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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Congestion control for packetised video on the internet

Wakeman, Ian John January 1995 (has links)
No description available.
2

Determination of the compressibility of excipients used for formulation of tablets with theophylline.

Kousoulidou, Viktoria January 2015 (has links)
1 Abstract Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: Assoc. Prof. PharmDr. Zdenka Sklubalova, Ph.D. Student: Viktoria Kousoulidou Title of Thesis: Determination of the compressibility of excipients used for formulation of tablets with theophylline The current thesis is focused on the compressibility properties of five powders used in tablet formulation: Comprecel, Spherolac, DI-CAFOS D160, DI-CAFOS A150 as excipients and Theophylline as the active substance. The particle size, moisture content, bulk density and flowability of the powders are determined. The powders are compressed and the results are evaluated by means of the parameters of the compaction equation and the force-displacement method (compression under 5, 10, 15 kN). Then, the crushing strength of tablets prepared from each powder by the force-displacement method is measured. The average values of the crushing strength are used to calculate the tensile strength of the tablets. Best compressibility is found in Comprecel and Theophylline with tensile strength values of 1.31 MPa under 5 kN, 3.31 MPa under 10 kN, 4.75 MPa under 15 kN and 1.02 MPa under 5 kN, 2.27 MPa under 10 kN, 3.09 MPa under 15 kN, respectively.
3

Hodnocení disoluce tablet obsahujících theofylin a směsi dvou typů hydrogenfosforečnanu vápenatého a mikrokrystalické celulosy / Dissolution testing of tablets containing theophylline and mixtures of two types of calcium hydrogen phosphates and microcrystalline cellulose

Vávrová, Kateřina January 2017 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of Pharmaceutical technology Consultant: PharmDr. Pavel Ondrejček, Ph.D. Student: Kateřina Vávrová Title of Thesis: Dissolution testing of tablets containing theophylline and mixtures of two types of calcium hydrogen phosphates and microcrystalline cellulose The aim of this thesis was the dissolution testing of tablets containing theophylline, the mixture of two dicalcium phosphate types and microcrystalline cellulose. The influence of tablet composition on the dissolution profiles was evaluated. The tablets were prepared from the mixtures containing microcrystalline cellulose, dicalcium phosphate anhydrous and dihydrate. These substances were used as fillers. Prepared mixtures contained theophylline as a model active ingredient and magnesium stearate as lubricant. Afterwards, the dissolution tests were done. For these tests, the basket method was utilized. As a dissolution medium the 0,1M hydrochloric acid solution was used. From the results of this experiment we concluded that we can influence the total amount of released theophylline and the speed of its release by the different ratio of microcrystalline cellulose and one of dicalcium phosphate types. The fastest theophylline dissolution was in tablets with high...
4

Hodnocení doby rozpadu tablet obsahujících theofylin / Evaluation of disintegration time of tablets containing theophylline

Brtnová, Soňa January 2015 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Thesis supervisor: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: Mgr. Pavel Ondrejček Student: Soňa Brtnová Title of Thesis: Evaluation of disintegration time of tablets containing theophylline The influence of used fillers on energetic profile of compression, especially influence on disintegration time of tablets with theophylline as a model drug, was studied in this thesis. Four tablet fillers were studied - microcrystalline cellulose Comprecel 102, lactose SpheroLac 100, calcium hydrogen phosphate anhydrous Di- Cafos A150 and calcium hydrogen phosphate dihydrate Di-Cafos D160. Tablets contained different proportion of two fillers, theophylline as a model drug and lubricant magnesium stearate. Tablets were compressed by the same compaction force 10 kN. The force- displacement record was evaluated using the particular energies of compaction process. Parameters of compaction process were influenced mostly by Comprecel 102. According to results there is no possibility to replace Di-Cafos D160 with Di-Cafos A150 in the mixtures. It was also found that SpheroLac 100 and Di-Cafos D160 shows similar behavior. Time of disintegration of tablets is mostly dependent on the used fillers. Tablets...
5

Hodnocení radiální pevnosti tablet obsahujících theofylin / Evaluation of tensile strength of tablets containing theophylline

Janoutová, Hana January 2015 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Student: Hana Janoutová Title of Thesis: Evaluation of tensile strength of tablets containing theophylline The aim of this thesis was to determine tensile strength of tablets containing theophylline. Tensile strength was studied as a function of the composition of mixtures of the used fillers and especially on their ratio. In the theoretical part, the used materials - lactose SpheroLac 100, microcrystalline cellulose Comprecel 102, dibasic calcium phosphate dihydrate Di-Cafos D160, anhydrous dibasic calcium phosphate Di-Cafos A150, theophylline and magnesium stearate are described. This work also evaluates force-displacement record, tensile strength and various factors that affect tensile strength. Parameters of force-displacement record and tensile strength of the tablets compressed with compresssion force 10 kN were evaluated in the experimental part. The measured results show that higher values of precompression energy (E1) and energy of plastic deformation (E2) were detected in mixtures A, C and E which contain Comprecel 102, and the lowest values were detected in mixtures B which contain Sphero-Lac 100 and Di-Cafos D160. Values of energy...
6

Hodnocení lisovatelnosti tablet s theofylinem pomoci lisovací rovnice / Evaluation of compressibility of tableting mixtures containing theophylline using a compaction equation

