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1
Petracca, Fernanda <1983>. "Constraints on neutrino mass fraction using Redshift Space Distortions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6728/1/Fernanda_Petracca_tesi.pdf.
Full textAbstract:
Redshift Space Distortions (RSD) are an apparent anisotropy in the distribution of galaxies due to their peculiar motion.
These features are imprinted in the correlation function of galaxies, which describes how these structures distribute around each other. RSD can be represented by a distortions parameter $\beta$, which is strictly related to the growth of cosmic structures.
For this reason, measurements of RSD can be exploited to give constraints on the cosmological parameters, such us for example the neutrino mass.
Neutrinos are neutral subatomic particles that come with three flavours, the electron, the muon and the tau neutrino. Their mass differences can be measured in the oscillation experiments.
Information on the absolute scale of neutrino mass can come from cosmology, since neutrinos leave a characteristic imprint on the large scale structure of the universe.
The aim of this thesis is to provide constraints on the accuracy with which neutrino mass can be estimated when expoiting measurements of RSD. In particular we want to describe how the error on the neutrino mass estimate depends on three fundamental parameters of a galaxy redshift survey: the density of the catalogue, the bias of the sample considered and the volume observed.
In doing this we make use of the BASICC Simulation from which we extract a series of dark matter halo catalogues, characterized by different value of bias, density and volume.
This mock data are analysed via a Markov Chain Monte Carlo procedure, in order to estimate the neutrino mass fraction, using the software package CosmoMC, which has been conveniently modified.
In this way we are able to extract a fitting formula describing our measurements, which can be used to forecast the precision reachable in future surveys like Euclid, using this kind of observations.
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Petracca, Fernanda <1983>. "Constraints on neutrino mass fraction using Redshift Space Distortions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6728/.
Full textAbstract:
Redshift Space Distortions (RSD) are an apparent anisotropy in the distribution of galaxies due to their peculiar motion.
These features are imprinted in the correlation function of galaxies, which describes how these structures distribute around each other. RSD can be represented by a distortions parameter $\beta$, which is strictly related to the growth of cosmic structures.
For this reason, measurements of RSD can be exploited to give constraints on the cosmological parameters, such us for example the neutrino mass.
Neutrinos are neutral subatomic particles that come with three flavours, the electron, the muon and the tau neutrino. Their mass differences can be measured in the oscillation experiments.
Information on the absolute scale of neutrino mass can come from cosmology, since neutrinos leave a characteristic imprint on the large scale structure of the universe.
The aim of this thesis is to provide constraints on the accuracy with which neutrino mass can be estimated when expoiting measurements of RSD. In particular we want to describe how the error on the neutrino mass estimate depends on three fundamental parameters of a galaxy redshift survey: the density of the catalogue, the bias of the sample considered and the volume observed.
In doing this we make use of the BASICC Simulation from which we extract a series of dark matter halo catalogues, characterized by different value of bias, density and volume.
This mock data are analysed via a Markov Chain Monte Carlo procedure, in order to estimate the neutrino mass fraction, using the software package CosmoMC, which has been conveniently modified.
In this way we are able to extract a fitting formula describing our measurements, which can be used to forecast the precision reachable in future surveys like Euclid, using this kind of observations.
3
Barratt, Ian Robert. "Radiometric determination of the true mass flow rate of solids in a pneumatic suspension." Thesis, University of Greenwich, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313221.
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Melia, F. "Constancy of the cluster gas mass fraction in the Rh=ct Universe." The Royal Society, 2016. http://hdl.handle.net/10150/615118.
Full textAbstract:
The ratio of baryonic to dark matter densities is assumed to have remained
constant throughout the formation of structure. With this, simulations
show that the fraction $f_{\rm gas}(z)$ of baryonic mass to total mass in
galaxy clusters should be nearly constant with redshift $z$. However,
the measurement of these quantities depends on the angular distance to the source,
which evolves with $z$ according to the assumed background cosmology. An accurate
determination of $f_{\rm gas}(z)$ for a large sample of hot ($kT_e> 5$ keV),
dynamically relaxed clusters could therefore be used as a probe of the
cosmological expansion up to $z< 2$. The fraction $f_{\rm gas}(z)$
would remain constant only when the ``correct" cosmology is used to fit the data.
In this paper, we compare the predicted gas mass fractions for both $\Lambda$CDM
and the $R_{\rm h}=ct$ Universe and test them against the 3 largest cluster samples
\cite{1,2,3}. We show that $R_{\rm h}=ct$ is consistent with a constant
$f_{\rm gas}$ in the redshift range $z\lesssim 2$, as was previously shown
for the reference $\Lambda$CDM model (with parameter values $H_0=70$ km s$^{-1}$
Mpc$^{-1}$, $\Omega_m=0.3$ and $w_\Lambda=-1$). Unlike $\Lambda$CDM, however,
the $R_{\rm h}=ct$ Universe has no free parameters to optimize in fitting the
data. Model selection tools, such as the Akaike Information Criterion (AIC)
and the Bayes Information Criterion (BIC), therefore tend to favor
$R_{\rm h}=ct$ over $\Lambda$CDM. For example, the BIC favours $R_{\rm h}=ct$
with a likelihood of $\sim 95\%$ versus $\sim 5\%$ for $\Lambda$CDM.
5
Tunc, Mehmet Sefik. "Relationship between Alkaline Pulp Yield and the Mass Fraction and Degree of Polymerization of Cellulose in Pulp." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/TuncMS2003.pdf.
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Srzic, Veljko. "Significance of transport dynamics on concentration statistics and expected mass fraction based risk assessment in the subsurface." Doctoral thesis, KTH, Mark- och vattenteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133455.
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This thesis relies on a Langrangian framework used for conservative tracer transport simulations through 2-D heterogeneous porous media. Conducted numerical simulations enable large sets of concentration values in both spatial and temporal domains. In addition to the advection, which acts on all scales, an additional mechanism considered is local scale dispersion (LSD), accounting for both mechanical dispersion and molecular diffusion. The ratio between these two mechanisms is quantified by the Peclet (Pe) number. In its base, the thesis gives answers to contaminant concentration features when influenced by: i) different log-conductivity variance; ii) log-conductivity structures defined by the same global variogram but with different log conductivity patterns cor-related; and iii) for a wide range of Peclet values. Results conducted by Monte Carlo (MC) analysis show a complex interplay between the aforementioned pa-rameters, indicating the influence of aquifer properties to temporal LSD evolu-tion. A stochastic characterization of the concentration scalar is done through moment analysis: mean, coefficient of variation (CVC), skewness and kurtosis as well as through the concentration probability density function (PDF). A re-markable collapse of higher order to second-order concentration moments leads to the conclusion that only two concentration moments are required for an accurate description of concentration fluctuations. This explicitly holds for the pure advection case, while in the case of LSD presence the Moment Deriv-ing Function (MDF) is involved to ensure the moment collapse validity. Fur-thermore, the expected mass fraction (EMF) concept is applied in groundwater transport. In its origin, EMF is function of the concentration but with lower number of realizations needed for its determination, compared to the one point PDF. From practical point of view, EMF excludes meandering effect and incorporates information about exposure time for each non-zero concentration value present. Also, it is shown that EMF is able to clearly reflect the effects of aquifer heterogeneity and structure as well as the Pe value. To demonstrate the uniqueness of the moment collapse feature and ability of the Beta distribution to account for the concentration frequencies even in real cases, Macrodisper-sion Experiment (MADE1) data sets are used.QC 20131104
7
Vogel, Alexander L. [Verfasser]. "Complementary mass spectrometric techniques for the characterization of the organic fraction in atmospheric aerosols / Alexander L. Vogel." Mainz : Universitätsbibliothek Mainz, 2014. http://d-nb.info/1048498255/34.
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LAZZATI, ZELDA. "Speciation of particulate matter's organic fraction and its mechanis of action on human health." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7466.
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Three main researches have been employed for the implementation of a protocol analysis for the characterization and quantification of the lignin fraction in the particulate matter at the concentration matrix level; the implementation of different methods of analysis of the toxic interesting pollutants, Oxy-PAHs; Nitro-PAHs and the Bisphenol A, that together with the large set of performed analysis, allowed the characterization of some PM fractions in relation with Indoor and Outdoor concentrations, human exposure and Urban – Rural – Remote sites composition. At last an in silica method was developed for the research of the proteins involved in the interaction with the pollutants of interest, optimized on Bisphenol A because of its history and recent interaction study with the Nuclear Receptors. From the involved pathway the Blood Serine Proteases are used to test the accuracy and reproducibility of obtained Autodock4.0 and Dock4.0 data. The method results useful for research on the biological mechanism of action in relation with both matrix concentrations and in vivo and in vitro studies. The data predicted will be confirmed by NMR analysis. The newest docking program gives more and more reproducible data, accurate and empirically shaped on the domain problem, at last the experimental data had to confirm or not confirm the predictions.
9
Golon, Agnieszka [Verfasser]. "Characterization of complex mixtures of the light shredder waste fraction and caramelization processes by mass spectrometry / Agnieszka Golon." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2013. http://d-nb.info/1037012488/34.
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Capasso, Raffaella. "The gas mass fraction and the dynamical state in x-ray luminous clusters of galaxies at low redshift." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7913/.
Full textAbstract:
Gli ammassi di galassie sono le strutture gravitazionalmente legate con le più profonde buche di potenziale, pertanto è previsto che questi contengano una frazione di barioni non molto diversa da quella cosmologica.
Con l’introduzione di modelli sempre più accurati di fisica barionica all’interno di simulazioni idrodinamiche è stato possibile predire la percentuale cosmica di barioni presente negli ammassi di galassie.
Unendo questi modelli previsionali con misure della frazione di gas in ammassi e informazioni sulla densità di barioni dell’Universo si può ottenere una stima della densità di materia cosmica Ωm.
L'obiettivo di questo lavoro di Tesi è la stima di Ωm a partire dalla frazione di gas osservata in questi sistemi.
Questo lavoro era stato già fatto in precedenza, ma tenendo in considerazione solo gli ammassi più massivi e dinamicamente rilassati.
Usando parametri che caratterizzano la morfologia della distribuzione di brillanza superficiale nei raggi X, abbiamo classificato i nostri oggetti come rilassati o disturbati, laddove presentassero evidenze di recenti attività di interazione. Abbiamo dunque valutato l’impatto degli oggetti disturbati sulla stima del parametro cosmologico Ωm, computando il Chi2 tra la frazione di massa barionica nell’Universo e quella da noi ricavata. Infine abbiamo investigato una relazione tra il valore della frazione di gas degli ammassi rilassati e quello dei disturbati, in modo da correggere quindi questi ultimi, riportandoli nei dintorni del valore medio per i rilassati e usarli per ampliare il campione e porre un vincolo più stringente su Ωm.
Anche con il limitato campione a nostra disposizione, è stato possibile porre un vincolo più stretto su Ωm, utilizzando un maggior numero di oggetti e riducendo così l’errore statistico.
11
Whiston, Philip John. "Measurement of mass fraction burnt and turbulent burning velocity in a four cylinder spark ignition engine fuelled with simulated biogas." Thesis, Staffordshire University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293557.
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Hennig, C., J. J. Mohr, A. Zenteno, S. Desai, J. P. Dietrich, S. Bocquet, V. Strazzullo, et al. "Galaxy Populations in Massive Galaxy Clusters to z = 1.1: Color Distribution, Concentration, Halo Occupation Number and Red Sequence Fraction." OXFORD UNIV PRESS, 2017. http://hdl.handle.net/10150/623801.
