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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Design of Copper-Catalyzed Multicomponent Reactions and Applications to Natural Product Synthesis

Meng, Fanke January 2015 (has links)
Thesis advisor: Amir H. Hoveyda / Chapter 1. Ligand-Controlled Site-Selective NHC–Cu-Catalyzed Protoboration of Monosubstituted Allenes. Site-selective proto–boryl additions to monosubstituted allenes promoted by NHC–Cu complexes are disclosed. Synthetically useful 1,1-disubstituted and Z-trisubstituted alkenylboron compounds are afforded in high efficiency (71%–92% yield) and site selectivity (88% to >98%) through proper choice of NHC ligands. Mechanistic study with the assistance of DFT calculations indicates that protonation of 2-boron-substituted allylcopper complex occurs through six-membered cyclic transition state. The utility of this protocol is demonstrated through application to fragment synthesis of an antibiotic macrolide natural product elansolid A. Chapter 2. Cu-Catalyzed Chemoselective Copper–Boron Additions to Monosubstituted Allenes Followed by Allyl Additions to Carbonyl Compounds. The first examples of catalytic generation of 2-boron-substituted allylcopper species and their in situ use for C–C bond formation are described. The reactions are performed in the presence of bisphosphine– or NHC–Cu complexes at 22 oC. High-value alcohol-containing alkenylboron compounds are provided in high efficiency (68–92% yield after oxidation) and stereoselectivity (88:12 to >98:2 dr). The reactions proceed with exclusive γ-addition mode through a cyclic six-membered transition state. Enantioselectivity can be achieved with chiral bisphosphine ligands in up to 97:3 enantiomeric ratio. Chapter 3. Chemo-, Site- and Enantioselective Copper–Boron Additions to 1,3-Enynes Followed by Site- and Diastereoselective Additions of the Resulting Allenylcopper Complexes to Aldehydes. Catalytic enantioselective multicomponent reactions involving 1,3-enynes, aldehydes and B2(pin)2 are described. The resulting products contain a primary C–B(pin) bond, as well as alkyne- and hydroxyl-substituted tertiary stereogenic centers. A critical feature is high enantioselectivity of the initial Cu–B addition to an alkyne-substituted terminal alkene. The key mechanistic issues are investigated by DFT calculations. Reactions are promoted in the presence of the Cu complex of an enantiomerically pure C1-symmetric bisphosphine and are complete in 8 h at ambient temperature. Products are generated in 66–94% yield (after oxidation or catalytic cross-coupling), 90:10 to >98:2 diastereomeric ratio, and 85:15–99:1 enantiomeric ratio. Aryl-, heteroaryl-, alkenyl-, and alkyl-substituted aldehydes and enynes are suitable substrates. Utility is demonstrated through catalytic alkylation and arylation of the organoboron compounds as well as applications to synthesis of fragments of tylonolide and mycinolide IV. Chapter 4. Multifunctional Alkenylboron Compounds through Single-Catalyst-Controlled Multicomponent Reactions and Their Applications in Scalable Natural Product Synthesis. A facile multicomponent catalytic process that begins with a chemo-, site- and diastereoselective copper–boron addition to a monosubstituted allene followed by addition of the resulting boron-substituted organocopper intermediate to an allylic phosphate, generating products that contain a stereogenic center, a monosubstituted alkene and an easily functionalizable Z-trisubstituted alkenylboron group in up to 89% yield with >98% branch selectivity and stereoselectivity and an enantiomeric ratio greater than 99:1. The copper-based catalyst is derived from a robust heterocyclic salt that can be prepared in multigram quantities from inexpensive starting materials and without costly column chromatography purification. The utility of the method is demonstrated through enantioselective synthesis of gram quantities of two natural products, rottnestol and herboxidiene/GEX1A. Chapter 5. Cu-Catalyzed Enantioselective Allyl and Propargyl 1,6-Conjugate Additions through 3,3’-Reductive Elimination. Catalytic enantioselective 1,6-conjugate additions of allyl-type nucleophiles promoted by NHC–Cu complexes are reported. Propargyl and 2-boron allyl 1,6-conjugate products are formed in high efficiency, diastereo- and enantioselectivity. The unique mechanistic feature is that the transformations proceed through Cu-catalyzed 3,3’-reductive elimination, that is unprecedented for copper catalysis. Further mechanistic study and application to complex molecule synthesis will be conducted. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
22

