Log in

Relevant bibliographies by topics / Spectra / Dissertations / Theses

Dissertations / Theses on the topic 'Spectra'

To see the other types of publications on this topic, follow the link: Spectra.

Author: Grafiati

Published: 4 June 2021

Last updated: 1 August 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Spectra.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Rozario, Hoimonti Immaculata. "Spectroscopic study of acetylene and hydrogen cyanide." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Physics and Astronomy, c2012, 2012. http://hdl.handle.net/10133/3415.

Full text

Abstract:

High-resolution molecular spectroscopy has been used to study acetylene line parameters and emission spectra of hydrogen cyanide. All acetylene spectra were recorded in our laboratory at the University of Lethbridge using a 3-channel tuneable diode laser spectrometer. N2-broadened line widths and N2-pressure induced line shifts have been measured for transitions in the v1+v3 band of acetylene at seven temperatures in the range 213–333K to obtain the temperature dependences of broadening and shift coefficients. The Voigt and hard-collision line profile models were used to retrieve the line parameters. The line-broadening and line-shift coefficients as well as their temperature-dependent parameters have been also evaluated theoretically, in the frame work of a semi-classical approach based on an exponential representation of the scattering operator, an intermolecular potential composed of electrostatic quadrupole–quadrupole and pairwise atom–atom interactions as well as on exact trajectories driven by an effective isotropic potential. The experimental results for both N2-broadening and shifting show good agreement with the theoretical results. We have studied the line intensities of the 1νl20←0νl20 band system from the HCN emission spectrum. The infrared emission spectrum of H12C14N was measured at the Justus-Liebig University, Giessen, Germany. The emission spectrum was analyzed with the spectrum analysis software Symath running using Mathematica as a platform. This approach allowed us to retrieve information on band intensity parameters.
viii, 112 leaves : ill. ; 29 cm

APA, Harvard, Vancouver, ISO, and other styles

2

Bandeira, Nuno Filipe Cabrita. "Spectral networks algorithms for de novo interpretation of tandem mass spectra." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3274510.

Full text

Abstract:

Thesis (Ph. D.)--University of California, San Diego, 2007.
Title from first page of PDF file (viewed October 2, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 141-152).

APA, Harvard, Vancouver, ISO, and other styles

3

Harvey, Pierre Dominique. "Applications of vibrational spectroscopy and NMR spin-lattice relaxation time measurements to organometallic and organic molecular crystals." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=73986.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Strömwall, Joakim. "Staggered Ladder Spectra." Thesis, Karlstads universitet, Fakulteten för teknik- och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-13872.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Barnes, David James. "Rational Equivariant Spectra." Thesis, University of Sheffield, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486771.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Al-Doujan, Fawwaz Awwad. "Spectra of graphs." Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306195.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Angeltveit, Vigleik. "Noncommutative ring spectra." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/34549.

Full text

Abstract:

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2006.
Includes bibliographical references (p. 87-91).
Let A be an Ax ring spectrum. We give an explicit construction of topological Hochschild homology and cohomology of A using the Stasheff associahedra and another family of polyhedra called cyclohedra. Using this construction we can then study how THH(A) varies over the moduli space of AO structures on A, a problem which seems largely intractable using strictly associative replacements of A. We study how topological Hochschild cohomology of any 2-periodic Morava K-theory varies over the moduli space of AO structures and show that in the generic case, when a certain matrix describing the multiplication is invertible, the result is the corresponding Morava E-theory. If this matrix is not invertible, the result is some extension of Morava E-theory, and exactly which extension we get depends on the AO structure. To make sense of our constructions, we first set up a general framework for enriching a subcategory of the category of noncommutative sets over a category C using products of the objects of a non-E operad P in C. By viewing the simplicial category as a subcategory of the category of noncommutative sets in two different ways, we obtain two generalizations of simplicial objects.
(cont.) For the operad given by the Stasheff associahedra we obtain a model for the 2-sided bar construction in the first case and the cyclic bar and cobar construction in the second case. Using either the associahedra or the cyclohedra in place of the geometric simplices we can define the geometric realization of these objects.
by Vigleik Angeltveit.
Ph.D.

APA, Harvard, Vancouver, ISO, and other styles

8

Browne, Sarah Louise. "E-theory spectra." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/17812/.

