Let A and B be real or complex C*-algebras. Let V and W be real or complex (right) full Hilbert C*-modules over A and B, respectively. Let T be a linear bijective map from V onto W. We show the following four statements are equivalent. (a) T is a unitary operator, i.e., there is a ∗-isomorphism £\ : A ¡÷ B such that <Tx,Ty> = £\(<x,y>), ∀ x,y∈ V ; (b) T preserves TRO products, i.e., T(x<y,z>) =Tx<Ty,Tz>, ∀ x,y,z in V ; (c) T is a 2-isometry; (d) T is a complete isometry. Moreover, if A and B are commutative, the four statements are also equivalent to (e) T is a isometry. On the other hand, if V and W are complex Hilbert C*-modules over complex C*-algebras, then T is unitary if and only if it is a module map, i.e., T(xa) = (Tx)£\(a), ∀ x ∈ V,a ∈ A.

Ternary chalcopyrite compounds are the semiconductors with suitable properties to be used as absorber materials in thin film solar cells. AgInSe2 is a promising candidate with its several advantages over the widely used CuInSe2. The purpose of this study was to optimize the physical properties of the Ag-In-Se (AIS) thin films that were deposited by e-beam evaporation of Ag3In5Se9 single crystal powder for solar cell applications by means of post-annealing process under nitrogen atmosphere. The as-grown AIS thin films were annealed at 200, 300 and 400oC and their structural, optical, electrical and photoelectrical properties were examined to observe the effects of post-annealing process. Structural characterization of the films was performed by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) analyses. Optical properties of the films were investigated by optical transmittance measurements. Electrical and photoelectrical properties of the films were examined by temperature dependent conductivity, photoconductivity under different illumination intensities and spectral photoresponse measurements. It was discovered that the annealing of AIS thin films at 200oC resulted in the best physical properties for solar cell applications. The obtained films were polycrystalline with mixed binary and ternary crystalline phases, such as Ag3In5Se9, AgInSe2 and InSe, and showed n-type conductivity with room temperature conductivity value of 2.3x10-6 (Ohm&shy / cm)-1. The band gap energy of the 200oC-annealed films was determined as 1.68 eV from spectral photoresponse measurements. The results of the study revealed that the inadequate Ag incorporation and segregation and/or reevaporation of Se atoms at high annealing temperatures were the major problems encountered in producing single phase polycrystalline AgInSe2 thin films. The required stoichiometry of thin films should be maintained during the growth of the films by means of an alternative deposition procedure and the films should be selenized during post-annealing process.

<p>The convective drying of thin layers of multicomponentliquid mixtures into an inert gas, and the influence ofdifferent process controlling mechanisms on drying selectivityis studied. Drying experiments under gas-phase-controlledconditions are performed by low intensity evaporation, fromfree liquid surfaces, of ternary mixtures without non-volatilesolutes. Liquid-side-controlled experiments are carried out bydrying a multicomponent polymeric solution containing twovolatile components, one non-volatile polymer and an optionalnonvolatile softening substance.</p><p>Mathematical models to describe gas- andliquid-side-controlled drying based on interactive diffusion inboth liquid and gas phases as the main mechanisms for masstransfer are developed. For gas-phase-controlled drying, astability analysis of the ordinary differential equations thatdescribes the evaporation process is performed. Isothermal andnon-isothermal drying processes are considered in batch andcontinuous modes. The mathematical model to describe thecomposition profiles during batch drying of the polymeric film,considering liquid resistance, is solved numerically. Due tothe lack of experimental data, properties for this polymericsystem are estimated by using established methods. Ananalytical solution of the diffusion equation, by assuming anisothermal drying process and a constant matrix ofmulticomponent diffusion coefficients is developed. For thecontinuous case, liquid-side resistance is studied by modellingevaporation of a multicomponent falling liquid film into aninert gas including indirect heating.</p><p>The results of the gas-phase-controlled model are in goodagreement with experimental results. For the polymeric film,the agreement is only qualitative since the model does notaccount for a membrane that develops on the film surface. Thestability analysis permits the prediction of trajectories andfinal state of a liquid mixture in a gas-phase-controlleddrying process. For isothermal evaporation of ternary mixturesinto pure gas, the solutions are trajectories in the phaseplane represented by a triangular diagram of compositions. Thepredicted ternary dynamic azeotropic points are unstable orsaddle. On the other hand, binary azeotropes are stable whenthe combination of the selectivities of the correspondingcomponents is negative. In addition, pure component singularpoints are stable when they are contained within theirrespective isolated negative selectivity zones. Undernon-isothermal conditions, maximum temperature valuescharacterise stable azeotropes. Incremental loading of the gaswith one or more of the components leads to a node-saddlebifurcation, where a saddle azeotrope and a stable azeotropecoalesce and disappear. For continuous drying, the singularpoints are infinite and represent dynamic equilibrium pointswhose stability is mainly dependent on the ratio of inletgas-to-liquid flow rates. As long as the process isgas-phasecontrolled, these results also apply to a porous solidcontaining a liquid mixture.</p><p>In general, liquid-side control makes the drying processless selective but it is difficult to maintain this conditionduring the whole process. Under the influence of its owndynamics, a process starting as liquid-side-controlled tendstowards a gas-phase-controlled process. The presence ofnon-volatile components and indirect heating may delay thisdevelopment. Considering the evolution of the processcontrolling steps and its influence on selectivity, a modelaimed at describing the complete trajectory of a drying orevaporation process must include the coexistence of allrelevant mechanisms.</p><p><b>Keywords:</b>ternary mixture, falling film, diffusionequation, gas-phase control, liquid-phase control, selectivity,stability analysis, polymeric solution, evaporation, azeotrope,batch drying, continuous drying.</p>

