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1
Little, D. A. "Electron-N₂⁺ scattering and dynamics". Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1464074/.
Testo completoAbstract (sommario):
Molecular nitrogen, N₂, is the most abundant molecule in the terrestrial atmosphere. Its cation N₂⁺ is therefore prevalent in the earth's ionosphere as well as in nitrogen plasmas produced for reasons varying from lightning strikes to combustion. Any model which seeks to describe plasmas in air must contain a description of nitrogen ion chemistry. Despite this, there is a distinct paucity of data describing electron-N₂⁺ interactions and the resultant bound and quasi-bound electronic structure of N₂. The characterisation of these states is essential for describing dissociative recombination which is the main destroyer of molecular ions in a plasma. This thesis aims to alleviate this problem by performing extensive ab initio R-matrix calculations to create a comprehensive map of the highly-excited electronic structure of N₂ which can the be used to perform a dissociative recombination cross-section calculation. Potential energy curves were found by performing resonant and bound state calculations for all singlet and triplet molecular symmetries of N₂ up to l ≤ 4. The use of a dense grid meant that highly-excited electronic states could be found with an unprecedented level of detail. Many of the states were previously unknown. A new fitting method was developed for the characterisation of resonant states using the time-delay method. It was shown that whilst the R-matrix method is not competitive with conventional quantum chemistry techniques for low lying valence states, it is particularly appropriate for highly-excited states, such as Rydberg states. The data gained from these calculations was then used as an input for a multichannel quantum defect theory calculation of a dissociative recombination cross-section. A description is given of how to prepare the data from the R-matrix calculation for input into a multichannel quantum defect theory dissociative recombination cross-section calculation. Cross-sections were found for v=0-3 including three ionic cores. Whilst previous studies of dissociative recombination using R-matrix data required some empirical intervention, the cross-section found in this thesis is completely ab initio and is in good agreement with experiment.
2
Alvares, Raul. "Holographic descriptions of large N gauge dynamics". Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/347732/.
Testo completoAbstract (sommario):
We use the AdS/CFT correspondence to study different aspects of large N dynamics of gauge theories in the strongly coupled regime. We present three models designed to capture some of the physics present in QCD at low energies or QCD-type theories such as walking tecnhicolor. We use the D3/D7 system to study chiral symmetry breaking in two different contexts: In the first model we break chiral symmetry with an arbitrary running coupling which has a pion in its spectrum. We derive integral equations for the quark condensate and pion decay constant by matching our model to a low energy chiral lagrangian and discuss the implications for technicolor theories. In the second model we study the on set of chiral symmetry breaking at the edge of the conformal window in QCD in the Veneziano limit and show a BKT-type transition. Finally, in the context of AdS/QCD we extend the ”hard wall” model to include the tensor operator ¯φσ^(μν)ψ dual to a two form satisfying a self duality condition and study numerically the spectrum of vector mesons.
3
Hodgson, Matthew David. "Spin dynamics of n-doped gallium arsenide". Thesis, University of York, 2014. http://etheses.whiterose.ac.uk/6662/.
Testo completoAbstract (sommario):
The emerging technology of spintronics promises to revolutionise computing by allowing considerably more energy efficient computing than is currently possible. Gallium Arsenide is one candidate material for use in semiconductor spintronic devices and as such detailed study of the spintronic properties of Gallium Arsenide is required. In this thesis we develop a semiclassical approach to the simulation of the electron population in Gallium Arsenide. We then use this model to look at the properties of the electron system, in particular the time taken for the electron population to undergo spin depolarisation. Comparison of the results to experimental values for the spin depolarisation suggest that the currently well accepted approach is accurate for low to moderate n type doping densities, but for higher densities there is a significant departure from the experimentally obtained results. We explore a number of improvements to the usual model showing substantial improvement in the range of densities that can be accurately predicted. As Dilute Magnetic Semiconductors have been the topic of substantial research, we also apply the model to investigate the properties of an magnetic impurity in n doped Gallium Arsenide. We compare the results to the Langevin enhanced Landau Lifshitz Gilbert equation, which shows good agreement allowing us to predict an appropriate damping constant as a result of the magnetic interaction with the electron population. We also investigate the nature of the noise felt by the magnetic atom showing that the usual white noise approximation is of limited validity.
4
Wooten, E. Wrenn. "Structure, conformation and dynamics of N-linked oligosaccharides". Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253421.
Testo completo
5
Allison, Susan. "Intermolecular structure and dynamics of aqueous N-methylacetamide". Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/2427.
Testo completoAbstract (sommario):
The twin questions of how and why protein molecules fold into the specific topologies which enable them to fulfill their biological function have been the subject of continuous scientific investigation since the early twentieth century. Interactions between biological macromolecules and water are obviously crucial to both folding and function but attempts to gain understanding are impeded by the size and complexity of these systems. A useful approach is to consider much simpler model systems which capture some essential element of real biological systems but are experimentally and theoretically tractable. N-methylacetamide (NMA) is a minimal model of the peptide linkage which forms the backbone of protein molecules. Its behaviour in aqueous solution therefore captures the important competition between peptide - peptide and peptide - water hydrogen bonds which arises in protein hydration. In this thesis aqueous NMA solutions are studied across the full concentration range using classical molecular dynamics simulation. This gives access to the complete spectrum of behaviour between the two important limiting cases of dilute NMA in water and, conversely, dilute water in NMA. Water is now known to be an active player in biological interactions and the simple system studied here displays significant disruption of the structure and dynamics of pure water with the addition of only a small proportion of peptide groups. At dilute NMA concentrations water molecules continue to form system-size hydrogen bonded networks. Water molecules appear to optimise their local tetrahedral order by forming hydrogen bonds with a combination of NMA and water neighbours, rather than solely with members of their own species. NMA molecules hydrogen bond through the amide and carbonyl groups to form linear and branched chains in both the pure liquid and in the aqueous solutions. In the NMA rich region water molecules preferentially donate both hydrogens to chain-end or midchain carbonyl oxygens, forming bridges between NMA chains which resemble buried water configurations found in protein cavities. These bridge structures are thought to contribute to the observed slowing of the system dynamics at these concentrations. The investigation of dynamics by classical simulation is complemented by a quasielastic neutron scattering study of NMA in its liquid and aqueous phases.
6
Purchase, Steve. "N-body algorithms and applications to galactic dynamics". Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/12811.