Análise comparativa de aproximações não-hiperbólicas dos tempos de trânsito de dados sísmicos multicomponente utilizando tecnologia OBN / Comparative analysis of nonhyperbolic travel-time approximations of multicomponent seismic data using OBN technology

Nelson Ricardo Coelho Flores Zuniga 23 February 2017 (has links)
A análise de velocidades é uma etapa fundamental para o processamento sísmico e é realizada ajustando a curva de tempos de trânsito calculada pela aproximação hiperbólica com a curva observada no registro sísmico. Entretanto, na sísmica de exploração são facilmente encontrados modelos que apresentam características que tornam um evento de tempos de trânsito não-hiperbólico, algo que é intensificado quando utilizados dados sísmicos multicomponente, os quais apresentam eventos de ondas convertidas. Outro fator importante é a utilização de tecnologia OBN que também torna o evento menos hiperbólico devido à geometria de aquisição. Dessa maneira é fundamental utilizar-se aproximações que consigam controlar essa não-hiperbolicidade para realizar a análise de velocidades. O estudo numérico proposto no presente trabalho focou em analisar a complexidade das funções objetivo, e sua qualidade e eficiência no ajuste de curvas dos tempos de trânsito com diferentes aproximações. Os modelos estudados, originados de perfis de poços da Bacia de Santos, apresentam diferentes características que tornam as análises propostas mais complexas. Dessa forma, as aproximações utilizadas são de igual complexidade, e pelo fato de utilizarem três parâmetros, o estudo foi tratado como um problema de inversão seguindo um critério de otimização. Com o conjunto de informações obtidas nos testes, foi determinado quão complexa é cada aproximação, e a qualidade e eficiência que ela apresenta para obter os resultados almejados. Sendo assim, foi possível identificar as aproximações mais indicadas para cada modelo estudado, para cada tipo de evento de reflexão e para todos os modelos de uma forma genérica. / The velocity analysis is a fundamental tool in the seismic processing, and it is performed fitting the calculated travel-time curve to the curve recorded in the seismic record. However, in the seismic survey, there are many models that present characteristics which make a travel-time event nonhyperbolic. This is intensified with using multicomponent seismic data, which present converted wave events. Another important factor is the use of the OBN technology that makes an event less hyperbolic due to its geometry acquisition. Therefore, we must use approximations which could control this nonhyperbolicity to perform the velocity analysis. The numerical study proposed here aimed to analyze the complexity of the objective functions and the quality and the efficiency of the travel-time curve fitting with different approximations. The models under study, elaborated from well logs data of the Santos Basin, shown different characteristics making the proposed analysis more complex. Thus, the approximations are of equal complexity, and due to the fact of the using three parameters, the study was treated as an inverse problem solved by an optimization criterion. With the set of obtained informations, it was determined how complex each approximation is. The quality and the efficiency of each approximation were also studied. Thus, it was possible to identify the most appropriate approximations for each model tested, for each kind of reflection event, and for all situations studied here in a general form.
23

Análise comparativa de aproximações não-hiperbólicas dos tempos de trânsito de dados sísmicos multicomponente utilizando tecnologia OBN / Comparative analysis of nonhyperbolic travel-time approximations of multicomponent seismic data using OBN technology

