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Dissertations / Theses on the topic 'Elastic; Inelastic'
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1
Kula, Mathias. "Elastic and Inelastic Electron Tunneling in Molecular Devices." Licentiate thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3958.
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Greenwood, Jason B. "Elastic and inelastic scattering of electrons from ions." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282155.
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Moreno, Carrascosa Andrés. "Theory of elastic and inelastic X-ray scattering." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31442.
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X-rays have been widely exploited to unravel the structure of matter since their discovery in 1895. Nowadays, with the emergence of new X-ray sources with higher intensity and very short pulse duration, notably X-ray Free Electron Lasers, the number of experiments that may be considered in the X-ray regime has increased dramatically, making the characterization of gas phase atoms and molecules in space and time possible. This thesis explores in the theoretical analysis and calculation of X-ray scattering atoms and molecules, far beyond the independent atom model. Amethod to calculate inelastic X-ray scattering from atoms and molecules is presented. The method utilizes electronic wavefunctions calculated using ab-initio electronic structure methods. Wavefunctions expressed in Gaussian type orbitals allow for efficient calculations based on analytical Fourier transforms of the electron density and overlap integrals. The method is validated by extensive calculations of inelastic cross-sections in H, He+, He, Ne, C, Na and N2. The calculated cross-sections are compared to cross-sections from inelastic X-ray scattering experiments, electron energy-loss spectroscopy, and theoretical reference values. We then begin to account for the effect of nuclear motion, in the first instance by predicting elastic X-ray scattering from state-selected molecules. We find strong signatures corresponding to the specific vibrational and rotational state of (polyatomic) molecules. The ultimate goal of this thesis is to study atomic and molecular wavepackets using time-resolved X-ray scattering. We present a theoretical framework based on quantum electrodynamics and explore various elastic and inelastic limits of the scattering expressions. We then explore X-ray scattering from electronic wavepackets, following on from work by other groups, and finally examine the time-resolved X-ray scattering from non-adiabatic electronic-nuclear wavepackets in the H2 molecule, demonstrating the importance of accounting for the inelastic effects.
4
Fty, Peter Elliot. "A theoretical study of resonances observed in '1'2C+'1'2C scattering." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390508.
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Lensky, Vadim. "Elastic and inelastic pion reactions on few nucleon systems." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=984838856.
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Ray, Tathagata. "Modeling of multi-dimensional inelastic and nonlinear elastic structural systems." Thesis, State University of New York at Buffalo, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3598742.
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<p> This dissertation is about a consistent smooth <i><b>modeling of multidimensional nonlinear elastic and inelastic structural systems.</b></i> </p><p> First, the <i><b>One-Dimensional Smooth Hysteretic Model</b></i> <b> (1D SHM)</b> and its various features, such as, a) basic hysteresis, b) kinematic hardening, c) strength and stiffness degradations, d) pinching, e) gap-closing, and f) asymmetric yielding are reformulated in <i><b> time independent incremental form.</b></i> The areas, in which the SHM needed further advancements, such as: a) nonlinear post-elastic spring, b) modified Gaussian pinching, c) alternative pinching model using tangent function, d) variable gap length, e) degradation of post-elastic stiffness, and f) embedding variation of strength in the expression of tangent stiffness are developed. With these additional features 1D SHM can emulate some of the complex nonlinear behaviors of structural members adequately. </p><p> Further, a modified version of 1D SHM is re-formulated to simulate the <i><b> nonlinear elastic</b></i> behavior. Spectra for <i><b>nonlinear elastic and inelastic</b></i> structures are developed, using the modified SHM and the parent SHM, respectively. These spectra are generated for various strength reductions, and inherent and supplemental damping. The difference between the two types of damping is explained both theoretically and numerically. The nonlinear elastic formulation can be applied to evaluate and design of "weakened structures" structures equipped with novel negative stiffness devices (NSD). </p><p> The final part of the dissertation expands the multi dimensional plasticity model to 3D space frame elements that include strength and stiffness deteriorations, large deformations and rotations, using flexibility based corotational formulation and incremental multi-axial theory of plasticity. </p><p> In the first phase of the above research, <b>a new corotational formulation, based on flexibility modeling of space frames with large deformations and rotations, expanding prior developments,</b> is done. The new expansion incorporates a) coupled axial, flexural and shear deformations, b) rigid rotations of chords with respect to the stationary global reference frame, c) formulation of geometric stiffness matrix by taking variations of the force equilibrium equation, d) re-derivation of the entire formulation in time-independent incremental form, and e) inclusion of improved numerical techniques within the corotational system. Using the modified formulation, several elastic large deformation-rotations and buckling problems of space frames, previously solved by various researchers through stiffness based approach, can be analyzed. </p><p> The second phase of the forgoing research involved: <b>a) coupling between 3D geometric nonlinearity with large deformation and rotation, and multi-axial theory of plasticity, and b) incorporation of strength and stiffness deteriorations in the model.</b> The resulting model combines the classical <i> axial load-biaxial moment</i> (P-M-M) interaction, coupled with geometric nonlinearity. Standard <i>Newton method</i> of iteration scheme is employed to generate the <b>three dimensional hysteresis loops</b> for stress resultants and deformational variables. For cases, where the structure experiences plastic buckling (i.e. when the determinant of the global tangent stiffness matrix approaches zero due to coupled material and geometric nonlinearity), the arc length method, with modifications done for cyclic loading analysis, is used to track the cyclic buckling and post-buckling equilibrium paths. Finally, hysteretic energy based strength degradation and deformational ductility based stiffness degradation are incorporated in the yield surface based on P-M-M interaction and the elastic stiffness matrix, respectively. Several <b> benchmark examples</b> for 3D beams are presented to illustrate the above developments. (Abstract shortened by UMI.)</p>
7
Ma, Ming. "Elastic and inelastic analysis of panel collapse by stiffener buckling." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-170150/.
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Kuninaka, Hiroto. "Theoretical and Numerical Studies of Inelastic Impacts of Elastic Materials." Kyoto University, 2004. http://hdl.handle.net/2433/147714.
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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(人間・環境学)<br>甲第10955号<br>人博第242号<br>15||197(吉田南総合図書館)<br>新制||人||60(附属図書館)<br>UT51-2004-G802<br>京都大学大学院人間・環境学研究科人間・環境学専攻<br>(主査)教授 冨田 博之, 教授 宮本 嘉久, 助教授 早川 尚男, 助教授 阪上 雅昭<br>学位規則第4条第1項該当
9
Yoo, Rae Hak. "Elastic and inelastic responses of columns after sudden loss of bracing." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-162306/.
