Dissertations / Theses on the topic 'Photons migration'
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Saarela, J. (Juha). "Photon migration in pulp and paper." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514275845.
Full textHuang, Yingqing. "Characterization of dense suspensions using frequency domain photon migration." Texas A&M University, 2003. http://hdl.handle.net/1969.1/2207.
Full textXu, Zhoujia. "Migration from electronics to photonics in multicore processor." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45394.
Full textIncludes bibliographical references (leaf 54).
Twenty - first opportunities for Gigascale Integration will be governed in part by a hierarchy of physical limits on interconnect. Microprocessor performance is now limited by the poor delay and bandwidth performance of the on - chip global wiring layer. This thesis is envisioned as a critical showstopper of electronic industry in the near future. The physical reason behind the interconnect bottleneck is the resistive nature of metals. The introduction of copper in place of aluminum has temporarily improved the interconnect performance, but a more disruptive solution will be required in order to keep the current pace of progress, optical interconnect is an intriguing alternative to metallic wires. Many - core microprocessors will push performance per chip from the 10 gigaflop to the 10 teraflop range in the coming decade. Pin limitations, the energy cost of electrical signaling, and the non - scalability of chip - length global wires are significant bandwidth impediments. Silicon nanophotonic based many core architecture are introduced in order to meet the bandwidth requirements at acceptable power levels.
by Zhoujia Xu.
M.Eng.
Pan, Tianshu. "Application and modeling of near-infrared frequency domain photon migration for monitoring pharmaceutical powder blending operations." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4433.
Full textDali, Sarabjyot Singh. "Analysis of dense colloidal dispersions with multiwavelength frequency domain photon migration measurements." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1751.
Full textHouston, Jessica Perea. "Near infrared optical lymphography for cancer diagnostics." Diss., Texas A&M University, 2005. http://hdl.handle.net/1969.1/4807.
Full textWu, Jun 1968. "Photon migration in turbid media : time-resolved optical imaging in tissue-like phantom." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10792.
Full textMikaelsson, Therese. "Electronic Energy Migration/Transfer as a Tool to Explore Biomacromolecular Structures." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-86794.
Full textGesta, Emmanuelle. "Study of the interaction and migration mechanisms in the systems polymer/insecticide." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1093.
Full textThe main objective of the works presented in this manuscript was to study some of the parameters ruling the efficacy and the durability of the mosquito nets with incorporated insecticide in the polyethylene yarns. To achieve this goal, two lines of research were identified: the study of the insecticide migration phenomena in the yarns and the study of the photodegradation mechanisms of the molecule of interest: the deltamethrin.The study of the influence of the nets fabrication process on the polyethylene morphology showed that the cold-drawing step was critical to define the morphological (crystallinity and orientation of the crystalline structure) and mechanical properties. The observed influence of the heat-setting appeared less important (slight increase of the crystalline lamellae thickness). However, the heat-setting induced modifications which affected the migration of the insecticide molecules in the yarns. Indeed, while a delay is observed in the desorption curves of the non-heat-set yarns, this time-lag disappeared in the heat-set yarns. It was also shown that the low evaporation rate of deltamethrin permits to impede the migration of deltamethrin out of the yarns.The study of the photodegradation of deltamethrin permitted to highlight the main degradation mechanisms (isomerization, ester cleavage and cyclopropane cleavage). Antioxidant and UV absorber additives can be used to reduce the deltamethrin degradation rate
Rasmussen, John C. "Development of a radiative transport based, fluorescence-enhanced, frequency-domain small animal imaging system." Thesis, [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1067.
Full textGurfinkel, Mikhail. "Cancer diagnostics using dynamic near-infrared optical imaging and fluorescent contrast agents." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3162.
Full textLissau, Jonas Sandby. "Non-Coherent Photon Upconversion on Dye-Sensitized Nanostructured ZrO2 Films for Efficient Solar Light Harvesting." Doctoral thesis, Uppsala universitet, Fysikalisk kemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229831.
Full textRyderfors, Linus. "Two-Photon Excited Fluorescence Depolarisation : Experimental and Theoretical Development." Doctoral thesis, Uppsala University, Department of Photochemistry and Molecular Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9285.
