National Repository of Grey Literature 33 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Electronic RLC meter
Dvořák, Radim ; Hanák, Pavel (referee) ; Lattenberg, Ivo (advisor)
This work deals with measurement methods of passive components R, L ,C used almost in every electrical circuit. Work describes progress of choosing the right methods for measurement and also the process of designing the autonomous RLC meter with use of ATMEL microprocessor chips. The RLC meter will be powered from rechargable battery and will be able to measure primary attributes of RLC components.
The simulation of steel rod improvement by the induction lines heat treatment
Chmiel, David ; Turoň, Rostislav (referee) ; Kouřil, Miloslav (advisor)
Bachelor thesis deals with possibilities of simulation of induction heat treatment. Literary analysis is focused on the method of induction treatment, the physical nature and its use for the heat treatment. For completeness is in the end comparison of different methods of heat treatment. The experimental part describes the future of quenching and tempering of steel bars in company Třinecké železárny a.s. Also is contained method of simulation of the heat treatment in computer program QTSteel and the subsequent design of parameters for a continuous processing.
Forming lines molding hot weighing up to 100 kg
Smyček, Ondřej ; Humlíček, Jaroslav (referee) ; Omes, Jiří (advisor)
This project was made within the engineering studies and its aim was to design an assembly line to product assigned components of appropriate quality and quantity, using the technology of hot extrusion, both backward and forward. A series of technology steps was suggested, parameters necessary for individual operations were set and on this basis, adequate machines were chosen. The conclusion of this work contains technical-economical evaluation for the chosen options which expects the ten-year return with average production of 40 000 pieces.
Unit for wireless transmission of electrical energy
Jelínek, Aleš ; Kopečný, Lukáš (referee) ; Žalud, Luděk (advisor)
The aim of this work is to prove the practical applicability of the concept of contactless energy transfer using induction coils. The first part deals with the mathematical model and theoretical proof of the concept being able to work in practice and describes the process of detecting resonance of receiver circuit on transmitter side. Next chapter describes hardware solution of the experimental prototype. The last part contains measurement results of a coupling coefficient of coils and discusses performance and notable features of the prototype.
Magnetostriction vibration power generator
Šumpelová, Jana ; Singule, Vladislav (referee) ; Hadaš, Zdeněk (advisor)
This thesis deals with the idea of energy harvesting from mechanical vibration. It describes the magnetostrictive principle as a possibility to obtain an electrical energy. It is about a generator made of a beam with Terfenol-D material and a coil. The model of this device is created in Matlab/Simulink and FEMM application. For various values of measured vibration, these methods are then compared. In FEMM, you can improve energy gain by modeling of various environmental conditions and with using of another materials (e.g. by adding of permanent magnets). The outcome of the this thesis expresses the ability to harvest the energy with designed magnetostrictive generator compared to the already created models of the piezoelectric and electromagnetic generator. Based on these results, it is possible to determine which generator is more suitable for particular application.
Chicken antibodies as a tool of cytochrome P450 immunodetection
Mácová, Iva ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
Cytochrome P450 is an important enzyme which catalyzes a large amount of reactions of endogenous and exogenous metabolism. There are compounds which increase expression of this enzyme and it leads up to the carcinogen activation and cancer formation. It includes much propagated chemopreventive compounds which are consumed abundantly in dietary supplements. It is therefore important to have the methods for determination of cytochrome P450 induction. One of these methods is the cytochrome P450 immunodetection by Western blotting. The detection of proteins on the membrane is done by the specific antibodies mostly gained from mammals. In this bachelor thesis there is the evidence that the antibodies from hen egg serve as well as the mammalian antibodies. The cytochromes P450 1A1 and 1A2 was detected by these egg antibodies after rat exposure to the model chemopreventive compounds β-naphthoflavone.
