|
|
Influence of Mixing Line Parameters Adjustment on Mixture´s Properties
Smiřický, Jan ; Kučera, František (referee) ; Petrůj, Jaroslav (advisor)
The main goal of this thesis is to set optimal rubber mixture processing parameters in Barum Continental Ltd. Dispersion is one of the most important tire production steps. Although rubber mixing has been researched by several generations of experts, there are still some unexplored influencing variables. The automotive companies are keen on the reduction of emissions and therefore pushes the tire manufactures as they can contribute to emission reduction, as well as the enhancement of tire toughness. Enhancement of tire toughness causes the decreasing of rolling resistance. Higher toughness is exhibited by tires made of rubber filled by surface modified silica. Silica filled mixtures creates a three-dimensional net which is capable to coexist with a net made by vulcanization reaction. Other goals of this thesis are to understand the process and technologies used for mixing rubber mixtures designated for tire production.
|
|
|
Ergodic Theory
Lisko, Adrian ; Hlubinka, Daniel (advisor) ; Štěpán, Josef (referee)
This Bachelor Thesis compiles basics of ergodic theory. Motivation for writing this text was interesting topic and linkeage between it and the mathematics already learned. The Thesis begins with defining measure-preserving transformations and continues with recurrence and Poincarré's recurrence theorem to ergodicity and Birkhoff's ergodic theorem and mixing. In the end, it is shown that Birkhoff's ergodic theorem generalizes Kolmogorov's strong law of large numbers for stationary random sequences. Theory is demonstrated on a handful of examples of basic transformations.
|
|
|
Empiciral Estimates in Stochastic Programming; Dependent Data
Kolafa, Ondřej ; Kaňková, Vlasta (advisor) ; Dupačová, Jitka (referee)
This thesis concentrates on stochastic programming problems based on empirical and theoretical distributions and their relationship. Firstly, it focuses on the case where the empirical distribution is an independent random sample. The basic properties are shown followed by the convergence between the problem based on the empirical distribution and the same problem applied to the theoretical distribution. The thesis continues with an overview of some types of dependence - m-dependence, mixing, and also more general weak dependence. For sequences with some of these types of dependence, properties are shown to be similar to those holding for independent sequences. In the last section, the theory is demonstrated using numerical examples, and dependent and independent sequences, including sequences with different types of dependence, are compared.
|
|
|
Study of influence of a hydrophilic carrier on the dissolution rate of the BCS II drug
Bunes, Andrea Suther ; Šklubalová, Zdeňka (advisor) ; Vraníková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical Technology Supervisor: Assoc. Prof. PharmDr. Zdenka Šklubalová, Ph.D. Consultant: Mgr. Jana Brokešová Student: Andrea Suther Bunes Title of Thesis: Study of influence of hydrophilic carriers on the dissolution rate of a BCS II drug The aim of this thesis was to study the effect of mixing and co-milling with hydrophilic carriers on the dissolution rate of a model BCS II drug meloxicam. The mixtures of two different drug loads (1-1, 1-8) were characterized for granulometric and dissolution parameters. USP-4 apparatus assembled with a flow-through powder cell (an open loop) was used to estimate meloxicam relative dissolution rate rrel (min-1 ). Mixing with lactose, particularly in a higher ratio, increased the relative dissolution rate in comparison to the pure meloxicam. The effect was further increased by co-milling, but an unfavourable event of agglomeration occurred, especially for the 1-1 drug-excipient ratio sample. Adding chitosan solved this problem due to the formation of interactive mixture. The co-milled sample containing chitosan and lactose in a 1-8 ratio showed the highest rrel = 0.48 min-1 .
|
|
|
Continual double-helicoidal mixer
Černý, Jan ; Malach, František (referee) ; Malášek, Jiří (advisor)
This work focuses on the process of mixing particulate materials and the design of the screw mixer for this activity. The theoretical part describes the mixing and properties of particulate matter. Subsequently, individual devices serving for different types of mixing are analyzed. The practical part contains calculations of the main dimensions and the required power consumption. The choice of suitable drive, bearings and gear is followed. Finally, the analysis of the blade shaft load and the strength analysis of the mixer blade using Autodesk Inventor are performed. Part of this work is enclosed drawing documentation of equipment assembly and selected partial components.
|
|
|
Continual double-helicoidal mixer
Černý, Jan ; Malach, František (referee) ; Malášek, Jiří (advisor)
This work focuses on the process of mixing particulate materials and the design of the screw mixer for this activity. The theoretical part describes the mixing and properties of particulate matter. Subsequently, individual devices serving for different types of mixing are analyzed. The practical part contains calculations of the main dimensions and the required power consumption. The choice of suitable drive, bearings and gear is followed. Finally, the analysis of the blade shaft load and the strength analysis of the mixer blade using Autodesk Inventor are performed. Part of this work is enclosed drawing documentation of equipment assembly and selected partial components.
|
|
| |
|
|
Device for magnetic stirring of suspension with ferromagnetic particles
Zítka, Jan ; Knobloch, Jan (referee) ; Červinka, Dalibor (advisor)
The aim of this work deals with the design and manufacture of a device for mixing of magnetic beads in solution by magnetic field. It is based on my previous bachelor thesis, where the device was created for one microtube (one sample). In this following work, the three improved variants for mixing and separation of 96 samples at one time were designed. The first variant of device, derived from functional prototype from bachelor thesis, was manufactured. First, the magnetic circuit and power converter were designed. Subsequently, the device was manufactured just for one microtube due to functionality testing. The third variant was realized only experimentally, the construction was designed in CAD program, and individual parts were created using 3D printer. As an alternative solution, which should be the compromise among electromagnetic and mechanical stirring, additional prototype was manufactured using 3D printer and CNC instrument. This prototype utilizes neodymium magnets and a stepper motor. The capability of magnetic beads mixing in solution was verified.
|
|
|
The influence of flocculation conditions (global shear rate and time) on the shape and structure of formed aggregates and the efficiency of their separation by sedimentation and filtration
Pivokonský, Martin ; Vašatová, Petra ; Pivokonská, Lenka ; Petříček, Radim ; Filipenská, Monika
A summary research report on the influence of hydrodynamic conditions of flocculation (the intensity of mixing, residence time, etc.) on the property of the aggregates (size, shape, structure, etc.), that have a major impact on the separation steps (sedimentation, filtration) during water treatment. The report will be used by the water treatment plants with the technology of high intensity flocculation.
|
|
|
Homogenization of powder blends using a high-speed mixer
Perďochová, Kristína ; Šklubalová, Zdeňka (advisor) ; Mužíková, Jitka (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of: Department of Pharmaceutical Technology Supervisor: doc. PharmDr. Zdeňka Šklubalová, Ph.D. Consultant: PharmDr. Karel Palát, CSc. Student: Kristína Perďochová Title of Thesis: Homogenization of powder blends using a high-speed mixer This work focuses on using a high-speed mixer for the powder mixing process in pharmaceutical technology. Shortened experimental plan was used to study the influence of three factors (mixing speed, mixing time and weight of the mixture) in order to achieve the overall homogenity of the mixture containing acetylsalicylic acid and microcrystalline cellulose. Individual samples were compressed into tablets. The homogenity of the mixture was evaluated using near infrared spectroscopy (NIR). The standard devations of the measured spectra were observed. The best results obtained from studied mixtures were achieved by a combination of mixing 150 g of mixture, rotational speed of 900 rpm and mixing time of 30 seconds.
|
guest ::