Full textWe have studied fundamental aspects of time-resolved two-photon excited fluorescence depolarisation. The thesis presents experimental as well as theoretical progress. We show that a multi-photon induced instrumental response function obtained from a suspension of gold nanoparticles is appropriate for the analysis of two-photon excited fluorescence decays obtained using time-correlated single photon counting detection. Theoretical expressions have been derived for the fluorescence anisotropy decay obtained upon two-photon excitation of various molecular systems in liquid solutions: a) an anisotropic rigid rotor that undergoes rotational diffusion in the presence of ultrafast unresolved restricted reorientations, e.g. librations. b) a molecular group covalently attached to a stationary macromolecule, and undergoing local reorientation in a uniaxial ordering potential. A new approach to the analysis of two-photon excited fluorescence depolarisation experiments was developed, which combines data obtained by using linearly and circularly polarised excitation light, in a global manner. In the analysis, knowledge about unresolved reorientations was obtained from one-photon excitation studies of the corresponding systems. By means of this procedure it has been possible to obtain quantitative information about the molecular two-photon absorption tensor for perylene and two of its derivatives. Thereby the symmetry of the final excited and intermediate vibronic states could be assigned. The analysis reveals that the two-photon transition studied with the 800 nm laser exhibits mixed character. An important finding from the experiments was that the two-photon absorption tensor appears to be solvent dependent. Furthermore, the thesis presents the first theoretical treatment of two-photon excited donor-donor energy migration in the presence of molecular reorientation and which applies the extended Förster theory. Explicit expressions for molecules that belong to the point groups D2h, D2 and C2v are given. Preliminary experiments are finally also reported on a two-photon excited donor-donor energy migration system consisting of a bisanthryl-bisteroid.
Hubert, Christophe. "PROCESSUS DE MIGRATION MOLECULAIRE PHOTO-INDUITE EN MILIEU POLYMERE. APPLICATION A LA REALISATION DE NANOSTRUCTURES ORGANISEES OPTIQUEMENT." Phd thesis, Université Paris Sud - Paris XI, 2003. http://tel.archives-ouvertes.fr/tel-00111028.
Full textAprès un rappel des méthodes classiques de micro et nanostructuration ainsi que des propriétés des polymères azoïques dans le cadre de la création de réseaux de surface, la première partie du manuscrit est consacrée à l'étude de l'influence de divers paramètres expérimentaux sur la formation spontanée de ces structures, parmi lesquels la polarisation du faisceau d'écriture ou bien encore la puissance d'irradiation. Une comparaison des résultats obtenus dans notre cas avec différents processus de structuration photo-assistés déjà étudiés et dont les origines physiques sont clairement établies est ensuite effectuée, ceci afin de déterminer les paramètres clefs gouvernant la création de ces structures hexagonales en même temps que leurs origines.
Dans une seconde partie, une synthèse des différentes expériences réalisées en vue d'évaluer la validité d'effets dits de « feedback optique » tels que ceux observés dans des systèmes de valves à cristaux liquides est effectuée. Ceci a permis de mettre en évidence la difficulté d'interprétation du processus de structuration hexagonal photoinduit : il n'est pas exclu qu'un phénomène de feedback optique soit à l'origine du processus de structuration, mais dans l'état actuel des différentes expériences ayant pu être menées, un phénomène nouveau et original de structuration propre aux polymères azoïques ne peut être écarté afin d'expliquer totalement les différents résultats obtenus.
Enfin, la dernière partie de ce travail est consacrée à la mise en oeuvre de ces structures hexagonales dans des dispositifs photoniques et plus particulièrement dans des diodes électroluminescentes organiques, ceci afin de contrôler leurs propriétés d'émission. Il est notamment démontré que dans le cas d'un pompage optique, due à la diffraction de Bragg, il est possible d'augmenter le rendement d'émission de tels dispositifs en découplant une partie de la lumière initialement guidée dans les différentes couches de la diode. Due à l'orientation hexagonales des structures, l'augmentation du rendement apparaît comme étant plus importante que celle obtenue lors de l'utilisation d'un réseau unidimensionnel.
Hubert, Christophe. "Processus de migration moléculaire photo-induite en milieu polymère : application à la réalisation de nanostructures organisées optiquement." Paris 11, 2003. https://tel.archives-ouvertes.fr/tel-00111028.
Full textThis work deals with the study of a new all optical structuration process of azo-polymer films. We show that the irradiation with normal incidence of an azo-polymer film by a uniform laser beam which wavelength is in the absorption band of the azo-molecules, can lead to the formation of a quasi hexagonal surface relief grating at the surface of a polymer film. After a brief review of different methods of micro and nanostructuration as well as the properties of azo-polymer films in the case of the surface relief gratings formation, we study in the first part of this manuscript the influence of several experimental parameters on the spontaneous optically controlled formation of these photoinduced structures, among them the light polarization direction and the irradiation power. The different results obtained in our case are then compared with different photo-assisted structuration processes already proposed and whose physical origins are clearly established, in order to determine the key parameters governing the formation of these hexagonal structures as well as their origins. In the second part, a synthesis of the different experiments performed in order to evaluate the validity of effects so called "optical feedback effect" observed in liquid crystal light valve systems is performed. The interpretation of the photoinduced hexagonal structuration process appears to be difficult: it is not excluded that an optical feedback phenomenon could be at the origin of the structuration process, but at the present, according to the different experiments performed, a new and original phenomenon of structuration adapted to azo-polymers films cannot be excluded in order to fully explain the different results obtained
Hubert, Christophe. "Processus de migration moléculaire photo-induite en milieu polymère, application à la réalisation de nanostructures organisées optiquement /." Gif-sur-Yvette : CEA Saclay, Direction des systèmes d'information, 2003. http://catalogue.bnf.fr/ark:/12148/cb39167457s.