Zuniga, Nelson Ricardo Coelho Flores 23 February 2017 (has links)
A análise de velocidades é uma etapa fundamental para o processamento sísmico e é realizada ajustando a curva de tempos de trânsito calculada pela aproximação hiperbólica com a curva observada no registro sísmico. Entretanto, na sísmica de exploração são facilmente encontrados modelos que apresentam características que tornam um evento de tempos de trânsito não-hiperbólico, algo que é intensificado quando utilizados dados sísmicos multicomponente, os quais apresentam eventos de ondas convertidas. Outro fator importante é a utilização de tecnologia OBN que também torna o evento menos hiperbólico devido à geometria de aquisição. Dessa maneira é fundamental utilizar-se aproximações que consigam controlar essa não-hiperbolicidade para realizar a análise de velocidades. O estudo numérico proposto no presente trabalho focou em analisar a complexidade das funções objetivo, e sua qualidade e eficiência no ajuste de curvas dos tempos de trânsito com diferentes aproximações. Os modelos estudados, originados de perfis de poços da Bacia de Santos, apresentam diferentes características que tornam as análises propostas mais complexas. Dessa forma, as aproximações utilizadas são de igual complexidade, e pelo fato de utilizarem três parâmetros, o estudo foi tratado como um problema de inversão seguindo um critério de otimização. Com o conjunto de informações obtidas nos testes, foi determinado quão complexa é cada aproximação, e a qualidade e eficiência que ela apresenta para obter os resultados almejados. Sendo assim, foi possível identificar as aproximações mais indicadas para cada modelo estudado, para cada tipo de evento de reflexão e para todos os modelos de uma forma genérica. / The velocity analysis is a fundamental tool in the seismic processing, and it is performed fitting the calculated travel-time curve to the curve recorded in the seismic record. However, in the seismic survey, there are many models that present characteristics which make a travel-time event nonhyperbolic. This is intensified with using multicomponent seismic data, which present converted wave events. Another important factor is the use of the OBN technology that makes an event less hyperbolic due to its geometry acquisition. Therefore, we must use approximations which could control this nonhyperbolicity to perform the velocity analysis. The numerical study proposed here aimed to analyze the complexity of the objective functions and the quality and the efficiency of the travel-time curve fitting with different approximations. The models under study, elaborated from well logs data of the Santos Basin, shown different characteristics making the proposed analysis more complex. Thus, the approximations are of equal complexity, and due to the fact of the using three parameters, the study was treated as an inverse problem solved by an optimization criterion. With the set of obtained informations, it was determined how complex each approximation is. The quality and the efficiency of each approximation were also studied. Thus, it was possible to identify the most appropriate approximations for each model tested, for each kind of reflection event, and for all situations studied here in a general form.
24

Ladungsträger- und Anregungsdynamik in halbleitenden Polymerschichten mit eingemischten Emittern und Ladungsträgerfallen / Charge and excitation dynamics in semiconducting polymer layers doped with emitters and charge carrier traps