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We study the galaxy populations in 74 Sunyaev-Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z similar to 1.1 with 4 x 10(14)M(circle dot) <= M-200 <= 3 x 10(15)M(circle dot). Using the band containing the 4000 angstrom break and its redward neighbour, we study the colour-magnitude distributions of cluster galaxies to similar to m(*) + 2, finding that: (1) The intrinsic rest frame g - r colour width of the red sequence (RS) population is similar to 0.03 out to z similar to 0.85 with a preference for an increase to similar to 0.07 at z = 1, and (2) the prominence of the RS declines beyond z similar to 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R(200) with a concentration of c(g) = 3.59(-0.18)(+0.20), 5.37(-0.24)(+0.27) and 1.38(-0.19)(+0.21) for the full, the RS and the blue non-RS populations, respectively, but with similar to 40 per cent to 55 per cent cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N-200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The RS fraction within R-200 is (68 +/- 3) per cent at z = 0.46, varies from similar to 55 per cent at z = 1 to similar to 80 per cent at z = 0.1 and exhibits intrinsic variation among
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Warburton, Charles Arthur. "The effect of sludge age and aerobic sludge mass fraction on low F/M filament bulking in intermittent aeration nitrogen removal systems." Master's thesis, University of Cape Town, 1991. http://hdl.handle.net/11427/22119.
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Since 1989 a wide ranging program of research has been under way to identify the factors that effect low F/M filament proliferation. Completed work has established an important factor conducive to low F /M filament proliferation - the presence of anoxic and aerobic zones, or, alternating anoxic-aerobic conditions in a system. It was also established that the presence or absence of readily biodegradable COD (RBCOD) or slowly biodegradable COD (SBCOD) were not deciding factors in their proliferation. The research presented in this thesis focuses on the effects of; • sludge age, • magnitude of the aerobic mass fraction, • magnitude of the nitrate concentration during the anoxic period, on the low F /M filaments. The experimental set-up consisted of two intermittently. aerated anoxic-aerobic (20 minute cycles, peak DO 2 to 2,5 mgO/l), single reactor completely mixed continuously fed systems. The experimental investigation was chronologically divided into 3 phases and examined the effect of the following conditions on the low F/M filaments.
14
Wanchoo, Rohan. "Modeling and Numerical Simulation of Multi-Species Flow in a Fiberglass Reinforced Plastic Boat Manufacturing Plant." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1236057306.
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Gaie-Levrel, François. "Développement d'un instrument d'analyse physico-chimique en temps réel pour l'étude de la fraction organique de l'aérosol atmosphérique : SPLAM : Single particle Laser Ablation Mass Spectrometry." Paris 7, 2009. http://www.theses.fr/2009PA077038.
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Part omniprésente de l'atmosphère, les aérosols atmosphériques sont connus pour être impliqués dans la chimie hétérogène atmosphérique et pour leurs impacts tant climatique que sanitaire. De nos jours, ces effets sont encore mal connus notamment en raison de la caractérisation encore incomplète de la composition chimique des aérosols atmosphériques et plus particulièrement de la fraction organique secondaire (AOS). Une meilleure connaissance du cycle de vie des AOS permettrait alors de mieux comprendre leurs impacts. Ce travail de thèse, mené dans cet objectif, a consisté à développer et caractériser un instrument d'analyse de particules individuelles en temps réel pour l'étude d'AOS produits en chambre de simulation atmosphérique (CSA) complémentaire aux techniques d'analyses traditionnelles. Ce développement a porté sur les trois étapes qui composent cet instrument : (1)- un système de lentilles aérodynamiques permet d'introduire les particules au sein de l'instrument sous la forme d'un faisceau de particules peu divergent (2) - une chambre de détection optique, composée de deux laser continus à 403 nm, permet de déterminer k taille des particules détectées et de déclencher un laser excimère (KrF, 248 nm) qui permet leur vaporisation et leur ionisation (3) - un spectromètre de masse à temps de vol (TOF-MS) linéaire permet l'analyse des ions produits lors de l'impulsion du laser excimère et donc l'accès à la composition chimique des particules individuelles précédemment détectées. Finalement, les premières expériences sur des aérosols modèles ainsi que sur des AOS produits en CSA ont permis de valider le principe d'analyse particule par particule de cet instrumentAtmospheric aerosols are known to impact on human health, atmospheric chemistry and climate. To date, these effects are still poorly understood, partly due to incomplete characterisation of aerosol chemical composition, in particular its secondary organic fraction (SOA). A better comprehension of the SOA formation and ageing mechanisms allows a better understanding of these impacts. In this context, this thesis work was dedicated to the development and the characterisation of an analytical technique of individual particles in real time for the SOA studies produced in smog chamber. The three parts of the instrument were developed : (1) - an aerodynamic lens System which permits the introduction of a beam of very low divergence of particles into the instrument (2) - an optical detection chamber, composed of two continuous laser at 403 nm, which permits to size the detected particles and to trigger a KrF eximer laser (248 nm) allowing for their vaporisation and ionisation (3) a linear time-of-flight mass spectromeier (TOF-MS) which analyses the ions produced during the excimer laser pulse and therefore gives access to the chemical composition of individual particles detected in the second part of the instrument. Finally, the first experiments of some models aerosols and SOA produced in a smog chamber validated the individual particle analysis of the instrument
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Grimes, Matthew, Paul Myrdal, and Poonam Sheth. "Cosolvent Effect on Droplet Evaporation Time, Aerodynamic Particle Size Distribution, and Differential Throat Deposition for Pressurized Metered Dose Inhalers." The University of Arizona, 2015. http://hdl.handle.net/10150/614123.
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Class of 2015 AbstractObjectives: To evaluate the in vitro performance of various pressurized metered dose inhaler (pMDI) formulations by cascade impaction primarily focusing on throat deposition, fine particle fraction (FPF), and mass-median aerodynamic diameter (MMADR) measurements Methods: Ten solution pMDIs were prepared with varying cosolvent species in either low (8% w/w) or high (20% w/w) concentration. The chosen cosolvents were either alcohol (ethanol, n-propanol) or acetate (methyl-, ethyl-, and butyl acetate) in chemical nature. All formulations used HFA-134a propellant and 0.3% drug. The pMDIs were tested by cascade impaction with three different inlets to determine the aerodynamic particle size distribution (APSD), throat deposition, and FPF of each formulation. Theoretical droplet evaporation time (DET), a measure of volatility, for each formulation was calculated using the MMADR. Results: Highly volatile formulations with short DET showed consistently lower throat deposition and higher FPF than their lower volatility counterparts when using volume-constrained inlets. However, FPF values were not significantly different for pMDI testing with a non-constrained inlet. The MMADR values generated with volume-constrained inlets did not show any discernible trends, but MMADR values from the non-constrained inlet correlated with DET. Conclusions: Formulations with shorter DET exhibit lower throat deposition and higher FPF, indicating potentially better inhalational performance over formulations with longer DET. There appear to be predictable trends relating both throat deposition and FPF to DET. The shift in MMADR values for volume-constrained inlets suggests that large diameter drug particles are preferentially collected in these inlets.
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Moss, Joshua J. "Measurement of the branching fraction for the decay neutral kaon(long) going to pion-antipion-positron-electron in the high M(pi-pi) invariant mass region." W&M ScholarWorks, 2007. https://scholarworks.wm.edu/etd/1539623516.
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A measurement of the branching fraction for the rare decay K0L → pi+pi-e +e- was performed using data collected from experiment E871 which ran at the AGS of Brookhaven National Laboratory. Analysis of the data revealed 27.7 +/- 7.4 signal events in the signal region, 0.4905 GeV < Mpipiee < 0.505 GeV together with 13.3 +/- 3.7 background events. The branching fractions of ( 8.5+/-2.3stat +/-1.0sys ) x 10-6 using the phenomenological model acceptance and ( 2.3+/-0.6stat +/-0.3sys ) x 10-6 using the chiral perturbation model represent the first measurements for K0L → pi+pi-e +e- in the dipion invariant mass region 0.475 GeV < Mpipi < 0.497 GeV. These results support the prediction of chiral perturbation theory rather than that of the phenomenological model.
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Caravita, Caterina. "Dark matter and stellar populations in the central region of early-type galaxies." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15847/.
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This thesis work is aimed at the investigation of the dark matter (DM) amount and distribution in early-type galaxies (ETGs), in relation with the stellar properties, constrained by observations of the kinematic fields of galaxies. In particular, we focus on observations of the projected stellar velocity dispersion in the central region of ETGs. A robust determination of the DM amount and distribution is an open issue, which we explore from two complementary points of view. A top-down approach, with priority given to cosmology, based on the predictions of numerical cosmological simulations, and a bottom-up approach, with priority given to the galactic astrophysics. This is accomplished by using the original numerical code JASMINE (Jeans AxiSymmetric Models of galaxies IN Equilibrium), first developed by Posacki et al. 2013, to build dynamical models of ETGs, based on the solution of the Jeans equations. Our Jeans modelling produces axisymmetric (oblate) spheroids with anisotropic stellar orbits. In this thesis work, we focus on spherical isotropic galaxy models, composed of stars, DM and a central supermassive black hole (BH). The stellar component is modelled by a deprojected de Vaucouleurs or Jaffe density profile and satisfies the Faber-Jackson and size-luminosity Scaling Laws. The BH mass, M_BH, is related to the total stellar mass, M_star, by the Magorrian relation. The DM component is modelled by the NFW density profile. We explore the effect on the dynamics of stars, due to the stellar and DM properties, such as the assumption of a fixed stellar mass-to-light ratio, Upsilon_star,dyn, and fixed halo parameters beta and c (halo-to-stellar scale radius ratio and halo concentration, respectively). We intend to investigate how much the DM amount and distribution can vary, while reproducing a given value for the projected central velocity dispersion of stars, sigma_e8 (luminosity-weighted within R_e/8). Our study suggests that sigma_e8 is not a good [...]
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Johansson, Anna CV. "Solvation properties of proteins in membranes." Doctoral thesis, Stockholms universitet, Institutionen för biokemi och biofysik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-27437.
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Knowledge about the insertion and stabilization of membrane proteins is a key step towards understanding their function and enabling membrane protein design. Transmembrane helices are normally quite hydrophobic to insert efficiently, but there are many exceptions with unfavorable polar or titratable residues. Since evolutionary conserved these amino acids are likely of paramount functional importance, e.g. the four arginines in the S4 voltage sensor helix of voltage-gated ion channels. This has lead to vivid discussion about their conformation, protonation state and cost of insertion. To address such questions, the main focus of this thesis has been membrane protein solvation in lipid bilayers, evaluated using molecular dynamics simulations methods. A main result is that polar and charged amino acids tend to deform the bilayer by pulling water/head-groups into the hydrophobic core to keep their hydrogen bonds paired, thus demonstrating the adaptiveness of the membrane to allow specific and quite complex solvation. In addition, this retained hydration suggests that the solvation cost is mainly due to entropy, not enthalpy loss. To further quantify solvation properties, free energy profiles were calculated for all amino acids in pure bilayers, with shapes correlating well with experimental in vivo values but with higher magnitudes. Additional profiles were calculated for different protonation states of the titratable amino acids, varying lipid composition and with transmembrane helices present in the bilayer. While the two first both influence solvation properties, the latter seems to be a critical aspect. When the protein fraction in the models resemble biological membranes, the solvation cost drops significantly - even to values compatible with experiment. In conclusion, by using simulation based methods I have been able to provide atomic scale explanations to experimental results, and in particular present a hypothesis for how the solvation of charged groups occurs.
