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Soľ v potravinách a možnosti použitia jej náhražiek
Kertysová, Klaudia
The theme of this bachelor work is "Salt in the food, and the possibility of using substitutes." The salt was formed many years ago and in addition seas also occurs in the soil. It was very valuable. People it in addition to dochucovania, the preservation of been used as a means of payment. Benefits you in three ways. Mountain extraction, evaporation or leaching where there is a brine. Salt consists of sodium and chlorine. These are elements, which ensure the proper function of the organism. Thus, the salt is for the metabolism. Exceeding of daily recorded doses, however, can lead to deterioration of health. The most common disease is hypertension. Salt is used in meat, in dairy but also in baker industry. Ensures correct structure of the final products and is also active against the microbial perish.. High salt intake is a global problem. Therefore, using a variety of reimbursement of salts, which reduce the salt content in the food.
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Studie možných zdrojů znečištění na vybraném úseku vodního toku Račický v obci Odunec
Dobrovolný, Michal
The bachelor’s thesis with the theme of „Study of possible sources of pollution in the selected part of the watercourse“ deals with possible sources of pollution of the selected part of Račický potok. The theoretical part treats the characteristics of surface water and their preservation including valid legislation. After that there are described the ways of surface water pollution including particular elements and substances, which contaminate water. The practical part deals with collecting of the individual samples in selected collection points and their laboratory analysis. As the magnitudes for the analysis were selected: the amount of oxygen dissolved in water, electrolytic conductivity, the reaction of pH in the water, nitrate nitrogen, nitrite nitrogen, total phosphorus. In another chapters the results are interpreted and discussed with the valid legislation. The evaluation of the analysis shows a deterioration of the quality of the water, which is in Odunec caused by releasing the sewage water right into the watercourse and the absence of phosphorus precipitation in ČOV Krhov. In the conclusion there are suggested possible steps for improvement of the water quality in the selected area.
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Kinetic determination of nitrites with spectrophotometric detection
Vašíčková, Pavla ; Nesměrák, Karel (advisor) ; Rychlovský, Petr (referee)
Title: Kinetic determination of nitrites with spectrophotometric detection Annotation: The proposal and optimization of the kinetic determination of nitrites in water samples is the aim of this bachelor thesis. The method is based on the ability of nitrites to catalyze the oxidation of toluidine blue by bromate in acidic media. The course of the reaction is monitored by spectrophotometrically, using a decrease of the absorbance band at 653 nm in the constant period of time from the beginning of the reaction. The dual-chanel manifolds FIA apparatus was proposed and optimized. The calibration dependency in the range of 0,05-1,00 mg ml-1 was measured. The instrumental limit of detection of 0,038 mg ml-1 and limit of quantification of 0,125 mg ml-1 were calculated. The method was applied on real sample of river water. Key words: nitrites, flow-injection analysis, kinetic catalytic methods
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The influence of the surrounding landscape , fishery management , external and internal factors on water quality in ponds
Janáček, Štěpán ; Vach, Marek (advisor)
The thesis deals with the influences that affect water quality in the ponds . It focuses on selected factors which define water quality . These include e.g. the amount of dissolved oxygen in the water , ammonia, etc. To determine the change in water quality in a fish breeding tank, measured quality of water at the inlet of the tank and at its drain. I enter into the analysis and facts about the amount of fish stocking in ponds , basin shape , location of the pond in the countryside , farming in the watershed .
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Factors Affecting the Distribution of Nitrification's Final Products during Biological Pre-Treatment of Fugate
Kyselová, Aneta ; Švehla, Pavel (advisor) ; Zuzana, Zuzana (referee)
In this diploma thesis, the influence of chemical composition of fugate, pH value, temperature and other factors on representation of final products of nitrification during biological pretreatment of fugate produced in agricultural biogas stations was evaluated.