Full text

Abstract:

This thesis combines the fields of functional analysis and topology. $C^\ast$-algebras are analytic objects used in non-commutative geometry and in particular we consider an invariant of them, namely $E$-theory. $E$-theory is a sequence of abelian groups defined in terms of homotopy classes of morphisms of $C^\ast$-algebras. It is a bivariant functor from the category where objects are $C^\ast$-algebras and arrows are $\ast$-homomorphisms to the category where objects are abelian groups and arrows are group homomorphisms. In particular, $E$-theory is a cohomology theory in its first variable and a homology theory in its second variable. We prove in the case of real graded $C^\ast$-algebras that $E$-theory has $8$-fold periodicity. Further we create a spectrum for $E$-theory. More precisely, we use the notion of quasi-topological spaces and form a quasi-spectrum, that is a sequence of based quasi-topological spaces with specific structure maps. We consider actions of the orthogonal group and we obtain a orthogonal quasi-spectrum which we prove has a smash product structure using the categorical framework. Then we obtain stable homotopy groups which give us $E$-theory. Finally, we combine these ideas and a relation between $E$-theory and $K$-theory to obtain connections of the $E$-theory orthogonal quasi-spectrum to $K$-theory and $K$-homology orthogonal quasi-spectra.

APA, Harvard, Vancouver, ISO, and other styles

9

Ajohani, Maha. "SPECTRAL PHASOR ANALYSIS ON ABSORBANCE SPECTRA FOR QUANTIFYING THE CONTENT OF DYE MIXTURES." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1464191406.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Suzuki, Nao. "Cosmology from quasar spectra." Diss., Connected to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3189997.

Full text

Abstract:

Thesis (Ph. D.)--University of California, San Diego, 2005.
Title from first page of PDF file (viewed March 7, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 344-361).

APA, Harvard, Vancouver, ISO, and other styles

11

Wiley, James Hugh. "Raman spectra of celluloses." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/5748.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Lewia, Stephen D. "Spectra of stable sonoluminescence." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23775.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Bousbouras, Spiros. "Finite spectra of sentences." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435789.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Lambert, Hendrick C. "Interstellar electron density spectra /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9901445.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Taylor, Melinda Marie. "Analysis of Cepheid Spectra." Thesis, The University of Sydney, 1998. http://hdl.handle.net/2123/388.

Full text

Abstract:

Using high resolution optical spectra from Mount John University Observatory, Mount Stromlo Observatory and the Anglo-Australian Observatory, new, high accuracy radial velocity curves have been obtained for the two bright southern Cepheids l carinae (HR 3884) and beta doradus (HR 1922). An indepth investigation into period variations, cycle-to-cycle and long-term variations in the velocity curves and the reliability of the combination of velocity data from different observatories is carried out. Evidence for shock waves in the atmosphere of l car and resonance in beta dor is discussed. A grid of static model atmospheres incorporating plane-parallel geometry is compared with the observational spectra of both Cepheids, using line depth ratios, to determine the variation in effective temperature, surface gravity and microturbulence with phase. This information is used to determine the phase dependence of the surface-brightness for both Cepheids. The surface brightness variation with phase was found to follow an almost linear relationship. The distance to and radius of the Cepheids are determined using both a near-infrared version of the Barnes-Evans method and the Fourier Baade-Wesselink (BW) method. The derived radii and distances agree within the limits of the errors for both methods. The Fourier BW method was found to be very sensitive to phase shifts between the photometric and spectroscopic data and the derived distance highly dependent on the assumed reddening. An investigation into line profile variations in l car and beta dor has revealed the magnitude of these phenomena increase as the pulsational period of the Cepheid increases. It is estimated that line level variations introduce an additional uncertainty into derived radii of approximately 4 per cent for beta dor and 10 per cent in lcar. The uncertainty introduced into derived distances and radii by line profile asymmetries was estimated to be of the order of 6 per cent in beta dor and 10 per cent in l car. A comparative analysis is made of the hydrogen line radial velocity curves of l car and beta dor. A trend in the properties of these radial velocity curves with period has been revealed. In longer period Cepheids, the Halpha line seems to be forming in a region that does not partake in the pulsation as a whole, probably in a chromospheric shell. A quantitative analysis of the asymmetries in these lines reveal large redward asymmetries near maximum infall velocity. The magnitude of these asymmetries and the period for which they are present are larger in l Car than in beta dor. The blueward asymmetries in the Halpha line in l Car are comparable in magnitude to the redward asymmetries while the other lines exhibit only small blueward asymmetries. A qualitative analysis of these line profiles with phase reveal no conclusive evidence for line doubling in these Cepheids. Evidence of emission is found in the Halpha and H Beta lines of beta dor and l car. The strength and duration of the emission is found to be greater in the longer period Cepheid. Although it is likely that this emission is shock-related, theoretical work is needed to determine the exact origin of the emission. A non-LTE radiative hydrodynamic model for l Car has been created. This atmosphere will be used in further work to calculate synthetic spectral line profiles which will aid the interpretation of our observational results.