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Jasim, Mahdi H. "Elastic and inelastic scattering of fast neutrons in fusion reactor materials." Thesis, Aston University, 1985. http://publications.aston.ac.uk/10594/.
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In this 'WOrk , the angular distributions for eTastic ·and. iBela:~ii.tc scattering of fast neutrons in fusion .reactor materials l'ia:~te<~ studied Lithium and wad material are- -likely' ';;i;"be ~n CCIUfX)nents of fusion reactor wall con£igut'atiQn qesign .. .We m=asurements were perfonnedusing an associated part;icl~,~~-; flight technique • The 14 and 14 .. 44 Mev neutrons were p~u¢ed 1;Jy. ;tli.$ T(d,n} 4He reaction with deut.erons Peinga<;eelerated in a 150kev SAME..S type Jaccelerator at ASTON and in.the 3. Mev ~~ at the Jo.i;nt Radiation. Centre I Birmingham I. res~vely; .. The q,ss.Qcj.a.~~ alpha-particles and fast. neu.tJ;qri$ Were; deteeteCl!. ~;¥.'~l :o£'·~·:p~a;§~¢; scintillator rrpunted on. a fa:st£GC1.Jsed photoroillmplj;er<t~,.;·1n~j samples used were e~ended flatpl.a:tesj of tb.icJ<n~ss~s upt.o'0~9-~... . free-path for Uthium and 1.562 Irean-fre~path fC)r ~~ • . The differential elastic seatteringcrQSs-.seefiQns· 'Wer~'tteas~ea,'for 14 Mev neutron.s for vgriousthicJmesses Qf Lithiunl ~. ~d inthel angular range from zero to; 90/ •• ]naooit.iorf , tile; angul;at':',: distributions of elastically scattered 14,.44 Mev .neutrons;·· £liein . Lithium. samples were studied in thes~' angular range: •. Inelastic scattering to the 4.63 Mev state in ~Lian<l the state I and 4 •. 1 Mev state I' in 2013Bb hay;e:been :meas~ed.T1ie,resria:Jts: . are ca:npared to ENDF!l3-IV data files and to previous fuea$ur~ts .,:' For the Lead samples the differential neutron sca,~terin9:¢:'Q$.$""'·: sections for discrete 3 Mev ranges and tile' angplardistributiQhS~lie' measured The increase in effective cross-section due tQlIJ\llt;;£plll~; . scattering effects I as the sample thic:1mess:, increas.ed:waS 'foun(~Ft.Q; . be predicted by tile empirical .relation cY =Q;:exp.(K-x}. A g96d,:E~;j;.t:Q, the eJ{perirrental data was obtained using the universa.1C0~t.;inl:.,"~i~'~ The differential elastics¢q;ttering "'crQss,,,:,,,section da:£a for,~,. . samples Qf Lithium and Lead were, a,nal:yzed in terms of' optical' nPii~it, .' calculations using the. conputer code. RARCMPPararnetersear~, procedures produced good fits' to the· cross-sections • . . For the case of thick samples of Lithium and Lead , th¢rrea:s.~ed:· angular distributions of :the scattered neutrons we.re'~p3Iesi tQ,tl1,$ .. predictions of the continuous slowing down model.
11
Betz, Andreas. "Elastic and inelastic scattering in graphene studied by microwave transport and noise." Paris 6, 2012. http://www.theses.fr/2012PA066354.
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Cette thèse traite la diffusion élastique et inélastique dans le graphène, étudiée par dynamique des porteurs et par le bruit en GHz. D'abord, nous étudions les propriétés haute fréquences des FETs graphène sur des substrats différents. D'intérêt particulier est la fréquence de transit, définissant les capacités d'amplification de courant, et la transconductance: la sensibilité de grille. Valeurs élevées sont obtenues pour les deux paramètres dans les mesures GHz. Ils restent important même dans des dispositifs miniaturisés. Nous introduisons des condensateurs de graphene à effet de champ comme sonde de mécanismes de diffusion élastique. Nous pouvons acceder directement à la constante de diffusion et sa dépendance en densité de porteurs. Ce dernier définit le type de disordre présent. Nos nouvelles expériences GHz révèlent un temps de transport constant. Ceci est en désaccord avec les théories classiques, mais prend en charge le mécanisme de désordre de masse. Par ailleurs, nous étudions la diffusion inélastique des porteurs par les phonons acoustiques dans le graphène, qui est une première realisation dans une géométrie 2D. La thermométrie de bruit cryogénique large bande est utilisée pour détecter le courant de bruit à partir de lequelle nous trouvons la température électronique Te en fonction de la puissance P. Au bias élevée, nous trouvons P~Sigma*Te^4, comme le prédit la théorie. C'est le signe révélateur de refroidissement par phonons 2D. Par analyise plus creusee, nous trouvons les valeurs exactes de la constante de couplage electron-phonon acoustique, Sigma. Nos mesures indiquent l'importantance du desordre dans la relaxation de l'énergie électron-phonon<br>This thesis discusses the elastic and inelastic scattering in monolayer graphene, investigated by means of microwave carrier dynamics and noise. First we study the high frequency properties of graphene FETs on different substrates. Particular interest lies e. G. In the transit frequency, defining the transistor's current amplification capabilities, and the transconductance representing its gate sensitivity. High values are obtained for both parameters in GHz measurements. We find in particular that they remain substantial even in miniaturised devices. We introduce top-gated graphene field-effect capacitors as a probe of elastic scattering mechanisms in graphene. We are able to directly access the diffusion constant and its dependence on carrier density. The latter defines the type of scattering present in the graphene. Our novel GHz experiments reveal a constant transport scattering time. This is in disagreement with conventional theories, but supports the random Dirac mass disorder mechanism. Furthermore, we study inelastic scattering of charge carriers by acoustic phonons in graphene which is a first realisation in a 2D geometry. Broadband cryogenic noise thermometry is used to detect the current noise from which we extract the average electron temperature Te as a function of Joule power P. At high bias we find P~Sigma*Te^4 as predicted by theory. This is the tell-tale sign of 2D phonon cooling. From a heat equation analysis of data in a broad bias range, we extract accurate values of the electron-acoustic phonon coupling constant Sigma. Our measurements point to an important effect of lattice disorder in the electron-phonon energy relaxation
12
Jandke, Jasmin Maria [Verfasser]. "Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors / Jasmin Maria Jandke." Karlsruhe : KIT Scientific Publishing, 2019. http://d-nb.info/1184402590/34.
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Jandke, Jasmin [Verfasser]. "Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors / Jasmin Maria Jandke." Karlsruhe : KIT Scientific Publishing, 2019. http://d-nb.info/1184402590/34.