Full textGuiet, Romain. "Étude des mécanismes cellulaires et moléculaires de la migration des macrophages humains dans des environnements en trois dimensions." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1487/.
Full textTissue infiltration of macrophages is an aggravating factor in many diseases such as chronic inflammation and cancer. Macrophages that infiltrate tumors are called tumor-associated macrophages (TAMs). They promote tumor growth, angiogenesis, invasion and metastasis. Thus, inhibition of macrophage infiltration has become a therapeutic goal. Recently, the team demonstrated that macrophages use the amoeboid (depending on ROCK) or the mesenchymal (depending on proteases) migratory mode according to the extracellular matrix (ECM) architecture in three dimensions (3D). In addition, the study of the mesenchymal migration mode showed that it is dependent on Hck (a phagocyte-specific tyrosine kinase) and its ability to reorganize podosomes (ECM-degrading actin-rich structures) into rosettes. My thesis project was organized around two axes 1) the identification of substrates of Hck and the characterization of their role in the organization of podosomes and 3D migration of macrophages, and 2) the study of the 3D migration mechanisms of primary human monocytes/ macrophages within an in vitro tumor model: tumor cell spheroids. By a proteomic approach, I have identified potential partners and substrates of Hck, including the protein Filamin A (FLNa), a protein interacting with the actin cytoskeleton and integrins. Using different tools (recombinant proteins, antibodies, shRNA. . . ) I showed that: 1) Hck phosphorylates FLNa in vitro, 2) FLNa is localized to podosomes and is necessary for their organization as rosettes under the control of Hck, 3) the podosomes of FLNa-deficient cells have a shorter life span, and 4) the expression of FLNa is required for mesenchymal migration, but not for amoeboid migration of macrophages in a 3D ECM. Thus, FLNa could be a substrate of Hck necessary for the formation and stabilization of podosomes and their organization as rosettes, and is required for the mesenchymal migration of macrophages. In parallel, I developed a model of tumor cell spheroids, which allowed me to show that the infiltration of monocytes or macrophages in this in vitro tissue model of tumor is dependent on ROCK and proteases, signature of the use of the two migration modes. Then, when spheroids were embedded into ECM, I demonstrated that the presence of macrophages infiltrated into the spheroids is necessary to trigger the invasiveness of tumor cells. Indeed, macrophages infiltrate first the surrounding ECM and tumor cells follow macrophages in the matrix outside of the spheroid. Hck-/- macrophages, that are defective in mesenchymal migration, are significantly less effective in promoting the invasion of tumor cells. These results indicate that the activity of migration and matrix remodeling exerted by macrophages is prominent in tumor invasion. These results have established the migratory mode of macrophages infiltrating an in vitro tumor model and a mechanism required for tumor invasiveness promoted by macrophages. Thus during my thesis, I characterized the molecular and cellular mechanisms of 3D migration of human macrophages. Indeed, I have been able to: 1) identify a protein necessary for the mesenchymal migration of macrophages, 2) highlight the use by macrophages of the amoeboid and mesenchymal migration modes during their infiltration into an in vitro tumor model in 3D and 3) show that the matrix remodeling activity of macrophages during their migration plays a critical role in tumor cell invasion
Garrot, Damien. "Etude par microscopie en champ proche des phénomènes de migration de matière photo-induite dans les matériaux photochromiques." Paris 11, 2006. http://www.theses.fr/2006PA112046.
Full textThe main goal of this PhD work is to study photo-induced matter deformation phenomena in thin polymeric film containing azobenzene moieties. This study is based on the in-situ observation of surface relief gratings kinetic of formation under illumination by an interference pattern. The observation relies on a coupled microscopy technique, allowing to correlate photo-induced morphology with the electromagnetic field distribution, with a resolution better than the lattice pitch. The study as a function of the light polarisation and of the film thickness shows that four microscopic mechanisms are involved in the photo-induced deformation of the azo-polymer: the optical reorientation of chromophore, the local reorganization of the matrix, oriented matter transport and the photobleaching. The contribution of these different mechanisms is evidenced by two phenomena observed for the first time. First, the kinetic of deformation presents a transition between two regimes, one, at short time, in phase with the light excitation, the other, at longer time, in opposition of phase. Second, the morphology of the induced relief grating depends strongly on the film thickness. This PhD work shed light on previous and somehow contradictory results, in particular in term of response of azo-polymer films at an excitation in near filed and far field optics
Davies, Christopher W. "Quantification of Optical Parameters Using Frequency Domain Functional Near-Infrared Spectroscopy (FD-fNIRS)." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1559369168541587.
Full textKalinin, Stanislav. "Electronic Energy Transfer within Asymmetric Pairs of Fluorophores: Partial Donor-Donor Energy Migration (PDDEM)." Doctoral thesis, Umeå : Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-338.