Testo completoAbstract (sommario):
Typically galaxies contain 1011 stars and globular clusters contain 106 stars. In order to investigate the dynamical evolution of these systems one may perform numerical simulations (N-body simulations); which in turn are restricted to 103 to 107 particles depending on the required accuracy and adopted evolutionary model. For the N-body direct method the computational effort scales at least as O(N3), and thus the need for efficient and accurate evolutionary models and advances in hardware in apparent. A review of the N-body evolutionary models is presented and, with the advent of parallel super computers, the parallelisation of these evolutionary models is investigated. In particular, we discuss the parallelisation of a direct method N-body code; focusing upon a new parallelisation strategy, implementing the evolutionary model with a portable parallel language (High Performance Fortran), and reducing the communication costs between processors by a suitable implementation of the Hypersystolic algorithm. A dynamical system, such as a galaxy, may oscillate about a stable equilibrium if it is excited above that state. These modes of oscillation may persist long enough to have observable consequences, despite being weakly damped. The moods of oscillation are investigated with a range of evolutionary models. The simplest mode to detect and simulate is the "fundamental" mode or "l = 0" mode, which manifests itself as a radical oscillation of the entire system. To investigate this mode a King W0 = 1 theoretical model is adopted. The effect of adopting a softened gravitational potential to generate the forces between stars on the fundamental mode is investigated with a direct method N-body evolutionary model, and these results are compared to those which use an SCF (self-consistent field) type code. The presence of small and amplitude fundamental mode oscillations is detectable when the perturbation particle method is used, which would otherwise be undetectable for another N-body evolutionary model, due to particle noise. Furthermore, the source of heavy damping in direct method N-body simulations is found to be phase mixing. The experimental fundamental mode oscillations are found to match well with the theoretically predicted frequencies. A more complicated mode, the "sloshing" mode or "l = 1" is also studied. This mode manifests itself in the density centre shifting or sloshing about. To investigate this mode a King W0 = 5 model is adopted, and the results compared to an analytical predicted frequency.
7
Fabrizzi, Karina Paola. "Microbial ecology and C and N dynamics in Agroecosystems". Diss., Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/241.
Testo completo
8
Figueiredo, Nuno Miguel Ramos. "Dinâmica do azoto em campos alagados para produção de arroz em Salvaterra de Magos". Master's thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/4479.
Testo completo
9
Musanur, Abrar Siraj. "Development of an empirical force field and molecular dynamics simulation of N,N'-dialkylimidazolium ionic liquids". Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/53737.
Testo completoAbstract (sommario):
Thesis (MSc)--Stellenbosch University, 2004ENGLISH ABSTRACT: In an ongoing study an empirical force field that can correctly model N,N'- dialkylimidazolium halide ionic liquids, the Imidazolium Ionic Liquid Force Field - IILFF, was developed based on experimental data obtained from the Cambridge Structural Database (CSD) and data calculated using Gaussian98. Different conformations of the isolated cations were optimised at the Hartree-Fock level using the 6-31G(d) basis set. Structural, vibrational and partial atomic charge data of the lowest energy conformation of each cation were taken as observables during optimisation of the force field parameters. Initial parameters of the IILFF were taken from existing force fields and were optimised using the above mentioned data. The IILFF was used to minimise isolated cations as well as crystals. These results were successfully tested against isolated cations minimised using Gaussian98 and the experimental crystals. Finally, the melting process of the 1,3-dimethylimidazolium chloride crystal was studied using an NPT ensemble starting from an ordered crystal cell and increasing the simulation temperature beyond the experimental melting temperature. The IILFF was then used to calculate the potential energy of the system.
AFRIKAANSE OPSOMMING: In 'n voortgaande studie om 'n empiriese kragveld te bou wat N,N' -dialkielimidasoliumhalied ioniese vloeistowwe korrek kan modelleer is die Imidasolium Ioniese Vloeistof Kragveld (nVK) ontwikkel. Die kragveld is ontwikkel gebasseer op eksperimentele data verkry uit die Cambridge Strukturele Databasis (CSD) asook uit data vanaf Gaussian98 berekeninge. Verskillende konformasies van die geïsoleerde katione is geoptimiseer deur middel van Hartree Fock 6-31G(d) berekeninge. Strukturele data, asook vibrasies en gedeeltelike atoom ladings van die laagste energie konformasie van elke katioon is gebruik as waarneembare veranderlikes vir die bepaling van die optimale kragveld parameters. Beginwaardes vir die nVK is geneem uit bestaande kragvelde en geoptimiseer met behulp van bogenoemde data. Die IIVK is gebruik om geïsoleerde katione asook kristalle te minimiseer. Die resultate is suksesvol getoets teen geïsoleerde katione wat met behulp van Gaussian98 geminimiseer is en eksperimenteel bepaalde kristalle. Laastens is die smeltproses van die 1,3-dimetielimidasolium chloried kristal bestudeer met behulp van 'n NPT ensemble. Daar is begin by 'n geordende kristal en die simulasie temperatuur is verhoog tot meer as die eksperimentele smeltpunt. Die IIVK is dan gebruik om die potensiële energie van die sisteem te bepaal.
10
Andrews, Maximilian N. [Verfasser]. "Molecular dynamics on monomeric IAPP in solution / Maximilian N. Andrews". Dortmund : Universitätsbibliothek Technische Universität Dortmund, 2011. http://d-nb.info/1012572943/34.
Testo completo
11
Schwenker, Sören N. [Verfasser], e Reiner [Akademischer Betreuer] Lauterbach. "Genericity in Network Dynamics / Sören N. Schwenker ; Betreuer: Reiner Lauterbach". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/120330157X/34.
Testo completo
12
Solinas, Gavino <1984>. "N-Heterocyclic carbene complexes of rhodium: structures, dynamics and catalysis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5637/.