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Maleck, Andrea Eden. "Second-order inelastic and modified elastic analysis and design evaluation of planar steel frames." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/19610.
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Berggren, Peter. "Elastic and inelastic scattering effects in conductance measurements at the nanoscale : A theoretical treatise." Doctoral thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-261609.
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Elastic and inelastic interactions are studied in tunnel junctions of a superconducting nanoelectromechanical setup and in response to resent experimental superconducting scanning tunneling microscope findings on a paramagnetic molecule. In addition, the electron density of molecular graphene is modeled by a scattering theory approach in very good agreement with experiment. All studies where conducted through the use of model Hamiltonians and a Green function formalism. The nanoelectromechanical system comprise two fixed superconducting leads in-between which a cantilever suspended superconducting island oscillates in an asymmetric fashion with respect to both fixed leads. The Josephson current is found to modulate the island motion which in turn affects the current, such that parameter regions of periodic, quasi periodic and chaotic behavior arise. Our modeled STM setup reproduces the experimentally obtained spin excitations of the paramagnetic molecule and we show a probable cause for the increased uniaxial anisotropy observed when closing the gap distance of tip and substrate. A wider parameter space is also investigated including effects of external magnetic fields, temperature and transverse anisotropy. Molecular graphene turns out to be well described by our adopted scattering theory, producing results that are in good agreement with experiment. Several point like scattering centers are therefore well suited to describe a continuously decaying potential and effects of impurities are easily calculated.
16
Watts, Elizabeth Kathleen. "Quantum state-resolved studies of elastic and inelastic scattering of H₂ from Cu and Pd /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Metin, Asli. "Inelastic Deformation Demands On Moment-resisting Frame Structures." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607423/index.pdf.
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Interstory drift ratio is an important parameter for the determination of the structural performance under strong ground motions. A probabilistic procedure is proposed in this study to estimate the inelastic maximum interstory drift ratio. The procedure considers the uncertainties associated with the strong ground motions and structural behavior. Elastic and inelastic response history analyses of reinforced-concrete, moment-resisting frames are used together with a near-fault strong ground motion data set to derive the probabilistic procedure. The elastic and inelastic response history analysis results are evaluated in a statistical manner to present the probabilistic approach proposed here. The method presented basically makes use of the fundamental mode properties of the frame systems and modifies the elastic maximum interstory drift ratio by a modifying factor that is determined from the idealized lateral strength capacity (pushover analysis) of the structure. As a part of this thesis, the performance of recently improved nonlinear static procedures that are used in estimating the deformation demands on structural systems are also evaluated using the single- and multi-degree-of-freedom response history analyses results obtained during the conduct of the study.
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Ozen, Onder Garip. "Comparison Of Elastic And Inelastic Behavior Of Historic Masonry Structures At The Low Load Levels." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12608248/index.pdf.
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Conventional methods used in the structural analysis are usually insufficient for the analysis of historical structures because of the complex geometry and heterogeneous material properties of the structure. Today&rsquo<br>s computing facilities
and methods make FEM the most suitable analysis method for complex structural geometry and heterogeneous material properties. Even the shrinkage, creep of the
material can be considered in the analysis. Because of this reason Finite Element Method (FEM) is used to analyze such structures. FEM converts the structure into finite number of elements with specific degree of freedoms and analyses the
structure by using matrix algebra. However, advanced FEM methods considering the inelastic and time dependent behavior of material is a very complex and difficult task and consumes considerable time. Because of this reason, to analyze every historical structure is not feasible by applying advanced inelastic FEM, whereas elastic FEM analysis at low load levels is very helpful in understanding the behavior of the structure.The analysis of a masonry gate in the historical city, Hasankeyf is the case study of this thesis. Different common software are used in FEM to compare the
stresses, deformations, modal shapes etc. of the same structure. Besides the inelastic behavior of the structure is investigated and compared with the elastic behavior of the structure. The study is intended to show that at the low load levels elastic FEM analysis is sufficient to understand the response of the structure and is preferable to the inelastic FEM analysis unless a very complex analysis is required
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Resler, David Alan. "Structure of 14C via Elastic and Inelastic Neutron Scattering from 13C: Measurement, R-matrix Analysis, and Shell Model Calculations." Ohio University / OhioLINK, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1472558171.
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Lee, Zhongbo [Verfasser]. "Incorporate elastic and inelastic scattering into image calculation for low-voltage transmission electron microscope / Zhongbo Lee." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2014. http://d-nb.info/1049987411/34.
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Jandke, Jasmin Maria [Verfasser], and W. [Akademischer Betreuer] Wulfhekel. "Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors / Jasmin Maria Jandke ; Betreuer: W. Wulfhekel." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1148551247/34.
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Deutschmann, Tim. "On Modeling Elastic and Inelastic Polarized Radiation Transport in the Earth Atmosphere with Monte Carlo Methods." Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-161475.
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The three dimensional Monte Carlo radiation transport model McArtim is extended
to account for the simulation of the propagation of polarized radiation and the inelastic
rotational Raman scattering which is the cause of the so called Ring effect.
From the achieved and now sufficient precision of the calculated Ring effect new opportunities
in optical absorption spectroscopy arise. In the calculation the method of
importance sampling (IS) is applied. Thereby one obtains from an ensemble of
Monte Carlo photon trajectories an intensity accounting for the elastic
aerosol particle-, Cabannes- and the inelastic rotational Raman scattering (RRS) and
simultaneously an intensity, for which Rayleigh scattering is treated as an elastic scattering
process. By combining both intensities one obtains the so called filling-in (FI,
which quantifies the filling-in of Fraunhofer lines) as a measure for the strength of
the Ring effect with the same relative precision as the intensities.
The validation of the polarized radiometric quantities and the Ring effect is made by comparison
with partially published results of other radiation transport models.
Furthermore the concept of discretisation of the optical domain into grid cells is extended
by making grid cells arbitrarily joining into so called clusters, i.e. grid cell aggregates.
Therewith the program is able to calculate derivatives of radiometrically or spectroscopically
accessible quantities, namely the intensities at certain locations in the atmospheric radiation field
and the light path integrals of trace gas concentrations associated thereto, i.e. the product of the DOAS (differential optical absorption spectroscopy) method, with respect to optical
properties of aerosols and gases in connected spatial regions.
The first and second order derivatives are validated through so called self-consistency tests.
These derivatives allow the inversion of three dimensional tracegas and aerosol concentration
profiles and pave the way down to 3D optical scattered light tomography. If such tomographic inversion scheme is based solely on spectral intensitites the available second order derivatives allows the consideration of the curvature in the cost function and therefore allows implementation
of efficient optimisation algorithms.