APA, Harvard, Vancouver, ISO, and other styles

16

Taylor, Melinda Marie. "Analysis of Cepheid Spectra." University of Sydney, Physics, 1998. http://hdl.handle.net/2123/388.

Full text

Abstract:

Using high resolution optical spectra from Mount John University Observatory, Mount Stromlo Observatory and the Anglo-Australian Observatory, new, high accuracy radial velocity curves have been obtained for the two bright southern Cepheids l carinae (HR 3884) and beta doradus (HR 1922). An indepth investigation into period variations, cycle-to-cycle and long-term variations in the velocity curves and the reliability of the combination of velocity data from different observatories is carried out. Evidence for shock waves in the atmosphere of l car and resonance in beta dor is discussed. A grid of static model atmospheres incorporating plane-parallel geometry is compared with the observational spectra of both Cepheids, using line depth ratios, to determine the variation in effective temperature, surface gravity and microturbulence with phase. This information is used to determine the phase dependence of the surface-brightness for both Cepheids. The surface brightness variation with phase was found to follow an almost linear relationship. The distance to and radius of the Cepheids are determined using both a near-infrared version of the Barnes-Evans method and the Fourier Baade-Wesselink (BW) method. The derived radii and distances agree within the limits of the errors for both methods. The Fourier BW method was found to be very sensitive to phase shifts between the photometric and spectroscopic data and the derived distance highly dependent on the assumed reddening. An investigation into line profile variations in l car and beta dor has revealed the magnitude of these phenomena increase as the pulsational period of the Cepheid increases. It is estimated that line level variations introduce an additional uncertainty into derived radii of approximately 4 per cent for beta dor and 10 per cent in lcar. The uncertainty introduced into derived distances and radii by line profile asymmetries was estimated to be of the order of 6 per cent in beta dor and 10 per cent in l car. A comparative analysis is made of the hydrogen line radial velocity curves of l car and beta dor. A trend in the properties of these radial velocity curves with period has been revealed. In longer period Cepheids, the Halpha line seems to be forming in a region that does not partake in the pulsation as a whole, probably in a chromospheric shell. A quantitative analysis of the asymmetries in these lines reveal large redward asymmetries near maximum infall velocity. The magnitude of these asymmetries and the period for which they are present are larger in l Car than in beta dor. The blueward asymmetries in the Halpha line in l Car are comparable in magnitude to the redward asymmetries while the other lines exhibit only small blueward asymmetries. A qualitative analysis of these line profiles with phase reveal no conclusive evidence for line doubling in these Cepheids. Evidence of emission is found in the Halpha and H Beta lines of beta dor and l car. The strength and duration of the emission is found to be greater in the longer period Cepheid. Although it is likely that this emission is shock-related, theoretical work is needed to determine the exact origin of the emission. A non-LTE radiative hydrodynamic model for l Car has been created. This atmosphere will be used in further work to calculate synthetic spectral line profiles which will aid the interpretation of our observational results.

APA, Harvard, Vancouver, ISO, and other styles

17

鄧愛紅 and Aihong Deng. "Some studies towards improving positron lifetime spectroscopy for semiconductors." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31214083.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Bing, Zhou. "Crosshole resistivity and acoustic velocity imaging : S.5-D helmholtz equation modeling and inversion /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phb613.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Borde, Arnaud. "One-Dimensional Power Spectrum and Neutrino Mass in the Spectra of BOSS." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01023004.