Full textPequeño, Bueno Andrea. "Palabras, imágenes, cosas: sentidos de pertenencia y vínculos transnacionales en inmigrados/as chilenos/as en Barcelona, España, a partir de la cultura material visual." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/457428.
Full textMy doctoral research explores identity formation processes and transnational family experiences among Chilean immigrants living in mixed (binational) unions in Barcelona, Spain. In this effort, I pay attention to material culture, with a focus on photography. I analyze immigrants’ displacement trajectories and the conformation of family life and romantic partnerships, as well as ties with the country, culture and nucleus of origin. In sum, I look at the relationships and continuous adjustments that such processes entail and the different identities that come into play (gender, country of origin, socio-professional status, among others). I do this by focusing on the role of objects and images in such life experiences. In tandem, I analyze how these processes are affected by the migrant’s partner (place of origin and characteristics). This research project is ethnographic and qualitative in nature. My fieldwork (undertaken between 2012 and 2015 in the Province of Barcelona, Autonomous Community of Cataluña) is based on participant observation and in-depth interviews. During interviews, I included guided tours of domestic spaces (Hometour) and a shared visualization and discussion of family photos. In some cases, interviewees constructed- through objects and images- narratives about their migration process and couple life. My informants are people who were born in Chile, lived there until they reached the legal age of majority (18 years), and now reside in Barcelona in heterosexual binational unions. They exhibit diverse migratory profiles and motivations (economic, studies and love) as well as varied sociodemographic characteristics. I also included, as a counterpoint, an informant in an endogamic union (Chile/Chile). I included this informant to explore the relative influence of partner’s place of origin on the construction of a sense of belonging and transnational ties. His migratory trajectory (political exile) has contributed to the analytical richness of this study. The biographic particularities and varied sociodemographic characteristics of my interviewees (in terms of gender, age, socio-professional status, time residing in Barcelona, among others) further enrich this study. The methodology I deployed and the analysis of data itself contribute to the understanding of visual and material culture’s social and personal meanings in the experiences of immigrants and in their transnational ties. This research also delves on the ways immigrants represent themselves and the narratives they produce, allowing for a reconstruction of biographic trajectories and family relations, among other aspects. Even though there is a wealth of research on migration and material culture, up until recently few studies approached these two aspects together and the links between them. In this sense, my dissertation is a contribution. This contribution is accentuated by the fact that the Chilean population who has migrated to Cataluña and Spain, receives very scant attention among academic circles, even more so when it comes to considering binational couples. Finally, I would like to add that my doctoral studies were supported by Chile’s government program: Programa Formación de Capital Humano Avanzado, launched by the Comisión Nacional de Investigación Científica y Tecnológica (CONICYT).
Opanasyuk, Oleg. "A new approach to the analyses of fluorescence depolarisation experiments in the presence of electronic energy transport." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-50050.
Full textNorlin, Nils. "Extended Förster Theory of Electronic Energy Transport within Pairs of Reorienting Chromophoric Molecules." Doctoral thesis, Umeå universitet, Kemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-22471.
Full textBanks, Aaron M. "The seasonal movements and dynamics of migrating humpback whales off the east coast of Africa." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4109.
Full textROCHA, Bruno César Luz Macena. "Estudo da sazonalidade, distribuição, abundância e comportamento migratório do tubarão-baleia (Rhincodon typus Smith, 1828) no Arquipélago de São Pedro e São Paulo." Universidade Federal Rural de Pernambuco, 2010. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6245.
Full textMade available in DSpace on 2017-02-08T15:28:37Z (GMT). No. of bitstreams: 1 Bruno Cesar Luz Macena Rocha.pdf: 2783358 bytes, checksum: 0c7cc3375d48be56cad1fcf79ba55824 (MD5) Previous issue date: 2010-06-17
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
In Saint Peter and Saint Paul archipelago (SPSPA), located at mid-Atlantic ridge, near to Equator line, population aspects of whale sharks was analized through in situ observation on distribution, seasonality, different behavior, and photo-identification. The movements of whale sharks was tracked using two models of satellite tag: SAT (Satellite Argos-linked transmitter) and PSAT (Pop up satellite archival transmitting tag) in one male (TB-01; 4.8 m) and one female (TB-02; 8.5 m),respectively. Whale shark occur in SPSP adjacencies yearround,although, are more abundant in the first semester, mainly, in February, March, and June. The annual record mean was 10.8 year-1 between 2000 and 2009. The size ranges from 1.8 to 14.0 m with mean± s.d. equal to 7.4± 2.4 m and the majority (62.9%) of whale sharks smaller than 9.0 m, under the estimated size at first maturation. Data received from Argos Satellite system indicate that the whale shark swam away from archipelago heading west. Both sharks spent the major of the time at surface, and the TB-02 dove into bathypelagic zone, attaining the maximum depth of 1,976 m. This was the first initiative to understand behavioral and population dynamics aspects of the whale sharks as well as the movement in Brazil and Equatorial Atlantic from SPSPA and will continue in the hope of building better conservation strategies.