The influence of the instrument function on the spectra is analysed in order
to mathematically assess the potential of DOAS to a sufficient degree. It turns out
that the detailed knowledge of the instrument function is required for an advanced
spectral analysis.
Concludingly the mathematical separability of narrow band signatures of absorption and
the Ring effect from the relatively broad band influence of the elastic scattering processes
on the spectra is demonstrated which corresponds exactly to the DOAS principle. In that procedure
the differential signal is obtained by approximately 4 orders of magnitude faster
then by the separate modelling with and without narrow band structures.
Thereby the fusion of the separated steps DOAS spectral analysis and subsequent
radiation transport modeling becomes computationally feasible.
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Jandke, Jasmin [Verfasser], and W. [Akademischer Betreuer] Wulfhekel. "Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors / Jasmin Maria Jandke ; Betreuer: W. Wulfhekel." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1148551247/34.
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Hepting, Matthias [Verfasser], and Bernhard [Akademischer Betreuer] Keimer. "Ordering phenomena in nickelate heterostructures studied by elastic and inelastic photon scattering / Matthias Hepting ; Betreuer: Bernhard Keimer." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1123572461/34.
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Abel, Eric T. "Elastic and inelastic X-ray scattering studies of the low dimensional spin-1/2 quantum magnet TiOCl." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/45414.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2007.<br>MIT Science Library Copy: printed in pages.<br>Also issued printed in pages.<br>Includes bibliographical references (leaves 177-183).<br>The ground state for a one dimensional spin 1/2 Heisenberg chain coupled to phonons is a dimerized singlet state known as a "spin-Peierls" state. Currently, the spin-Peierls state is realized in only a handful of known compounds. Even after decades of scientific scrutiny, there is an absence of direct measurements of the lattice dynamics associated with the transition. In this work we present an extensive study of a new one dimensional spin-Peierls compound, TiOC1. The magnetic susceptibility strongly indicates a singlet ground state, with two apparent anomalies observed at T, ,=65 K and Tc2=92 K. Specific heat measurements have been performed and the associated entropy changes quantified. The 65 K transition exhibits a thermal hysteresis, indicative of a first order phase transition. A detailed synchrotron x-ray study of the structure reveals the appearance of superlattice peaks at ( ... ) below 65 K. The intensity of the peaks drop very sharply above T, and a thermal hysteresis is observed which is consistent with a first order phase transition at 65 K. We find that the temperature region between 65 K and 92 K is characterized by a novel incommensurate state. The incommensurate reflections appear at ( ... ). The temperature dependence of the intensity of the incommensurate peaks shows a more gradual onset, with no thermal hysteresis. The incommensurate wavevectors change continuously as a function of temperature and can be analyzed in terms of a mean field theory of phase shifted discommensurations. The observation of the third harmonics enabled a careful characterization of the underlying real space superstructure. We find that all of the observed scattering can be reproduced by a one dimensional long-wavelength modulation of a locally dimerized structure.<br>(cont.) The lattice dynamics above T 2were characterized by inelastic x-ray scattering measurements. By analyzing the data in terms of a damped harmonic oscillator response function, we are able to extract the phonon frequency and damping for all observed modes. We find a longitudinal acoustic phonon branch whose damping increases for q-vectors close to the zone boundary, which is also associated with an apparent softening of the frequency. Both of these anharmonic effects increase as T2 is approached, and are consistent with a soft phonon description of the dimerization. The anomalous phonon damping and softening are then analyzed using the Cross & Fisher theory of spin-phonon interaction leading to a spin-Peierls transition. We find that the theory succeeds in describing the data for a narrow temperature range about Tc2, for q near the zone boundary. It does not account for the anharmonic effects observed at high temperatures. Our experimental analysis represents one of the most in-depth quantitative tests of the Cross & Fisher theory to date. In addition our results suggest that TiOCl is a particularly ideal realization of a spin-Peierls system.<br>by Eric T. Abel.<br>Ph.D.
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Suwonjandee, Narumon. "The measurement of the quasi-elastic neutrino-nucleon scattering cross section at the tevatron." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1078428464.
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Deutschmann, Tim [Verfasser], Manfred [Akademischer Betreuer] Wendisch, Manfred [Gutachter] Wendisch, and Detlev [Gutachter] Reiter. "On Modeling Elastic and Inelastic Polarized Radiation Transport in the Earth Atmosphere with Monte Carlo Methods : On Modeling Elastic and Inelastic PolarizedRadiation Transport in the Earth Atmosphere withMonte Carlo Methods / Tim Deutschmann ; Gutachter: Manfred Wendisch, Detlev Reiter ; Betreuer: Manfred Wendisch." Leipzig : Universitätsbibliothek Leipzig, 2015. http://d-nb.info/1239423934/34.
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Shirazi, Nejad Ramin [Verfasser], and C. [Akademischer Betreuer] Wieners. "A parallel elastic and inelastic heterogeneous multiscale method for rate-independent materials / Ramin Shirazi Nejad ; Betreuer: C. Wieners." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1140785958/34.
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Freitas, André de Sousa. "Estudo da reação 10B+120Sn em energias em torno da barreira Coulombiana utilizando diferentes técnicas experimentais." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-07062018-183705/.
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A reação 10B+120Sn foi medida no Laboratório Aberto de Física Nuclear (LAFN) do Instituto de Física da Universidade de São Paulo, em energias próximas a barreira coulombiana (VB = 35 MeV). Distribuições angulares de espalhamento elástico e inelástico foram obtidas, e o canal de transferência de um nêutron do alvo para o projétil foi identificado. Além disso, foram feitas medidas utilizando a técnica de detecção em coincidências gamma-partícula no espectrômetro Saci-Perere (Sistema Ancilar de Cintiladores e Pequeno Espectrômetro de Radiação Eletromagnética com Rejeição de Espalhamento). Tais medidas possibilitaram a identificação do processo de fusão completa, a partir da detecção dos raios-gamma provenientes do núcleo composto 127Cs, formado pela absorção de toda carga do projétil pelo alvo, seguido da evaporação de nêutrons. Eventos relacionados ao processo de fusão incompleta, originados da quebra do projétil 10B, também foram identificados. Uma descrição teórica dos principais resultados experimentais foi realizada dentro do formalismo de canais acoplados, utilizando o potencial de São Paulo para descrever a parte real da interação nuclear entre os núcleos participantes da reação.<br>The 10B+120Sn reaction was measured at the \"Laboratório Aberto de Física Nuclear\" (LAFN, acronym in Portuguese) of the \"Instituto de Física da Universidade de São Paulo\", at energies around the Coulomb barrier (VB = 35 MeV). Angular distribuitions for the elastic and inelastic scattering were obtained, and the transfer channel of a neutron from the target to the projectile was also identified. Besides that, another set of measurements were carried out using the gamma-particle coincidence techinique with the ancillary system of scintillators and gamma-ray detectors Saci-Perere (acronym of \"Sistema Ancilar de Cintiladores e Pequeno Espectrômetro de Radiação Eletromagnética com Rejeição de Espalhamento\"). Such measurements have allowed the identification of the complete fusion process through the detection of gamma-rays coming from the compound nuclei 127Cs, formed by the absorption of the total projectile charge by the target, followed by the evaporation of neutrons. Events related to the incomplete fusion process, originated from the breakup of 10B, were also identified. A theoretical description of the main experimental results has been performed within the coupled channel formalism, using the São Paulo potential to represent the real part of the nuclear interaction between the two reacting nuclei.
