial and dangerous which aids to raise awareness of students about this topic. These outputs can be put into the...
|
|
|
Use of energetic by-products and other secondary raw materials for the alpha gypsum production
Moldrzyk, Jan ; Jiroušková, Kateřina (referee) ; Dvořák, Karel (advisor)
Thesis focus on the longterm research in an area of alpha gypsum production by non pressure method in chloride salt solutions production, which is researched by Institute od technology of building materials and components, Faculty of civil engineering for many years. The result of given research is non pressure equipment for alpha gypsum production. The scope of this research was to make a production of alpha gypsum more efficient through modification of the facility itself and through an optimalization of dehydration process. The scientific aim of this process was to compare an influence of dehydratation solutions of CaCl2, NaCl and KCl on the final product provided that molarity of solutions was at the same level.
|
|
|
The development of composites based on inorganic binders designed for the extreme applications
Janoušek, Petr ; Šácha, Libor (referee) ; Dufka, Amos (advisor)
The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
|
|
|
Plasma diagnostics of electric discharges generated in selected configurations in liquids
Vašíček, Michal ; Bartlová, Milada (referee) ; Kozáková, Zdenka (advisor)
My diploma thesis is focused on a comparison of direct-current and high frequency (15-80 kHz) electric discharge, which generates non-thermal plasma in water solution of sodium chloride. Mainly current-voltage and Lissajous charts are discussed in the first part of this thesis. These charts describe different discharge phases: electrolysis, bubble formation, discharge breakdown and discharge regular operation in a pin-hole of a dielectric barrier. Influence of frequency, electrolyte conductivity, thickness of the diaphragm (or length of the capillary) and pin-hole diameter on discharge breakdown and bubble generation was studied, too. Measurements were realized in a polycarbonate reactor with total volume of 110 ml, which was divided by a changeable polyacetal insulating wall. This wall divided the reactor into two approximately equal spaces with one stainless steel planar electrode in each part. The Shapal-MTM ceramic discs (thickness of 0.3–1.5 mm and diameter of the central pin-hole of 0.3-0.9 mm) were mounted in the centre of the insulating wall. Initial conductivity of sodium chloride solution was chosen within the interval of 100900 S/cm. The second part of my thesis compares an influence of the direct-current (DC) and high frequency (HF) power sources on physical solution properties (conductivity, pH and temperature) and generation of hydrogen peroxide. A plasma reactor with total volume of 4 l and with mixing set up was divided into two equal spaces with one planar platinum electrode in each part. Diaphragm with thickness of 0.6 mm and pin-hole diameter of 0.6 mm was installed in the middle of the separating wall. Experiment was held at discharge operation of 45 W for 40 minutes with both power sources. Detection of hydrogen peroxide was realised by using a titanium reagent forming a yellow complex, which was analysed by absorption spectroscopy. If HF discharge power is plotted as a function of applied frequency, exponential decrease of frequency with increasing power can be observed. Higher breakdown voltage is necessary for thicker dielectric barriers, on the other hand for bigger diameter of the pin-hole lower breakdown voltage and higher power is needed in DC as well as in HF regime. Breakdown voltage is decreased by the increasing conductivity in both regimes; due to more charge carriers in the higher conductivity lower breakdown voltage is needed. However frequency in HF regime and DC discharge power increases. HF discharge power is decreased by the increasing conductivity. Solution conductivity and temperature are increased by initial conductivity value in both discharge regimes. Solution pH drops to acidic conditions when HF or DC positive regime is applied due to the generation of reactive species and electrolysis (in DC regime). However solution becomes alkaline when DC negative regime is applied. Concentration of hydrogen peroxide is produced linearly when HF or DC negative regime is applied and it depends on initial solution conductivity.
|
|
|
Preparation of high performance sulphate binder by nonpressure method
Urban, Karel ; Novák, Jan (referee) ; Dvořák, Karel (advisor)
Institut of Technology building materials and components in FAST VUT Brno is for several years engageding by research of unpressurized production of high sulphate binders and also by developing a dehydrating apparatus. This work follows on this research. The main aim of this work is to prepare the alpha calcium sulfate hemihydrate by method of dehydration in the various solutions the chloride salts of the same molal concentration in an innovative dehydration apparatus. Another aim is monitoring the influence dehydrating solutions on the basis of KCl, NaCl and CaCl2 on the properities of made gypsum.
|
|
| |
|
|
Vliv osmotického stresu na růst rostlin bramboru v in vitro podmínkách
Franek, Ondřej
Osmotic stress influences productivity and crop yield of plants significantly. This bachelor thesis is a literature review summarizing the acclimation of plants under osmotic stress and tolerance of plants to osmotic stress, observes issues of abscisic acid in the relation to osmotic stress and other markers as osmoprotectants and dehydrins. Screening experiment in vitro culture of potato plants (Solanum tuberosum L.) in agar stiffened media containing stressors as sodium chloride, sucrose and polyethylene glycol was carried. Plant growth parameters such as solids content and length of roots was observed. RIA method was used to determine the content of abscisic acid in plant leaves influenced by stressors.
|
|
| |
|
| |
|
| |
guest ::