No Arquipélago de São Pedro e São Paulo (ASPSP), localizado na dorsal meso-Atlântica, próximo à linha do Equador, foram analisados aspectos da população do tubarão baleia por meio de observação in situ. Informações sobre a distribuição e sazonalidade de ocorrência, diferentes comportamentos foram coletados e, quando possível, os espécimes foram fotografados para posterior individualização. Para elucidação do deslocamento do tubarão-baleia, a partir do ASPSP, foram utilizados dois modelos de transmissores via satélite, o SAT (Satellite Argos-linked tag) e o PSAT (Pop up satellite archival transmitting tag) em um macho (TB-01) e uma fêmea (TB-02) de 4,8 e 8,5 m, respectivamente. Os tubarões-baleia visitam o arquipélago durante o ano inteiro, entretanto, o primeiro semestre possui uma frequência mais elevada, principalmente nos meses de fevereiro, março e junho. A média anual de registros foi 10,8 ano-1 entre 2000 e 2009. Os comprimentos variaram entre 1,8 e 14,0 m com média± d.p. igual a 7,4± 2,4 m, com a maior parte (62,9%) dos tubarõesbaleia com comprimento abaixo do tamanho estimado para primeira maturação. Os dados dos transmissores recebidos pelo Sistema Argos de satélites indicaram que os tubarões se afastaram do ASPSP, logo após a marcação, em direção oeste. Ambos os tubarões permaneceram a maior parte do tempo na superfície e o TB-02 realizou mergulhos batipelágicos alcançando a profundidade máxima de 1.976 m. Esta foi a primeira iniciativa para se compreender aspectos populacionais e comportamentais, bem como da movimentação de tubarões-baleia no Brasil e no Atlântico Equatorial a partir do ASPSP e terá continuidade na expectativa de construir de estratégias espaciais de conservação.
Yang, Lei. "Hole Transport Materials for Solid-State Mesoscopic Solar Cells." Doctoral thesis, Uppsala universitet, Fysikalisk kemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-232271.
Full textBernert, Constantin. "Untersuchung photorefraktiver Materialien mittels optischer Ptychographie." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-216063.
Full textIn the present thesis the novel microscopy technique of ptychography is applied to the investigation of photorefractive materials. Photorefractive materials exhibit a change of the refractive index due to the exposure to light. The method of ptychography determines the refractive index change of the material together with the intensity distribution of the laser beam that was used for its generation. In one part of the experiment the time dependence of the refractive index change versus the generation time is investigated, in the other part of the experiment the dependence of the refractive index change to the polarisation of the laser beam is examined. Microscopic parameters of the photorefractive charge migration are determined with the utilisation of a numerical simulation of the photorefractive effect and its comparison with the measurement. Finally, the whole space charge field with the corresponding space charge density is calculated from a set of ptychographic measurements of one refractive index change with different polarisation directions of the laser. The presented experiments and their evaluation show, that the method of ptychography opens a new possibility for a quantitative understanding of the photorefractive effect
SAVO, ROMOLO. "Transport in Complex Heterogeneous Photonic Structures." Doctoral thesis, 2013. http://hdl.handle.net/2158/797466.
Full textLin, Huang-Yi, and 林皇屹. "High frequency photon migration spectroscopy by mode locked laser." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/75683869600540789694.
Full text國立交通大學
照明與能源光電研究所
102
In this paper, we use the higher-order-harmonic modulations of mode-locked laser pulses to offer multiple modulation frequencies for Frequency Domain Photon Migration (FDPM) System. Combined with a demodulation circuit, we demonstrate a GHz FDPM system, which breaks the bandwidth limitation of modulated source. In addition,for future clinical applications, we build a portable mode- locked Yb-fiber laser.
Hoffmann, Joe. "Three-Dimensional Biomimetic Patterning to Guide Cellular Migration and Organization." Thesis, 2012. http://hdl.handle.net/1911/71659.
Full textPo-AnChen and 陳柏安. "Investigation and Design of Miniature Receivers for Non-Invasive Frequency Domain Photon Migration Examination Systems." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/yrbjh6.
Full text國立成功大學
電機工程學系
102
Two miniature FDPM receivers is achieved in this thesis to replace the partial function of the NA-based system. Due to the compact receiver, it can be cost-down and be portable. The first one is a separate signal sources structure with extra phase error elimination. Also, Noise analysis is applied to estimate the system performance. The second receiver is a joint signal source structure to reduce the number of high frequency signal sources. Phase cancellation problem caused by joint signal source is solved by adding image rejection mixer. Severe amplitude variation caused by signal non-synchronous can also be solved by the joint signal source structure. The average amplitude and phase error of the separate structure are less than 8 % and 0.2°, respectively. The error of absorb and scatter coefficient are about 10 % and 3 %, respectively. Also, the average amplitude and phase error of the joint structure are less than 2.5% and 0.35°. The error of absorb and scattering coefficient are about 4.67 % and 3.38 %, respectively. These results show that the miniature receivers can achieve low error compared to the NA-based system with thousand times cheaper and much smaller size.