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Jurčík, Michal. "Modelování elastických a neelastických kolizí." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220296.
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Master's thesis deals with vehicles collisions within an environment of logistic distribution storehous. The aim is to avoid potential collisions that can occur between these vehicles. In the first chapter are detailed collisions of particles and elements impact for the law of conservation of energy and momentum. In further sections is carried out detailed research of elastic and inelastic collisions in an ideal environment, which are the theoretical basis for the simulation of the real environment. Collisions are supported by detailed calculations and added pictures. The second chapter deals with the development of double-layer application simulating elastic collisions in an ideal environment. In subchapters are descriptions of the classes and methods for computing prediction of collisions with examples of source code. The last section describes the software platform JavaFX and used animation classes that are required for visualization issues. The last chapter, which is the main goal of the work is done by the expansion of the existing design environment of storehouse and vehicles. Particular chapters then describe the cases of various types of collisions their detection and avoidance. There is an application designed to address this issue, with a description of the classes and methods. Used methods are supported with flowcharts for easier understanding.
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Ziegler, Fabian. "Investigation of the Structure and Dynamics of Multiferroic Systems by Inelastic Neutron Scattering and Complementary Methods." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E5A6-5.
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Morais, Maria Carmen. "O efeito de estados de estrutura alfa no espalhamento 16O+12C e na reação de captura astrofísica 12C()16O." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21102010-110812/.
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Neste trabalho, investigou-se o espalhamento elástico 16O+12C, considerando o efeito da troca de uma partícula alfa entre o projétil e o alvo que conduz aos mesmos núcleos do canal de entrada (transferência elástica). Foram analisadas distribuições angulares em uma faixa de energias que, no referencial de centro de massa, vai de 8,55 MeV até 56,57 MeV. A barreira coulombiana desse sistema está em torno de 11MeV. Foram realizadas medidas de distribuição angular das reações de transferência elástica e inelástica no sistema 16O+12C, em Elab = 46, 26 MeV. A análise dessas medidas forneceu os fatores espectroscópicos, 12C+_alfa _ 16O, do estado fundamental e dos estados excitados J_ = 2+ e J_ = 1, ambos logo abaixo do limiar de emissão alfa, em 7,16 MeV. A partir do valor da amplitude espectroscópica do estado J_ = 2+, determinou-se um valor confiável para o Coeficiente de Normalização Assintótica, 1,05± 0,13(105 fm1/2), este valor foi usado para calcular a largura reduzida desse estado e realizando um cálculo de matriz R determinou-se o fator S astrofísico em energias em torno do pico de Gamow, S(E2)=37keVb.<br>The 16O+12C elastic scattering was investigated considering the effect of exchange of an alpha particle between projectile and target leading to the same nuclei of the entrance channel (elastic transfer). Angular distributions were analyzed in an energy range from 8.55 MeV to 56.57 MeV in the center of mass frame. The Coulomb barrier is around 11MeV for this system. Measurements of angular distributions of elastic and inelastic transfer reactions to states of the 16O in the 16O+12C system were performed at Elab = 46, 26MeV. Those measurements provided the spectroscopic factors of 12C+_ 16O for the ground state and for J_ = 2+ and J_ = 1 16O excited states, both just below the _-threshold at 7.16 MeV. The Asymptotic Normalization Coefficient (ANC) for the J_ = 2+ state was obtained (1.05 ±0,13(105 fm1/2)) and used to calculate the reduced width of this state, with this value a R-matrix calculation was performed to determine the astrophysical S-factor in energies around the Gamow peak, S(E2)=37keVb.
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Mira, Joele Paulus. "The role played by quasi-elastic and inelastic break-up of the 12C and 16O projectiles in the production of intermediate mass fragments at 14-35 MeV/u." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85756.
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Kundu, Ashoke. "Monte Carlo simulation of gas-filled radiation detectors." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/987/.
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Duda, Mandy [Verfasser], Jörg [Gutachter] Renner, Wolfgang [Gutachter] Friederich, and Jörg [Gutachter] Mutterlose. "An integrated experimental study on elastic and inelastic properties of sandstones and the role of transient pore pressure / Mandy Duda ; Gutachter: Jörg Renner, Wolfgang Friederich, Jörg Mutterlose ; Fakultät für Geowissenschaften." Bochum : Ruhr-Universität Bochum, 2012. http://d-nb.info/120935831X/34.
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Barratt, Julian P. "Neutron scattering studies of heavy fermion behaviour in YbNiâ†2Bâ†2C." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365688.
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Öhrn, Angelica. "Neutron Scattering at 96 MeV." Doctoral thesis, Uppsala universitet, Tillämpad kärnfysik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8425.
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Data on elastic scattering of 96 MeV neutrons from 56Fe, 89Y and 208Pb in the angular interval 10-70° are presented. The previously published data on 208Pb have been extended, as a new method has been developed to obtain additional information at the most forward angles. The results are compared with phenomenological and microscopic optical potentials. The theory predictions are in general in good agreement with the experimental data. A study of the deviation of the zero-degree cross section from Wick's limit has been performed. The data on 208Pb are in agreement with Wick's limit, while those on lighter nuclei overshoot the limit significantly. A novel analysis method has been developed to obtain the inelastic neutron emission cross sections from the existing 56Fe data. The method is based on folding a trial spectrum with the response of the detector setup. The data cover the angular interval 26-65° and an excitation energy range of 0-45 MeV, ranges hitherto not studied. The results are compared with nuclear model predictions and found to be in good agreement with the experimental data.
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Dhakal, Sushil. "Study of DD Neutrons and their Transmission in Iron Spheres." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1478097309006943.
