Studium deformačních mechanismů v hořčíkové slitině s texturou pomocí pokročilých in-situ metod

Název práce: Studium deformačních mechanism· v hořčíkové slitině s texturou pomocí pokročilých in-situ metod Autor: Bc. Jan Dittrich Katedra: Katedra fyziky materiál· Vedoucí diplomové práce: RNDr. Peter Minárik, PhD., Katedra fyziky materiál· Abstrakt: Cílem předkládané práce je zkoumání vzájemného vztahu textury a ak- tivace jednotlivých deformačních mechanism· během deformace válcované hořčí- kové slitiny AZ31. K dosažení uvedeného cíle byla využita kombinace pokročilých in-situ metod, poskytujících vzájemně se doplňující informace o procesech, pro- bíhajících uvnitř materiálu během jeho deformace. Využití kombinace neutronové difrakce a akustické emise umožnilo studovat jak náhlé, tak pozvolné procesy, související se změnami mikrostruktury materi- álu v d·sledku jeho deformace. In-situ deformace vzork· uvnitř vakuové komory skenovacího elektronového mikroskopu, doplněná o analýzu difrakce zpětně odra- žených elektron·, umožnila bezprostřednější sledování vývoje mikrostrukturních změn. Pozorování povrchu deformovaných vzork· vysokorychlostní kamerou poté umožnilo přímé a okamžité sledování náhlých proces·, k nimž během deformace docházelo. Výsledky provedených měření potvrdily očekávanou anizotropii mechanických vlastností vzork· r·zných orientací v·či experimentálně zjištěné textuře zkouma- ného...Title: Investigation of deformation mechanisms in textured magnesium alloy by advanced in-situ methods Author: Bc. Jan Dittrich Department: Department of Physics of Materials Supervisor: RNDr. Peter Minárik, PhD., Department of Physics of Materials Abstract: This thesis aims to investigate the correlation between texture and the activation of particular deformation mechanisms during the deformation of a rolled magnesium alloy AZ31. A combination of advanced in-situ techniques, providing complementary information about the processes within the material during its deformation, was employed to achieve this goal. The combination of neutron diraction and acoustic emission measurements allowed to investigate both rapid and continuous processes related to changes of the material microstructure resulting from its deformation. The in-situ loading of the sample inside the chamber of a scanning electron microscope, coupled with the electron backscatter diraction analysis, provided more direct observations of the microstructural evolution. Furthermore, the high-speed camera imaging of the deformed sample surface enabled a direct, real-time view of the occurring rapid processes. The results of the experiments conrmed the anisotropy of the mechanical behaviour of samples oriented diversely with respect to the...Department of Physics of MaterialsKatedra fyziky materiálůMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

Studium deformačních mechanismů v hořčíkové slitině s texturou pomocí pokročilých in-situ metod

Title: Investigation of deformation mechanisms in textured magnesium alloy by advanced in-situ methods Author: Bc. Jan Dittrich Department: Department of Physics of Materials Supervisor: RNDr. Peter Minárik, PhD., Department of Physics of Materials Abstract: This thesis aims to investigate the correlation between texture and the activation of particular deformation mechanisms during the deformation of a rolled magnesium alloy AZ31. A combination of advanced in-situ techniques, providing complementary information about the processes within the material during its deformation, was employed to achieve this goal. The combination of neutron diraction and acoustic emission measurements allowed to investigate both rapid and continuous processes related to changes of the material microstructure resulting from its deformation. The in-situ loading of the sample inside the chamber of a scanning electron microscope, coupled with the electron backscatter diraction analysis, provided more direct observations of the microstructural evolution. Furthermore, the high-speed camera imaging of the deformed sample surface enabled a direct, real-time view of the occurring rapid processes. The results of the experiments conrmed the anisotropy of the mechanical behaviour of samples oriented diversely with respect to the...Název práce: Studium deformačních mechanism· v hořčíkové slitině s texturou pomocí pokročilých in-situ metod Autor: Bc. Jan Dittrich Katedra: Katedra fyziky materiál· Vedoucí diplomové práce: RNDr. Peter Minárik, PhD., Katedra fyziky materiál· Abstrakt: Cílem předkládané práce je zkoumání vzájemného vztahu textury a ak- tivace jednotlivých deformačních mechanism· během deformace válcované hořčí- kové slitiny AZ31. K dosažení uvedeného cíle byla využita kombinace pokročilých in-situ metod, poskytujících vzájemně se doplňující informace o procesech, pro- bíhajících uvnitř materiálu během jeho deformace. Využití kombinace neutronové difrakce a akustické emise umožnilo studovat jak náhlé, tak pozvolné procesy, související se změnami mikrostruktury materi- álu v d·sledku jeho deformace. In-situ deformace vzork· uvnitř vakuové komory skenovacího elektronového mikroskopu, doplněná o analýzu difrakce zpětně odra- žených elektron·, umožnila bezprostřednější sledování vývoje mikrostrukturních změn. Pozorování povrchu deformovaných vzork· vysokorychlostní kamerou poté umožnilo přímé a okamžité sledování náhlých proces·, k nimž během deformace docházelo. Výsledky provedených měření potvrdily očekávanou anizotropii mechanických vlastností vzork· r·zných orientací v·či experimentálně zjištěné textuře zkouma- ného...Department of Condensed Matter PhysicsKatedra fyziky kondenzovaných látekMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