Testo completoAbstract (sommario):
A series of imidazolium salts of the type [BocNHCH2CH2ImR]X (Boc = t-Bu carbamates; Im = imidazole) (R = Me, X = I, 1a; R = Bn, X = Br, 1b; R = Trityl, X = Cl, 1c) and [BnImR’]X (R’ = Me, X = Br, 1d; R’ = Bn, X = Br, 1e; R’ = Trityl, X = Cl, 1g; R’ = tBu, X = Br, 1h) bearing increasingly bulky substituents were synthetized and characterized. Subsequently, these precursors were employed in the synthesis of silver(I)-N-heterocyclic (NHC) complexes as transmetallating reagents for the preparation of rhodium(I) complexes [RhX(NBD)(NHC)] (NHC = 1-(2-NHBoc-ethyl)-3-R-imidazolin-2-ylidene; X = Cl; R = Me, 4a; R = Bn, 4b; R = Trityl, 4c; X = I, R = Me, 5a; NHC = 1-Bn-3-R’-imidazolin-2-ylidene; X = Cl; R’ = Me, 4d, R’ = Bn, 4e, R’ = Trityl, 4g; R’ = tBu, 4h).
VT NMR studies of these complexes revealed a restricted rotation barriers about the metal-carbene bond. While the rotation barriers calculated for the complexes in which R = Me, Bn (4a,b,d,e and 5a) matched the experimental values, this was not true for the complexes 4c,g, bearing a trityl group for which the values are much smaller than the calculated ones. Energy barriers for 4c,g, derived from a line shape simulation, showed a strong dependence on the temperature while for 4h the rotational energy barrier is stopped at room temperature.
The catalytic activity of the new rhodium compounds was investigated in the hydrosilylation of terminal alkynes and in the addition of phenylboronic acid to benzaldehyde.
The imidazolium salts 1d,e were also employed in the synthesis of new iron(II)-NHC complexes.
Finally, during a six-months stay at the University of York a new ligand derived from Norharman was prepared and employed in palladium-mediated cross-coupling.
13
Ostle, Nicholas John. "Short-term N and C dynamics in a grassland soil". Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325766.
Testo completo
14
Resta, Nicoletta. "Molecular dynamics simulations of precursor derived Si-C-N ceramics". [S.l. : s.n.], 2005. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11878655.
Testo completo
15
Schwenker, Sören N. Verfasser], e Reiner [Akademischer Betreuer] [Lauterbach. "Genericity in Network Dynamics / Sören N. Schwenker ; Betreuer: Reiner Lauterbach". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/120330157X/34.
Testo completo
16
Modak, Viraj Prakash. "Surface Freezing in n-Alkanes: Experimental and Molecular Dynamics Studies". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1449013699.
Testo completo
17
Rose, Evan Noah. "Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions". Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334.
Testo completo
18
Cornforth, Daniel. "Synergism in N-player GamesAdaptive dynamics analysis of synergism in N-player games with basic payoff model". Thesis, Uppsala University, Department of Mathematics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-120032.
Testo completo
19
Shah, Sultana Sarvatara. "Decadal Responses in Soil N Dynamics at a Paired Watershed Experiment in Maine". Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/ShahSS2002.pdf.
Testo completo
20
Yi, Yong. "Fault tolerant N-DOF Gough-Stewart platforms kinematics, dynamics, and design /". Laramie, Wyo. : University of Wyoming, 2005. http://proquest.umi.com/pqdweb?did=888857891&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Testo completo
21
Buschhaus, Hannah Ariel Elizabeth. "¹⁵N discrimination as an indicator of nitrogen dynamics in Populus trichocarpa". Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31914.
Testo completoAbstract (sommario):
The current understanding of nitrogen stable isotope ratios in plant tissues
increasingly emphasizes the relationship between plant growth and nitrogen nutrition in
determining plant δ15N. This demand relative to supply is thought to influence the
plant's ability to discriminate against the heavier 15N. Discrimination (Dplant) is then
linked to the ratio of efflux to influx. Factors which influence either of these thus affect
Dplant- This thesis examines genotypic differences and physiological manipulations in
Populus trichocarpa to further test the proposed efflux/influx model for Dplant.
Substrate depletion experiments used ramets grown in hydroponic media
containing 200µM NH4
+ . Root pruning to reduce the plant's capacity to supply N
correspondingly increased the rate of NH4
+ uptake and decreased Dplant. Shoot pruning
and genotypic variation did not appear to play a significant role in determining Dplant as
assessed by this method. Substrate depletion experiments also allowed us to calculate
the root NH4
+ influx and efflux from the δ15N and the net uptake rate. This novel
application of the efflux/influx model for discrimination generated efflux and influx
values that corroborated existing radiolabelled 13N studies. The ability to accurately
calculate efflux and influx using stable isotope methods at natural abundance levels
provides a new, non-radioactive approach for further nutrient-uptake efficiency studies.
In steady-state experiments, ramets were grown at either ambient (400ppm) or
elevated (800ppm) atmospheric CO2 concentrations in either 200µM or 400µ.M NH4
+
hydroponic media. Within the treatments, Dplant corresponded to the relative growth rate
responses, signifying its dependence on physiological growth factors. Genotypic
differences in the discrimination values of P. trichocarpa provenances could be
manipulated by changing the supply/demand regimes. Plant tissue δ15N revealed an
unexpected but distinct foliar enrichment. These data prompted the development of a
revised efflux/influx model that accounts for translocation and subsequent assimilation of
NH4
+ in the leaves. This newest model now provides testable hypotheses for future NH4
+
translocation and assimilation studies.Forestry, Faculty of
Graduate
22
Johnson, Walter Sir Anthony Jr. "The Dynamics of Complex Surfaces in n-Dimensions Using Computer Graphics". NSUWorks, 1998. http://nsuworks.nova.edu/gscis_etd/610.
Testo completoAbstract (sommario):
Visualizing the dynamics of n-dimensional graphics is made possible by high speed, high quality computer graphics, and special techniques. One can visualize the dynamics of a complex surface in n-dimensions by differential manifold segmentation theory and special techniques that utilize surface subdivision algorithms. Techniques like collapsibility, decomposability, separation, and object projection allow a complex surface of multivariate composition to be defined in n-dimensions using computer graphics. These techniques look at n-dimensional manifolds as locally Euclidean in that each of its points has some sufficiently small neighborhood that looks like n-dimensional Euclidean space. These techniques recursively subdivide the complex surface into smaller parts until the projection of a part covers at most one pixel on the screen. The intensity of this pixel is set to the average intensity of the corresponding subarea in the parameter range. The part of the surface corresponding to this subrange is then considered to be displayed. The process stops when the whole surface is displayed.