<p>Among the obstacles for the commercialization of the MoltenCarbonate Fuel Cell (MCFC), the dissolution of thestate-of-the-art lithiated NiO cathode is considered as aprimary lifetime limiting constraint. Development ofalternative cathode materials is considered as a main strategyfor solving the cathode dissolution problem. LiFeO₂and LiCoO₂had earlier been reported as the most promisingalternative materials; however, they could not satisfactorilysubstitute the lithiated NiO. On the other hand, ternarycompositions of LiFeO₂, LiCoO₂and NiO are expected to combine some desirableproperties of each component. The aim of this work was todevelop alternative cathode materials for MCFC in the LiFeO₂-LiCoO₂-NiO ternary system. It was carried out byinvestigating electronic conductivity of the materials, firstin the form of bulk pellets and then in ex-situ sinteredporous-gas-diffusion cathodes, and evaluating theirelectrochemical performance by short-time laboratory-scale celloperations.</p><p>Materials in the LiFeO₂-NiO binary system and five ternary sub-systems,each with a constant molar ratio of LiFeO₂:NiO while varying LiCoO₂content, were studied. Powders withcharacteristics appropriate for MCFC cathode fabrication couldbe obtained by the Pechini method. The particle size of LiFeO₂-LiCoO₂-NiO powders considerably depends on thecalcination temperature and the material composition. Theelectrical conductivity study reveals the ability of preparingLiFeO₂-LiCoO₂-NiO materials with adequate electricalconductivity for MCFC cathode application.</p><p>A bimodal pore structure, appropriate for the MCFC cathode,could be achieved in sintered cathodes prepared usingporeformers and sub-micron size powder. Further, this studyindicates the nature of the compromise to be made between theelectrical conductivity, phase purity, pore structure andporosity in optimization of cathodes for MCFC application. Cellperformance comparable to that expected for the cathode in acommercial MCFC could be achieved with cathodes prepared from20 mole% LiFeO₂- 20 mole% LiCoO₂- 60 mole% NiO ternary composition. It shows aniR-corrected polarization of 62 mV and a iR-drop of 46 mV at acurrent density of 160 mAcm^-2at 650 °C. Altogether, this study revealsthe possibility of preparing LiFeO₂-LiCoO₂-NiO cathode materials suitable for MCFCapplication.</p><p>Keywords: molten carbonate fuel cell (MCFC), MCFC cathode,LiFeO₂-LiCoO₂-NiO ternary compositions, electrical conductivity,porous gas diffusion electrodes, polarization, electrochemicalperformance, post-cell characterization.</p>

The thesis is a summary and discussion of eight papers. During the last decades, precipitation has become increasingly acidic due to the extensive use of fossil fuels. In areas of poorly buffered bedrocks, e.g. Scandinavia, northeastern United States, this phenomenon has resulted in elevated amounts of Al(III) being leached into streams and lakes. Recent findings reveal that these elevated Al-concentrations could cause fish death and decreasing forest production. In the present thesis, the importance of taking naturally occurring substances into consideration when discussing Al(III) in natural waters, is emphasized. On the basis of a chemical characterization of relevant ligand classes in a natural water, the complex formation between Al^+, hydroxide ions and the inorganic ligand carbonic acid, the low-molecular weight organic ligand citric acid and the high-molecular weight model substances gallic acid, 1,2-dihydroxynaphtha-lene-4-sulfonate, 1,2-naphthoquinone-4-sulfonate, pyrocatechol and salicylic acid were investigated. The investigations were performed as series of Potentiometrie titrations and data were processed by means of the least-squares computer program LETAGROPVRID using a technique called pqr-analysis, permitting an unbiased search for complex model (and corresponding equilibrium constants) to be made. In most systems studied, the complexation at high ligand excesses can be described by a series of mononuclear complexes AIL-AIL^. Tentatively, the whole series consists of octahedrally coordinated (water and ligand oxygens) AI(III). At lower ligand excesses, the significance and in some cases even predominance of ternary mono- and polynuclear hydroxo complexes is demonstrated. In two of the systems, binary aluminium hydroxo species are evaluated. The potential importance of the substances with respect to Al-com-plexation in natural waters are indicated in a number of model calculations. The solubility of the clay mineral kaolinite is calculated as a function of -lg[H+] and ligand concentration. It is shown that citric acid, gallic acid, 1,2-dihydroxynaphthalene-4-sulfonate, pyrocatechol and salicylic acid contribute quite significant to the total solubilities, even at very low concentrations. As a complement and background to the equilibrium studies, the corrosion rate for one of the naturally occurring Al-bearing minerals, corundum, is reported. In this investigation, performed with a leach-ant solution of ground-water composition, an experimental technique was employed which made it possible to divide the corrosion into chemical and mechanical losses. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1983</p> / digitalisering@umu