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Aquino, Adriano. "Análise proteômica dos ovos de codorna não fertilizados em diferentes tempos e temperaturas de estocagem." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75133/tde-18082015-100420/.
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O uso de codornas japonesas (Coturnix coturnix japonica) como modelo animal para estudos relacionados a indústria avícola está crescente em decorrência do aumento no consumo de carne e ovos. O ovo possui várias aplicações e a sua funcionalidade está correlacionada com a composição química e, mais especificamente, com seu alto valor proteico. Contudo, o ovo é um alimento altamente perecível, pois pode perder sua qualidade rapidamente entre o período de estocagem e consumo. A qualidade do ovo pode ser afetada por condições ambientais como tempo e temperatura de estocagem. Parâmetros convencionais como pH, massa e a unidade Haugh são usados para a avaliação da qualidade do ovo. Além disso, técnicas analíticas podem ser utilizadas para a avaliação de qualidade em diversas matrizes alimentares. Assim, o presente trabalho tem como objetivos a avaliação e identificação de proteínas presentes em ovos de codorna japonesa submetidos a diferentes tempos e temperaturas de estocagem empregando técnicas eletroforéticas e espectrometria de massas, além de, ferramentas estatísticas. Durante estocagem à 0-21 dias, observou um aumento no pH, diminuição na massa do ovo e uma mudança significativa no proteoma das amostras nos períodos de 14 a 21 dias. Além disso, os resultados de análise de componentes principais (PCA) demostraram a influência da temperatura pela formação de 4 grupos independentes para amostras de albúmen e 3 grupos para as amostras de plasma e fração granular, respectivamente. Para o plasma, as amostras estocadas à 25 °C e controle se agruparam. Já para a fração granular, o agrupamento ocorreu entre as amostras estocadas a 25 °C com a 37 °C, demonstrando similaridade entre si. As proteínas com os níveis significativamente (p <0.05) alterados durante a estocagem pertencem as famílias serpina (ovalbumina), transferrina (ovotransferrina), inibidores Kazal tipo de protease (ovoinibidor). Para a ovotransferrina, proteína encontrada em todas as amostras foi observado a formação de isoformas no albúmen, plasma e fração granular nas amostras estocadas a 37 °C, sendo um bom indicador de controle de qualidade. Por fim, para as amostras de albúmen fracionadas por OFFGEL e analisadas por 1D-PAGE foi observado a formação de isoformas tanto para a ovalbumina quanto para a ovotransferrina bem como a degradação de ovoinibidor nas amostras estocadas por 21 dias a 37 °C, fatos que podem estar associados ao desbaste. Esses eventos afirmam a influência do tempo e temperatura de estocagem na qualidade do ovo de codorna.The use of Japanese quail (Coturnix coturnix japonica) as animal model for studies related to the poultry industry is becoming more common due to the increased consumption of meat and eggs. The egg has a variety of applications and its functionality is correlated to the chemical composition and, more specifically, its high protein value. However, the egg is a highly perishable food, and it can lose its quality between the period of storage and consumption. The egg quality can be affected by environmental conditions such as storage time and temperature. Conventional parameters such as pH and Haugh unit mass are used for egg quality assessment. Furthermore, analytical techniques can be used for quality assessment in various food matrices. This study aims to review and to identify proteins present in Japanese quail eggs submitted at different times and storage temperatures using electrophoretic techniques and mass spectrometry techniques, as well as statistical tools. During storage at 0-21 days, observed an increase in pH, decrease in egg mass and a significant change in the proteome of samples during the 14 to 21 day period. Moreover, the principal component analysis results (PCA) have shown the influence of temperature because of the formation of the four groups to albumin samples and three groups for the plasma and granules fraction samples, respectively. In plasma, the samples stored at 25 ° C and clustered control. As for the granule fraction pooling occurred between samples stored at 25 ° C to 37 ° C, showing similarities among them. The proteins with significant levels (p <0.05) of change during the storage belong to serpin family (albumin), transferrin (ovotransferrin), Kazal type protease inhibitors (ovoinhibitor). Ovotransferrin, a protein isoform found in albumin, plasma and granules fraction samples and was observed the formation of more isoforms in samples stored at 37 ° C, a good to quality control lost indicator. Finally, for the albumen samples that were fractionated by OFFGEL and analyzed by 1D-PAGE, the formation of both isoforms to ovalbumin was observed as well as ovotransferrin and ovoinhibitor degradation in samples stored for 21 days at 37 ° C that can be associated to thinning. These events affirm the influence of time and storage temperature on quail egg quality.
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Aquino, Phillip A. "PREDICTION OF PREMIXED INTERNAL COMBUSTION ENGINE MASS FRACTON BURNED PROFILES USING A PHYSICAL FORM OF THE WIEBE FUNCTION AND THE THEORY OF TURBULENT FLAME BRUSH THICKNESS DYNAMICS." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1606987013001077.
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Milkie, Jeffrey A. "Condensation of hydrocarbon and zeotropic hydrocarbon/refrigerant mixtures in horizontal tubes." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51825.
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An experimental investigation of condensation of hydrocarbons and hydrocarbon/refrigerant mixtures in horizontal tubes was conducted. Heat transfer coefficients and frictional pressure drops during condensation of a zeotropic binary mixture of R245fa and n-pentane in a 7.75 mm internal diameter round tube were measured across the entire vapor-liquid dome, for mass fluxes ranging from 150 to 600 kg m-2 s-1, and reduced pressures ranging from 0.06 to 0.23. Condensation experiments were conducted for the mixture, as well as its pure constituents over a similar range of conditions. In addition, condensing flow of the hydrocarbon propane was documented visually using high-speed video recordings. Results from these experiments were used to establish the two-phase flow regimes, void fractions, and liquid film thicknesses during condensation of propane flowing through horizontal tubes with internal diameters of 7 and 15 mm. These measurements were made over mass fluxes ranging from 75 to 450 kg m-2 s-1, operating pressures ranging from 952 to 1218 kPa, and vapor qualities ranging from 0.05 to 0.95. Liquid film thickness and void fraction data were subsequently be used to assist the development of heat transfer and pressure drop models. In particular, the heat transfer coefficients and pressure drops observed in the mixture were compared with the corresponding values for the pure constituents. Models for heat transfer and pressure drop in the pure components as well as the mixtures were developed based on the data from the present study. This work extends the available literature on two-phase flow regimes for air-water mixtures, steam, and refrigerants to include hydrocarbons. Additionally, the limited information on condensation in multi-constituent hydrocarbon-hydrocarbon and refrigerant-refrigerant mixtures was extended to include hydrocarbon-refrigerant mixtures. The findings of this study are expected to benefit applications such as refrigeration, low-grade heat-driven power generation, and the development of heat exchangers for the chemical and process industries.
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Le, Maître Johann. "Développement de la spectrométrie de masse à ultra- haute résolution associée à la spectrométrie de mobilité ionique pour la caractérisation de coupes pétrolières lourdes. structural analysis of heavy oil fractions afterr hydrodenitrogenation by high-resolution tandem mass spectrometry and ion mobility spectrometry Structural analysis of neutral nitrogen compounds refractory to the hydrodenitrogenation process of heavy oil fractions by high-resolution tandem mass spectrometry and ion mobility-mass spectrometry Chemical characterization of 15 biocrudes obtained from hydrothermal liquefaction of industrially cultivated wild micro algae Chemical characterization with different analytical techniques, a way to understand the process: Case of the paraffinic base oil production line Exploring complex mixtures by cyclic ion mobility high-resolution mass spectrometry – Application towards Petroleum. Simulation and modeling of Collision Cross Section for structural elucidation of heavy oil fraction by ion mobility-mass spectrometry: Using polyaromatic hydrocarbons compounds mixture as calibration standard Characterization of sulfoxides compounds in dimeric distribution of heavy oil fractions by positive-ion electrospray ionization FTICR mass spectrometry Structural analysis of Petroporphyrins from asphaltene by trapped ion mobility coupled with a Fourier transform ion cyclotron resonance mass spectrometer. Cyclic ion mobility spectrometry coupled to high-resolution time-of-flight mass spectrometry equipped with atmospheric solid analysis probe for the molecular characterization of combustion particulate matter. Structural study of analogues of Titan’s haze by trapped ion mobility coupled with a Fourier transform ion cyclotron mass spectrometer." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR051.
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L'évolution des réserves de pétrole implique l'utilisation en raffinerie de pétroles bruts non conventionnels, bien souvent plus lourds et donc difficiles à caractériser. Les produits pétroliers sont en effet des mélanges chimiques extrêmement complexes. La partie légère et volatile peut être analysée par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC/MS), permettant l'identification des composés par l'utilisation de mesures de masses précises et de modèles de fragmentation. Cependant ces techniques sont inadaptées à l'analyse des fractions lourdes. Dans la pratique, la caractérisation des mélanges les plus complexes implique l'utilisation de spectromètres de masse à ultra-haute résolution généralement par analyse directe sans séparation chromatographique. La technique de référence est aujourd’hui la spectrométrie de masse à transformée de Fourier par résonance cyclotronique des ions (FTICR). Grâce à une résolution supérieure à 106 et à une précision de mesure de masse inférieure à 0,1 ppm, cet instrument permet de séparer toutes les espèces présentes dans un produit pétrolier et d'attribuer à chaque valeur de m/z une composition élémentaire unique. Ceci permet d'obtenir très facilement des cartes moléculaires qui peuvent être présentées graphiquement en utilisant le diagramme de Kendrick, le diagramme de van Krevelen ou le nombre d'insaturations (DBE) en fonction du nombre de carbones. Ce travail de thèse a permis grâce à la caractérisation moléculaire de produits pétroliers (Vacuum Gas Oil, Pétroles Bruts, Matériel Interfacial, Asphaltènes et Bio-Oil…) d'aborder la complexité de leur traitement dans l’outil de raffinage. Des protocoles d'analyses des échantillons ont été développés, à l'aide de différentes sources d'ionisation à pression atmosphérique (ESI, APCI et APPI) ainsi que par désorption/ionisation laser (LDI) sur le spectromètre de masse FTICR 12T. Les informations sur le contenu isomérique des produits pétroliers ont ensuite été déterminées grâce à l'apport de la spectrométrie de mobilité ionique (IMS)The evolution of oil reserves requires the use in refineries of unconventional crude oils, which are often heavier and therefore difficult to characterize. Petroleum products are in fact extremely complex chemical mixtures. The light and volatile part can be analysed by gas chromatography coupled with mass spectrometry (GC/MS), allowing the identification of compounds by using precise mass measurements and fragmentation models. However, these techniques are inappropriate for the analysis of heavy fractions. In practice, the characterization of the most complex mixtures involves the use of ultra-high-resolution mass spectrometers generally by direct analysis without chromatographic separation. The reference technique today is Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR). With a resolution of more than 106 and a mass measurement accuracy of less than 0.1 ppm, this instrument can separate all the species present in a petroleum product and assign a unique elemental composition to each m/z value. This makes it very easy to obtain molecular maps that can be presented graphically using the Kendrick diagram, the van Krevelen diagram or the number of unsaturations (DBE) as a function of the number of carbons. This thesis work has allowed thanks to the molecular characterization of petroleum products (Vacuum Gas Oil, Crude Oil, Interfacial Material, Asphaltenes and Bio-Oil...) addressing the complexity of their treatment in the refining tool. Protocols for sample analysis have been developed, using different sources of ionization at atmospheric pressure (ESI, APCI and APPI) as well as laser desorption/ionization (LDI) on the FTICR 12T mass spectrometer. Information on the isomeric content of petroleum products was then determined using ion mobility spectrometry (IMS)
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Vuitik, Guilherme Araujo. "Estudo de parâmetros envolvidos na transferência de oxigênio em meio hídrico aerado por bolhas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-03102013-103745/.