Ming-CingWang and 王銘慶. "Variation of Glucose Concentration in Tissue Phantom Monitored with a Frequency Domain Photon Migration System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90739157622952838873.
Full text國立成功大學
光電科學與工程學系
101
In this thesis, we demonstrate the use of optical method, frequency domain photon migration system (FDPM), to determine physiological parameters of biological tissues. It use a 808 nm laser diode as the light source coupled with mathematical photon transport models to accurately determine optical absorption (µa) and reduced scattering (µs′) properties of phantoms. Here, we employed the fiber probe with the FDPM technique to quantify the optical properties of in-vitro phantom. First, we use FDPM system to measure five glucose concentration liquid phantoms of various absorption and scattering properties. Second, we speculate that resolve the slight variation of optical properties is the advantage of the broad bandwidth FDPM system by using the diffusion model. Third, we implement the scaling Monte Carlo method by using Matlab. The scaling method can reduce computation time by nearly 5 orders of magnitude, and the error is less than 3% which is compared with the original Monte Carlo algorithm. The scaling Monte Carlo algorithm can be used obtain spatially resolved reflectance spectra of tissue with different optical parameters without significantly affecting simulation time. Finally, we speculate that resolve the slight variation of optical properties in scaling Monte Carlo method is 100 mg/dl. In addition, we combine the simulated result at 808 and 1550 nm with the specific advantage. Our study reveals that the FDPM system provides a fast and noninvasive way for tissue composition quantification.
Shang-PinYeh and 葉上賓. "Measuring the Optical Properties of Superficial Turbid Sample Using the Steady State Frequency Domain Photon Migration System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/68135953063422377774.
Full text國立成功大學
光電科學與工程學系
100
In this thesis, we demonstrate the use of optical method, steady state frequency domain photon migration system (SSFDPM), to determine physiological parameters of biological tissues. It uses near-infrared light (from 600 to 1100 nm) coupled with mathematical photon transport models to accurately determine optical absorption (µa) and reduced scattering (µs′) properties of tissues. Absorption coefficient (µa) and reduced scattering coefficient (µs′) can be used to determine the chromophore concentrations, such as oxygenated hemoglobin, deoxygenated hemoglobin, water, and lipid, of biological tissues. Here, we employed the diffusing probe with the SSFDPM technique to quantify the optical properties of in-vivo skin. First, we characterize the stability of the amplitude and phase of the frequency domain photon migration system (FDPM) so that we can understand the limitations of our system. Second, we prepare four samples of different absorption to study the system linearity. Third, we use FDPM system to measure six liquid phantoms of various absorption and scattering properties. Finally, we combine the steady state (SS) and FDPM which is called SSFDPM to measure the liquid phantom, and quantify the chromophore concentrations of liquid phantoms. In addition, we carry out SSFDPM measurements on the in-vivo dorsal forearm and show the quantitative physiological concentration and compare with SS measurements. Our study reveals that the SSFDPM system provides a fast and noninvasive way for tissue composition quantification.
Ming-WeiLee and 李銘偉. "Using a frequency domain photon migration system in the reflectance mode for rapidly quantifying the tissue oxygen saturation and arterial oxygen saturation." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8dh69m.
Full text國立成功大學
光電科學與工程學系
103
A frequency domain photon migration system in the reflectance mode for rapidly quantifying the tissue oxygen saturation and arterial oxygen saturation are presented in this study. The proposed system improves the shortcomings and limitations of the commercial pulse oximeters, including the reflectance mode overcomes the position limits of the transmissive mode, while the advantages of measuremental method can simultaneously measure the tissue oxygen saturation and arterial oxygen saturation and widely measuring range of arterial oxygen saturation. The results presented in the frequency domain photon migration system, we rapidly measured the accuracy of optical properties and mean absolute percentage error in three wavelengths which from 1.3% to about 11%, indicating the accuracy of optical properties within a reasonable range. In vivo experiments we measured six healthy adults totally, four men and two women, the measured positions include two parts: fingers and palm, measured environment is under static stability and under pressure with 60mmHg reached vein atresia. We analyzed the absorption coefficient, reduced scattering coefficient for each wavelength, oxy-hemoglobin concentration, deoxy-hemoglobin concentration, tissue oxygen saturation, pulsating with change amount of oxy-hemoglobin concentration and deoxy-hemoglobin concentration, arterial oxygen saturation, and optical properties of frequency domain response analysis information for each wavelength. The system can provide a wealth of physiological information, but relatively stability of the system is very important. In vivo experiments in Section 4.3, stability of the system can become better. We will improve the stability of the system for the first goal in future work.
Po-JungHuang and 黃柏蓉. "Determination of the skin optical properties from frequency domain photon migration measurements carried out at source to detector separations shorter than 3 mm." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/fef4b5.