Full text

Abstract:

The framework of the studies presented in this thesis is the one-dimensional power spectrum of the transmitted flux in the Lyman-alpha forests. The Lyman-alpha forest is an an absorption pattern seen in the spectra of high redshift quasars corresponding to the absorption of the quasar light by the hydrogen clouds along the line of sight. It is a powerful cosmological tool as it probes relatively small scales, of the order of a few Mpc. It is also sensible to small non-linear effects such as the one induced by massive neutrinos.First, we have developed two independent methods to measure the one-dimensional power spectrum of the transmitted flux in the Lyman-alpha forest. The first method is based on a Fourier transform, and the second on a maximum likelihood estimator. The two methods are independent and have different systematic uncertainties. The determination of the noise level in the data spectra was subject to a novel treatment, because of its significant impact on the derived power spectrum. We applied the two methods to 13,821 quasar spectra from SDSS-III/BOSS DR9 selected from a larger sample of over 60,000 spectra on the basis of their high quality, large signal-to-noise ratio, and good spectral resolution. The power spectra measured using either approach are in good agreement over all twelve redshift bins from =2.2 to =4.4, and scales from 0.001 (km/s)^−1 to 0.02 (km/s)^−1. We carefully determined the methodological and instrumental systematic uncertainties of our measurements.Then, we present a suite of cosmological N-body simulations with cold dark matter, baryons and neutrinos aiming at modeling the low-density regions of the IGM as probed by the Lyman-alpha forests at high redshift. The simulations are designed to match the requirements imposed by the quality of BOSS and eBOSS data. They are made using either 768^3 or 192^3 particles of each type, spanning volumes ranging from (25 Mpc/h)^3 for high-resolution simulations to (100 Mpc/h)^3 for large-volume ones. Using a splicing technique, the resolution is further enhanced to reach the equivalent of simulations with 3072^3 = 29 billion particles of each type in a (100 Mpc/h)^3 box size, i.e. a mean mass per gas particle of 1.2x10^5 solar masses. We show that the resulting power spectrum is accurate at the 2% level over the full range from a few Mpc to several tens of Mpc. We explore the effect on the one-dimensional transmitted-flux power spectrum of 4 cosmological parameters (n_s, sigma_8, Omega_m ,H_0), 2 astrophysical parameters (T_0, gamma) related to the heating rate of the IGM and the sum of the neutrino masses. By varying the input parameters around a central model chosen to be in agreement with the latest Planck results, we built a grid of simulations that allows the study of the impact on the flux power spectrum of these seven relevant parameters. We improve upon previous studies by not only measuring the effect of each parameter individually, but also probing the impact of the simultaneous variation of each pair of parameters. We thus provide a full second-order expansion, including cross-terms, around our central model. We check the validity of the second-order expansion with independent simulations obtained either with different cosmological parameters or different seeds for the initial condition generation. Finally, a comparison to the one-dimensional Lyman-alpha forest power spectrum obtained in the first part with BOSS data shows an excellent agreement.Eventually, even if there are still some potential biases and systematic errors that need to be studied in our simulation, we performed cosmological fits combining our measurement of the one-dimensional power spectrum and other cosmological probes such as the CMB results provided by Planck. These preliminary results are very encouraging as they lead to some of the tighest cosmological constraints as of today, especially on the sum of the neutrino masses with an upper limit of 0.1 eV.

APA, Harvard, Vancouver, ISO, and other styles

20

Régnier, David. "Contribution à l'étude des gammas prompts de fission." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENI065.

Full text

Abstract:

Cette thèse a essentiellement été motivée par la montée en puissance de la thématique des échauffements nucléaires en réacteurs. Elle avait pour objectif la mise en place de méthodes permettant la simulation de l'émission des gammas prompts de fission. Pour répondre à cette attente, différents algorithmes de désexcitation d'un noyau ont été implémentés. Ils ont été testés avec succès via plusieurs calculs d'application (rapport d'embranchement isomérique, largeur radiative totale, etc). Ces méthodes ont ensuite été mises en oeuvre dans le cadre du code de fission FIFRELIN. L'outil qui en résulte, permet la détermination d'un grand nombre d'observables de fission, dans le cadre d'un modèle unique. Une étude de sensibilité des résultats à différents éléments du calcul a été réalisée. Enfin, des simulations de la fission spontanée du 252Cf, et des fissions induites par neutrons thermiques sur l' 235U et le 239Pu ont été menées. Les spectres des gammas prompts pour ces trois systèmes fissionnants ont pu être déterminés. Les résultats obtenus sont en très bon accord avec les données expérimentales disponibles, dont certaines ont été publiées récemment (2012 et 2013)
This PhD thesis has essentially been motivated by the nuclear heating problematic in reactors. The main goal of this work was the production of methods capable of simulating the prompt gamma emission from fission. First of all, several algorithms for the treatment of the nucleus deexcitation were implemented. They have been succesfully tested through various calculations (isomeric branching ratio, total radiative width, etc). These methods were then incorporated in the frame of the fission code FIFRELIN. The tool which results from this work, enables the determination of numerous fission observables in the frame of a single consistent model. A sensitivity study of the results to several numerical and nuclear models has been realized. At last, calculation have been lead for the 252Cf spontaneous fission and the thermal neutron induced fission of 235U and 239Pu. The prompt gamma spectra obtained for those three fissionning systems have been determined. The results are in good agreement with available experimental data, including recent measurements published in 2012 and 2013