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Embora seja uma técnica tradicional, empregada largamente em processos industriais, a operação unitária de aeração pode ser otimizada ao se utilizar modelos matemáticos que descrevam seu comportamento hidrodinâmico. Diversas equações se prestam a esse fim, no entanto, avanços tecnológicos, tanto no campo instrumental como computacional, permitiram a obtenção de equações mais realísticas e abrangentes. Neste trabalho foram ajustadas e avaliadas equações para descrever três importantes parâmetros envolvidos na transferência de oxigênio em meio hídrico: coeficiente volumétrico de transferência de massa, fração de vazios e velocidade ascensional de bolhas. Para tanto, ademais da utilização de conceitos teóricos amplamente difundidos no meio acadêmico, empregou-se um conjunto de dados já existente. Essa combinação permitiu a avaliação e aproximação das equações teóricas à realidade experimental através de coeficientes de ajuste empíricos. Foram obtidos os seguintes resultados: a) revisão bibliográfica e sugestão da correlação que melhor descreve o coeficiente volumétrico de transferência de massa; b) correlação que descreve a fração de vazios, a partir da analise da concentração de bolhas segundo distribuições gaussianas; c) correlação que descreve a velocidade ascensional de bolhas em plumas. A complexidade de cada parâmetro obtido deixou clara a importância da análise isolada, precedendo a convolução dos mesmos em um único modelo, pois embora as resposta e recomendações apresentadas não forneçam conclusões definitivas sobre todos os aspectos envolvidos na transferência de oxigênio em meio hídrico, suas considerações pontuais contribuem sobremaneira ao domínio do fenômeno global, beneficiando modelagens matemáticas futuras.Although it is a traditional technique, widely employed in industrial processes, the unit operation of aeration can be optimized when resorting to mathematical models which describe their hydrodynamic behavior. A range of equations lends itself to this purpose, however, technological advances both in the instrumental as computational field, allowed the achievement of equations more realistic and comprehensives. In this study were adjusted and evaluated equations to describe three important parameters involved in the oxygen transfer in the hydric medium: volumetric mass transfer coefficient, void fraction and upflow bubble velocity. To this end, besides the use of theoretical concepts widely disseminated in the academic literature, it was employed a set of already existing data. This combination allowed the evaluation and approximation of theoretical equations to experimental reality by means of empirical adjustment coefficients. Were obtained the following results: a) literature review and suggestion of the best correlation which describes the volumetric mass transfer coefficient, b) correlation which describes the fraction of voids, from the analysis of the concentration of bubbles by Gaussian distributions, c) correlation which describes the upflow velocity of swarms of bubbles. The complexity of each parameter obtained made clear the importance of the isolated analysis, preceding the convolution of them in a single model because although the answers and recommendations given fail to supply definitive conclusions on all aspects involved in the transfer of oxygen in hydric medium, their specific considerations contribute to the knowledge of the global phenomenon, benefiting deeply future mathematical models.
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Perakis, Nikolaos. "Separation et detection selective des composes soufres dans les fractions lourdes des petroles : geochimie des benzo (b) thiophenes." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13093.
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Analyse et dosage des composes soufres presents dans une coupe lourde du petrole aramco 90 par chromatographie gazeuse avec detection soit par photometrie de flamme soit par spectrometrie de masse haute resolution. Etude comparative des methodes d'analyse. Etude des composes soufres dans des echantillons de petrole de rozel point et de schiste bitumineux de timahdit grace a l'identification par synthese de nouvelles familles d'alkylbenzo (b) thiophenes
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Gulfo, Cabrales Rafael Antonio. "Recuperación de solutos del hielo proveniente de un crioconcentrador de placas : cinética y concentración." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/279310.
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Research about the cryoconcentration process of food fluids is an important area of study.
Cryoconcentration is a concentration process of fluids by separating water into ice shape. Freeze concentration, allows to obtain an organoleptic product of high quality, because of the low temperatures used during processing. However, a feature of the technique is the limitation of the concentration (from 45 to 55 °Brix) due to increasing the viscosity of the fluid and solutes retention in the ice.
The objective of the current memory thesis is to investigate the recovery of solutes in the ice from a cryoconcentrator in falling-film layer, using the technique of fractional melting.
The works are developed into three phases:
a) In the first phase, the concentration of the fluid in a cryoconcentrator (Freeze concentrator) in falling- film layer was made.
b) In the second phase, fractional thaws at controlled temperatures (20, 25 and 30 °C) were performed.
c) The third phase allowed to establish, from the results, a method of calculation that involves melting fraction with concentration and time, allowing resemblance to operate with the ice of juices obtained by freeze concentration process.
The results presented here are not only of academic interest, but also has technological importance,because it allows to simulate the recovery process of retained solutes in the ice of fruit juices and get: time thaw, the concentration and amount obtained for any fraction of the mass of ice. This allows studies on the recovery of the different fractions, in order to establish the best economic viabilityLa investigación sobre el proceso de crioconcentración de fluidos alimenticios es un área importante de estudio. La crioconcentración es un proceso de concentración de fluidos mediante la separación del agua en forma de hielo. La crioconcentración, permite obtener un producto de alta calidad organoléptica, debido a las bajas temperaturas utilizadas durante el proceso. Sin embargo, una característica de la técnica es la limitación de la concentración (de 45 a 55 ºBrix) por el aumento de la viscosidad del fluido y a la retención de solutos en el hielo. El objetivo de la presente memoria de tesis es investigar la recuperación de solutos en el hielo proveniente de un crioconcentrador en capa en película descendente, utilizando la técnica de deshielo fraccionado. Los trabajos se desarrollan en tres fases: a) En la primera fase se realizó la concentración del fluido en un crioconcentrador en capa en película descendente. b.) En la segunda fase, se realizaron los deshielos fraccionados a temperaturas controladas (20, 25 y 30 ºC). c) La tercera fase permitió establecer, a partir de los resultados obtenidos, un procedimiento de cálculo que relaciona la fracción de deshielo con la concentración y el tiempo, permitiendo operar por semejanza con los hielos de zumos obtenidos en un proceso de crioconcentración. Los resultados presentados en este trabajo no sólo son de interés académico sino que también tiene importancia tecnológica debido a que permite simular el proceso de recuperación de solutos retenidos en el hielo de zumos de fruta y obtener: el tiempo de deshielo, la concentración y la cantidad obtenida para cualquier fracción de la masa del hielo. Esto permite realizar estudios sobre la recuperación de las distintas fracciones, con el fin de establecer la mejor viabilidad económica
La recerca sobre el procés de crioconcentració de fluids alimentaris és un tema d'estudi important. La crioconcentració és un procés de concentració dels fluids a través de la separació de l'aigua en forma de gel. La concentració per congelació, permet obtenir un producte d'alta qualitat organolèptica, degut a les baixes temperatures utilitzades durant el procés. No obstant això, una característica de la tècnica és la limitació de la concentració (de 45 a 55 °Brix) mitjançant l'augment de la viscositat del fluid i la retenció de soluts en el gel. La memòria d'aquesta tesi pretén investigar la recuperació de soluts retinguts en el gel d'un crioconcentrador de pel·lícula descendent, utilitzant la tècnica de desgel fraccionat. Els assaigs es duen a terme en tres fases: (a) en la primera fase es concentra el fluid en un crioconcentrador de película descendent. (b) en la segona fase, s'estudien els desgels fraccionats a temperatures fixades (20, 25 i 30 °C). (c) la tercera etapa va permetre establir, basada en els resultats obtinguts, un procediment de càlcul que relaciona la fracció de desgel amb la concentració i el temps, permetent operar per semblança amb els gels de sucs obtinguts d'un procés de crioconcentració. Els resultats presentats en aquest treball no només són d'interès acadèmic, també té importància tecnològica ja que permet simular el procés de recuperació de soluts retinguts en gel procedent de sucs de fruita i aconseguir: temps de descongelació, concentració i la quantitat obtinguda per qualsevol fracció de massa de gel. Això permet dur a terme estudis sobre la recuperació de les diferents fraccions, per tal d'establir la millor viabilitat econòmica.
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Rebillard-Soulie, Alex. "Etendre nοs cοnnaissances sur la matière nucléaire chaude dans la régiοn de faible densité." Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC244.
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Les clusters légers dans la matière nucléaire apparaissent à des densités inférieures à la densité de saturation nucléaire. Ils peuvent jouer un rôle important dans des scénarios astrophysiques comme les supernovae à effondrement de cœur, où les propriétés de la matière nucléaire influence la propagation de l'onde de choc et le parcours des neutrinos émis. À de telles densités, des effets de milieu sont présents et modifient les propriétés des clusters formés, leur abondance et, par conséquent, la dynamique des supernovae. Nous avons utilisé un modèle champ moyen relativiste (RMF) avec des clusters comme degrés de liberté explicites et des échanges de mésons virtuels. Ce modèle possède un couplage clusters-méson empirique qui nécessite d’être calibré avec des observations expérimentales. À partir des collisions d'ions lourds, nous avons sélectionné des événements afin de construire différents ensembles statistiques correspondant à des conditions thermodynamiques particulières. Dans ces ensembles, nous avons extrait les compositions chimiques en terme de fractions massique des isotopes d’hydrogène et d’hélium. En parallèle, nous avons renforcé l’utilisation de l’hypothèse d’équilibre par l’étude des propriétés d’isoscaling. Enfin, dans une analyse bayésienne, nous avons comparé les ensembles expérimentaux avec des calculs issus du modèle RMF, où la densité, la température et le couplage clusters-méson sont libres. Nous avons réussi à reproduire les fractions massiques expérimentales des différents clusters, en considérant une densité unique pour chaque ensemble. Pour étudier les limites de cette analyse et l’étendre à d’autres systèmes, une nouvelle expérience a été réalisée avec le multidétecteur INDRA-FAZIA. D’importantes améliorations ont été apportées sur le dispositif, ce qui a permis d’améliorer significativement ses performances, notamment en termes d’identification isotopique. Ainsi, la quasi-totalité du travail de réduction des données (calibration en énergie et identification) a été achevée pour cette nouvelle expérience. Dans le cadre d'une étude préliminaire, l'analyse a été initiée sur les événements de type vaporisation, mais elle nécessite des efforts supplémentairesLight clusters in nuclear matter appear at densities below nuclear saturation density. They can play an important role in astrophysical scenarios like core-collapse supernovae, where the properties of nuclear matter influence the shock wave propagation and the path of emitted neutrinos. At such densities, in-medium effects are present and modify the properties of the formed clusters, their abundance, and, consequently, the dynamics of supernovae. We used a relativistic mean field (RMF) model with clusters as explicit degrees of freedom and virtual meson exchanges. This model includes an empirical cluster-meson coupling that requires calibration with experimental observations. From heavy ion collisions, we selected events to construct different statistical ensembles corresponding to particular thermodynamic conditions. In these ensembles, we extracted the chemical compositions in terms of the mass fractions of hydrogen and helium isotopes. In parallel, we strengthened the use of the equilibrium hypothesis by studying isoscaling properties. Finally, in a Bayesian analysis, we compared the experimental ensembles with calculations from the RMF model, where density, temperature, and cluster-meson coupling are free parameters. We successfully reproduced the experimental mass fractions of the various clusters, considering a unique density for each ensemble. To explore the limitations of this analysis and extend it to other systems, a new experiment was conducted with the INDRA-FAZIA multidetector. Significant improvements were made to the device, which has considerably enhanced its performance, particularly in terms of isotopic identification. Consequently, nearly all of the data reduction work (energy calibration and identification) has been completed for this new experiment. In a preliminary study, the analysis began on vaporization-type events, but further efforts are required
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Roberts, James. "A regularity theory for Fractional Harmonic Maps." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760897.