Full text國立成功大學
光電科學與工程學系
103
In this study, we propose a method to measure human skin with SDS = 1mm by FDPM system. In order to improve the shortcomings of traditional photon propagation model, we established a new photon propagation model which combined the GPU-MCML and ANN method to derive the sample absorption coefficient、reduced scattering coefficient corresponding to the amplitude and phase delay with the frequency. The new model can substitute traditional Monte Carlo model and standard diffusion equation which have some using limitation. In simulation, Monte Carlo is considered as a gold standard model of photon propagation. However it consumes lots of time to do the simulation. Compared with Monte Carlo, the percent deviation of amplitude and phase which simulated by artificial neural networks are about 4% and 6%, respectively. In the other hand, comparing with Monte Carlo, the percent deviation of amplitude and phase which simulated by standard diffusion equation are about 30% and 17%, respectively. Therefore compared with diffusion equation the new model with a 1mm source to detector separation indeed has its absolute advantage. We also use the homogeneous phantom which optical properties is known to confirm the feasibility of the artificial neural networks model. In experience,we measured three position of three healthy adults, including the finger, the inner forearm and outer forearm with the artificial neural networks model extrapolated absorption coefficient、reduced scattering coefficient with three wavelengths. And then we put the absorption coefficient into the chromophore fitting to quantify the chromophore concentrations of tissue and StO2. In conclusion, our new artificial neural networks model has better efficiency and wider applied range than other traditional model, which can accurately calculate the optical properties of the superficial skin tissue.
RAHARIMANITRA, Fabia Nirina. "Contribution à l'étude des architectures basées sur le multiplexage en temps et en longueur d'onde dans le réseau d'accès, permettant la migration vers la nouvelle génération de PON (NG-PON) à 10 Gbits/s." Phd thesis, 2012. http://tel.archives-ouvertes.fr/tel-00740848.
Full textGibb, Giselle Renee. "Humpback whales (Megaptera novaeangliae) in the South Pacific breeding grounds : an allocation from feeding areas and an abundance estimate of whales specific to French Polynesia waters." Thesis, 2009. http://hdl.handle.net/1957/11995.
Full textGraduation date: 2010
Henriques, Renato F. "Monitorização da zona costeira tendo em vista a sua vulnerabilidade – aplicação à zona costeira noroeste de Portugal." Doctoral thesis, 2007. http://hdl.handle.net/1822/42711.
Full textA elevada dinâmica que caracteriza a zona costeira portuguesa tem implicações directas para as comunidades humanas aí instaladas. Nos últimos anos agudizou-se, nalguns locais, a migração para o interior do sistema praia/duna, pondo em perigo algumas localidades e levando ao aumento da construção de obras de defesa costeira, por vezes feitas com carácter de emergência. O aumento do conhecimento sobre o comportamento dinâmico das zonas costeiras é um contributo fundamental para a elaboração de planos de gestão integrada destas zonas. A monitorização contínua é a melhor forma de obter dados que permitam conhecer a sua tendência evolutiva, possibilitando a previsão de cenários futuros. Este trabalho deve ser estendido a toda a costa portuguesa, ser baseado em meios técnicos diversificados e realizado com a maior frequência possível. Se a monitorização for realizada com técnicas demasiado caras, a eficácia desejada deste importante trabalho pode ser comprometida. A presente dissertação centrou-se no desenvolvimento de técnicas de monitorização de baixo custo, baseadas em fotografia aérea. Foram desenvolvidos protótipos de obtenção de fotografia aérea utilizando poucos recursos económicos, mas com qualidade suficiente para ser utilizada na monitorização das mudanças nas zonas costeiras. Foram escolhidos três segmentos da costa noroeste de Portugal, situados entre a Praia de Cortegaça e a Praia de Mira, para os quais foi feita a comparação entre a fotografia obtida com os protótipos desenvolvidos e a fotografia histórica existente. A partir deste trabalho, foi possível calcular taxas médias de migração, ao longo de diversos períodos temporais, a partir da medição da mobilidade de indicadores de migração costeira. Foi, também, possível, conjugando a fotografia aérea com técnicas de SIG, estudar a ocorrência de galgamentos marinhos na região entre o Furadouro e a praia do Torrão do Lameiro. Tendo em conta que o conhecimento da dinâmica costeira não pode ser dissociado do conhecimento dos sedimentos em movimento, foi realizada uma colheita de sedimentos na praia e na plataforma continental adjacente, na região do Furadouro. Embora tenham sido colhidas poucas amostras, foi já possível detectar alguns padrões na distribuição de sedimentos; foram identificadas diferenças entre a dimensão dos sedimentos colhidos a mais de 1000 metros da costa e a dos colhidos na praia e na pré-praia.