APA, Harvard, Vancouver, ISO, and other styles

21

White, Katie Margaret. "Statistical analysis of visible absorption spectra and mass spectra obtained from dyed textile fibers." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4646.

Full text

Abstract:

The National Academy of Sciences recently published a report which calls for improvements to the field of forensic science. Their report criticized many forensic disciplines for failure to establish rigorously-tested methods of comparison, and encouraged more research in these areas to establish limitations and assess error rates. This study applies chemometric and statistical methods to current and developing analytical techniques in fiber analysis. In addition to analysis of commercially available dyed textile fibers, two pairs of dyes are selected for custom fabric dyeing based on the similarities of their absorbance spectra and dye molecular structures. Visible absorption spectra for all fiber samples are collected using microspectrophotometry (MSP) and mass spectra are collected using electrospray ionization (ESI) mass spectrometry. Statistical calculations are performed using commercial software packages and software written in-house. Levels of Type I and Type II error are examined for fiber discrimination based on hypothesis testing of visible absorbance spectra profiles using a nonparametric permutation method. This work also explores evaluation of known and questioned fiber populations based on an assessment of statistical p-value distributions from questioned-known fiber comparisons with those of known fiber self-comparisons. Results from the hypothesis testing are compared with principal components analysis (PCA) and discriminant analysis (DA) of visible absorption spectra, as well as PCA and DA of ESI mass spectra. The sensitivity of a statistical approach will also be discussed in terms of how instrumental parameters and sampling methods may influence error rates.
ID: 030423335; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2010.; Includes bibliographical references (p. 112-119).
M.S.
Masters
Department of Chemistry
Sciences

APA, Harvard, Vancouver, ISO, and other styles

22

Pianalto, Frederick Scott 1961. "Laser spectroscopy of strontium-sulfide and alkaline earth monoborohydrides." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276739.

Full text

Abstract:

Three gas phase alkaline earth molecules were analyzed using dye laser spectroscopy. The A¹Σ⁺ - X¹Σ⁺ transition of gas phase SrS was studied with high resolution techniques. The 0-0, 0-1, 1-1, 2-1, 3-0, 3-2, 4-1, 5-1, and 5-2 bands were rotationally analyzed and spectroscopic constants were determined. The A¹Σ⁺ state was extensively perturbed. Ground state (X¹Σ⁺) constants derived from the analysis of the nine vibrational levels include: ωₑ = 388.2643 cm⁻¹, Bₑ = 0.1208034(33) cm⁻¹, and rₑ = 2.439687(14) Å. Excited state (A¹Σ⁺) constants determined include: Tₑ = 13932.7068(10) cm⁻¹, ωₑ = 339.1454(20) cm⁻¹, Bₑ = 0.1139895(38) cm⁻¹, and rₑ = 2.511601(17) Å. The spectra of calcium and strontium borohydrides were observed using low resolution laser spectroscopy. The spectra were assigned to the Ã²A₁ - Ẋ²A₁ and Ḃ²E - Ẋ²A₁ transitions of CaBH₄ and SrBH₄. The vibrational frequencies of the metal-ligand stretch determined for CaBH₄ were 457 cm⁻¹ (Ẋ²A₁), 473 cm⁻¹ (Ā²A₁), and 465 cm⁻¹ (Ḃ²E). The corresponding SrBH4 frequencies were 399 cm⁻¹, 420 cm⁻¹, and 421 cm⁻¹.

APA, Harvard, Vancouver, ISO, and other styles

23

Gregory, Lorna Anne. "Ziegler spectra of valuation rings." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/ziegler-spectra-of-valuation-rings(aed20f0f-16c6-40a2-9187-2cc60eae6e9a).html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Lijzenga, Johannes. "Discrimination of simplified vowel spectra." [S.l. : [Groningen] : s.n.] ; [University Library Groningen] [Host], 1997. http://irs.ub.rug.nl/ppn/156418908.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Falklöf, Olle, and Bo Durbeej. "Modeling of phytochrome absorption spectra." Linköpings universitet, Beräkningsfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-92393.