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Our purpose is to define, and develop a regularity theory for, Intrinsic Minimising Fractional Harmonic Maps from Euclidean space into smooth compact Riemannian manifolds for fractional powers strictly between zero and one. Our aims are motivated by the theory for Intrinsic Semi-Harmonic Maps, corresponding to the power one-half, developed by Moser. Our definition and methodology are based on an extension method used for the analysis of real valued fractional harmonic functions. We define and derive regularity properties of Fractional Harmonic Maps by regarding their domain as part of the boundary of a half-space, equipped with a Riemannian metric which degenerates or becomes singular on the boundary, and considering the regularity of their extensions to this half-space. We show that Fractional Harmonic Maps, and their first order derivatives, are locally Hölder continuous away from a set with Hausdorff dimension depending on the dimension of the domain and the fractional power in question. We achieve this by establishing the corresponding partial regularity of extensions of Fractional Harmonic Maps which minimise the Dirichlet energy on the half-space. To prove local Hölder continuity, we develop several results in the spirit of the regularity theory for harmonic maps. We combine a monotonicity formula with the construction of comparison maps, scaling in the Poincaré inequality and results from the theory of harmonic maps, to prove energy decay sufficient for the application of a modified decay lemma of Morrey. Using the Hölder continuity of minimisers, we prove a bound for the essential supremum of their gradient. Then we consider the derivatives in directions tangential to the boundary of the half-space; we establish the existence of their gradients using difference quotients. A Caccioppoli-type inequality and scaling in the Poincaré inequality then imply decay estimates sufficient for the application of the modified decay lemma to these derivatives.
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Khan, Nazmul. "Sparse Lagrangian MMC-LES Combustion Modelling of Liquid Sprays." Thesis, The University of Sydney, 2017. https://vuir.vu.edu.au/39312/.
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This thesis provides a detailed investigation of turbulent combustion modelling of liquid sprays. Modelling of liquid sprays is a challenging task due to the existence of a wide range of complexities in both liquid and gas phases and their interaction in the spray and combustion process. In such multiphase flow, there is a need to address all physical processes involved in each individual phase and jointly in the interaction of phases. In a multiphase flow, there are physical processes with respect to flow, energy, chemical reactions, and flame propagation. In the liquid phase, the physical processes include dispersion, evaporation, volatile formation and exchange of heat and mass transfer with the gas phase. In the gas phase, there is turbulent flow, mixing and chemical reactions. The model that is derived and validated in this thesis extends the existing capabilities of liquid spray modelling by introducing a novel model for heat and mass transfer in the liquid phase that is coupled with the gas phase simulation. The model is comprised of an Eulerian LES model for the gas phase mass, momentum, and reference mixture fraction, a Lagrangian fuel particle (LFP) model for the dispersion, evaporation, heat and mass transfer and volatile formation, and a second Lagrangian stochastic particle model based on a multiple mapping conditioning (MMC) to represent the turbulent reacting chemistry. This study simulates three experimental validation cases from the University of Sydney combustion lab: non-reacting kerosene, evaporating acetone and reacting acetone. The axial and radial profiles of droplets, gas velocity and gas phase temperature are in good agreement with experimental measurements. Importantly the results of the finite volume and Lagrangian stochastic particle schemes are shown to be consistent with each other.
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Piedra-Cueva, Jose Carlos Ismael. "Contribution à l'étude des mécanismes de transport des sédiments cohésifs." Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10200.
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Deux processus de transport des sediments fins sont etudies: i) l'erosion d'un lit depose de vase et le transport en suspension par un courant, ii) le transport lagrangien de vase induit par l'action de la houle dans une couche de vase fluide. I) une etude experimentale de l'erosion d'un lit depose de vase par un courant est realisee dans le canal sedimentologique a circulation du laboratoire d'hydraulique de france. Cette etude est precedee d'une etude hydrodynamique qui precise les conditions pour lesquelles le courant applique un frottement quasiment uniforme sur toute la surface du lit et produit une erosion reguliere du lit. Une analyse theorique montre que les effets de stratification du sediment en suspension sont negligeables lorsque la concentration moyenne sur la verticale est inferieure a 5 g/l. Les variations temporelles de la concentration de sediment en suspension permettent de mesurer l'erosion du lit. Les resultats experimentaux mettent en evidence une loi d'erosion adimensionnelle ou le taux d'erosion varie lineairement avec la difference entre le frottement exerce sur le fond par le courant et la rigidite du lit a sa surface. La dependance du coefficient de proportionnalite avec le nombre de richardson et le gradient de rigidite a la surface du lit est etudiee. Les experiences montrent que l'erosion du lit diminue significativement lorsque le gradient de rigidite a la surface du lit augmente. Ii) le transport lagrangien de vase induit par l'action de la houle dans une couche de vase fluide est etudie theoriquement dans un systeme visqueux a deux couches a partir des equations du mouvement ecrites en coordonnees de lagrange. La comparaison des resultats avec les mesures de sakakiyama & bijker (1989) montre un bon niveau de concordance
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Tomasini, Jérôme. "Géométrie combinatoire des fractions rationnelles." Thesis, Angers, 2014. http://www.theses.fr/2014ANGE0032/document.
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Le but de cette thèse est d’étudier, à l’aide d’outils combinatoires simples, différentes structures géométriques construites à partir de l’action d’un polynôme ou d’une fraction rationnelle. Nous considérerons d’abord la structure de l'ensemble des solutions séparatrices d’un champ de vecteurs polynomial ou rationnel. Nous allons établir plusieurs modèles combinatoires de ces cartes planaires, ainsi qu’une formule fermée énumérant les différentes structures topologiques dans le cas polynomial. Puis nous parlerons de revêtements ramifiés de la sphère que nous modéliserons, via un objet combinatoire nommée carte équilibrée, à partir d’une idée originale de W.Thurston. Ce modèle nous permettra de démontrer (géométriquement) de nombreuses propriétés de ces objets, et d’offrir une nouvelle approche et de nouvelles perspectives au problème d’Hurwitz, qui reste encore aujourd’hui un problème ouvert. Et enfin nous aborderons le sujet de la dynamique holomorphe via les primitives majeures dont l’utilité est de permettre de paramétrer les systèmes dynamiques engendrés par l’itération de polynômes. Cette approche nous permettra de construire une bijection entre les suites de parking et les arbres de Cayley, ainsi que d’établir une formule fermée liée à l’énumération d’un certain type d’arbres relié à la fois aux primitives majeures et aux revêtements ramifiés polynomiauxThe main topic of this thesis is to study, thanks to simple combinatorial tools, various geometric structures coming from the action of a complex polynomial or a rational function on the sphere. The first structure concerns separatrix solutions of polynomial or rational vector fields. We will establish several combinatorial models of these planar maps, as well as a closed formula enumerating the different topological structures that arise in the polynomial settings. Then, we will focus on branched coverings of the sphere. We establish a combinatorial coding of these mappings using the concept of balanced maps, following an original idea of W. Thurston. This combinatorics allows us to prove (geometrically) several properties about branched coverings, and gives us a new approach and perspective to address the still open Hurwitz problem. Finally, we discuss a dynamical problem represented by primitive majors. The utility of these objects is to allow us to parameterize dynamical systems generated by the iterations of polynomials. This approach will enable us to construct a bijection between parking functions and Cayley trees, and to establish a closed formula enumerating a certain type of trees related to both primitive majors and polynomial branched coverings
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Pourshahian, Soheil. "Characterization of Ribonucleoproteins by Cross-linking and Mass Spectrometry." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1212077571.
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Pailha, Mickaël. "Dynamique des avalanches granulaires immergées : rôle de la fraction volumique initiale." Aix-Marseille 1, 2009. https://tel.archives-ouvertes.fr/tel-00433171.
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Le cadre général de cette thèse est d'obtenir une meilleure compréhension des écoulements géophysiques comme les glissements de terrains. Dans tous ces évènements, on sait que le couplage entre milieu granulaire et uide interstitiel joue un rôle important. Lors du démarrage, la présence d'eau inue sur la déformation des sols ; ainsi, des sols initialement diérents se comportent diéremment. Cette thèse présente une expérience et un modèle mettant en évidence les phénomènes physiques lors du déclenchement des avalanches immergées. Notamment, la dynamique de l'avalanche dépend fortement de la fraction volumique de l'empilement initial, le déclenchement étant fortement retardé lors d'une légère compaction initialeInitiation of underwater granular avalanches : inuence of the inital volume fraction. The aim of this thesis is to obtain a better understanding of geophysical ows like landslides. In those events, the coupling between the granular material and the uid play an important role during the initiation. This thesis studies physical phenomenon during the initiation of underwater granular avalanches with an experiment and a model. The ow is shown to strongly depends on the initial volume fraction, its initiation being dramtically delayed by a slight
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Qin, Huan. "Averages of fractional exponential sums weighted by Maass forms." Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/5607.
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The purpose of this study is to investigate the oscillatory behavior of the fractional exponential sum weighted by certain automorphic forms for GL(2) x GL(3) case. Automorphic forms are complex-values functions defined on some topological groups which satisfy a number of applicable properties. One nice property that all automorphic forms admit is the existence of Fourier series expansions, which allows us to study the properties of automorphic forms by investigating their corresponding Fourier coefficients. The Maass forms is one family of the classical automorphic forms, which is the major focus of this study.
Let f be a fixed Maass form for SL(3, Z) with Fourier coefficients Af(m, n). Also, let {gj} be an orthonormal basis of the space of the Maass cusp form for SL(2, Z) with corresponding Laplacian eigenvalues 1/4+kj^2, kj>0. For real α be nonzero and β>0, we considered the asymptotics for the sum in the following form Sx(f x gj, α, β) = ∑Af(m, n)λgj(n)e(αn^β)φ(n/X) where φ is a smooth function with compactly support, λgj(n) denotes the nth Fourier coefficient of gj, and X is a real parameter that tends to infinity. Also, e(x) = exp(2πix) throughout this thesis.