In dieser Arbeit wird das neue Prinzip der „Selbstinkompatiblen Lösungsmittel“ vorgestellt. Es wird theoretisch abgeleitet, dass eine Mischung aus zwei Substanzen mit ungünstigen Wechselwirkungen bereitwillig eine weitere Substanz aufnehmen sollte, die diese ungünstigen Wechselwirkungen durch Verdünnen vermindert. Dies sollte umso stärker ausgeprägt sein, je ungünstiger die Wechselwirkungen zwischen den beiden ersten Substanzen sind. Da sich jedoch Substanzen mit sehr ungünstigen Wechselwirkungen physikalisch nicht mischen, entstand die Idee, diese Substanzen durch eine kovalente Bindung aneinander zu binden. Ein solches Molekül, das aus zwei inkompatiblen Hälften besteht, wird im Folgendem Selbstinkompatibles Lösungsmittel genannt. Die in dieser Arbeit gewählten Substanzen zeigen mäßige Inkompatibilität, deshalb ist ein Vergleich zwischen einfachen physikalischen Mischungen und kovalent verknüpften Molekülhälften noch möglich. Dieses Prinzip wird für binäre und ternäre Mischungen quantitativ berechnet und experimentell in drei Serien von Experimenten bestätigt: i) unter Verwendung von Lösungskalorimetrie und Bestimmung der Wechselwirkungsparameter zwischen Komponente 3 und einer bereits hergestellt physikalischen binären Mischung aus Komponente 1 und 2, ii) unter Verwendung von Lösungskalorimetrie und Bestimmung der Wechselwirkungsparameter zwischen Komponente 3 und den selbstinkompatiblen Losungsmitteln, die den in (i) gewählten Mischungen entsprechen und iii) aus der Sättigungslöslichkeit der Komponente 3 in den entsprechenden selbstinkompatiblen Lösungsmitteln. In diesen drei verschiedenen Messserien wird stets der gleichen Trend beobachtet: Die Selbstinkompatibilität eines Lösungsmittels begünstigt den Lösevorgang. / In this thesis a new principle of Self Incompatible Solvent is introduced. It is shown theoretically that a preexisting mixture of two substances (compound 1 and 2) with unfavorable interactions will readily dissolve a third compound because it diminishes the unfavorable interaction between the compound 1 and 2 by dilution. This behavior should be the stronger the more unfavorable the interactions between compound 1 and 2 are. However, substances with strong unfavorable interactions will not mix. Therefore the idea pursued here is to enforce the desired preexisting mixture for example by linking compound 1 covalently to compound 2. Such a molecule that is composed of two incompatible parts is called Self Incompatible Solvent in this work. In this thesis examples of incompatible compounds that show moderate incompatibility are chosen, therefore it was possible to do a comparison between simple physical mixtures and covalently linked incompatible molecules. The theoretical prediction of the theory is compared with experiments. This principle is calculated quantitatively for binary and ternary mixtures and compared with the experimental results in three distinct series of experiments: i) by using solution calorimetry and calculation of the interaction parameters between compounds 3 and the preexisting binary mixture of compound 1 and 2, ii) by using solution calorimetry and calculation of the interaction parameters between compound 3 and the Self Incompatible Solvent that correspond to the mixtures used in (i) and iii) from the saturation solubility of compound 3 in the Self Incompatible Solvent. The results obtained from the theoretical prediction and these obtained from the three different series of experiments show the same trend: the self incompatibility of the solvent improves the dissolution process.