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Boztosun, Ismail. "Coupled-channels calculations for the scattering of deformed light heavy-ions : a challenge to the standard approach." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325373.
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Záchej, Samuel. "Monte Carlo simulace elektronového rozptylu v rastrovacím prozařovacím elektronovém mikroskopu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242036.
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This thesis deals with an electron scattering in STEM microscopy on objects with dif-ferent shapes, such as cuboid, sphere and hollow capsule. Monte Carlo simulations are used for description of multiple electron scattering. Except the theoretical analysis of the electron scattering and simulation methods, the thesis contains design and realiza-tion of an algorithm simulating electron scattering in given objects. In addition, there is a design for robustness evaluation of the simulation, based on comparison between results and known signals for a given object. Reliability of the algorithm was verified by experimental measurements of the electron scattering on a carbon layer.
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Mestar, Mohammed. "Kinematic Behaviour of Cross Laminated Timber (CLT) Shearwalls with Openings." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40929.
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An integrated experimental and numerical research program investigating the elastic and inelastic performance as well as the kinematic behaviour of shearwalls with openings is presented in this study. The influence of the geometrical dimensions of the wall configurations and the mechanical properties and configurations of hold-downs on both elastic and inelastic behaviours including the possible kinematic modes of the shearwalls are investigated. The research also proposes the concept of equivalent-frame-model applicable for shearwalls where openings are cut-out from CLT panels. Are also presented, five racking tests performed on full scale CLT walls in order to validate the numerical models as well as the equivalent frame model.
From review of the available literature emerges that for CLT shearwalls with openings, studies are not at the same level of abundance in research compared to walls without openings, due to the simple reason that SSW is generally a widespread technique. Thus, the kinematic behaviour and the coupling effect are inexistent and presented here.
The investigations of the wall’s behaviour in the elastic and inelastic ranges demonstrate the important effect of the lintel and wall segment slenderness as well as the hold-down stiffness effect on the mechanical behaviour and the global kinematic behaviour as well. It is found that the kinematic modes can change when the walls are stressed beyond their elasticity limit. The failure mode and the global ductility are highly dependent on the hold-down configurations particularly for walls with door openings. The degree of coupling decrease with increased hold-down stiffness and the wall segment width.
With regards to the equivalent frame model, a reasonable fit is found between the proposed EFM and a detailed 2D area element model when the global elastic stiffness and tensile load in the hold-down were compared. The model is successfully validated through five full-scale tests on CLT shearwalls with door or window opening as well as two published studies on walls with door openings. The EFM is capable of predicting the behaviour in the wall with reasonable accuracy, especially for walls whose behaviour was dominated by the hold-down behaviour.
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Erdogan, Burcu. "Simple Models For Drift Estimates In Framed Structures During Near-field Earthquakes." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608699/index.pdf.
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Maximum interstory drift and the distribution of this drift along the height of the structure are the main causes of structural and nonstructural damage in frame type buildings subjected to earthquake ground motions. Estimation of maximum interstory drift ratio is a good measure of the local response of buildings. Recent earthquakes have revealed the susceptibility of the existing building stock to near-fault ground motions characterized by a large, long-duration velocity pulse. In order to find rational solutions for the destructive effects of near fault ground motions, it is necessary to determine drift demands of buildings. Practical, applicable and accurate methods that define the system behavior by means of some key parameters are needed to assess the building performances quickly instead of detailed modeling and calculations.
In this study, simple equations are proposed in order for the determination of the elastic interstory drift demand produced by near fault ground motions on regular and irregular steel frame structures. The proposed equations enable the prediction of maximum elastic ground story drift ratio of shear frames and the maximum elastic ground story drift ratio and maximum elastic interstory drift ratio of steel moment resisting frames. In addition, the effects of beam to column stiffness ratio, soft story factor, stiffness distribution coefficient, beam-to-column capacity ratio, seismic force reduction factor, ratio of pulse period to fundamental period, regular story height and number of stories on elastic and inelastic interstory drift demands are investigated in detail. An equation for the ratio of maximum inelastic interstory drift ratio to maximum elastic interstory drift ratio developed for a representative case is also presented.
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Gedik, Nuh. "Recombination and propagation of quasiparticles in cuprate superconductors." Berkeley, Calif. : Oak Ridge, Tenn. : Lawrence Berkeley National Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/842568-Q1sG4c/native/.
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doctoral thesis, Ph.D, University of California, Berkeley, Berkeley, CA.<br>Published through the Information Bridge: DOE Scientific and Technical Information. "LBNL--55855" Gedik, Nuh. USDOE Director. Office of Science. Office of Basic Energy Sciences 05/20/2004. Report is also available in paper and microfiche from NTIS.
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ROSSI, JUNIOR ERNESTO S. "Determinacao experimental do potencial nucleo-nucleo e da densidade do projetil sup(18)O, por meio do espalhamento quase-elastico em nucleos-alvos na camada f-p." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10914.
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Chelda, Samir. "Simulation du parcours des électrons élastiques dans les matériaux et structures. Application à la spectroscopie du pic élastique multi-modes MM-EPES." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2010. http://tel.archives-ouvertes.fr/tel-00629659.
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La spectroscopie EPES (Elastic Peak Electron Spectroscopy) permet de mesurer le pourcentage he d'électrons rétrodiffusés élastiquement par la surface d'un échantillon soumis à un bombardement électronique. C'est une méthode non destructive et extrêmement sensible à la surface. L'objectif de ce travail est de modéliser le cheminement des électrons élastiques dans la matière grâce à une simulation informatique basée sur la méthode Monte Carlo. Cette simulation contribue de manière essentielle à la connaissance et à l'interprétation des résultats expérimentaux obtenus par spectroscopie EPES. Nous avons, de plus, adapté cette simulation à différentes surfaces transformées à l'échelle micrométrique et nanométrique. A l'aide d'une méthode originale, basée sur une description couche par couche du matériau, j'ai réalisé un programme informatique (MC1) rendant compte du cheminement des électrons élastiques dans les différentes couches du matériau. Le nombre d'électrons ressortant de la surface dépend de nombreux paramètres comme : la nature du matériau à étudier, l'énergie des électrons incidents, l'angle d'incidence, les angles de collection des analyseurs. De plus, je me suis intéressé à l'effet de la rugosité de la surface et j'ai démontré qu'elle joue un rôle déterminant sur l'intensité du pic élastique. Ensuite, grâce à l'association de la spectroscopie EPES et de la simulation Monte Carlo, j'ai déduit les modes de croissance de l'or sur substrat d'argent et de cuivre. Les effets de l'arrangement atomique et des pertes énergétiques de surfaces ont ensuite été étudiés. Pour cela, une deuxième simulation MC2 tenant compte de ces deux paramètres a été réalisée permettant d'étudier les surfaces à l'échelle nanométriques. Ces paramètres jusqu'alors non pris en compte dans notre simulation MC1, joue un rôle essentiel sur l'intensité élastique. Ensuite, j'ai obtenu une formulation simple et exploitable pour l'interprétation des résultats obtenus par la simulation MC2 pour un analyseur RFA. Afin de valider, les différents résultats de la simulationMC2, j'ai réalisé des surfaces de silicium nanostructurées, à l'aide de masques d'oxyde d'alumine réalisés par voie électrochimique. J'ai pu créer des nano-pores par bombardement ionique sous ultravide sur des surfaces de silicium. Afin de contrôler la morphologie de la surface, j'ai effectué de l'imagerie MEB ex-situ. La simulation Monte Carlo développée associée aux résultats EPES expérimentaux permet d'estimer la profondeur, le diamètre et la morphologie des pores sans avoir recours à d'autres techniques ex-situ.Cette simulation MC2 permet de connaître la surface étudiée à l'échelle nanométrique.