Surfaces in four space exhibit properties that are prohibited in three space. As an example, non-orientable surfaces may be free of self-intersection in four space. The goal of this dissertation is to marry the classical Gaussian models, Euclidean n-space, and Markovian decision process to interactive computer graphics, and to provide a formal geometric foundation for the dynamics of Complex Surfaces in n-dimensions. These structures are used to describe the dimensional shape properties of objects. Various methods such as collapsing, and decomposing are used to make sense of the shapes of objects in a larger dimensional space than the familiar 3 dimensional world. This dissertation describes solutions to several problems associated with manipulating n-dimensional surfaces, and presents visualization techniques for multivariate systems.
23
He, Qiaolin. "Numerical study of solutions to Prandtl equations and N-S equations /". View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?MATH%202007%20HE.
Testo completo
24
Deshmukh, Mandar Vinayakrao. "NMR investigations on structure, dynamics and function of VAT-N and DOTATOC". [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972317864.
Testo completo
25
Sandberg, Malin. "Calcium dynamics and vesicle-release proteins in a prion-infected neuronal cell line /". Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-245-4/.
Testo completo
26
Iuliano, Jay R. "A Solution to the Circular Restricted N Body Problem in Planetary Systems". DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1612.
Testo completoAbstract (sommario):
This thesis is a brief look at a new solution to a problem that has been approached in many different ways in the past - the N body problem. By focusing on planetary systems, satellite dynamics can be modeled in a fashion similar to the Circular Restricted Three Body Problem (CR3BP) with the Circular Restricted N Body Problem (CRNBP). It was found that this new formulation of the dynamics can then utilize the tools created from all the research into the CR3BP to reassess the possibility of different complex trajectories in systems where there are more than just two large gravitational bodies affecting the dynamics, namely periodic and semi-periodic orbits, halo orbits, and low energy transfers It was also found that not only system dynamics, but models of the Jacobi constant could also be formulated similarly to the CR3BP. Validating the authenticity of these new sets of equations, the CRNBP dynamics are applied to a satellite in the Earth-Moon system and compared to a simulation of the CR3BP under identical circumstances. This test verified the dynamics of the CRNBP, showing that the two systems created almost identical results with relatively small deviations over time and with essentially identical path trends. In the Jovian system, it was found the mass ratio required to validated the assumptions required to integrate the equations of motion was around .1$\%$. Once the mass ratio grew past that limit, trajectories propagated with the CRNBP showed significant deviation from trajectories propagated with a higher fidelity model of Newtonian motion. The results from the derivation of the Jacobi constant are consistent with the 3 body system, but they are fairly standalone.
27
De, Mol Eva. "Structure, dynamics and interactions of the N-terminal domain of the androgen receptor". Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/147275.
Testo completoAbstract (sommario):
Prostate cancer (PCa) is the second most common cancer in men after lung cancer. Around 1.1 million men worldwide were diagnosed with PCa in 2012. PCa depends essentially on androgen stimulation for growth and cell survival. The androgen receptor (AR) is a nuclear hormone receptor that is activated by androgenic hormones and the protein through which the physiological effects of androgens are mediated. The AR is necessary for normal prostate development, growth and physiology but also has an important role in the progression of PCa. It is an essential regulator of tumor growth, spread and survival of cancer cells in castration-resistant prostate cancer (CRPC), a stage of the disease that has become resistant to the current therapies, and thus represents a potential therapeutic target.
The AR is composed of four domains: the N-terminal domain (NTD), which is thought to be intrinsically disordered, the DNA-binding domain (DBD) containing two zinc fingers, the hinge region and the ligand-binding domain (LBD) that binds both testosterone and dihydrotestosterone (DHT). The AR NTD plays a crucial role in the constitutive activity of the AR in tumors from patients with castration resistance. Currently, there is no effective treatment for CRPC. The transactivation by the NTD is independent on androgens and therefore circumvents the two current therapeutic strategies that directly target the androgen signaling axis and aim to prevent binding of androgens to the AR LBD. For this reason, we have characterized the conformational properties of the intrinsically disordered NTD, and in particular the activation function 1 (AF1) region, which contains transactivation units Tau-1 and Tau-5 important for AR transactivation. Due to the intrinsically disordered nature of these regions, nuclear magnetic resonance (NMR) spectroscopy has been used to assign the protein backbone of AF1* (AR 142-448) and to describe its secondary structure and dynamic characteristics. We found that, in vitro, AF1* has a low tendency to self-associate into a dimer. In addition, regions of AF1* with higher secondary structure propensity and less flexibility are also involved in dimerization of AF1* and coincide with regions previously identified to be functional (core Tau-1 and Tau-5).
In this thesis, the role of the AR NTD in transcriptional activation was also investigated at the molecular level. We have studied its interaction with RAP74, a subunit of the general transcription factor IIF (TFIIF). Interaction of the 433WHTLF437 motif of AR, located within the Tau-5 region, with RAP74 enables transactivation in CRPC cells. This novel mechanism could explain aberrant transactivation in cells of castration-resistant patients. Our data suggest that phosphorylation of residues N-terminal to the motif may be necessary for this interaction to occur.