During the experiment, fugate from biogas station Nový Dvůr with N-amon concentration in the range of 1300 - 3200 mg/l at input was processed. Results from the time period beginning on 21. September 2015 and ending on 22. December 2015 (day 0 - 93) were assessed. Nitrification reactor of five liter operational volume was placed in a laboratory at temperatures ranging from 20.4 to 25.2 degrees Celsius. During the experiment, volumetric loading of N-amon reactor ranged from 0,18 to 0,44 kg/(m3.d) and efficiency of N-amon removal from 68,6 to 96,9 percent. Hydraulic period of water delay was being decreased from 12,3 days to approximately 4,2 days during the experiment. pH value was regulated by NaOH to be approximately 7.
The experiment proved that it was possible to attain the process of nitrification in the aggressive medium of fugate. It was ascertained that pH value, which determined current concentration of Free Nitrous Acid (FNA), had significant influence on representation of final products of nitrification. Concentrations of N-NO2 in the reflux from the reactor were being increased from 130 up to 1840 mg/l during the process on the grounds of pH value fluctuations and increasing FNA concentration which inhibited activity of nitrite oxidizing bacteria (NOB). The representation of N-NO2 from day 0 to day 93 of the experiment gradually increased from 19 percent up to 95 percent. Concentrations of N-NO3 from day 0 to day 3 increased from 570 to 1056 mg/l and conversely from day 3 to day 93 they gradually decreased from 570 mg/l to approximately 100 mg/l. Representation of N-NO3 decreased from 80 percent to 5 percent from day 0 to day 93 and it was not possible to retain them as dominant products of nitrification on the ground of sensitivity of NOB.
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Influence of humic substance HS 1500 on tolerance of Sterlet to nitrite
BULÍČEK, Vojtěch
The aim of the thesis was to assess the effect of humic substance HS 1500 on the tolerance of Sterlet (Acipenser ruthenus) to nitrite. Preparation Huminfeed was used as a source of substance HS 1500. Tolerance of Sterlet to nitrite was assessed on the basis of the results of acute toxicity tests and the results of haematological and biochemical blood examination of fish that were exposed to increased concentrations of nitrite in the presence and absence of preparation Huminfeed.
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Hematological changes in fish exposed to nitrites
FRANĚK, Roman
The aim of the thesis was to determine the effect of nitrite on hematological indices of rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus). After the fish were exposed to various concentrations of nitrites were determined 48hLC50. For the main test only fractional concentrations of these values were used. For rainbow trout it was 8 mg.l-1 NO2?, for Nile tilapia 11 mg.l-1 NO2?. The exposure of both species lasted for 48 hours. From fish blood were made blood smears to determine the influence of nitrite on size changes of erythrocytes and hematological parameters were set also. The effect of nitrite on changes in the ultrastructure of erythrocytes was determined by the electron microscopy. The erythrocyte nuclei of rainbow trout showed significant (p <0.05) shrinkage. The images of the electron microscope showed an increased amount of changes, especially in the form of various units within the cytoplasm of erythrocytes, was also visible nuclei shrinkage. There was significant (p < 0.01) reduction in the amount of hemoglobin and significant (p < 0.01) increase in the concentration of methemoglobin levels of the exposed groups. In the number of erythrocytes and hematocrit were not detected any changes. Hematological parameters of Nile tilapia did not show any size changes in the measured parameters, no changes were detected in the count of erythrocytes, hemoglobin and hematocrit values.
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Tolerance of Nile tilapia to nitrites
BROŽ, Pavel
The aim of this thesis was to evaluate the effect of increased concentrations of nitrite to Nile tilapia (Oreochromis niloticus) at different concentrations of chloride. Tilapias adults were exposed for 14 days to nitrite at the concentration of 3 mg.l?1 NO2? (i.e. concentration commonly found in recirculation systems). After 14 days the experimental fishes were divided into 4 group, which differed in concentrations of nitrite and chloride. These groups of fish were held in different conditions for the next seven days. Using standard clinical procedures the following haematologic biochemical parameters were determined: RBC, WBC, Hb, PCV, MetHb, MCV, MCH, MCHC, NO2-, GLU, Ca, Mg, TP, NH3. The tested nitrite concentration was not high enough to cause strong differences of pursued parameters. Only some of them (Hb, MetHb, MCHC) were statistically significant.
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