Interaction of food additives with xenobiotic metabolising enzymes
Jandová, Eliška ; Hodek, Petr (advisor) ; Koblihová, Jitka (referee)
Recently the use of various food supplements as a part of a healthy lifestyle has been very popular. Although most of them are natural products, their excessive consumption may not always be beneficial for health. Dietary supplements are usually of a flavonoid character. Flavonoid compounds are found in plants and they have beneficial effects on human health. For their antioxidant, anti-allergy and chemopreventive effects they are extensively studied. However, in recent years the negative impacts of flavonoids have been described, often caused by their excessive consumption. It has been shown that they interact with cytochrome P450, which play an important role in the biotransformation of xenobiotics. The change in the metabolism of xenobiotics (whether drugs or carcinogens) can cause serious health problems, including a tumor growth. Beside cytochrome P450, there is another possible points of intervention, cytochrome b5 (or NADH:cytochrome b5 reductase), which effects the catalytic cycle of cytochrome P450. Another point of potential danger is the elimination of xenobiotics out of the organism. There is a complex system of transporters, in which P-glycoprotein plays a very significant role. P-glycoprotein is involved in transmembrane efflux of xenobiotics, preventing the aggregation of these...
The Role of Bmp4 and Bmp8b proteins in genesis of mouse primordial germ cells
Vegrichtová, Markéta ; Tlapáková, Tereza (advisor) ; Petelák, Aleš (referee)
Primordial germ cells are precursors of sexual breeding organisms. For induction of their formation are necessary growth factors from extraembryonic ectoderm. There are key proteins BMP4 a BMP8b among these factors. These proteins form both homodimers and heterodimers and through receptor complexes and SMAD proteins are indicating the competent cells of proximal epiblast, which give rise to the primordial germ cells and other structures of embryonic mezoderm. Although BMP4 and BMP8b proteins signal similarly, they are mutually indispensable and though for induction of primordial germ cells are both necessary. Up to now, it was proposed several models of their interaction, but not yet completely accurate.
Activation of carcinogens in gastrointestinal tract
Zawadová, Dorota ; Hodek, Petr (advisor) ; Koblihová, Jitka (referee)
HAA are compounds which are showing numerous carcinogenic impacts on studied animals even human cells. These carcinogenes arise during the heat processing of meat or during (cigarette) smoking. Activation of these compounds is required to their carcinogenic effect. Most of all HAA are first activated by cytochrome P450 (CYP) especially subfamily 1A1 and 1A2. As a consequence of activation with these enzymes are created N-hydroxylamines, which weakly reacting with DNA. For better formation of DNA aducts one more activation is essential. More reactive acetate and sulphate esters arise by second activation from N- hydroxylamines. The esters are produced by sulphotranspherase (SULT) even N- acetotranspherase (NAT). When we affect these enzymes we could positive control the formation of carcinoma. Caffeic acid is considered as a strong inhibitor of one SULT subfamily (phenolic sulfotranspherase P - PST). On the other side as a good inhibitor of NAT is considered (known) quercetin. (in czech) Key words: Heterocyclic amine, biotransformation, cytochrome P450, sulfotransferase, N-acetyltransferase
Activation of carcinogens in gastrointestinal tract
Zawadová, Dorota ; Hodek, Petr (advisor) ; Koblihová, Jitka (referee)
The Bachelor Thesis deals with an activation of heterocyclic aromatic amines (HAA) which have numerous carcinogenic effects on studied animals and human cells. These carcinogens are formed during the heat processing of meat and during the smoking. However, further transformation of the compounds is required to gather their carcinogenic effect. Most of all HAA are first activated by cytochrome P450 (CYP), especially its forms 1A1 and 1A2. The products of this activation - N-hydroxylamines - are further activated in conjugation reactions. In this work, we were focused on the transformation of N-hydroxylamines to more reactive acetate esters and sulphate esters, which is catalyzed by sulphotranspherase (SULT) and N-acetyltranspherase (NAT), respectively. The affection of these enzymes can control the formation of carcinoma. For example, some dietary compounds, such as caffeic acid and quercetin, are the most common inhibitors of these enzymes: caffeic acid is considered as a strong inhibitor of phenolic sulphotranspherase (P-PST), whereas quercetin is a good inhibitor of NAT. On the other hand, some dietary compounds can also induce an opposite effect: for instance, phenol acids induce the P-PST. (in Czech) Key words: Heterocyclic aromatic amines, biotransformation, cytochrome P450,...

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