We proved a bound of the weighted average sum of Sx(f x gj, α, β) over all Laplacian eigenvalues, which is better than the trivial bound obtained by the classical Rankin-Selberg method. In this case, we allowed the form varies so that we can obtain information about their oscillatory behaviors in a different aspect. Similar to the proofs of the subconvexity bounds for Rankin-Selberg L-functions for GL(2) x GL(3) case, the method we used in this study includes several sophisticated techniques such as weighted first and second derivative test, Kuznetsov trace formula, and Voronoi summation formula.
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Milani, Ernest J. "A fractional proposal for architecture." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/46261.
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"It has neither name nor place. I shall repeat the reason why I was describing it to you: from the number of imaginable cities we must exclude those whose elements are assembled without a connecting thread, an inner rule, a perspective, a discourse. With cities, it is as with dreams: everything imaginable can be dreamed, but even the most unexpected dream is a rebus that conceals a desire or its reverse, a fear. Cities, like dreams are made of desires and fears, even the thread of their discourse is secret, their rules are absurd, their perspectives deceitful, and everything conceals something else." "Cities also believe they are the work of the mind or of chance, but neither the one nor the other suffices to hold up their walls. You take delight not in a city's seven or seventy wonders, but in the answer it gives to a question of yours."Master of Architecture
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Taylor, Wendy Jane. "A measurement of b-quark fragmentation fractions in p¢p collisions at [centre of mass energy]=1.8 TeV." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0004/NQ41323.pdf.
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Wang, Xiaoguang. "Dynamics of McMullen maps and Thurston-type theorems for rational maps with rotation domains." Angers, 2011. http://www.theses.fr/2011ANGE0067.
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Cette thèse comporte essentiellement deux parties. La première concerne la connexité locale des ensembles de Julia des fractions rationnelles. Nous utilisons les puzzles de Yoccoz pour étudier les applications de McMullen et montrons que la frontière du bassin de l'infini est toujours une courbe de Jordan. Ceci donne une réponse positive à une question de Devaney. Nous montrons également que ces ensembles de Julia sont localement connexes sauf pour certains cas spéciaux. La deuxième partie concerne la théorie de Thurston sur une caractérisation des fractions rationnelles. Nous établissons un théorème de décomposition : tout revêtement ramifié ayant un domaine de rotation se décompose, suivant une multicourbe, en un nombre fini d'applications de Siegel et de Thurston, tel que les combinatoires et le problème de réalisation rationnelle de ces pièces décomposées dominent essentiellement ceux de l'application originale. En guise d'application, nous démontrons un théorème à la Thurston pour une classe de fractions rationnelles ayant des anneaux d'HermanThe thesis mainly consists of two subjects : the first subject relates to the local connectivity of Julia sets for rational maps. We develop Yoccoz puzzle techniques to study McMullen maps and show that the boundary of the bassin of infinity is always a Jordan curve if the Julia set is not a Cantor set. This give a positive answer to a question of Devaney. We also show the Julia set of McMullen is locally connected except some special cases. The second concerns with Thurston's theory on characterization of rational maps. We establish a "decomposition theorem" : every branched covering with rotation domains can be decomposed along a stable multicurve into finitely many Siegel maps or Thurston maps, such that the combinatorics and rational realizations of these resulting maps essentially dominate the original one. As an application, we prove a Thurston type theorem for a class rational maps with Herman rings
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Gibson, Gavin Jarvis. "Modules of generalized fractions, direct systems of determinantal maps and other topics in commutative algebra." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/14902.
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Björk, Elisabeth. "Production and application of fine fractions made of chemical pulp for enhanced paperboard strength." Licentiate thesis, Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-40246.
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For all kinds of paperboard packages, the bending stiffness of the paperboard is a crucial property. In multi-ply folding boxboard (FBB) grades, this is obtained by placing different stocks in the outer and centre plies of the board. In the outer plies, a stock with a high tensile stiffness is used, typically made from refined kraft pulp fibres. In the middle ply/plies a stock with more bulky properties is placed, typically comprising of a high proportion of CTMP (chemi-thermomechanical pulp). CTMP fibres are stiffer and more inflexible with poor bonding abilities resulting in low strength properties. To increase the bonding strength in the middle ply, broke, containing chemical pulp is added, and sometimes refined chemical kraft pulp as well. Both fibres and fines, i.e. smaller fibre fragments, in a pulp have a significant contribution to the properties of the product. Fines produced during refining of chemical pulp are especially beneficial for increasing the strength. To achieve pulp fraction with higher fines content the pulp can be fractionated with a micro-perforated screen basket; a fine fraction produced from a screen with very small holes will contain a large proportion of fines. By adding such a fine fraction to a middle ply stock, the bulk properties of the main pulp, for example a CTMP, can be conserved as less refining of this pulp is required to achieve the targeted strength properties. However, a drawback is that the fine fraction usually has a very low mass concentration after the screening process as a lot of water pass through the screen together with the fines and fibre fragments. The excess water must be removed to maintain the water balance of the papermaking process. Further, the larger volumes require extra pumping capacity. A resource-efficient production of a fine fraction must target a high fine fraction mass concentration and a high content of fines and short fibre fragments in order to be implemented industrially. The focus of the present work was on separation efficiency (i.e. the difference in fibre length distribution caused by screening) and process efficiency (i.e. the concentration of the fine fraction) for production of a fine fraction of chemical pulp by screening, and the utilisation of the fine fraction as strength agent. Pilot-scale fractionation trials with a pressure screen with different microperforated screen baskets were performed in order to evaluate how the separation efficiency and process efficiency were affected by parameters such as feed concentration, pulp type (hardwood or softwood kraft pulp), hole size of the screen, and refining treatment prior to screening. The trials were evaluated using fibre length distributions, flow rates and concentrations of viii the feed flow and the fractions. Here, two complementary quantitative measures, Proportion in fine fraction (for process efficiency) and Fine fraction enrichment (for separation efficiency), were developed. To evaluate the strength enhancing effect of the obtained fine fraction, a lab scale study was performed where the fine fraction of a highly refined pulp was compared with the highly refined pulp as strength agent for a CTMP. The results of this study were verified in a pilot paper machine trial. In a second pilot paper machine trial, sheets with different CTMP proportions in the middle ply were studied in order to find out if the bulk could be increased while maintaining strength, by using a fine fraction made from refined chemical pulp. Regarding process efficiency, it was found that the most important parameter to obtain a high fine fraction concentration was a high feed concentration. Further, a higher fine fraction concentration for a given screening process was also obtained when using hardwood pulp and refining the pulp prior to the screening process. A higher feed concentration also had a positive effect on the separation efficiency. Small holes and a smooth surface of the screen basket were also important to improve the separation efficiency. It was shown that, when used as a strength agent in a CTMP pulp, the fine fraction of highly refined kraft pulp was twice as efficient as the highly refined kraft pulp, when added at equal mass proportion. However, both in the lab and pilot trial the strength increase was accompanied by a decreased bulk. This was expected, and to avoid this the proportion of the bulky CTMP had to be increased. The pilot paper machine trial with an increased CTMP proportion in the middle ply and a fine fraction of refined kraft pulp as strength agent demonstrated that it was possible to produce sheets with an increased bulk and maintained z-strength.Böjstyvheten är en viktig egenskap för alla sorters hårda förpackningar. I flerskiktskartong får man böjstyvhet genom att ha ytterskikt med hög dragstyvhet tillverkade av fibrer från kemisk massa och ett mittskikt med hög bulk från styva fibrer, ofta med en stor andel CTMP (kemitermomekanisk massa). CTMP-fibrer är styva men ger lägre styrka i arket. För att öka styrkan i mittskiktet tillsätter man utskott (kasserad kartong) som delvis innehåller kemisk massa, och ibland även ren högmald kemisk massa. Både fibrer och finmaterial (fines) har stor betydelse för slutproduktens egenskaper. Fines som skapas vid malning av kemisk massa är särskilt effektiva för att öka styrkan. Genom att fraktionera massa med en mikroperforerad sil kan man få en finfraktion med högt finesinnehåll. Mikroperforerade silar är effektiva för längdfraktionering av massa; fines anrikas i den fraktionen som passerar silen medan långa fibrer stannar i den andra fraktionen. Genom att använda en sådan finfraktion i mittskiktet kan man få tillräcklig styrka och samtidigt behålla mer av bulken från CTMP:n genom att man inte behöver mala den för att få styrka. En nackdel är att finfraktionen vanligtvis har väldigt låg masskoncentration eftersom mycket vatten passerar silen tillsammans med fines och fiberfragment. Detta extra vatten måste tas bort för att vattenbalansen i papperstillverkningsprocessen ska bibehållas. Dessutom kräver den större volymen ökad pumpkapacitet. För att kunna använda en finfraktion industriellt behövs en effektiv produktion med hög koncentration och högt finesinnehåll. Fokus i det här arbetet lades på separationseffektivitet (skillnaden i fiberlängdsfördelning som resultat av silningen) och processeffektivitet (koncentrationen i finfraktionen) för tillverkning av en finfraktion av kemisk massa genom silning samt dess utnyttjande som styrkehöjande tillsats i ett mittskikt av kartong. För att utvärdera hur separationseffektiviteten och processeffektiviteten påverkas av parametrar som koncentrationen i flödet in till silen, typ av kemisk massa (gjord av lövved eller barrved), hålstorlek i silen samt malningen av massan, gjordes fraktioneringsförsök i pilotskala med en trycksil med olika mikroperforerade silkorgar. Resultatet av fraktioneringen utvärderades med hjälp av fiberlängdsfördelningar, flöden och koncentrationer i flödet till silen och de två fraktionerna efter silen. För utvärderingen togs två olika utvärderingsmetoder fram: Proportion i finfraktionen (för processeffektivitet) och Finfraktionsanrikning (för x separationseffektivitet). För att utvärdera hur effektiv en finfraktion av kemisk massa var som styrkeadditiv i ett CTMP-ark gjordes labbförsök där tillsats av högmald kemisk massa jämfördes med tillsats av enbart en finfraktion av den högmalda kemiska massan. Resultaten verifierades med ett försök på en pilotpappersmaskin. I ett följande försök på pilotpappersmaskinen tillverkades ark med ökat CTMP-innehåll för att öka bulken, och med en tillsats av en finfraktion av kemisk massa som styrkeadditiv. När det gäller processeffektivitet var hög koncentration i flödet till silen den viktigaste parametern för att få hög koncentration på finfraktionen. Detta var också positivt för separationseffektiviteten, färre av de längre partiklarna hamnade i finfraktionen. Vidare blev finfraktionens koncentration högre för lövvedsmassa. En finfraktion som ska användas som styrkeadditiv ska vara tillverkad av mald massa, malning av massan var också fördelaktigt för finfraktionens koncentration. Små hål och en slät yta på silkorgen var också positivt för separationseffektiviteten. Som styrkeadditiv i CTMP var finfraktionen av högmald kemisk massa dubbelt så effektiv som den högmalda kemiska massan vid lika stor tillsats. Men i både labbförsök och pilotförsök minskade bulken när styrkan ökade. Det var väntat eftersom att ersätta en del av originalmassan som har hög bulk, med en finfraktion eller högmald massa, som båda har mycket lägre bulk, alltid minskar bulken på arket. För att undvika en bulkförlust måste massasammansättningen i arket ändras. Försöket på pilotpappersmaskinen med ökat CTMP innehåll och en finfraktion av mald kemisk massa som styrkeadditiv visade att det är möjligt att tillverka ett ark med högre bulk och bibehållen styrka.
