Anisotropie svrchního pláště pod Severními Apeninami z dat mezinárodního experimentu RETREAT (Itálie)

Název práce: Anisotropie svrchního pláště pod Severními Apeninami z dat mezinárodního experimentu RETREAT (Itálie) Autor: Helena Munzarová Katedra / Ústav: Katedra geofyziky Vedoucí diplomové práce: RNDr. František Gallovič, Ph.D. Katedra geofyziky Konzultant diplomové práce: RNDr. Jaroslava Plomerová, DrSc. Geofyzikální ústav Akademie věd ČR Abstrakt: V této diplomové práci zpracováváme data mezinárodního pasivního seismologického experimentu RETREAT (2003-2006) ve snaze přispět k poznání struktury svrchního pláště pod Severními Apeninami. V Severních Apeninách dochází k aktivní kolizi mezi Tyrhénskou a Adriatickou litosférickou deskou (zanořující se západním směrem). Kolize je doprovázená zpětným pohybem kolizního příkopu ve východním směru. Směrová závislost odchylek v časech šíření vln P, společně se změnami polarizací rychlých štěpených střižných vln indikují, že pozorovaná anisotropie seismických rychlostí je odrazem fosilní anisotropie uvnitř plášťové litosféry a anisotropie, vznikající v důsledku aktuálního tečení v astenosféře. Kontinentální Adriatickou desku je možné rozdělit přinejmenším na dvě oblasti s vlastní fosilní orientací anisotropní struktury. Rovněž jsme vyhodnocovali provázanost seismické anisotropie a heterogenit, zde reprezentovaných vysokorychlostní zanořující se Adriatickou deskou....Title: Anisotropy of the upper mantle under the Northern Apennines based on data from the international experiment RETREAT (Italy) Author: Helena Munzarová Department: Department of Geophysics Supervisor of the master thesis: RNDr. František Gallovič, Ph.D. Department of Geophysics Consultant of the master thesis: RNDr. Jaroslava Plomerová, DrSc. Institute of Geophysics, Czech Academy of Sciences Abstract: In this master thesis, we process data recorded during the passive seismic experiment RETREAT (2003-2006) in the Northern Apennines with the aim to explore the upper mantle structure in the region. Active orogeny in the Northern Apennines relates to the collision of the Tyrrhenian and Adriatic (subducting westward) plates and is accompanied by an eastward retreat of the trench. Directional dependences of P-wave travel-time deviations together with variations of the fast split polarization azimuths of teleseismic SKS waves are derived from data recorded during experiment RETREAT. Both the fossil anisotropic structure in the mantle lithosphere and the anisotropy due to the present-day flow in the sub-lithospheric mantle are sources of the observed velocity-anisotropy patterns. Thick continental Adriatic plate can be divided into at least two sub-regions with their own fossil fabrics. We have also tried to...Department of GeophysicsKatedra geofyzikyFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

THE CARBON COMPOSITE MATERIALS WITH THE INORGANICAL MATRIX

katedra: KTM; přílohy: 1 CD ROM; rozsah: 89 s., 7 s. obr. přílohTéma: Uhlíkové kompozitní materiály s anorganickou matricí Hlavní náplní této diplomové práce je sledování kompozitů, zejména změna vlastností kompozitů s různým obsahem uhlíkových vláken při různé době stáří. Rešeršní část diplomové práce obsahuje základní charakteristiky a rozdělení kompozitů, používaných vláken pro kompozity a běžně používaných matric pro tyto materiály. Dále je zde popsán geopolymer, který je v této práci použit jako matrice. Závěrem rešeršní části jsou popsány vybrané druhy výroby kompozitních dílů. Experimentální část popisuje použité materiály pro vyrobené vzorky. Dále je v této části zpracováno měření akustické pohltivosti, elektrické vodivosti, mechanických vlastností a termické vodivosti kompozitních dílů s uhlíkovými vlákny v geopolymerní matrici. Byly modelovány závislosti veličin na obsahu uhlíkových vláken a na stáří geopolymeru.Thesis: The carbon composite materials with the inorganical matrix The principal content of the dissertation work is to watch how the characteristics of the composite changes at different periods with different amount of the carbon fibres. The theoretical part of the dissertation work includes the fundamental characteristics and classification of the composites, the fibres used for the composites and the common use of matrix for these materials. Further on, the geopolymer is described, which is used as the matrix in the dissertation work. There are selected types of composite production described in the final part of the theoretical part. The experimental part of the dissertation work describes the materials used for the samples made. It is It is worked on the measuring of an acoustic resistance, an electric conductivity, mechanical properties and a thermal conductivity of the composites with the carbon fibres in the geopolymeric matrix. Dependencies quantities were modelled for volume carbonic fibres and for age geopolymer

Translation Reinitiation Relies on the Interaction between eIF3a/TIF32 and Progressively Folded cis-Acting mRNA Elements Preceding Short uORFs