Jaiser, Frank January 2006 (has links)
In Leuchtdioden wird Licht durch die Rekombination von injizierten Ladungsträgern erzeugt. Das kann einerseits in anorganischen Materialien geschehen. In diesem Fall ist es notwendig, hochgeordnete Kristallstrukturen herzustellen, die die Eigenschaften der Leuchtdioden bestimmen. Ein anderer Ansatz ist die Verwendung von organischen Molekülen und Polymeren. Auf Grund der Vielseitigkeit der organischen Chemie können die Eigenschaften der verwendeten halbleitenden Polymere schon während der Synthese beeinflusst werden. Außerdem weisen auch diese Polymere die bekannte mechanische Flexibilität auf. Die Herstellung von flexiblen, großflächigen Beleuchtungsquellen und Anzeigelementen ist so möglich.<br> Die erste Leuchtdiode mit einem halbleitenden Polymer als Emitter wurde 1990 hergestellt. Seither hat das Forschungsgebiet eine rasante Entwicklung genommen. Auch erste kommerzielle Produkte sind erhältlich. Im Zuge dieser Entwicklung wurde deutlich, dass die Eigenschaften von polymeren Leuchtdioden – beispielsweise Farbe und Effizienz – durch die Verwendung mehrerer Komponenten in der aktiven Schicht deutlich verbessert werden können. Gleichzeitig ergeben sich neue Herausforderungen durch die Wechselwirkungen der verschiedenen Filmbestandteile. Während die Komponenten oft entweder zur Verbesserung des Ladungstransportes oder zur Beeinflussung der Emission zugegeben werden, muss darauf geachtet werden, dass die anderen Prozesse nicht negativ beeinflusst werden. In dieser Arbeit werden einige dieser Wechselwirkungen untersucht und mit einfachen physikalischen Modellen erklärt.<br> So werden zunächst blau emittierende Leuchtdioden auf der Basis von Polyfluoren untersucht. Dieses Material ist zwar ein sehr effizienter blauer Emitter, jedoch ist es anfällig für chemische Defekte, diese sich nicht vollständig verhindern lassen. Die Defekte bilden Fallenzustände für Elektronen, ihr Einfluss lässt sich durch die Zugabe von Lochfallen unterdrücken. Der zugrunde liegende Prozess, die Beeinflussung der Ladungsträgerbalance, wird erklärt. Im Folgenden werden Mischsystemen mit dendronisierten Emittern, die gleichzeitig eine Falle für Elektronen bilden, untersucht. Hier wird die unterschiedliche Wirkung der isolierenden Hülle auf die Ladungs- und Energieübertragung zwischen Matrix und Farbstoffkern der Dendrimere untersucht. In Mischsystemen haben die Natur der angeregten Zustände sowie die Art und Weise des Ladungsträgertransportes einen großen Einfluss auf diese Transferprozesse. Außerden hat auch hier die Ladungsträgerbalance Auswirkungen auf die Emission. Um den Ladungsträgereinfang in Fallenzuständen zu charakterisieren, wird eine Methode auf Grundlage der Messung des zeitaufgelösten Photostroms in organischen Mischfilmen weiterentwickelt. Die erzielten Ergebnisse zeigen, dass die Übertragung der für geordnete Systeme entwickelten Modelle des Ladungsträgertransportes nicht ohne weiteres auf Polymersysteme mit hoher Unordnung übertragen werden können. Abschließend werden zeitaufgelöste Messungen der Phosphoreszenz in entsprechenden Mischungen aus Polymeren und organometallischen Verbindungen vorgestellt. Auch diese Systeme enthalten üblicherweise weitere Komponenten, die den Ladungstransport verbessern. In diesen Filmen kann es zu einer Übertragung der Tripletts vom Emitter auf die weiteren Filmbestandteile kommen. Bei Kenntnis der in Frage kommenden Wechselwirkungen können die unerwünschten Prozesse vermieden werden. / Light-emitting diodes generate light from the recombination of injected charge carriers. This can be obtained in inorganic materials. Here, it is necessary to produce highly ordered crystalline structures that determine the properties of the device. Another possibility is the utilization of organic molecules and polymers. Based on the versatile organic chemistry, it is possible to tune the properties of the semiconducting polymers already during synthesis. In addition, semiconducting polymers are mechanically flexible. Thus, it is possible to construct flexible, large-area light sources and displays.<br> The first light-emitting diode using a polymer emitter was presented in 1990. Since then, this field of research has grown rapidly up to the point where first products are commercially available. It has become clear that the properties of polymer light-emitting diodes such as color and efficiency can be improved by incorporating multiple components inside the active layer. At the same time, this gives rise to new interactions between these components. While components are often added either to improve the charge transport or to change the emission, it has to made sure that other processes are not influenced in a negative manner. This work investigates some of these interactions and describes them with simple physical models.<br> First, blue light-emitting diodes based on polyfluorene are analyzed. This polymer is an efficient emitter, but it is susceptible to the formation of chemical defects that can not be suppressed completely. These defects form electron traps, but their effect can be compensated by the addition of hole traps. The underlying process, namely the changed charge carrier balance, is explained. In the following, blend systems with dendronized emitters that form electron traps are investigated. The different influence of the insulating shell on the charge and energy transfer between polymer host and the emissive core of the dendrimers is examined. In the blend, the nature of the excited states as well as the method of the charge transport through the layer are of great importance to the transfer. Again, the charge carrier balance influences the emission. To characterize the trapping of charges in trap states, a method based on the measurement of transient photocurrents is enhanced. The results show that models developed for ordered systems can not simply be transferred to polymer systems with a high degree of disorder. Finally, time-resolved measurements of the phosphorescence decay in blends of polymers with organo-metallic compounds are shown. Usually, these systems contain more components that facilitate charge transport. Thus, triplets may be transferred from the phosphorescent dye other components of the film. Knowing the underlying interactions, unwanted processes can be suppressed.
25

Unprotected Aziridine Aldehydes in Isocyanide-based Multicomponent Reactions

Rotstein, Benjamin Haim 19 December 2012 (has links)
While unprotected amino aldehydes are typically not isolable due to imine formation and consequent polymerization, stable unprotected aziridine aldehydes are useful and available reagents. Moreover, reversible hemiacetal and hemiaminal formation enable these compounds to reveal both their electrophilic and nucleophilic functional groups. This exceptional arrangement allows for aziridine aldehyde dimers to participate in and disrupt the mechanisms of an array of well-known organic reactions, including isocyanide-based multicomponent reactions. The scope and selectivity patterns of aziridine aldehyde induced amino acid or peptide macrocyclization have been investigated. A small library of constrained tri-, tetra-, and penta-peptide macrocycles – representing the most difficult cyclic peptides to synthesize – has been prepared. The scope of aziridine aldehyde participation in multicomponent reactions was also expanded to Ugi and Passerini reactions that do not employ tethered amine and acid functional groups. In order to facilitate cellular imaging of peptide macrocycles a fluorescent isocyanide reagent was prepared and applied to prepare mitochondrial targeting macrocycles. Thioester isocyanide reagents were synthesized to enable rapid assembly of cycle-tail peptides through ligation technology.
26