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Boudaoud, Nawal. "Potentialités d'utilisation du nez électronique à spectromètre de masse pour la caractérisation de la fraction volatile du liège oenologique." Phd thesis, INAPG (AgroParisTech), 2006. http://pastel.archives-ouvertes.fr/pastel-00001930.
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Cette thèse traite des possibilités d'utilisation de deux techniques d'espace de tête - spectrométrie de masse (DHS-MS et SPME-MS) pour la caractérisation rapide des composés volatils et semi-volatils du liège oenologique dans le cadre d'applications "origine contrôlée" et "contrôle qualité" des bouchons basée sur leur critères olfactifs. Les étapes préliminaires nécessaires à la mise au point du DHS-MS et de la SPME-MS ont permis de déterminer les paramètres de l'analyse selon des critères basés sur la simplicité de mise en oeuvre, la rapidité de l'analyse par rapport à des méthodes classiques (GC-MS et l'analyse sensorielle) et la stabilité du système évaluée par le coefficient de variation et par une analyse de variance. Ces deux techniques ont été mises en oeuvres suivant deux axes d'études distincts : Le DHS-MS: le potentiel discriminant de cette technique a été évalué sur des échantillons de rondelles de liège miroirs à travers deux applications (discrimination de l'origines géographique des échantillons et discrimination des échantillons présentant des intensités croissantes d'odeur de moisi). Les méthodes d'analyses multivariées (ACP et PLS) employées aux traitement des résultats se sont avérées efficaces. Cependant, le traitement des données a montré que l'information chimique spécifique aux différences entre les échantillons peut être masquée ou noyée par les spectres de masses des composés non caractéristiques ou présents en grande quantité dans l'espace de tête du DHS-MS. La filtration des données peut alors être une solution permettant de mieux cibler l'information discriminante. Par ailleurs, les empreintes spectrales des échantillons analysés à des périodes différentes peuvent contenir une source de variabilité entraînant une baisse du pouvoir prédictif du modèle. Dans ce cas une remise à jour du modèle, présente alors une solution efficace à ce problème. Le SPME-MS: le potentiel discriminant du cette technique a été évalué sur des échantillons de planches de liège brutes à travers une étude de discrimination de l'origine géographique des échantillons. Le traitement des résultats a montré que ce couplage permet de distinguer facilement les lièges africains des lièges ibériques. Cependant, nous n'avons pas pu accéder à l'information discriminante entre les échantillons ibériques. Avec des résultats de discrimination encourageants et des durées d'analyses relativement courtes de 27 et de 12 minutes par échantillon, le DHS-MS et la SPME-MS ont toutefois montré que leur utilisation présentaient des limites et des difficultés que nous avons tenté de définir et de discuter tout au long de ce travail.
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Mattison, Mariell. "Influence of hardwood, softwoodand fractionated pulp in a stratifiedthree-layered fine paper : Lövved, barrved och fraktionerad massa ochdess inverkan på ett treskiktat finpapper." Thesis, Högskolan Dalarna, Grafisk teknik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:du-2389.
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Four different trials of stratified three-layered fine paper, of sulphate pulp, were performed to investigate if stratified fine fraction or fibres from birch can improve the properties of a paper compared to a reference sheet. All trials had five different scenarios and each scenario was calendered with different linear load. All sheets had a grammage of 80 g/m2.In the first trial, the paper contained birch, pine and filler of calciumcarbonate (marble), and was manufactured with the pilot paper machine XPM and the stratified headbox Formator at RCF (Stora Enso Research Center in Falun). The furnish consisted of 75% birch and 25% pine.The second trial contained coated sheets with paper from trial one as the base paper. The coating slip contained calciumcarbonate and clay and the amount was approximately 10-12 g/m2.The third trial, also with birch and pine but without filler, was performed at STFI (Skogsindustrins Tekniska Forskningsinstitut in Stockholm) with the laboratory scaled paper machine StratEx and the stratified headbox AQ-vanes. The furnish consisted of 75% birch and 25% pine, except for one scenario which contained of 75% pine and 25% birch.The last trial contained fractionated pulp of birch and pine and was performed at STFI. 50% was fine fraction and 50% was coarse fraction.This test does not show any clear benefits of making stratified sheets of birch and pine when it comes to properties such as bending stiffness, tensile index and surface smoothness. The retention can be improved with birch in the surface plies. It is possible that the formation can be improved with birch in the surface plies and pine in the middle ply. It is also possible that fine fraction in the surface plies and coarse fraction in the middle ply can improve both surface smoothness and bending stiffness. The results in this test are shown with confidence intervals which points out the difficulties of analysing sheets manufactured with a pilot paper machine or a laboratory scaled paper machine.
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Рачинський, Артур Юрійович. "Гідродинаміка і тепломасообмін в контактному утилізаторі теплоти газокрапельного типу." Thesis, КПІ ім. Ігоря Сікорського, 2017. https://ela.kpi.ua/handle/123456789/19313.
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Роботу присвячено експериментальним дослідженням, що направлені на підвищення ефективності роботи контактних тепломасообмінних апаратів шляхом збільшення міжфазної поверхні тепломасообміну при розпилені рідини відцентровими форсунками, впровадження яких приводить до суттєвої економії матеріальних та енергетичних ресурсів. Виконано комплексні експериментальні дослідження характеристик факелу розпилу рідини (густини зрошення, кута розкриття факела форсунки, середнього об’ємно-поверхневого діаметра крапель рідини). Встановлено вплив вхідних параметрів на відповідні характеристики та визначено площу поверхні крапель розпиленої рідини. Експериментально встановлено значення граничної температури нагріву води та її залежність від початкового паровмісту, при якій вода нагрівається до граничної температури в залежності від початкового паровмісту й витрати сухого повітря. Визначено параметричні границі ефективного використання відцентрової механічної форсунки без випаровування крапель нагрітої рідини. Експериментально досліджено інтенсивність тепло- і масоовіддачі в контактному апараті газокрапельного типу з відцентровою форсункою в умовах утилізації теплоти відхідних газів енергетичних агрегатів. Вперше отримано емпіричні залежності для розрахунку середніх коефіцієнтів тепловіддачі та масовіддачі, які відносяться до дійсної поверхні крапель розпиленої води. Встановлено особливості процесів переносу в газокрапельній системі та отримано узагальнювальні залежності для процесів тепло- і масовіддачі. На основі експериментальних досліджень характеристик розпилу та процесів тепломасообміну при конденсації пари з парогазової суміші на краплях розпиленої рідини розроблено методику розрахунку крапельного контактного утилізаційного апарату.Dissertation is devoted to experimental research, aimed at improving the efficiency of contact heat and mass transfer units by increasing the interfacial surface of heat and mass transfer during the liquid spraying by centrifugal nozzles, implementation of which results in significant savings of material and energy resources. Comprehensive experimental study of the characteristics of the liquid spraying torch (irrigation density, expansion angle of nozzle torch, the average volume-surface diameter of liquid droplets) was done. The influence of input parameters to the relevant properties was shown and surface area of the sprayed liquid droplets was defined. The limit temperature of water heating and its dependence on initial vapor content in which water is heated to the limit temperature depending on the initial vapor content and dry air output were experimentally set. The parametric borders of effective use of centrifugal mechanical nozzle without evaporation of heated liquid drops were defined. Intensity of heat and mass transfer in the contact gas-droplet unit with centrifugal nozzle in terms of heat utilization of energy units’ exhaust gases was experimentally researched. The empirical dependences for calculating the average heat transfer and mass transfer coefficients relating to the actual surface of the sprayed liquid droplets are obtained for the first time. The peculiarities of transfer processes in the gas-droplet system were determined and generalized dependence for heat and mass transfer were received. Based on experimental studies of spraying characteristics and heat and mass transfer processes at vapor condensation from vapor-gas mixture on the sprayed liquid droplets, the method of calculating the droplet contact utilization unit was developed.
Диссертация посвящена исследованиям, направленным на повышение эффективности работы контактных аппаратов путем увеличения межфазной поверхности теплообмена путем распыления жидкости, внедрение которых приводит к существенной экономии материальных и энергетических ресурсов. Работа содержит результаты экспериментальных исследований характеристик распыла и процессов тепломассоотдачи при конденсации пара из парогазовой смеси на каплях распыленной жидкости. Исследовано влияние температуры и давления воды на тонкость распыла (величину среднего объемно-поверхностного диаметра капель) для центробежной форсунки в параметрических условиях ее работы и применительно к условиям работы контактного утилизатора теплоты отходящих газов. На основании проведенных опытов получены новые зависимости величины среднего объемно-поверхностного диаметра капель для параметров распыливания жидкости с помощью центробежной форсунки в новом диапазоне изменения избыточного давления и температуры воды перед форсункой. В результате теоретического анализа движения капель жидкости в факеле распыления центробежной форсунки и использования экспериментальных данных по средним объемно-поверхностным диаметрам капель предложена методика определения действительной межфазной поверхности процессов тепломассообмена в контактных газожидкостных аппаратах капельного типа. Экспериментально определена зависимость граничной температуры нагрева воды в контактном аппарате газокапельного типа с центробежной форсункой применительно к условиям утилизации теплоты отходящих газов энергетических агрегатов. Исследования проведены в диапазоне избыточных давлений воды перед форсункой (0,2–0,6) МПа и объемной доли водяных паров парогазовой смеси на входе в аппарат от 0,02 до 0,45. Показано использование полученной зависимости для рас чета предельных значений параметров парогазового потока, ограничивающих область эффективной работы контактного аппарата с конденсацией пара и отсутствием режима испарения капель нагретой жидкости. Экспериментально определена интенсивность тепло- и массоотдачи в контактном аппарате газокапельного типа с центробежной форсункой в условиях утилизации теплоты отходящих газов энергетических агрегатов. Исследование проведены в диапазоне избыточного давления воды перед форсункой (0,2 - 0,6) МПа и объемной долей водяного пара парогазовой смеси на входе в аппарат от 0,08 до 0,35. По результатам экспериментальных исследований определены коэффициенты тепло- и массоотдачи, которые были отнесены к реальной поверхности капель. Полученные в работе результаты экспериментальных исследований коэффициентов тепло- и массоотдачи сравнивались с известными литературными данными для одиночной капли. Установлено, что интенсивность теплоотдачи для капель жидкости с парогазовым потоком выше, чем для одиночной капли, а для массоотдачи, ниже. Установлены особенности процессов переноса в газокапельной системе и получены обобщающие зависимости для процессов тепло- и массообмена для факела капель конуса распыла. В результате указанного комплекса работ предложена методика теплового расчета контактного газокапельного утилизатора теплоты низкотемпературных отходящих газов при распылении жидкости механической центробежной форсункой, которая учитывает реальные условия протекания процессов переноса в рассматриваемой двухфазной системе. Приведенная процедура теплового расчета утилизационной установки позволяет при заданных параметрах отходящих газов и воды на входе получить тип и количество распылителей для генерирования капель воды, выполнить компоновку в штатном коробе для отвода газов, рассчитать параметры теплоносителей на выходе с установки и определить ее теплопроизводительность.
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Рачинський, Артур Юрійович. "Гідродинаміка і тепломасообмін в контактному утилізаторі теплоти газокрапельного типу." Doctoral thesis, Київ, 2017. https://ela.kpi.ua/handle/123456789/19312.