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Barbosa, Marcel Dupret Lopes. "Estudo da interferência nuclear coulombiana nos isótopos de germânio." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-09122013-095720/.
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O estudo de características de isospin na excitação do estado 2 POT.+IND.1 foi implementado nos núcleos ANTPOT.70, 72, 74 Ge com a realização de medidas de espalhamento inelástico na região de interferência nuclear coulombiana (INC) com ANTPOT.6 Li de 28 MeV. A análise da INC, utilizando projéteis leves de interação isoescalar, na excitação de estados coletivos é uma ferramenta poderosa para evidenciar mudanças de estrutura em cadeias de núcleos, e fornecer resultados robustos para testes de modelos. A principal vantagem do método é a extração simultânea dos parâmetros de deformação de carga e massa das transições, minimizando as incertezas na razão entre as probabilidades reduzidas de transição elétrica e de massa, B(El) e B(ISl), indicadores importantes da coletividade dos estados nucleares. A análise foi realizada na aproximação de Born com ondas distorcidas e potencial óptico deformado (DWBA-DOMP), usando um conjunto de parâmetros de potencial óptico global. Os ajustes das previsões à distribuições angulares, empregando o método interativo de Gauss, exibiram excelente qualidade. Os parâmetros correlacionados extraídos na minimização do chi-quadrado, delta IND.n(comprimento de deformação nuclear) e C=delta IND.c/delta IND.n (razão entre os comprimentos de deformação de carga e nuclear), e suas incertezas, foram submetidos a testes estatísticos que os validaram. Dentre as grandezas determinadas a partir desses parâmetros, os valores de B(IS2), inéditos nos isótopos de Ge, mostraram uma mudança de estrutura não evidenciada pelos valores de B(E2). A probabilidade reduzida de transição isoescalar cresceu com o incremento do número de nêutrons, com um aumento abrupto no ANTPOT.74 Ge. Já a probabilidade reduzida de transição elétrica aumentou de maneira mais suave. Essa diferença de comportamento foi um reflexo da variação do parâmetro extraído C, que no ANTPOT.74 Ge indicou uma ) contribuição maior dos nêutrons frente aos prótons na excitação do primeiro estado quadrupolar. Os isótopos ANTPOT.70, 72 Ge, por outro lado, revelaram contribuições equivalentes e homogêneas para essas transições. Com a determinação precisa das contribuições de massa e de carga para a excitação do primeiro estado quadrupolar, novos subsídios estão disponíveis para futuros cálculos.<br>The analysis of the isospin character of the 2 POT.+ IND.1 excitation in the ANTPOT.70,72,74 Ge nuclei, with 28 MeV ANTPOT.6 Li, was applied to the inelastic scattering in the coulomb nuclear interference (CNI) region. The CNI measurements in the exitation of collective states with light isoscalar projectiles are powerful tools to evidence structure changes in nuclei chains, allowing tests of nuclear models. In this method the simultaneous extraction of the charge and mass deformation parameters, minimizes the uncertainties in the ratio of charge B(El) to mass B(ISl) trasition reduced probabilities, wich are important indicators of the nuclear collectivity. The present analysis was developed in the framework of the distorted wave Born approximation within a deformed optical potential approach (DWBA-DOMP), using a set of global optical model parameters. Excellent quality fits of the predictions to the experimental angular distributions, employing the Gauss iterative method, were obtained. The correlated parameters delta IND.N (nuclear deformation length) and C = delta IND.C/delta IND.N (ratio of charge to nuclear deformation lenghts), and their uncertainties extracted in the least squares method, were validated by statistical tests. The B(IS2) values for germanium isotopes, not previously reported, were determined in the analysis and revealed a structure change not evidenced by the B(E2) values. The isoscalar transition reduced probability raises when the neutron number increases, showing in the ANTPOT.74 Ge an abrupt enhancement. Nevertheless, the eletric transition reduced probability grows smoothly. This behavior was detected following the experimental extracted C parameters, indicating in the heavier isotope a predominance of neutrons in the first quadrupolar excitation. The ANTPOT.70,72 Ge isotopes, on the other hand, displayed equivalent and homogeneous contributions of protoons and neutrons. New information on mass and charge contributions for the 0 POT.+ IND.1 -> 2 POT.+ IND.1 transition, in the germanium isotopes, is now available for future theoretical interpretation.
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Röder, Falk. "Off-Axis Elektronenholographie elastisch und unelastisch gestreuter Elektronen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-115245.