Reinitiation is a gene-specific translational control mechanism characterized by the ability of some short upstream uORFs to retain post-termination 40S subunits on mRNA. Its efficiency depends on surrounding cis-acting sequences, uORF elongation rates, various initiation factors, and the intercistronic distance. To unravel effects of cis-acting sequences, we investigated previously unconsidered structural properties of one such a cis-enhancer in the mRNA leader of GCN4 using yeast genetics and biochemistry. This leader contains four uORFs but only uORF1, flanked by two transferrable 5′ and 3′ cis-acting sequences, and allows efficient reinitiation. Recently we showed that the 5′ cis-acting sequences stimulate reinitiation by interacting with the N-terminal domain (NTD) of the eIF3a/TIF32 subunit of the initiation factor eIF3 to stabilize post-termination 40S subunits on uORF1 to resume scanning downstream. Here we identify four discernible reinitiation-promoting elements (RPEs) within the 5′ sequences making up the 5′ enhancer. Genetic epistasis experiments revealed that two of these RPEs operate in the eIF3a/TIF32-dependent manner. Likewise, two separate regions in the eIF3a/TIF32-NTD were identified that stimulate reinitiation in concert with the 5′ enhancer. Computational modeling supported by experimental data suggests that, in order to act, the 5′ enhancer must progressively fold into a specific secondary structure while the ribosome scans through it prior uORF1 translation. Finally, we demonstrate that the 5′ enhancer's stimulatory activity is strictly dependent on and thus follows the 3′ enhancer's activity. These findings allow us to propose for the first time a model of events required for efficient post-termination resumption of scanning. Strikingly, structurally similar RPE was predicted and identified also in the 5′ leader of reinitiation-permissive uORF of yeast YAP1. The fact that it likewise operates in the eIF3a/TIF32-dependent manner strongly suggests that at least in yeasts the underlying mechanism of reinitiation on short uORFs is conserved

Technologie výroby textilního laminátu s obsahem nanovláken pro nanofiltry NANOVIA 2014

Předmětem této zprávy je souhrn technologických a výrobních informací souvisejících se způsobem výroby, metodami testování a technickými parametry textilního filtračního média, designovaného pro filtraci mikroorganismů (bakterií a virů) a velmi jemných prachových částic. Toto filtrační médium bylo designováno pro použití ve skládaném filtru. Ověření technologie výroby filtračního laminátu s nanovlákny bylo v celém výrobním rozsahu realizováno na průmyslových strojích, na kterých bude po ukončení projektu probíhat průmyslová výroba vyvinutého materiálu

Accurate ab initio spin densities

We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as basic quantity for the spatially resolved spin density distribution. The spin density matrix elements are directly determined from the second-quantized elementary operators optimized by the DMRG algorithm. As an analytic convergence criterion for the spin density distribution, we employ our recently developed sampling-reconstruction scheme [J. Chem. Phys. 2011, 134, 224101] to build an accurate complete-active-space configuration-interaction (CASCI) wave function from the optimized matrix product states. The spin density matrix elements can then also be determined as an expectation value employing the reconstructed wave function expansion. Furthermore, the explicit reconstruction of a CASCI-type wave function provides insights into chemically interesting features of the molecule under study such as the distribution of $\alpha$- and $\beta$-electrons in terms of Slater determinants, CI coefficients, and natural orbitals. The methodology is applied to an iron nitrosyl complex which we have identified as a challenging system for standard approaches [J. Chem. Theory Comput. 2011, 7, 2740].Comment: 37 pages, 13 figure

Outer-Sphere Contributions to the Electronic Structure of Type Zero Copper Proteins

Bioinorganic canon states that active-site thiolate coordination promotes rapid electron transfer (ET) to and from type 1 copper proteins. In recent work, we have found that copper ET sites in proteins also can be constructed without thiolate ligation (called “type zero” sites). Here we report multifrequency electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD), and nuclear magnetic resonance (NMR) spectroscopic data together with density functional theory (DFT) and spectroscopy-oriented configuration interaction (SORCI) calculations for type zero Pseudomonas aeruginosa azurin variants. Wild-type (type 1) and type zero copper centers experience virtually identical ligand fields. Moreover, O-donor covalency is enhanced in type zero centers relative that in the C112D (type 2) protein. At the same time, N-donor covalency is reduced in a similar fashion to type 1 centers. QM/MM and SORCI calculations show that the electronic structures of type zero and type 2 are intimately linked to the orientation and coordination mode of the carboxylate ligand, which in turn is influenced by outer-sphere hydrogen bonding

The role of dynamical polarization of the ligand to metal charge transfer excitations in {\em ab initio} determination of effective exchange parameters

The role of the bridging ligand on the effective Heisenberg coupling parameters is analyzed in detail. This analysis strongly suggests that the ligand-to-metal charge transfer excitations are responsible for a large part of the final value of the magnetic coupling constant. This permits to suggest a new variant of the Difference Dedicated Configuration Interaction (DDCI) method, presently one of the most accurate and reliable for the evaluation of magnetic effective interactions. This new method treats the bridging ligand orbitals mediating the interaction at the same level than the magnetic orbitals and preserves the high quality of the DDCI results while being much less computationally demanding. The numerical accuracy of the new approach is illustrated on various systems with one or two magnetic electrons per magnetic center. The fact that accurate results can be obtained using a rather reduced configuration interaction space opens the possibility to study more complex systems with many magnetic centers and/or many electrons per center.Comment: 7 pages, 4 figure