Full textAbstract:
Роботу присвячено експериментальним дослідженням, що направлені на підвищення ефективності роботи контактних тепломасообмінних апаратів шляхом збільшення міжфазної поверхні тепломасообміну при розпилені рідини відцентровими форсунками, впровадження яких приводить до суттєвої економії матеріальних та енергетичних ресурсів. Виконано комплексні експериментальні дослідження характеристик факелу розпилу рідини (густини зрошення, кута розкриття факела форсунки, середнього об’ємно-поверхневого діаметра крапель рідини). Встановлено вплив вхідних параметрів на відповідні характеристики та визначено площу поверхні крапель розпиленої рідини. Експериментально встановлено значення граничної температури нагріву води та її залежність від початкового паровмісту, при якій вода нагрівається до граничної температури в залежності від початкового паровмісту й витрати сухого повітря. Визначено параметричні границі ефективного використання відцентрової механічної форсунки без випаровування крапель нагрітої рідини. Експериментально досліджено інтенсивність тепло- і масоовіддачі в контактному апараті газокрапельного типу з відцентровою форсункою в умовах утилізації теплоти відхідних газів енергетичних агрегатів. Вперше отримано емпіричні залежності для розрахунку середніх коефіцієнтів тепловіддачі та масовіддачі, які відносяться до дійсної поверхні крапель розпиленої води. Встановлено особливості процесів переносу в газокрапельній системі та отримано узагальнювальні залежності для процесів тепло- і масовіддачі. На основі експериментальних досліджень характеристик розпилу та процесів тепломасообміну при конденсації пари з парогазової суміші на краплях розпиленої рідини розроблено методику розрахунку крапельного контактного утилізаційного апарату.
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Almabrok, Almabrok Abushanaf. "Gas-Liquid Two-Phase Flow in Up and Down Vertical Pipes." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8447.
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Multiphase flows occurring in pipelines with a serpentine configuration is an important phenomenon, which can be encountered in heat exchangers used in a variety of industrial processes. More specifically, in many industrial units such as a large cracking furnace in a refinery, the tubes are arranged in a serpentine manner and are relatively short. As flow negotiates round the 180o bend at the ends of the tubes, the generated centrifugal force could cause flow maldistribution creating local dry spots, where no steady liquid film is formed on the adjacent straight sections of the pipe. As a result, events including coking, cracking and overheating of heat transfer surfaces may occur and lead to frequent shutdown of the facilities. Consequently, this could increase operating costs and reduce production revenue. Thus, it is desirable to know the effect that the bends exert on the flow in the straight part of the pipe. Apart from this, knowledge of the bend effects on the flows in the pipeline could also be important for the design of other pipelines for gas/liquid transport, e.g. offshore gas and oil pipelines.
Quite a large number of studies have been found in the literature. The majority of them were for two-phase flow with small diameter pipes (i.d. ≤ 50 mm). However, studies with large diameter pipes (i.d. ≥ 100 mm), have increasingly been considered in recent years as problems related to large diameter vertical pipes are being encountered more and more often in industrial situations.
This thesis studies the effect of 180o bends on the characteristics and development of gas-liquid two-phase flows in large diameter downward and upward pipes. The study particularly focuses on the influence of serpentine configuration on flow structure, cross-sectional void distribution and circumferential liquid film profiles and their development along the downward and upward sections.
It was found that both the top and bottom bends have considerable impacts on flow behaviour, although to varying degrees. These impacts were highly dependent on the air and water flow rates. For sufficient flow rates, the bends were observed to create flow maldistribution in the adjacent straight section, due to the effects of centrifugal force. The air moved towards the inner zone of the bend and the water towards the outer zone, while a lesser quantity of water was identified on the other surfaces of the pipe.
Investigation of the film thickness development in the downward and upward sections showed that, the liquid film behaviour close to the bends was significantly different from those located further away. This can be attributed to the centrifugal force of the bends.
Examination of the power spectral density (PSD) along the downward and upward sections showed that, the shape of PSD located in the adjacent section to the bends, was substantially different from those located further away.
Furthermore, several flow regime maps were generated which showed that, in addition to bubbly, intermittent and annular flows, unstable flows existed along the upward section, particularly for low gas and water flow rates. In this study it was found that, the lower bend was periodically blocked by the liquid and then blown through by the accumulated air.
The data obtained from this study were compared with different theoretical correlations found in the existing literature. Some discrepancy between the results of the current study and those of previous published materials was noted. Updated correlations were presented which provided well results when they applied for the data obtained from the current study and previous studies.
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Belzile, Martin. "Bilan de masse de différents systèmes de séparation des fractions solide et liquide des déjections porcines directement sous les lattes." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24942/24942.pdf.
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WANDEKOKEN, FLÁVIA GALVÃO. "DEVELOPMENT OF METHOD FOR THE QUANTIFICATION OF VANADYL PORPHYRINS IN CRUDE OIL FRACTIONS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WITH FLOW INJECTION AND INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=30343@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
A cromatografia líquida de alta eficiência hifenada por injeção em fluxo com espectrometria de massa com plasma indutivamente acoplado (HPLC-FI-ICP-MS) foi utilizada para investigar vanádio ligado a porfirinas presente em frações de óleo cru. Em primeiro lugar, a amostra de óleo cru foi submetida a um fracionamento por meio de cromatografia líquida preparativa com detecção em UV-Vis, no comprimento de onda da banda Soret da porfirina (400 nm). As frações de porfirina obtidas foram então separadas numa coluna única de 250 mm, no HPLC e eluídas com fases móveis diferentes, metanol ou metanol:tolueno (80:20; v:v). A quantificação de V-porfirinas nas frações eluídas do HPLC foi feita pela medida do isótopo 51V no ICP-MS, usando-se soluções-padrão de octaetil-porfirina de vanádio (VO-OEP), preparados no mesmo solvente usado na fase móvel, e injetados pós-coluna diretamente no plasma. Um padrão de Ge em metanol (20 microgramas L−1) foi utilizado como padrão interno para minimizar interferências não-espectrais, tais como oscilações devido à injeção. O tratamento matemático do sinal com base no algoritmo de suavização do tipo Transformada Rápida de Fourier (FFT) foi utilizado para melhorar a precisão. As concentrações de V como V-porfirinas foram entre 2,7 e 11 mg kg-1 nas frações, valores próximos à concentração total de V nas frações de óleo cru estudadas.
High performance liquid chromatography hyphenated by flow injection to inductively coupled plasma mass spectrometry (HPLC–FI–ICP-MS) was used to investigate vanadium linked to porphyrins present in fractions of crude oil. First, the crude oil sample was submitted to fractionation by preparative liquid chromatography with UV-Vis detection, at the porphyrin Soret band wavelength (400 nm). The obtained porphyrin fractions were then separated in a 250 mm single column, in the HPLC, and eluted with different mobile phases, methanol or methanol:toluene (80:20; v:v). The quantification of V-porphyrins in the fractions eluted from HPLC was carried out by online measuring the 51V isotope in the ICP-MS, against vanadyl octaethylporphine standard solutions (VO-OEP), prepared in the same solvent as the mobile phase, and injected post-column directly into the plasma. A 20 micrograms L−1 Ge in methanol was used as internal standard for minimizing non-spectral interference, such as short-term variations due to injection. The mathematical treatment of the signal based on Fast Fourier Transform (FFT) smoothing algorithm was employed to improve the precision. The concentrations of V as V-porphyrins were between 2.7 and 11 mg kg−1 in the fractions, which were close to the total concentration of V in the fractions of the studied crude oil.
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Ndolo, Victoria Uchizi. "Characterisation of chemical components in manually isolated aleurone and associated layers from maize, wheat and barley kernels." Elsevier, 2013. http://hdl.handle.net/1993/30914.
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Health benefits related to consumption of whole grains have been attributed in part to phytochemical and micronutrient composition. Understanding the composition, structure and distribution of these components in different cereal grains is of potential importance in aiding the selection of whole grains and their processed fractions for inclusion in the diet, and as ingredients in development of new food products. The aim of this research was to characterise the chemical components in the botanical fractions of yellow corn, barley, wheat. Manual separation, a tedious and laborious technique that yields pure fractions, suitable for compositional analysis, was used to separate whole grains into pericarp, aleurone layer, germ and endosperm fractions. Component identification and quantification of tissue components was accomplished by several techniques. The study also explored the possibility of using spectral characteristics fluorescence intensity values to provide rapid estimates of the concentrations and distribution of ferulic acid (FA), a major phenolic compound in cereal grains. While composition of phenolic acids and carotenoids was similar, the distribution was significantly different (P < 0.05) among cereal types and grain fractions. Phenolic acids were concentrated in pericarp and aleurone fractions, followed by the germ and the endosperm had the lowest levels. Yellow corn exhibited the highest values. Carotenoids, lutein and zeaxanthin were concentrated in the germ and aleurone layer of wheat and barley while in yellow corn it was in the endosperm and aleurone layer. This is the first study to report on carotenoid composition of aleurone fractions. Mineral elements, thiamine and niacin were higher in wheat aleurone than in purple barley and yellow corn aleurone layers. These findings suggest that yellow corn aleurone layers have potential as a functional food ingredient despite the low micronutrient content. A positive, significant correlation (r= 0.421, p < 0.0001) was found between fluorescence intensity values and ferulic acid concentration. Thus, fluorescence intensity profiles are a promising approach for rapid assessment of FA concentration in grain in-situ. This work has provided information that would act as a database for selection of cereal fractions and guide the miller to obtain grain fractions with enriched levels of phytochemicals and micronutrients.February 2016
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Lababidi, Sami [Verfasser], Wolfgang [Akademischer Betreuer] Schrader, and Oliver J. [Akademischer Betreuer] Schmitz. "Effect of sample preparation on the characterization of crude oil and its complex fractions by high resolution mass spectrometry / Sami Lababidi. Gutachter: Oliver J. Schmitz. Betreuer: Wolfgang Schrader." Duisburg, 2013. http://d-nb.info/104183179X/34.
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Urban, Brook John. "Flash Pyrolysis and Fractional Pyrolysis of Oleaginous Biomass in a Fluidized-bed Reactor." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1431105367.
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Carrasco, Piaggio Matias. "Jauge conforme des espaces métriques compacts." Phd thesis, Université de Provence - Aix-Marseille I, 2011. http://tel.archives-ouvertes.fr/tel-00645284.
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L'objet principal de cette thèse est l'étude de la dimension conforme Ahlfors régulière ($\dim_{AR}X$) d'un espace métrique $X$. C'est un invariant numérique par quasisymétrie, introduit par P.\,Pansu, permettant la classification à quasi-isométrie près des espaces homogénes de courbure négative. Elle joue actuellement un rôle important en théorie géométrique des groupes et en dynamique conforme. A partir d'une suite de recouvrements d'un espace métrique compact $\left(X,d\right)$, on construit des distances de dimension contrôlée appartenant à la jauge conforme (Ahlfors régulière). On peut ainsi caractériser toutes les métriques de la jauge á homéomorphismes bi-Lipschitz prés. On montre comment calculer $\dim_{AR}X$ á partir de modules combinatoires en considérant un exposant critique $Q_N$. Comme conséquence de l'égalité $\dim_{AR}X=Q_N$, on obtient un critère général de dimension $1$. Les conditions sont données en termes de points de coupure locale de $X$. On donne par ailleurs des applications de ces résultats aux bords des groupes hyperboliques et aux ensembles de Julia des fractions rationnelles semihyperboliques.