Diploma thesis is about application of ultrasonic pulse velocity method to determinate the strengths of cements, if there is a relevant calibration relation.

Guinea pigs represent domesticated precocious rodents which became common pets. From the first day after birth they are fully vocal. This thesis was devoted to the vocalization of pups. The aim of the thesis was to 1) determine the age when the vocal individuality in whistle sound is demonstrable; 2) test possible ultrasonic signals emitted by young guinea pigs; 3) study the antipredator reactions and alarm calls to aerial (bird of prey) and terrestrial (dog) predators and human (control test). A total of 16 guinea pig pups were tested for vocal individuality, 28 pups for ultrasonic vocalization and 27 adolescents for predator recognition. When testing vocal ontogeny during the first 9 days after birth, I observed changes in temporal, frequency and parameter of intensity . When I test vocal individuality by cross-validated discriminant function analysis (DFA) based on ten acoustic parameters, calls were classified to correct animals with following success: day 1 = 71.9%, day 3 = 58.8%, day 5 = 53.10%, day 7 = 50.60% and day 9 = 63.10%. The highest frequency in whistle was 30.03 kHz. In predator discrimination reactions as freezing, fleeing and vigilance were observed. In the presence of dog, guinea pigs reacted for the longest time and most frequently by freezing. When confronted with a bird of prey, I observed for a longest time and most often fleeing and then freezing. When exposed to a human, guinea pigs showed mostly vigilance. Almost no vocalization was observed except for two events of alarm calls - drrr as in the presence of dog and chirrup as reaction to bird of prey. The following conclusions can be drawn from the presented results: 1) vocal individuality of guinea pigs is demonstrable immediately after birth and the rate of individually different vocal parameters changes with age; 2) guinea pigs are able to produce sound up to 30 kHz, i.e. within the ultrasound range, but signals of high frequencies are not crucial for their communication; 3) guinea pigs discriminate between terrestrial and aerial predators, but they emit alarm calls rather rarely.

The work deals with design and implementation of 2D ultrasound simulation. Applications of the ultrasound simulation can be found in medicine, biophysic or image reconstruction. As an example of using the ultrasound simulation we can mention High Intensity Focused Ultrasound that is used for diagnosing and treating cancer. The program is part of the k-Wave toolbox designed for supercomputer systems, specifically for machines with shared memory architecture. The program is implemented in the C++ language and using OpenMP acceleration.  Using the designed solution, it is possible to solve large-scale simulations in 2D space. The work also deals with merging and unification of the 2D and 3D simulation using modern C++. A realistic example of use is ultrasound simulation in transcranial neuromodulation and neurostimulation in large domains, which have more than 16384x16384 grid points. Simulation of such size may take several days if we use the original MATLAB 2D k-Wave. Speedup of the new implementation is up to 8 on the Anselm and Salomon supercomputers.

This diploma thesis deals with the study of possible interactions between hyaluronan (HA) and plasmid DNA (pDNA). Plasmid DNA was isolated from E. coli JM109 (pUC19) and resuspended in TE buffer as well as high molecular weight hyaluronan. Individual samples of pDNA, HA and pDNA-HA were characterized by gel electrophoresis, CD spectroscopy and high resolution ultrasonic spectroscopy. Agarose gel electrophoresis examined the effect of the addition of hyaluronan to plasmid DNA on the migration of samples to the positive electrode. Structural changes in pDNA-HA samples were examined using CD spectroscopy. Individual CD spectra describes the dependence of the difference in absorption coefficients for left-hand and right-handed elliptic polarized light at wavelength. High resolution ultrasonic spectroscopy has been used to study interactions. It is an analytical method based on ultrasonic velocity and attenuation. We classify this technique as a non-destructive method because the passing waves do not affect the structure of the analyzed sample.

This diploma thesis focuses on the study of temperature dependence of -carrageen, hyaluronan of low molecular weight (250–450 kDa) and hyaluronan of high molecular weight (1 500–1 750 kDa) in aqueous solutions. The description of temperature depending changes in properties of these substance is based on rheological method. This work concentrates on the characterization of viscoelasticity through measurement of the storage (elastic) and loss (viscous) modulus using -carrageen and hyaluronan solutions of different molecular weights and different concentrations depending on temperature (20–50 °C, alternatively, in carrageen, 20–80 °C). The temperature dependence was further measured using an uncommon technique called high resolution ultrasonic spectroscopy (HR-US) which measured relative velocity of selected concentrations of -carrageen and hyaluronan of high molecular weight depending on the temperature of heating and cooling (20–80 °C). The measurements of temperature dependence were carried out for varied oscillation frequencies of rheometer sensor/frequency of ultrasonic waves. Knowledge of temperature dependence of the investigated substances may be applied in drug chemistry, primarily with respect to degradation due to high temperatures. The measured data gives information about sol-gel temperature and gel-sol temperature of carrageen.