Finally, we wished to understand how the AR NTD can be targeted by small molecules. We have studied the mechanism of interaction of EPI-001, a small molecule that has recently been described as a potent inhibitor of AR interacting with the NTD of AR and causing the regression of CRPC. The results showed a specific recognition mechanism by which EPI-001 interacts with a low populated conformation of Tau-5, a conformation that is possibly related to the dimeric state of AF1.El cáncer de próstata (PCa) es el segundo tipo de cáncer más común en hombres después del cáncer de pulmón. Alrededor de 1.1 millones de hombres en todo el mundo se les diagnosticó PCa durante el año 2012. El cáncer de próstata depende esencialmente de la estimulación de los andrógenos para el crecimiento y la supervivencia celular. El receptor androgénico (AR) es un receptor de hormonas nuclear que es activado por las hormonas andrógenas y la proteína mediante la cual los efectos fisiológicos de los andrógenos se producen. El AR es necesario para el desarrollo normal de la próstata, su crecimiento y fisiología pero también tiene un papel muy importante en la progresión del cáncer de próstata. Por ello, es un regulador esencial para el crecimiento, diseminación y supervivencia de células cancerígenas en tumores de cáncer de próstata resistente a la castración (CRPC), y por tanto, representa una potencial diana terapéutica. Desde el punto de vista estructural y functional, el AR está compuesto por cuatro dominios: el dominio N-terminal (NTD) que se piensa que es intrínsicamente desordenado, el dominio de unión a DNA (DBD) que contiene dos dedos de zinc, la región bisagra y el dominio de unión de ligando (LBD) que une tanto testosterona como dihidro-testosterona (DHT). El NTD de AR juega un papel crucial en la actividad constitutiva del AR en tumores de pacientes con resistencia a la castración, el cancer de prostata más avanzado. Actualmente no existe un tratamiento efectivo para CRPC. La transactivación del NTD es independiente de los andrógenos y por tanto evita las estrategias actuales de tratamiento dirigidos al eje de señalización de andrógenos. Por esta razón, se ha realizado la caracterización de las propiedades conformacionales del NTD intrínsecamente desordenado del AR y en particular del AF1, la región más potente para la activación del AR que contiene los regiones Tau-1 y Tau-5. Debido a la naturaleza intrínsecamente desordenada de estos regiones, se ha realizado la caracterización por resonancia magnética nuclear (NMR) midiendo los parámetros de NMR que permiten la asignación del esqueleto proteico de AF1 que permiten describir sus características dinámicas y de estructura secundaria. Hemos encontrado que, in vitro, AF1* (AR 142-448) posee una tendencia reducida pero notable a asociarse a sí misma formando un estado dimérico. Además, las regiones de AF1* con una tendencia mayor de estructura secundaria y menor flexibilidad también están involucradas en la dimerización de AF1* y coinciden con las regiones que fueron previamente identificadas como funcionales (regiones centrales de Tau-1 y Tau-5). En esa tesis también se ha investigado el papel del NTD del AR en la activación transcripcional a nivel molecular. Se ha estudiado su interacción con RAP74, una subunidad del factor de transcripción general IIF (TFIIF). La interacción del motivo 433WHTLF437 de AR, localizado en la región Tau-5, permite la transactivación por unión con RAP74 en células CRPC. Este novedoso mecanismo podría explicar la transactivación incorrecta en células de pacientes resistentes a la castración. Nuestros datos sugieren que la fosforilación de residuos en el lado N-terminal del motivo puede ser necesario para que se produzca esta interacción. Por último, se ha buscado una explicación de cómo los compuestos actuales que interaccionan con el AR se unen al NTD. Para ello hemos probado a estudiar el mecanismo de interacción de EPI-001, una molécula pequeña que recientemente se ha descrito como un potente inhibidor de AR que interacciona con el dominio NTD de AR y produce la regresión del proceso cancerígeno durante el estado más avanzado. Los resultados obtenidos muestran un mecanismo de reconocimiento específico por el cual EPI-001 interacciona con una conformación poco poblada de Tau-5, conformación que posiblemente esté relacionada con el estado dimérico de AF1.
28
Uriarte, Adolfo. "Sediment dynamics on the inner continental shelf of the Basque country (N. Spain)". Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285661.
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Brucka, Marta Anna. "N-Heterocyclic carbene complexes of silver, rhodium and iron: structures, dynamics and catalysis". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3873/.
Testo completoAbstract (sommario):
The research performed in the framework of this Master Thesis has been directly inspired by the recent work of an organometallic research group led by Professor Maria Cristina Cassani on a topic related to the structures, dynamics and catalytic activity of N-heterocyclic carbene-amide rhodium(I) complexes1. A series of [BocNHCH2CH2ImR]X (R = Me, X = I, 1a’; R = Bz, X = Br, 1b’; R = trityl, X = Cl, 1c’) amide-functionalized imidazolium salts bearing increasingly bulky N-alkyl substituents were synthetized and characterized. Subsequently, these organic precursors were employed in the synthesis of silver(I) complexes as intermediate compounds on a way to rhodium(I) complexes [Rh(NBD)X(NHC)] (NHC = 1-(2-NHBoc-ethyl)-3-R-imidazolin-2-ylidene; X = Cl, R = Me (3a’), R = Bz (3b’), R = trityl (3c’); X = I, R = Me (4a’)).
VT NMR studies of these complexes revealed a restricted rotation barriers about the metal-carbene bond. However, while the rotation barriers calculated for the complexes in which R = Me, Bz (3a’,b’ and 4a) matched the experimental values, this was not true in the trityl case 3c’, where the experimental value was very similar to that obtained for compound 3b’ and much smaller with respect to the calculated one. In addition, the energy barrier derived for 3c’ from line shape simulation showed a strong dependence on the temperature, while the barriers measured for 3a’,b’ did not show this effect. In view of these results and in order to establish the reasons for the previously found inconsistency between calculated and experimental thermodynamic data, the first objective of this master thesis was the preparation of a series of rhodium(I) complexes [Rh(NBD)X(NHC)] (NHC = 1-benzyl-3-R-imidazolin-2-ylidene; X = Cl, R = Me, Bz, trityl, tBu), containing the benzyl substituent as a chiral probe, followed by full characterization. The second objective of this work was to investigate the catalytic activity of the new rhodium compounds in the hydrosilylation of terminal alkynes for comparison purposes with the reported complexes.
Another purpose of this work was to employ the prepared N-heterocyclic ligands in the synthesis of iron(II)-NHC complexes.
30
Bognonkpe, Jean Pierre Irénée. "Effect of land use on soil N dynamics at watershed scale in Africa /". Bonn : Verein zur Förderung der Agrikulturchemie, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=013226903&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Medeiros, Nicholas J. "Computational Fluid Dynamics Simulations of Radial Dispersion in Low N Fixed Bed Reactors". Digital WPI, 2015. https://digitalcommons.wpi.edu/etd-theses/1306.