Full text

Abstract:

Phytochromes constitute one of the six well-characterized families of photosensory proteins in Nature. From the viewpoint of computational modeling, however, phytochromes have been the subject of much fewer studies than most other families of photosensory proteins, which is likely a consequence of relevant high-resolution structural data becoming available only in recent years. In this work, hybrid quantum mechanics/molecular mechanics (QM/MM) methods are used to calculate UV-vis absorption spectra of Deinococcus radiodurans bacteriophytochrome. We investigate how the choice of QM/MM methodology affects the resulting spectra and demonstrate that QM/MM methods can reproduce the experimental absorption maxima of both the Q and Soret bands with an accuracy of about 0.15 eV. Furthermore, we assess how the protein environment influences the intrinsic absorption of the bilin chromophore, with particular focus on the Q band underlying the primary photochemistry of phytochromes.

APA, Harvard, Vancouver, ISO, and other styles

26

Francis, Paul John. "The classification of quasar spectra." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239185.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Rastogi, Ashwin. "Brane Constructions and BPS Spectra." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10836.

Full text

Abstract:

The object of this work is to exploit various constructions of string theory and M-theory to yield new insights into supersymmetric theories in both four and three dimensions. In 4d, we extend work on Seiberg-Witten theory to study and compute BPS spectra of the class of complete N = 2 theories. The approach we take is based on the program of geometric engineering, in which 4d theories are constructed from compactifications of type IIB strings on Calabi-Yau manifolds. In this setup, the natural candidates for BPS states are D3 branes wrapped on supersymmetric 3-cycles in the Calabi-Yau. Our study makes use of the mathematical structure of quivers, whose representation theory encodes the notion of stability of BPS particles. Except for 11 exceptional cases, all complete theories can be constructed by wrapping stacks of two M5 branes on Riemann surfaces. By exploring the connection between quivers and M5 brane theories, we develop a powerful algorithm for computing BPS spectra, and give an in-depth study of its applications. In particular, we compute BPS spectra for all asymptotically free complete theories, as well as an infinite set of conformal \(SU(2)^k\) theories with certain matter content. From here, we go on to apply the insight gained from our 4d study to 3d gauge theories. We consider the analog of the M5 brane construction in the case of 3d N = 2 theories: pairs of M5 branes wrapped on a 3-manifold. Using the ansantz of R-ﬂow, we study 3-manifolds consisting of Riemann surfaces fibered over R. When the construction is non-singular, the resulting IR physics is described by a free abelian Chern-Simons theory. The mathematical data of a tangle captures the data of the gauge theory, and the Reidemeister equivalances on tangles correspond to dualities of physical descriptions. To obtain interacting matter, we allow singularities in the construction. By extending the tangle description to these singular cases, we find a set of generalized Reidemeister moves that capture non-trivial mirror symmetries of 3d gauge theories. These results give a geometric origin to these well-known 3d dualities.
Physics

APA, Harvard, Vancouver, ISO, and other styles

28

Meesuk, L. "Vibrational spectra of polynuclear complexes." Thesis, University of East Anglia, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353290.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Harris, M. "Collisional effects in atomic spectra." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352727.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Zugic, Minjas. "Raman spectra of clathrate hydrates." Thesis, King's College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271176.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Mantilla, Jose G. (Jose Gabriel) 1972. "Models of plankton biomass spectra." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80212.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Frank, Stephan. "OVI Absorbers in SDSS Spectra." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1222116379.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Bunnell, Leah M. "SUBHARMONIC FREQUENCIES IN GUITAR SPECTRA." Cleveland State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=csu1624389777728368.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Clayton, Michael J. "Analysis of the ultraviolet emissions of nitric oxide from mid-latitude rocket observations." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA237340.

Full text

Abstract:

Thesis (M.S. in Physics)--Naval Postgraduate School, June 1990.
Thesis Advisor(s): Cleary, David D. "June 1990." Description based on signature page. as viewed on October 19, 2009. DTIC Identifiers: Dayglow, emission spectra, ultraviolet spectra, theses. Author(s) subject terms: Ultraviolet spectra, dayglow, nitric oxide. Includes bibliographical references (p. 57-58). Also available in print.