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Die Off-Axis-Elektronenholographie ist eine interferometrische Methode zur experimentellen Bestimmung von relativen Phasenschiebungen einer Elektronenwelle. Der Zugang zu diesen Phasenschiebungen ermöglicht z.B. die Bestimmung von intrinsischen elektrischen und magnetischen Feldern eines Objektes im Nanometerbereich. Für eine quantitative Interpretation der Resultate ist die Kenntnis des Rauschens der holographisch rekonstruierten Größen von hoher Bedeutung. In dieser Arbeit wird ein allgemeiner Formalismus abgeleitet, der den Rauschtransfer vom detektierten Hologramm in die rekonstruierten Amplituden- und Phasenbilder beschreibt. Anhand zielgerichteter Experimente wird dieser Formalismus unter Berücksichtigung von gemessenen Rauscheigenschaften des Detektors verifiziert. Im Zuge dessen wird eine experimentelle Methode entwickelt, die es erlaubt, durch Serienaufnahmen und Mittelungsprozeduren das Signal-zu-Rauschverhältnis in den holographischen Resultaten bei gleichbleibender Ortsauflösung erheblich zu verbessern. Daran knüpft sich eine Vielzahl von Anwendungen an, welche in dieser Arbeit in Auszügen aufgeführt werden. Die Grundlage für all diese Experimente besteht in den Welleneigenschaften des Elektrons, welche in der Interferenzfähigkeit (Kohärenz) des Elektrons zum Ausdruck kommen. Elektronen, welche unelastisch an einem Objekt streuen, verlieren diese Eigenschaft und es stellt sich die Frage, ob aus diesem Verlust zusätzliche Informationen über den Streuprozess bzw. über das Objekt selbst gewonnen werden können. Eine Größe, die neben der Intensität auch die Kohärenz der Elektronen beschreibt, ist die reduzierte Dichtematrix. Das motiviert, die Methode der Off-Axis-Elektronenholographie in der Sprache der Dichtematrizen zu formulieren und eine allgemeine Übertragungstheorie für ein holographiefähiges Transmissionselektronenmikroskop abzuleiten. Diese Theorie umfasst alle bisher bekannten Phänomene im Rahmen der Elektronenholographie und bietet darüber hinaus neue instrumentelle Ansätze zur Optimierung des Signal-zu-Rausch-Verhältnisses und zur Überwindung auflösungsbegrenzender Aberrationen. Vor diesem Hintergrund wird weiterhin die Kohärenz von Elektronen mittels energiegefilterter Off-Axis-Elektronenholographie untersucht, welche unelastisch an Siliziumoberflächen streuen und charakteristische Oberflächenplasmonen anregen. Für die Interpretation der Resultate werden zwei Modelle für die Dekohärenz des Elektrons infolge der Wechselwirkung mit einer Objektoberfläche entwickelt und unter Berücksichtigung der Aberrationen des Energiefilters mit dem Experiment verglichen<br>Off-axis electron holography provides access to the relative phase shift of an electron wave and allows the experimental determination of intrinsic electric and magnetic fields within an object at nanometre scale. A quantitative interpretation of the results requires the knowledge about the noise in the reconstructed data. In this work, a general formalism is derived describing the transfer of noise from an experimental hologram into reconstructed amplitude and phase images. Concerted experiments verify this formalism under consideration of measured noise properties of the detector. In this frame, a method based on series acquisition and averaging is developed to improve significantly the signal-to-noise ratio of the reconstructed amplitude and phase images at constant spatial resolution. The usefulnes of this method is demonstrated by selected experimental examples from the materials sciences. The capability to show interference, i.e. to be coherent, is a consequence of the electron's wave nature and provides the fundament for all applications of electron holography. By inelastic interaction with the object, the electron loses coherence and the question comes up, whether this loss mechanism contains additional information about the scattering process or even about the object itself. The reduced density matrix is introduced as a suitable quantity describing both intensity and coherence of scattered electrons. That motivates to formulate off-axis electron holography in the language of density matrices and to derive a general transfer theory for this quantity in a holography-dedicated transmission electron microscope. This theory reproduces all known phenomena related to off-axis electron holography and provides new instrumental approaches to improve the signal-to-noise ratio and to overcome resolution limiting aberrations. In this context, the coherence of electrons, which are inelastically scattered by silicon surfaces and have excited characteristic surface plasmons, is investigated by energy-filtered electron holography. For the interpretation of the experimental results, two models are developed for the decoherence of the electron by interaction with an object surface and are compared to the experiment under consideration of the aberrations of the energy-filter
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BERGNES, BRASEY CHANTAL. "Etude des processus directs elastique et inelastiques se produisant lors de la collision entre un ion d'helium et une cible d'hydrogene, pour une energie variant de 1,5 a 30 kev." Toulouse 3, 1988. http://www.theses.fr/1988TOU30204.
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Etude des sections efficaces doublement differentielles des processus elastiques et inelastiques au cours de la collision d'un faisceau d'ions de he avec h ou h::(2), entre 1,5 et 30 kev, pour des angles de diffusion compris entre 5' et 30**(o), par spectrometrie de perte d'energie du projectile. Comparaison des resultats a des valeurs calculees et mesurees anterieurement a d'autres auteurs. Proposition d'un modele permettant d'interpreter les resultats pour la cible h
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Chen, Jyun-Hao, and 陳俊皓. "Integration of Elastic and Inelastic Scattering Spectroscopic Systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/12978430971525547250.
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碩士<br>國立中興大學<br>物理學系所<br>103<br>Nanotechnology has been widely used in interdisciplinary fields. In order to find out more information of the characteristics in nanomaterials, the detection technologies are more and more important in the development of nanotechnology. In detection technology, the optical detection provides a nondestructive, simple, fast, qualitative and quantitative measurement.
Since the structures of most commercial instruments are considerably stable, however, they could not satisfy various experimental conditions. The purpose of this research is to design and build up a system which has integration of elastic and inelastic scattering spectroscopy system. In order to enhance the stability of the system, the standard procedures for calibrating, installing, and operating were designed. The light source of the system can be switched halogen lamp or laser to obtain different spectral information of samples. Furthermore, we can easily change the setting of system to meet our demand in different experiments.
Because the system is limited by the software controlling the rotation angle of the grating; the basic units of spectra is 1 nm, therefore, we scan mercury spectrum condition by erecting elastic scattering spectroscopy. Peak spectral characteristics of full width at half maximum will set at 0.1 nm to erect Raman scattering spectroscopy scanning mercury spectrum condition. In addition to the use of mercury outside resolution spectroscopy system, we further measure the elastic scattering spectrum of commercial gold nanoparticle and the Raman spectrum of aqueous sample (ie. acetone, isopropyl alcohol and water) to verify the feasibility of the system.
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Reid, Brian Paul. "Elastic, Inelastic, and Photofragment Scattering from Crossed Molecular Beams." Thesis, 1986. https://thesis.library.caltech.edu/11851/2/Reid_BP_1986.pdf.
Full textAbstract:
<p>Three sets of crossed molecular beam scattering experiments are described. In the first experiment, total differential cross sections are measured for collisions between two methane molecules. Treating the scattering as elastic, these cross sections are used to determine an isotropic intermolecular potential energy function for the methane-methane system. The second experiment involves the measurement of total differential cross sections and time-of-flight spectra for neon-chlorine scattering. These data are modeled using the infinite order sudden approximation for rotationally inelastic scattering, and an anisotropic potential function for neon-chlorine is determined. In the third experiment, the angular and time-of-flight distributions for the products of the three-body photofragmentation of 1,2-diiodotetrafluoroethane at 266 nm are measured. These data are analyzed to determine the product translational energy distributions.</p>