Testo completoAbstract (sommario):
Fixed bed reactors are widely applicable in a range of chemical process industries. Their ease of use and simplified operation make them an attractive and preferred option in reactor selection, however the geometric complexities within the bed as a result of the unstructured packing has made the design of such beds historically based on pseudo-homogenous models together with correlation-based transport parameters. Low tube-to-particle diameter ratio (N) beds, in particular, are selected for highly exothermic or endothermic reactions, such as in methane steam reforming or alkane dehydrogenation. Due to the large fraction of tube to catalyst particle contact in these low N beds, wall effects induce a mass transfer boundary layer at the wall, and in the case of thermal beds, a simultaneous resistance to heat transfer. Computational Fluid Dynamics (CFD) has been shown to be an accurate tool for experimental validation and predictive analysis of packed beds, and may be used to derive more accurate design parameters for fixed bed reactors. More specifically, the elucidation of dispersion, or the transport of reactant and product within the bed due to molecular diffusion and convective flow is of fundamental interest to the design of fixed beds. Computational Fluid Dynamics was used in this research to study solute dispersion in eight beds of varying N at a range of particle Reynolds numbers in the laminar flow regime. In the first stage of research, flow development was simulated in three-dimensional packed beds of spheres. Then, the reactor wall was sectioned to include a boundary condition of pure methane, from which the solute could laterally disperse into the bed. In the second stage, a two-dimensional representation of the bed was created using the commercial Finite Element Analysis software COMSOL Multiphysics. In these models, axial velocity profiles and radial methane concentration profiles taken from the 3-D models were supplied, and a fitting procedure by use of the Levenberg-Marquardt Least-Squares optimization algorithm was completed to fit radial dispersion coefficients and near-wall mass transfer coefficients to the CFD data. These optimization runs were conducted for all N at a number of bed depths in each case. Two sub-studies were conducted in which a constant velocity profile and a local velocity profile were supplied to the 2-D model, and the optimization re-run. It was found that this two parameter model did not fully account for various mechanisms of dispersion in the bed, namely the increasing rate of dispersion from the tube wall boundary layer up to the bed center, but only accounted for a diffusive-dispersion at the wall and a constant-rate, convective-dispersion everywhere else in the bed. Length dependency of dispersion coefficients were also noted, particularly in the developing sections of the bed. Nevertheless, the combined CFD and optimization procedure proved to be an accurate and time-efficient procedure for the derivation of dispersion coefficients, which may then lend themselves to the standard design of packed bed reactors.
32
Holman, Matthew Jon. "Symplectic maps for the N-body problem with applications to solar system dynamics". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/54394.
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Usui, Kota [Verfasser]. "Molecular dynamics simulations of aqueous Trimethylamine N-oxide solution and room temperature ionic liquids to reveal their microscopic dynamics / Kota Usui". Mainz : Universitätsbibliothek Mainz, 2018. http://d-nb.info/1153077876/34.
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34
Ahlstrom, Logan S., Ivan I. Vorontsov, Jun Shi e Osamu Miyashita. "Effect of the Crystal Environment on Side-Chain Conformational Dynamics in Cyanovirin-N Investigated through Crystal and Solution Molecular Dynamics Simulations". PUBLIC LIBRARY SCIENCE, 2017. http://hdl.handle.net/10150/622743.
Testo completoAbstract (sommario):
Side chains in protein crystal structures are essential for understanding biochemical processes such as catalysis and molecular recognition. However, crystal packing could influence side-chain conformation and dynamics, thus complicating functional interpretations of available experimental structures. Here we investigate the effect of crystal packing on side-chain conformational dynamics with crystal and solution molecular dynamics simulations using Cyanovirin-N as a model system. Side-chain ensembles for solvent-exposed residues obtained from simulation largely reflect the conformations observed in the X-ray structure. This agreement is most striking for crystal-contacting residues during crystal simulation. Given the high level of correspondence between our simulations and the X-ray data, we compare side-chain ensembles in solution and crystal simulations. We observe large decreases in conformational entropy in the crystal for several long, polar and contacting residues on the protein surface. Such cases agree well with the average loss in conformational entropy per residue upon protein folding and are accompanied by a change in side-chain conformation. This finding supports the application of surface engineering to facilitate crystallization. Our simulation-based approach demonstrated here with Cyanovirin-N establishes a framework for quantitatively comparing side-chain ensembles in solution and in the crystal across a larger set of proteins to elucidate the effect of the crystal environment on protein conformations.
35
Mizin, Kavita Lakshmi. "C and N Cycling Dynamics and Microbial Community Composition in High Tunnel Production Systems". UKnowledge, 2014. http://uknowledge.uky.edu/pss_etds/48.
Testo completoAbstract (sommario):
Across the United States, high tunnels are used as a means of season extension and control over climatic variability in fruit and vegetable production. However, high tunnel systems are an intensive form of agricultural production which may compromise soil and crop quality over time. This study examined the effects of the varying environmental conditions, created in two types of tunnel system, movable and stationary, on the flow of nitrogen from amendment to plant and impact on crop and soil quality parameters. The way nutrients cycled through these systems was different and the nutrient treatments had no consistent effects on soil nutrient parameters, although some microbial groups were affected by the nature of the nutrient amendment. No exposure to rainfall resulted in an accumulation of leachable NO3 in the stationary tunnels. Spinach yields were superior to those in a previous study at the same site however, leaf NO3 levels consistently exceeded EU maximum limits for fresh-sap leaf NO3. We cannot conclude from our data if there was a compromise of crop or soil quality in the high tunnel production systems and further investigation is necessary as high tunnels gain in popularity and make a larger footprint on the agricultural landscape.
36
Foster, Brett Lucas. "Modulation of resting human electroencephalographic dynamics by N-methyl-D-aspartate Antagonist Nitrous Oxide". Swinburne Research Bank, 2009. http://hdl.handle.net/1959.3/69924.
Testo completoAbstract (sommario):
Thesis (PhD) - Swinburne University of Technology, Brain Sciences Institute, 2009.A thesis submitted for the degree of Doctorate of Philosophy, Brain Sciences Institute, Swinburne University of Technology - 2009. Typescript. Bibliography: p. 153-183.
37
Feix, Felix. "Recombination dynamics in (In,Ga)N/GaN heterostructures: Influence of localization and crystal polarity". Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19134.