APA, Harvard, Vancouver, ISO, and other styles

35

梁詠霞 and Wing-har Joanne Leung. "High resolution laser spectroscopy of yttrium and nickel monohalides." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31243320.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Baliga, Shankar B. "Infrared spectrum of solid D̳2 and Raman spectra of solid H̳2, D̳2 and HD /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487264603218894.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Rowe, Penny. "Measurements of the foreign-broadened continuum of water vapor in the 6.3 micron band at -30 celsius /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/8604.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Benoit, Jean-Pierre. "Étude expérimentale et théorique d'une turbulence homogène soumise à des effets couplés de rotation et de déformation plane." Ecully, Ecole centrale de Lyon, 1992. http://www.theses.fr/1992ECDL0026.

Full text

Abstract:

L'étude théorique des caractéristiques anisotropes d'une turbulence homogène soumise à des gradients moyens plans est abordée dans l'espace spectral. Différents couplages du taux de rotation/déformation sont examinés de part et d'autre du cas central de cisaillement pur. La résolution du problème linéaire est réalisée sur l'équation du spectre de la fluctuation de vitesse. La solution numérique est détaillée dans le cas des écoulements elliptiques afin de faire le lien avec les études de stabilité de ces écoulements périodiques. L'approche non linéaire porte sur l'équation du tenseur spectral d'ordre 2. Une fermeture du type EDQNM est utilisée pour décrire l'évolution des corrélations triples. Le calcul du terme non linéaire de l'équation de Craya est simplifié en utilisant une décomposition en harmoniques sphériques pour le tenseur d'ordre 2. L'étude expérimentale, menée parallèlement, fournit les évolutions anisotropes des tensions de Reynolds pour les cas de couplage suivants: déformation pure plane, déformation dominante, cisaillement pur et rotation dominante. Les résultats linéaires donnent les tendances de l'anisotropie. Par contre, le calcul non linéaire se heurte à un problème de réalisabilité du tenseur spectral. Cet écueil tend à prouver que le degré de troncature des séries d'harmoniques sphériques, choisi égal à 2, pour une simplification de la modélisation, est trop bas

APA, Harvard, Vancouver, ISO, and other styles

39

Hoffmann, Tadziu. "Synthetic spectra of massive stars as tool for the spectral analysis of stars and stellar clusters." Diss., lmu, 2004. http://nbn-resolving.de/urn:nbn:de:bvb:19-27193.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Wong, Chi-ming, and 黃志明. "The equilibrium spectrum of cosmic ray positrons." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1985. http://hub.hku.hk/bib/B31207947.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Li, Stella, and 李加碧. "Development of a deep level optical spectroscopy system and its application to the study of defects in electron and neutron irradiatedgallium nitride." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31245705.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Yu, Nan. "The infrared spectrum of the helium molecular ion helium-3 positive helium-4." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184419.

Full text

Abstract:

This dissertation is concerned with the first experimental observation of the vibration-rotation spectrum of the helium molecular ion, ³He⁴He⁺. The Doppler-tuned fast-beam laser-resonance technique has been used. The ions produced in an electron-impact ion source form an ion beam of a few KeV and then intersect nearly colinearly with a CO IR laser beam of fixed frequency. The velocity of the ions is scanned to tune the ions into resonance with the laser frequency. Subsequent resonance detection is realized by using charge exchange processes of the ion with a target gas. Twelve spectral lines have been measured which correspond to nine different vibration-rotation transitions of the R branch in the fundamental band of the ground state of ³He⁴He⁺. The combination of the kinematic compression of the fast-beam method and the special frequency stabilization of the CO laser render an experimental accuracy of 0.0006 cm⁻¹ or 0.4 ppm. The accuracy exceeds that of the available theory by three orders of magnitude. The narrow spectral linewidth also allows partial resolution of the magnetic hyperfine structure due to helium-3. A hyperfine structure calculation has been carried out using a numerical multi-configuration self-consistent-field method. The agreement between the calculation and the observation is very satisfying.

APA, Harvard, Vancouver, ISO, and other styles

43

Sagave, Steffen. "Universal Toda brackets of ring spectra." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980393353.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Zaks, Michael. "Fractal Fourier spectra in dynamical systems." Thesis, [S.l.] : [s.n.], 2001. http://pub.ub.uni-potsdam.de/2002/0019/zaks.ps.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Berwald, Jesse James. "Computing multifractal spectra via simplicial measures." Diss., Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/berwald/BerwaldJ1211.pdf.