Matyášová, Andrea January 2015 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Technology Consultant: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Student: Andrea Matyášová Title of Thesis: Evaluation of compressibility of tableting mixtures containing theophylline using a compaction equation This thesis is aimed at the evaluation and comparison of excipients used in production of tablets. The compaction process of these excipients was evaluated using the parameters of the compaction equation. The mixtures of four fillers in various ratios were evaluated. These mixtures contained also theophylline as model drug and magnesium stearate as lubricant. The used three-exponential equation was previously developed by doc. RNDr. Milan Řehula, CSc. By using this compaction equation the volume reductions, speeds of volume reductions and consumed energies were calculated and evaluated. The results of this work showed that particular used fillers have different effect on the compaction process flow. That is caused primarily by different behavior of these materials during compaction and by formation of different types of bonds. Also the need of thorough cleaning and drying of compaction aid before compaction was confirmed.
7

Stanovení sypnosti směsí pro přípravu tablet s theofylinem / Determination of flow properties of mixtures for preparation of tablets containing theophylline

Brunettová, Monika January 2015 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: Doc. PharmDr. Šklubalová Zdeňka, Ph.D. Student: Brunettová Monika Title of Thesis: Determination of flow properties of mixtures for preparation of tablets containing theophylline The aim of this diploma thesis was to characterize the flow properties and moisture content of mixtures for preparation of tablets containing theophylline. Parameters were monitored depending mainly on the content of the fillers, that were dicalcium phosphate, microcrystalline cellulose and lactose. Twenty-five prepared mixtures with different ratios of these fillers were evaluated. Flowability was evaluated by three methods stated in Czech Pharmacopoeia 2009 - compressibility index and Hausner ratio, flow through an orifice and angle of repose. Moisture content was evaluated as a weight loss during drying. Mixtures containing dicalcium phosphate and lactose proved more appropriate in terms of flowability, their flow properties are passable. However, according to the moisture content, mixture with microcrystalline cellulose are more preferable.
8

Měření stresové relaxace směsí mikrokrystalické celulosy a hydrogenfosforečnanu vápenatého určených k přípravě tablet s theofylinem / Measurement of stress relaxation of mixtures of microcrystalline cellulose and calcium hydrogen phosphate intended for the preparation of tablets with theophylline

Hofmanová, Markéta January 2015 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Consultant: Doc. PharmDr. Sklubalova Zdenka, Ph.D. Student: Marketa Hofmanova Title of Thesis: Measurement of stress relaxation of mixtures of microcrystalline cellulose and calcium hydrogen phosphate intended for the preparation of tablets with theophylline The powder mixtures with theophylline were studied from the aspect of viscoelastic properties of used materials and tablets tensile strength. In the theoretical part the thesis concerned with description of materials which were used in the mixtures. They are: Microcrystalline cellulose Comprecel 102, calcium hydrogen phosphate anhydrate Di-Cafos A150, calcium hydrogen phosphate dihydrate Di-Cafos D160 and lactose SpheroLac 100. The thesis also deals with the stress relaxation test. The stress relaxation test, its evaluation by several methods and its use in the pharmacy and in different fields are described. The experimental part deals with viscoelastic characteristics of the mixtures. These characteristics were evaluated by stress relaxation test with maximal compression force 10 kN and dwell time 180 s. Also the tensile strength was evaluated. The highest values of parameters of elasticity A1-3 and plasticity P1-3 were measured in...
9

Hodnocení relaxace tablet s theofylinem / Evaluation of elastic recovery of tablets containing theophylline

Vitverová, Barbora January 2015 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: Doc. PharmDr. Šklubalová Zdeňka, Ph.D. Student: Barbora Vitverová Title of Thesis: Evaluation of elastic recovery of tablets containing theophylline This diploma thesis deals with evaluation of elastic recovery of tablets containing theophylline. The axial and radial elastic recovery is evaluated. Used materials are characterized in a theoretical part. It concerns microcrystalline cellulose Comprecel 102, lactose SpheroLac 100, calcii hydrogenphosphas anhydrous Di- Cafos A150, calcii hydrogenphosphas dihydrate Di-Cafos D160, magnesii stearas and theophylline. Further, compression process and its evaluation are described and also the elastic recovery of tablets after compression, its calculation and factors which can influence it. The experimental part of thesis deals with the elastic recovery of tablets. The tablets were compressed by compression strength 10 kN and the height and diameter were measured after 0, 3, 6 and 24 hours after compressing. The elastic recovery of tablets was calculated from these values. The dimensions of tablets at the maximal compression strength 10 kN were used as the initial values. From results is obvious that the highest elastic recovery is...
10

Investigation of cryptographic algorithms for the transfer of financial information

Martynenko, Mykola January 2010 (has links)
The purpose of the investigation is to determine the most effective solution, which allows safe storing and transmitting of financial information in terms of execution speed, resistance to hacking and ease of implementation. Research object is subject area related to the transfer of encrypted financial information like: encryption algorithms, algorithm of hashing functions, algorithm of electronic digital signature. The result of research is the software implementation of the server and client for sending encrypted information. Also client could only encrypt/decrypt information. The main part of research is to find the most suitable algorithm for transfer of encrypted banking information. The solution has been implemented on the Java programming language in programming environment IntelliJ IDEA 8, using Java Cryptography Extension (JCE) for digital signature.

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