Testo completoAbstract (sommario):
(In,Ga)N/GaN-Leuchtdioden wurden vor mehr als 10 Jahren kommerzialisiert, dennoch ist das Verständnis über den Einfluss von Lokalisierung auf die Rekombinationsdynamik in den (In,Ga)N/GaN Quantengräben (QG) unvollständig. In dieser Arbeit nutzen wir die temperaturabhängige stationäre und zeitaufgelöste Spektroskopie der Photolumineszenz (PL), um diesen Einfluss in einer typischen Ga-polaren, planaren (In,Ga)N/GaN-QG-Struktur zu untersuchen. Zusätzlich dehnen wir unsere Studie auf N-polare, axiale (In,Ga)N/GaN Quantumscheiben, nichtpolare Kern/Mantel GaN/(In,Ga)N µ-Drähte und Ga-polare, submonolage InN/GaN Übergitter aus. Während wir einen einfach exponentiellen Abfall der PL-Intensität in den nichtpolaren QG beobachten (Hinweise auf die Rekombination von Exzitonen), folgen die PL-Transienten in polaren QG asymptotisch einem Potenzgesetz. Dieses Potenzgesetz weist auf eine Rekombination zwischen individuell lokalisierten, räumlich getrennten Elektronen und Löchern hin. Für einen solchen Zerfall kann keine eindeutige PL-Lebensdauer definiert werden, was die Schätzung der internen Quanteneffizienz und die Bestimmung einer Diffusionslänge erschwert. Um nützliche Rekombinationsparameter und Diffusivitäten für die polaren QG zu extrahieren, analysieren wir die PL-Transienten mit positionsabhängigen Diffusionsreaktionsgleichungen, die durch einen Monte-Carlo-Algorithmus effizient gelöst werden. Aus diesen Simulationen ergibt sich, dass das asymptotische Potenzgesetz auch bei effizienter nichtstrahlender Rekombination (z. B. in den Nanodrähten) erhalten bleibt. Zudem stellen wir fest, dass sich die InN/GaN Übergitter elektronisch wie konventionelle (In,Ga)N/GaN QG verhalten, aber mit starkem, thermisch aktiviertem nichtstrahlenden Kanal. Des Weiteren zeigen wir, dass das Verhältnis von Lokalisierungs- und Exzitonenbindungsenergie bestimmt, dass die Rekombination entweder durch das Tunneln von Elektronen und Löchern oder durch den Zerfall von Exzitonen dominiert wird.(In,Ga)N/GaN light-emitting diodes have been commercialized more than one decade ago. However, the knowledge about the influence of the localization on the recombination dynamics and on the diffusivity in the (In,Ga)N/GaN quantum wells (QWs) is still incomplete. In this thesis, we employ temperature-dependent steady-state and time-resolved photoluminescence (PL) spectroscopy to investigate the impact of localization on the recombination dynamics of a typical Ga-polar, planar (In,Ga)N/GaN QW structure. In addition, we extend our study to N-polar, axial (In,Ga)N/GaN quantum disks, nonpolar core/shell GaN/(In,Ga)N µ-rods, and Ga-polar, sub-monolayer InN/GaN superlattices. While we observe a single exponential decay of the PL intensity in the nonpolar QWs, indicating the recombination of excitons, the decay of the PL intensity in polar QWs asymptotically obeys a power law. This power law reveals that recombination occurs between individually localized, spatially separated electrons and holes. No unique PL lifetime can be defined for such a decay, which impedes the estimation of the internal quantum efficiency and the determination of a diffusion length. In order to extract useful recombination parameters and diffusivities for the polar QWs, we analyze the PL transients with position-dependent diffusion-reaction equations, efficiently solved by a Monte Carlo algorithm. From these simulations, we conclude that the power law asymptote is preserved despite efficient nonradiative recombination in the nanowires. Moreover, we find that the InN/GaN superlattices behave electronically as conventional (In,Ga)N/GaN QWs, but with a strong, thermally-activated nonradiative channel. Furthermore, we demonstrate that the ratio of localization and exciton binding energy, both of which are influenced by the magnitude of the internal electric fields in the QWs, determines the recombination mechanism to be either dominated by tunneling of electrons and holes or by the decay of excitons.
38
Redmond, Miranda. "The Role Of N-Terminal Acidic Inserts On The Dynamics Of The Tau Protein". ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/758.
Testo completoAbstract (sommario):
Alzheimer’s disease (AD), the most prevalent neurodegenerative disease, is characterized in part by disruptions in axonal transport. Axonal transport is a process by which motor proteins carry organelles and other cargo made in the neuronal cell body along microtubule tracks to distal regions of the axon. The microtubule-associated protein (MAP) Tau plays a crucial role in regulating axonal transport, and is implicated in the development of AD and other types of dementia collectively known as Tauopathies. Tau is a neuronal-specific MAP that has six isoforms alternatively spliced from a single gene. These isoforms differ by the presence of zero, one, or two N-terminal acidic inserts and three or four C-terminal microtubule binding repeats. Tau is also known to be an intrinsically disordered protein that undergoes a dynamic equilibrium between static and diffusive states on the microtubule surface. The dynamics of Tau are important in the regulation of motor protein mediated axonal transport in neurons. Isoform-specific differences in the dynamic behavior of Tau on the microtubule surface, however, are not yet fully understood. Diffusive Tau is thought to be stabilized by electrostatic interactions between its N- and C-termini while static Tau is proposed to be extended with its C-terminal repeats contacting the microtubule and the N-terminus projected away from the microtubule surface. Thus, the N-terminal inserts may help regulate Tau’s dynamic behavior and function during axonal transport. In this study, the dynamics of two different isoforms of Tau, both with three-microtubule binding repeats but a different number of N-terminal acidic inserts, were assessed using single molecule imaging techniques and novel data analysis methods.
39
Hirayama, Takayuki. "Low Energy Dynamics of Four Dimensional N=1 Supersymmetric Gauge Theories and Phenomenological Applications". 京都大学 (Kyoto University), 2000. http://hdl.handle.net/2433/181112.
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40
Ando, Kaori. "Dynamics of Soil Organic Matter under Slash-and-Burn Agriculture in a Semiarid Woodland of Zambia". Kyoto University, 2014. http://hdl.handle.net/2433/189369.
Testo completoAbstract (sommario):
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第18476号
農博第2076号
新制||農||1025(附属図書館)
学位論文||H26||N4860(農学部図書室)
31354
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 舟川 晋也, 教授 縄田 栄治, 教授 間藤 徹
学位規則第4条第1項該当
41
Rauch, Sebastian, Klaus-Jochen Eichhorn, Ulrich Oertel, Manfred Stamm, Dirk Kuckling e Petra Uhlmann. "Temperature responsive polymer brushes with clicked rhodamine B: synthesis, characterization and swelling dynamics studied by spectroscopic ellipsometry". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-139314.