North Caspian Basin: 2D elastic modeling for seismic imaging of salt and subsalt

Bailey, Zhanar Alpysbaevna 12 April 2006 (has links)
The North Caspian Basin (NCB) contains a significant number of major oil fields, some of which are yet to be put into production. The reason why some of these fields are not yet put into production is the exploration challenge that the NCB poses. In particular, the complex geological structure of this region makes it quite difficult to image its oil fields with conventional seismic techniques. This thesis sheds more light on difficulties associated with acquiring and processing seismic data in the NCB. The two central tools for investigation of these imaging challenges were the construction of a geological model of the NCB and the use of an accurate elastic wave-propagation technique to analyze the capability of seismic to illuminate the geological structures of the NCB. Using all available regional and local studies and my knowledge gained with oil companies, where I worked on subsalt and suprasalt 2D and 3D seismic data from the North Caspian Basin, I constructed a 2D elastic isotropic 10-by-6 km geological model of a typical oil field located on the shelf of the Caspian Sea in the southeastern part of the North Caspian Basin, which has the largest oil fields. We have propagated seismic waves through this model. The technique we used to compute wave propagation is known as the Finite-Difference Modeling (FDM) technique. Generating 314 shot gathers with stationary multicomponent OBS receivers that were spread over 10 km took two weeks of CPU time using two parallel computers (8 CPU V880 Sun Microsystems and 24 CPU Sun Enterprise). We have made the data available to the public. The dataset can be uploaded at http://casp.tamu.edu in the SEGY format. The key conclusions of the analysis of these data are as follows: - Combined usage of P- and S-waves allows us to illuminate subsalt reef, clastics and complex salt structures despite the 4-km overburden. - Free-surface multiples and guided waves are one of the key processing challenges in NCB, despite relatively shallow (less than 15 m) shelf water.
27

Unprotected Aziridine Aldehydes in Isocyanide-based Multicomponent Reactions

Rotstein, Benjamin Haim 19 December 2012 (has links)
While unprotected amino aldehydes are typically not isolable due to imine formation and consequent polymerization, stable unprotected aziridine aldehydes are useful and available reagents. Moreover, reversible hemiacetal and hemiaminal formation enable these compounds to reveal both their electrophilic and nucleophilic functional groups. This exceptional arrangement allows for aziridine aldehyde dimers to participate in and disrupt the mechanisms of an array of well-known organic reactions, including isocyanide-based multicomponent reactions. The scope and selectivity patterns of aziridine aldehyde induced amino acid or peptide macrocyclization have been investigated. A small library of constrained tri-, tetra-, and penta-peptide macrocycles – representing the most difficult cyclic peptides to synthesize – has been prepared. The scope of aziridine aldehyde participation in multicomponent reactions was also expanded to Ugi and Passerini reactions that do not employ tethered amine and acid functional groups. In order to facilitate cellular imaging of peptide macrocycles a fluorescent isocyanide reagent was prepared and applied to prepare mitochondrial targeting macrocycles. Thioester isocyanide reagents were synthesized to enable rapid assembly of cycle-tail peptides through ligation technology.
28

Scintilátory na bázi komplexních oxidů / Oxide scintillator detectors

Lučeničová, Zuzana January 2016 (has links)
The presented thesis focused on the study of a new material concept of Ce3+ doped multicom- ponent aluminum garnets (GdLu)3(GaAl)5O12. High purity single crystalline epitaxial films were grown by the method of liquid phase epitaxy from the BaO-B2O3-BaF2 flux with spe- cial emphasis on the elimination of the potential impurities coming from the flux. Combined experimental study of photoelectron yield (under alpha excitation), decay kinetics of fast and delayed recombination in the milisecond time range (under e-beam excitation) and photo-, cathodo- and radio-luminescence spectroscopies were used to characterize the studied mater- ial. The single-step nonradiative energy transfer from the donor Gd3+ to an acceptor Ce3+ was observed in the low Gd, Ce doped LuAG films and established as long-range dipole - dipole interaction. Special attention was devoted to the positive effect of combined Gd and Ga substitution on the extensive suppression of shallow traps, which are responsible for the slow component in the scintillation response. The best obtained scintillation characteristics of the studied epitaxial films were comparable with the top performance bulk crystals. 1
29