Full text

Abstract:

Complex dynamical systems occur on many scales in the natural world, and serve as rich subjects of study. Examples include ecosystems, physiological systems, and financial markets. Simplified versions of these system can be described by dynamical systems. As such, understanding the qualitative behavior of dynamical systems provides an important window into real-world phenomena. In this manuscript we focus on the qualitative behavior described by the measure concentrated on the attractor of a dynamical system. A common way to study such complicated measures is through their multifractal spectra. We will describe a new method, developed to approximate the Sinai-Bowen-Ruelle measure on an attractor, that is based on the Vietoris-Rips complex. We use it to approximate various measures concentrated on a number of example sets, and demonstrate its efficacy by computing the corresponding multifractal spectra.

APA, Harvard, Vancouver, ISO, and other styles

46

Pikovsky, Arkady S., Michael A. Zaks, Ulrike Feudel, and Jürgen Kurths. "Singular continuous spectra in dissipative dynamics." Universität Potsdam, 1995. http://opus.kobv.de/ubp/volltexte/2007/1378/.

Full text

Abstract:

We demonstrate the occurrence of regimes with singular continuous (fractal) Fourier spectra in autonomous dissipative dynamical systems. The particular example in an ODE system at the accumulation points of bifurcation sequences associated to the creation of complicated homoclinic orbits. Two different machanisms responsible for the appearance of such spectra are proposed. In the first case when the geometry of the attractor is symbolically represented by the Thue-Morse sequence, both the continuous-time process and its descrete Poincaré map have singular power spectra. The other mechanism owes to the logarithmic divergence of the first return times near the saddle point; here the Poincaré map possesses the discrete spectrum, while the continuous-time process displays the singular one. A method is presented for computing the multifractal characteristics of the singular continuous spectra with the help of the usual Fourier analysis technique.

APA, Harvard, Vancouver, ISO, and other styles

47

Peiponen, K. E. (Kai-Erik). "Optical spectra analysis of turbid liquids." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514291685.

Full text

Abstract:

Abstract This thesis is devoted to methods of analyzing optical spectra obtained from turbid liquids, i.e., liquids that are optically very thick and/or scatter light. Data for spectral analysis were obtained with a new, multifunction spectrophotometer developed for industrial liquid samples. One characteristic of the spectrophotometer is that spectral analysis methods can be implemented into the software. Here, the emphasis was on data inversion methods, particularly the Kramers-Kronig analysis and the maximum entropy method, which can be used to gain information on the wavelength-dependent complex refractive index of liquid samples. Relating to such characteristics as density and colour, the complex refractive index also helps to identify the species that form a liquid. The methods were applied to study the internal reflection of light from the prism-liquid interface of the probe and to analyze surface plasmon resonance spectra. This study provided new methods of investigating the optical properties of relatively difficult objects, like offset inks, and of assessing adhesion forces between ink and the substrate system. Another important part of the thesis was the exploration of spectral analysis methods to obtain optical properties of nanoparticles in a liquid matrix. Bounds for the optical properties of multi-component structures in a liquid were considered with the aid of Wiener bounds.

APA, Harvard, Vancouver, ISO, and other styles

48

Li, Hao. "The microwave spectra of cyclopropyl bromide." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27583.

Full text

Abstract:

The microwave spectra of cyclopropyl bromide, C₃H₅Br, in its ground state, has been observed and analyzed in the frequency range 15-90 GHz. The spectra of two species were measured: C₃H₅⁷⁹Br and C₃H₅⁸¹Br. They contain strong a-type transitions and very weak c-type transitions which could not initially be assigned; all show Br quadrupole hyperfine structure with several large perturbations. A procedure specially developed for analysis of such spectra, which uses perturbations in the Br structure, was used to evaluate all the rotational constants accurately, as well as the Br quadrupole tensor, entirely from a-type R branch transitions. This has allowed some c-type transitions to be assigned. The principal values of the Br quadrupole tensor have been evaluated and have provided some information about the type of bonding involved in the C-Br bond.The centrifugal distortion constants have also been obtained.
Science, Faculty of
Chemistry, Department of
Graduate

APA, Harvard, Vancouver, ISO, and other styles

49

He, Zhiping. "Spectra of localization operators on groups." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0024/NQ39271.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Hunter, Aaron Matthew. "Arithmetic operations in first-order spectra." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq37553.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!