Testo completoAbstract (sommario):
Here, we report on a new temperature responsive polymer brush system with a terminal “click” functionality. Bifunctionalized poly(N-isopropylacrylamide) (PNiPAAm) with distinct functional end groups was synthesized by atom transfer radical polymerization (ATRP) and grafted to a modified silicon substrate. The presence of the active terminal alkyne functionality is validated using an azide-modified rhodamine B (N3-RhB) via copper(I) catalyzed alkyne–azide cycloaddition (CuAAC). The optical properties and swelling dynamics of an N3-RhB modified PNiPAAm brush are analyzed in dry state and in situ by VIS-spectroscopic ellipsometry (SE). The best-fit results are obtained using a Gaussian oscillator model and are confirmed by UV/VIS-spectroscopy. We observed evidence of interactions between the aromatic residues of the dye and the PNiPAAm amide groups, which significantly affect the swelling behavior of the modified polymer brushDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
42
Berjanskii, Mark. "Structure and dynamics of the N-terminal J-domain of T antigens of murine polyomavirus". MU online access free, to others for fee Free online access, 2002. http://wwwlib.umi.com/cr/mo/preview?3052146.
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43
Rauch, Sebastian, Klaus-Jochen Eichhorn, Ulrich Oertel, Manfred Stamm, Dirk Kuckling e Petra Uhlmann. "Temperature responsive polymer brushes with clicked rhodamine B: synthesis, characterization and swelling dynamics studied by spectroscopic ellipsometry". Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27823.
Testo completoAbstract (sommario):
Here, we report on a new temperature responsive polymer brush system with a terminal “click” functionality. Bifunctionalized poly(N-isopropylacrylamide) (PNiPAAm) with distinct functional end groups was synthesized by atom transfer radical polymerization (ATRP) and grafted to a modified silicon substrate. The presence of the active terminal alkyne functionality is validated using an azide-modified rhodamine B (N3-RhB) via copper(I) catalyzed alkyne–azide cycloaddition (CuAAC). The optical properties and swelling dynamics of an N3-RhB modified PNiPAAm brush are analyzed in dry state and in situ by VIS-spectroscopic ellipsometry (SE). The best-fit results are obtained using a Gaussian oscillator model and are confirmed by UV/VIS-spectroscopy. We observed evidence of interactions between the aromatic residues of the dye and the PNiPAAm amide groups, which significantly affect the swelling behavior of the modified polymer brush.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
44
Dumon, Alexandre Samuel. "Molecular organization of n-cyanobiphenyl liquid crystals on a molybdenite surface". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5782/.
Testo completoAbstract (sommario):
The alignement and anchoring of liquid crystals on solid surfaces is a key problem for modern device technology that until now has been treated empirically, but that can now be tackled by atomistic computer simulations. Molecular dynamics (MD) simulations were used in this thesis work to study two films of 7 and 8 n-alkyl-4’cyanobiphenyl (7CB and 8CB) liquid crystals , with a thickness of 15 nm, confined between two (001) surfaces of MoS2 (molybdenite). The isotropic and nematic phases of both liquid crystals were simulated, and the resulting structures characterized structurally.
A new force field was designed to model the interactions between the liquid crystal (LC) molecules and the surface of molybdenite, while an accurate force field developed previously was used to model the 7CB and 8CB molecules.
The results show that the (001) molybdenite surface induces a planar orientation in both the liquid crystals. For the nematic phase of 8CB, one of the two solid/LC interfaces is composed of a first layer of molecules aligned parallel to the surface, followed by a second layer of molecules aligned perpendicular to the surface (also called, homeotropic). The effect of the surface appears to be local in nature as it is confined to the first 15 Angström of the LC film. Conversely, for the nematic phase of 7CB, a planar ordering is established into the LC film.
The LC molecules at the interface with the molybdenite appear to align preferentially their alkyl chains toward the solid substrate. The resulting tilt angle of molecules was found to be in good agreement with experimental measurements available in literature.
Despite the fact that the MD simulations spanned a time range of more than 100 ns, the nematic phases of both 7CB and 8CB were found not to be completely formed. In order to confirm the findings presented in this thesis, we propose to extend the current study.
45
Ramadugu, Sai Kumar. "Carbohydrate-protein interactions: structure, dynamics and free energy calculations". Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/1731.
Testo completoAbstract (sommario):
The current thesis presents work on the structure and dynamics of oligosaccharides and polysaccharides as well as the free energetics of carbohydrate-protein interactions. By applying various computational tools such as molecular dynamics simulation, our in-house fast sugar structure prediction software, replica exchange molecular dynamics, homology modeling, umbrella sampling, steered molecular dynamics as well as the thermodynamic integration formalism, we have been able to study the role of water on the surface of homopolysaccharides as well as complex oligosachharides, we have been able to produce a prediction of the bound structure of triantennary oligosaccride on the asialoglycoprotein receptor, we have been able to estimate the free energy of binding of ManΑ1→2Man to the HIV-1 inactivating protein, Cyanovirin-N as well as the relative binding free energies of mutants of Cyanovirin-N to the same ligand.
46
Blatter, Anja Bettina [Verfasser], e N. [Akademischer Betreuer] Bäuerle. "Optimal control and dependence modeling of portfolios with Lévy dynamics / Anja Bettina Blatter. Betreuer: N. Bäuerle". Karlsruhe : KIT-Bibliothek, 2009. http://d-nb.info/1013695992/34.
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Jöckle, Philipp [Verfasser], e A. N. [Akademischer Betreuer] Unterreiner. "Visible Light-Triggered Precursor Molecules: Relating Reactivity and Ultrafast Dynamics / Philipp Jöckle ; Betreuer: A.-N. Unterreiner". Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/1200471350/34.
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48
Simon, Jean-Marc, e Jean-Pierre Bellat. "Adsorption kinetics of mixtures of n-hexane and 2-methylpentane on silicalite by nonequilibrium molecular dynamics". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-193628.
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Johnson, Andrew David. "Dynamics of hydrogen absorption into the N(111) bulk : spectroscopic identification and chemistry of subsurface hydrogen". Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/109625.
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Simon, Jean-Marc, e Jean-Pierre Bellat. "Adsorption kinetics of mixtures of n-hexane and 2-methylpentane on silicalite by nonequilibrium molecular dynamics". Diffusion fundamentals 6 (2007) 36, S. 1-2, 2007. https://ul.qucosa.de/id/qucosa%3A14213.
Testo completo