Organocatalytic acid mediated Mannich reactions and multicomponent boronate reactions to make chiral benzhydrils

Ramella, Daniele 22 January 2016 (has links)
Since its discovery in 1912, the Mannich reaction has been widely utilized in organic chemistry to form C-C bonds. Reactivity of an enol with an imine allows for easy formation of a [beta]-aminoketone. Enamines have also been widely utilized as convenient nucleophiles. In our work, unexpected reactivity of the [gamma] position of [beta]-enamidoesters in a Brønsted acid environment and high enantioselectivity of a Mannich reaction were achieved through chiral phosphoramidic acid catalysis. A novel class of chiral phosphoramidic acids was designed, synthesized from the corresponding diamines, with several sulfonyl N-protecting groups, and characterized. Their unique properties arise from their Brønsted acid nature, atropisomerism and ability to form complexes via H-bond. Once prepared, such catalysts were successfully used as organocatalysts for the regio- and enantioselective Mannich reaction of [beta]-enamidoesters and imines. Their activity is described as a method to reverse the regioselectivity of the nucleophile while achieving high enantioselectivities in the formation of chiral benzhydrils. A diverse range of imines has been tested, obtaining yields of up to 93% and enantioselectivities of up to 99:1. A few substituted enamines were also tested to study the influence of substituents on the regioselectivity. A mechanism for this reaction is proposed and kinetic studies confirmed that the reaction is first order in catalyst. The ozonolysis of the product of this Mannich reaction was performed to prove the absolute stereochemistry of the product; and a new efficient methodology for the asymmetric preparation of aminoacid [beta]-phenyl-[beta]-alanine benzyl ester is described. The reduction of the enamide moiety of the Mannich product was attempted via asymmetric hydrogenation and via hydride reduction to diastereomerically obtain 1,3-diamines, which are compounds of major synthetic interest. Unfortunately our attempts in this direction were not successful. Finally, a multicomponent reaction between an aldehyde, a substituted phenol, and a styrylboronate was developed as an alternative method for the preparation of chiral benzhydrils. This process is also organocatalytic and the methodology was optimized in the presence of 3-3'-disubstituted BINOLs. Yields up to 71% and enantioselectivities up to 96:4 were achieved. A mechanism for this organocatalytic reaction is also proposed.
30

Mass transfer during isothermal drying of a porous solid containing multicomponent liquid mixtures

Gamero, Rafael January 2004 (has links)
Mass transfer in a porous solid, partially saturated with asingle solvent and multicomponent liquid mixtures, has beenexperimentally and theoretically studied. A porous materialcontaining single liquids and mixtures of organic solvents wasisothermally dried. Experiments were performed using a jacketedwind tunnel, through which a humidity andtemperature-controlled air stream flowed. The wetted porousmaterial was placed in a cylindrical vessel, whose top isexposed to the air stream until the material became dried to acertain extent. Drying experiments with the single solventswater, methanol, ethanol and 2-propanol, were performed atdifferent temperatures and transient liquid content profileswere determined. In isothermal drying experiments with liquidmixtures,the transient concentration profiles of thecomponents along the cylindrical sample as well as the totalliquid content were determined. The liquid mixtures examinedwere water-methanolethanol and isopropanol-methanol-ethanol.Two different temperatures and initial compositions were usedin the experiments. Mathematical models that describe nonsteadystate isothermal drying of a solid containing single liquidsand multicomponent liquid mixtures were developed. In the solidwetted with a single liquid, capillary movement of the liquidwas the main mechanism responsible for mass transfer. In thesolid containing liquid mixtures, interactive diffusion inliquid phase was superimposed to the capillary movement of theliquid mixture. In addition, interactive diffusion of thevapours in empty pores was considered. The parameters todescribe the retention properties of the solid and thecapillary movement of the liquid were determined by comparingtheoretical and experimental liquid content profiles obtainedduring drying of the solid wetted with single liquids. Tosimulate the transport of the liquid mixtures these parameterswhere weighed according to liquid composition. A fairly goodagreement between theoretical and experimental liquidcomposition profiles was obtained if axial dispersion isincluded in the model when the moisture consists of amixture. Keywords:Internal mass transfer, capillary flow,multicomponent, diffusion, solvent mixtures

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