On the Yang-Mills two-loop effective action with wordline methods

We derive the two-loop effective action for covariantly constant field strength of pure Yang-Mills theory in the presence of an infrared scale. The computation is done in the framework of the worldline formalism, based on a generalization procedure of constructing multiloop effective actions in terms of the bosonic worldline path integral. The two-loop beta-function is correctly reproduced. This is the first derivation in the worldline formulation, and serves as a nontrivial check on the consistency of the multiloop generalization procedure in the worldline formalism.Comment: 8 pages, 4 figure

Femoral Arterial Thrombosis After Cardiac Catheterization In Infancy: Impact of Doppler Ultrasound for Diagnosis

Femoral arterial thrombosis (FAT) is a nonnegligible complication after cardiac catheterization (CC) in infancy. The aim of this study was to evaluate the impact of Doppler ultrasound (US) for diagnostic work-up after catheterization. We compared standard follow-up (FU) without Doppler US by relying on clinical signs of FAT with advanced FU using Doppler US of the femoral vessels. Between January and December 2009, we evaluated the rate of FAT in infants <12months of age using a multicenter, prospective observational survey. We analysed 171 patients [mean age 4.1±3.3 (SD) months; mean body weight 5.3±1.8kg] from 6 participating centres. The mean duration of catheter studies was 57.7±38.0min. The overall rate of FAT based on clinical diagnosis was 4.7% and was comparable in both groups [3.4% undergoing standard FU vs. 7.4% undergoing advanced FU (p=0.15)]. However, the overall rate of thrombosis as screened by Doppler US was greater at 7.1%, especially in patients after advanced FU [18.5% advanced vs. standard FU 1.7% (p<0.01)]. In conclusion, FAT remains a relevant and underestimated complication after catheterization in young infants when relying only on clinical signs of FAT. Therefore, to start effective treatment as soon as possible, we recommend Doppler US to be performed the day after C

QAnon in Deutschland

QANON IN DEUTSCHLAND QAnon in Deutschland / Dittrich, Miro (Rights reserved) ( -

Upgrading of Symbolic and Synthetic Knowledge Bases: Evidence from the Chinese Automotive and Construction Industries

This paper deals with the question of how upgrading of the symbolic and synthetic knowledge bases takes place and, by doing so, we contribute to the upgrading literature by linking upgrading with the concept of the differentiated knowledge bases. We discern a number of upgrading mechanisms, and based on empirical evidence from the construction industry and the automotive industry in China, we show that the main upgrading mechanisms for symbolic knowledge include learning-by-interacting in project teams and monitoring, while upgrading of synthetic knowledge takes place via technology transfer and learning-by-doing and-using. Mobility and on-the-job training and learning in Transnational Corporations are the main upgrading mechanisms contributing to the development of both knowledge bases

Simulation Based Planning of Machining Processes with Industrial Robots

Today, especially machining of large, integral constructed structural parts requires expensive machining centers. In contrast, modern industrial robots are characterized by flexible applications, large working spaces and low capital investment. Therefore, they provide high economical potential for machining applications in aerospace industry. However, their constructive characteristics like low stiffness and high sensitivity to vibrations lead to disadvantages compared with conventional machining centers. Due to this, extruded profiles were used as near to shape pre-products to reduce material removal rates within a new approach. Additionally, several methods for offline and online optimization of robot machining processes were developed and integrated in a new process chain for manufacturing of structural fuselage parts. Thereby, the conventional CAD-CAM process planning chain was extended with simulation based analyzation and optimization methods and a load-depending trajectory planning. The methods for offline process optimization within this novel process chain are presented in this paper

ADAM17 Inhibition Increases the Impact of Cisplatin Treatment in Ovarian Cancer Spheroids

Chemotherapy resistance is a major challenge in ovarian cancer (OvCa). Thus, novel treatment combinations are highly warranted. However, many promising drug candidates tested in two-dimensional (2D) cell culture have not proved successful in the clinic. For this reason, we analyzed our drug combination not only in monolayers but also in three-dimensional (3D) tumor spheroids. One potential therapeutic target for OvCa is A disintegrin and metalloprotease 17 (ADAM17). ADAM17 can be activated by chemotherapeutics, which leads to enhanced tumor growth due to concomitant substrate cleavage. Therefore, blocking ADAM17 during chemotherapy may overcome resistance. Here, we tested the effect of the ADAM17 inhibitor GW280264X in combination with cisplatin on ovarian cancer cells in 2D and 3D. In 2D, the effect on five cell lines was analyzed with two readouts. Three of these cell lines formed dense aggregates or spheroids (HEY, SKOV-3, and OVCAR-8) in 3D and the treatment effect was analyzed with a multicontent readout (cytotoxicity, viability, and caspase3/7 activation). We tested the combined therapy on tumor spheroids derived from primary patient cells. In 2D, we found a significant reduction in the half minimal (50%) inhibitory concentration (IC50) value of the combined treatment (GW280264X plus cisplatin) in comparison with cisplatin monotherapy in all five cell lines with both 2D readout assays (viability and caspase activation). In contrast, the combined treatment only showed an IC50 reduction in HEY and OVCAR-8 3D tumor spheroid models using caspase3/7 activity or CelltoxTM Green as the readout. Finally, we found an improved effect of GW280264X with cisplatin in tumor spheroids derived from patient samples. In summary, we demonstrate that ADAM17 inhibition is a promising treatment strategy in ovarian cancer