The high dynamical behaviour that characterizes the Portuguese coastal zone has direct implications for the human communities installed there. During the last years, inland migration of the dune/beach system has increased, putting some localities in danger and leading to the increased building of hard engineering coastal defences, sometimes with emergency character. The increased knowledge about the dynamic behaviour of the coastal zones is an important contribution to integrated coastal zone management (ICZM). Continuous monitoring is the best form of gathering important information that allows a better knowledge of the past evolution trend, making the forecast of future scenarios possible. This work should be extended to the total extend of the Portuguese coast, based on diversified techniques and carried out at the highest frequency. If based on expensive techniques, the desired effectiveness of this important work can be compromised. The present work was focused on the development of low-cost monitoring techniques, based on aerial photography. Prototypes for air photograph achievement has been developed, using low-cost resources, but with enough quality to be used for the surveying of coastal zone changes. Three segments of the Northwest coastal zone of Portugal, located between Cortegaça Beach and Mira Beach, were chosen. The comparison between photographs got with the developed prototypes and the existing historical photographs was done in those segments. With this work, it was possible to calculate average migration rates over different time periods, from the measurement of the mobility of coastal migration indicators. Through the combination of aerial photography with GIS techniques, it was also possible to study the occurrence of marine overwashes in the area between Furadouro and the beach of Torrão do Lameiro. Taking into account that the knowledge of coastal dynamics cannot be dissociated from the knowledge of the sediments in movement, a sampling of sediments from the beach and the adjacent continental shelf was carried out in the area of Furadouro. Although few samples were collected, some patterns in the distribution of sediments were recognized and size differences identified between sediments sampled at about 1000 meters from the coast and those sampled on the beach and in the nearshore.
Fundação para a Ciência e Tecnologia (FCT)
PATTELLI, LORENZO. "Imaging light transport at the femtosecond scale: a walk on the wild side of diffusion." Doctoral thesis, 2017. http://hdl.handle.net/2158/1087854.
Full textPattelli, Lorenzo. "Imaging light transport at the femtosecond scale." Doctoral thesis, 2018. http://hdl.handle.net/2158/1157248.
Full textBernert, Constantin. "Untersuchung photorefraktiver Materialien mittels optischer Ptychographie." Master's thesis, 2016. https://tud.qucosa.de/id/qucosa%3A30065.
Full textIn the present thesis the novel microscopy technique of ptychography is applied to the investigation of photorefractive materials. Photorefractive materials exhibit a change of the refractive index due to the exposure to light. The method of ptychography determines the refractive index change of the material together with the intensity distribution of the laser beam that was used for its generation. In one part of the experiment the time dependence of the refractive index change versus the generation time is investigated, in the other part of the experiment the dependence of the refractive index change to the polarisation of the laser beam is examined. Microscopic parameters of the photorefractive charge migration are determined with the utilisation of a numerical simulation of the photorefractive effect and its comparison with the measurement. Finally, the whole space charge field with the corresponding space charge density is calculated from a set of ptychographic measurements of one refractive index change with different polarisation directions of the laser. The presented experiments and their evaluation show, that the method of ptychography opens a new possibility for a quantitative understanding of the photorefractive effect.:1 Einleitung 2 Theoretische Vorbetrachtungen 2.1 Ptychographie 2.1.1 Messung 2.1.2 Modell und Rekonstruktion 2.1.3 Ortsauflösung 2.2 Photorefraktiver Efekt 2.2.1 Lithiumniobat - Musterbeispiel für die Photorefraktivität 2.2.2 Ein-Zentrum-Modell 2.2.3 Brechungsindexänderung 2.2.4 Hohe Intensitäten 2.3 Raumladungsfeld 2.3.1 Ableitung des Feldes aus den Messgrößen 2.3.2 Raumladungsverteilung 2.3.3 Oberflächendeformation 2.3.4 Dynamik der Ladungen und des Feldes 3 Messungen 3.1 Proben 3.1.1 Ptychographische Teststruktur 3.1.2 LiNbO3:Fe 3.2 Versuchsanordnung 3.2.1 Experimenteller Aufbau 3.2.2 Grenze der Ortsauflösung 3.2.3 Charakterisierung des Laserstrahls 3.2.4 Experimentelle Überprüfung der Näherungen 3.3 Dynamik der Brechungsindexänderung 3.4 Polarisationsabhängigkeit der Brechungsindexänderung 4 Auswertung 4.1 Dynamik des Raumladungsfeldes und der Ladungen 4.1.1 Simulation 4.1.2 Vergleich zwischen Messung und Simulation 4.1.3 Dynamik der Ladungsverteilung 4.1.4 Fazit 4.2 Berechnung des Raumladungsfeldes 4.2.1 Raumladungsfeld und Ladungsverteilung 4.2.2 Simulation 4.2.3 Asymmetrie der Ladungsverteilung 4.2.4 Fazit 5 Zusammenfassung Appendizes A Physikalische Konstanten B Tensoren für LiNbO3 C Ungenäherte Herleitung der Brechungsindexänderung D Implementierung eines iterativen Verfahrens zur Bestimmung der Dynamik des Ein-Zentrum-Modells E Quelltext der Implementierung des iterativen Verfahrens Literaturverzeichnis