The diploma thesis is focused on the study of interactions between hyaluronan of various molecular weights with CAE surfactant. This surfactant does not have the exact composition and there is not known their molecular weight. One of the main parameters needed to describe the interactions between surfactant and hyaluronan, there is the determination of critical micellar concentration. The value of critical micellar concentration of CAE is not known yet. All measurements were made for solutions in aqueous solution and 0.15 M NaCl. The determination of the molecular weight of this surfactant was performed by the technique SEC-MALS-dRI. High resolution ultrasonic spectroscopy was chosen to determine the critical micellar concentration and tensiometry was chosen as a complementary method. The interactions of CAE surfactant with polysaccharide of hyaluronan were showed by high resolution ultrasonic spectroscopy and densitometry. Compressibility was calculated from ultrasonic velocity and density.

Hydratace patří mezi nejdůležitější faktory ovlivňující sekundární strukturu a tím i funkci molekul v živých systémech. Díky vysoké afinitě tvoří molekuly vody specifické struktury jejichž složení a fyzikální vlastnosti jsou ovlivněny přítomností studované látky. Hyaluronan patří mezi biomolekuly s obrovskou schopností vázat a zadržovat vodu. Cílem této práce bylo prozkoumat hydratační vlastnosti hyaluronanu o různé molekulové hmotnosti a vyčíslit množství molekul vody v jednotlivých hydratačních vrstvách. V první části práce byla využita metoda diferenční kompenzační kalorimetrie. V druhé části diplomové práce, na základě rozdílné kompresibility, byla vázaná voda studována metodou vysoko rozlišovací ultrazvukové spektroskopie.

The study deals with the image reconstructions using the ultrasound propagation speed measuring and it extends the project of the ultrasound transmission tomography organised in cooperation with the research centre Forschungszentrum Karlsruhe (Germany). There were data processed which had been gained with the 3D ultrasound transmission tomography system (3D USCT). The ultrasound propagation speed was measured using the detection of ultrasound ray travelling time from a transmitter to a receiver. There were three new algorithms developed for the detection of an ultrasound impulse and the software generating suitable testing data. The developed algorithms were consequently tried with these data and, then, included into the existing software. All software was developed within the Matlab programming environment.

The first part of the Master´s thesis describes physical principles of ultrasound and fundamental variables of ultrasound field. It also deals with mathematical description of finite element method and outlines basic principles of ultrasound computed tomography. The second part introduces finite elements generator GMSH. This part focuses on the process of ultrasound field simulation and presents software that can be used for field simulation. The last part contains examples of models.

The model study of nonlinear effects in the ultrasound diagnostics is focused on developing and experimental verification of new computer algorithms for numerical modeling of the ultrasound field including nonlinear effects accompanying the ultrasound propagation in biological tissues. A theoretical analysis of nonlinearities in ultrasound propagation and their contribution to thermal and mechanical effects of diagnostic ultrasound applications was conducted. A numeric model of ultrasound propagating through a tissue model formed of a set of homogenous layers with defined physical parameters was developed in Matlab environment. The computation of ultrasound field spatial distribution is based on the angular spectrum method. For simulating of nonlinearities Burgers nonlinear wave equation is used. The resulting spatial distribution of the ultrasound field is described by the amplitudes of selected number of harmonic components of the acoustic pressure, by the mechanical index, by the harmonic distortion of the signal and by the spatial peak temporal average intensity of all considered components. The numerical model was experimentally verified using an unique ultrasound measurement system – the ultrasound measurement basin. The verified numeric model was used for assessing the veracity of mechanical index and tissue heating prediction during ultrasound applications in cases when the nonlinear effects are neglected in computations. The reliability of the mechanical index indicated by the diagnostic ultrasound instruments is also evaluated using the designed numeric model. The aim was to compare the indicated value usually obtained by derating the measurements in a water medium to the actual mechanical index present in the insonated tissue.