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A Study of the Properties of Compacts from silicified microcrystalline celluloses.
Nováková, Petra ; Mužíková, Jitka (advisor) ; Šnejdrová, Eva (referee)
V práci je studována pevnost tablet v tahu a doba rozpadu výlisků ze silicifikovaných mikrokrystalických celulos, Prosolv SMCC 90 a Prosolv HD 90, v závislosti na lisovací síle, přídavku dvou typů mazadel a dvou léčivých látek. Mazadla byla stearan hořečnatý a stearylfumarát sodný v koncentraci 0,5%, aktivní látky kyselina askorbová a acetylsalicylová v koncentraci 50%. Prosolv SMCC 90 byl lépe lisovatelný než Prosolv HD 90; výlisky měly vyšší pevnost a ta se zvyšovala s lisovací silou. Prosolv HD 90 byl více citlivý na přídavek mazadel a větší pokles pevnosti byl zaznamenán v přítomnosti stearylfumarátu sodného. Vliv mazadel na pevnost tablet v přítomnosti léčivých látek nebyla stejná. Doba rozpadu výlisků z Prosolvu HD 90 bez i s mazadly byla kratší než z Prosolvu SMCC 90 a zvyšovala se s rostoucí lisovací silou. Doba rozpadu se prodloužila přídavkem mazadel a významně byla zkrácena přídavkem léčivých látek. Výlisky s kyselinou askorbovou měly kratší dobu rozpadu než s kyselinou acetylsalicylovou a doba rozpadu nebyla výrazně ovlivněna přítomností mazadel.
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Rekombinace a reakce iontů v plazmatu
Varju, Jozef ; Glosík, Juraj (advisor) ; Kaňka, Adolf (referee)
One of the most interesting questions in contemporary interstellar chemistry is the HCN/HNC abundance ratio observed in dense interstellar clouds. The observed ratios vary from 80:1 to 1:5 depending on the object under observation. These ratios represent a striking deviation from thermochemical equilibrium. Dissociative recombination of HCNH+ has been invoked to explain these observations. It is suggested to study details of this recombination using FALP apparatus equipped with NIR Cavity Ringdown Absorption Spectrometer (IR - CRDS). In the presented work we have developed kinetic model describing formation of HCNH+/e- plasma and consequent production of HCN and HNC. Analysed and discussed are conditions of experiment and applicability of IR - CRDS for the proposed study. To confirm our analyses the preliminary experiments were carried out using microwave discharge cell equipped with IR - CRDS. Studies of H3O+ and H2D+ ions were carried out to put together the experiment. The absorption spectra in a plasma containing He/N2/CH4 were measured in order to determine transition frequencies for study of products of recombination of CNH+ ions.
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Photovoltaic silicon solar cells: study of materials and solar structures by the method of Fourier photoconductive spectroscopy
Holovský, Jakub ; Toušek, Jiří (advisor) ; Hlídek, Pavel (referee)
The use of Fourier transform infrared spectrometer for the measurement of Fourier Transform Photocurrent Spectroscopy (FTPS) has been recently reported and it is basis of this thesis. The main task of the thesis is extension of the FTPS to Surface Photovoltage (SPV) method. This method gives an unique possibility to evaluation of effective diffusion length L and effective surface recombination velocity (SRV) for thin or non-symmetrical semiconductor structures that can't be measured by standard techniques. These parameters play key role in good performance of solar cells absorbers. The experiments were carried out on c-Si material with surface passivated by silicon nitride. Sample is illuminated from the passivated side and the SPV signal is detected between the back capacitive contact and non-illuminated ohmic contact. One-dimensional continuity equation is solved to fit the measured spectrum. We have to ensure linearity of measured signal versus incident light intensity and account for frequency dependence. One measurement takes 30 seconds - that enables arbitrary variations. The influence of surface barrier height on SRV was assumed and additional constant illumination (light bias) was used to investigate its behavior and new relations were found. Beside SPV new elegant technique for interference...
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A study of the properties of tablets from coprocessed dry binder based on directly compressible starch and lactose.
Moučková, Eva ; Mužíková, Jitka (advisor) ; Řehula, Milan (referee)
The paper deals with the study of the properties of tablets from coprocessed dry binder StarLac. The properties under study included the tensile strength and disintegration time in dependence on compression force, addition of two lubricants (magnesii stearas, sodium stearylfumarate) in two concentrations (0,4. 0,8%) and a 50% addition of the active ingredient ascorbic acid. The compression forces were 15, 16, 17 kN, in the case of the tableting material with the active ingredient only 16 kN. The addition of magnesii stearas in a concentration of 0,4% increased the tensile strength, but in a concentration of 0,8% didn't. The same result is in the case of sodium stearyl fumarate for compression force 17 kN. The addition of lubricants increased the disintegration time of tablets, less in the case of Pruv. The addition of ascorbic acid decreased the tensile strength of tablets, the disintegration time was shorten. StarLac without and with magnesii stearas too offers the tablets with higher tensile strength and with shorter disintegration time then the physical mixture of Starch 1500 and Pharmatose DCL 15.
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Synthesis and study of ceramide analogues
Školová, Barbora ; Vávrová, Kateřina (advisor) ; Matějka, Pavel (referee) ; Šklubalová, Zdeňka (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of inorganic and organic chemistry Candidate: Mgr. Barbora Školová Supervisor: doc. PharmDr. Kateřina Vávrová, Ph.D. Title of doctoral thesis: Synthesis and study of ceramide analogues Ceramides (Cer) together with free fatty acids and cholesterol form intercellular lamellar space of the uppermost skin layer (stratum corneum, SC). This lipid matrix presents the proper skin barrier - it protects organism against outer environment and keeps its homeostasis as well. The composition and arrangement of the intercellular lipid matrix is essential for the skin barrier properties. In spite of this fact, the organization of SC lipids at the molecular level is not fully elucidated. The aim of this work is to contribute to more detailed insight into organization of skin barrier using SC lipid model membranes, in particular to find the structural parameters in ceramide molecules, which play a role in the maintenance of the skin barrier. The SC model membranes present a useful tool to study SC lipids, they mimic physiological or pathological conditions in the skin. The obtained results should be used in diagnosing or therapy of skin diseases characteristic with impaired barrier function, such as atopic dermatitis or psoriasis....
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