It has been observed that confusion exists in literature concerning the meaning and use of the term efficacy. Confusion is worsened by the use of the term as a general term describing agonist activity. The meaning of the terms intrinsic activity, efficacy and intrinsic efficacy as used in theoretical models of drug action was investigated. The classical occupation model, the two-state model, the ternary complex model (including conformational change and ideas surrounding G-proteins) and the operational model were studied in order to understand the historical and current usage of these terms. Although efficacy estimates are often reported as a molecular property, it was shown that agonist activity is tissue dependent and cannot be fully portrayed by an efficacy estimate. It was found that efficacy has a different definition in each model. This is not always recognized in literature. It was suggested that the term efficacy should only be used in the context of a specific model / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2007.

This study focuses on the architectural modification of pin-type small-molecule organic solar cells, in particular on the absorption layer and its influence on the key solar cell parameters, such as short circuit current density, fill factor and open circuit voltage. Three different approaches have been applied to improve the match between the solar spectrum and the spectral sensitivity of organic solar cells. In the first part, deposition parameters such as substrate temperature, gradient strength and (graded) absorption layer thickness are evaluated and compared to organic solar cells with homogeneously deposited absorption layers. Moreover, the gradient-like distribution of the absorption layer is characterized optically and morphological effects have been extensively studied. In order to isolate the origin of the efficiency improvement due to the graded architecture, voltage-dependent spectral response measurements have been performed and gave new insights. The second part concentrates on the efficient in-coupling of converted UV light, which is usually lost because of the cut off properties of organic light in-coupling layers. Via Förster resonance energy transfer, the absorbed UV light is re-emitted as red light and contributes significantly to higher short circuit current densities. The correlation between doping concentration, simple stack architecture modifications and the performance improvement is duly presented. In the third and last part, the impact of tri-component bulk heterojunction absorption layers is investigated, as these have potential to broaden the sensitivity spectrum of organic solar cells without chemical modification of designated absorber molecules. Along with the possibility to easily increase the photocurrent, an interesting behavior of the open circuit voltage has been observed. Knowledge about the impact of slight modifications within the solar stack architecture is important in order to be able to improve the device efficiency for the production of cheap and clean energy.

The Catalyst 6500 is a modern commercial switch, capable of processing millions of packets per second through the utilization of specialized hardware. One of the main hardware components aiding the switch in performing its task is the Ternary Content Addressable Memory (TCAM). TCAMs update themselves with data relevant to routing and switching based on the traffic flowing through the switch. This enables the switch to forward future packets destined to a location that has already been previously discovered - at a very high speed. The problem is TCAMs have a limited size, and once they reach their capacity, the switch has to rely on software to perform the switching and routing - a much slower process than performing Hardware Switching that utilizes the TCAM. A framework has been developed to analyze the switch’s performance once the TCAM has reached its capacity, as well as measure the penalty associated with a cache miss. This thesis concludes with some recommendations and future work.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-16T13:03:53Z No. of bitstreams: 1 JULIANA CORDEIRO NUNES - TESE (PPGEQ) 2017.pdf: 2293745 bytes, checksum: c60baeed38c440f535a6b8170f9736f4 (MD5) / Made available in DSpace on 2018-08-16T13:03:53Z (GMT). No. of bitstreams: 1 JULIANA CORDEIRO NUNES - TESE (PPGEQ) 2017.pdf: 2293745 bytes, checksum: c60baeed38c440f535a6b8170f9736f4 (MD5) Previous issue date: 2017-09-15 / A pesquisa por fontes alternativas de energia tem sido cada vez mais intensa. Nesse contexto, surge o biodiesel, biocombustível que apresenta as seguintes características: emite menos poluente que o diesel de petróleo, biodegradável, renovável, não tóxico, dentre outras. O biodiesel é produzido através da reação de transesterificação, onde o óleo vegetal ou a gordura animal reage com álcool de cadeia curta na presença de um catalisador. O óleo de girassol é uma oleaginosa com potencial utilização para a produção do biodiesel, visto que pode ser plantada no Nordeste brasileiro no período chuvoso. Após a reação de transesterificação, o produto reacional contém impurezas que precisam ser retiradas e, para isso, devem ser realizadas a lavagem e a purificação do produto reacional. Para realizar a lavagem e a purificação é necessário conhecer o equilíbrio líquido-líquido de misturas formadas por água, glicerina, biodiesel e álcool. E, para isso, pode ser preciso ter posse dos dados termodinâmicos. O objetivo deste trabalho é realizar o estudo termodinâmico sobre o equilíbrio de fases de sistemas ternários (biodiesel de girassol – álcool – glicerina) e pseudoquaternários (biodiesel de girassol – álcool – glicerina – água/ácido diluído). Para isso, foi utilizado o método da minimização da energia de Gibbs, à temperatura e pressão constantes. Para representar as fases formadas em cada sistema, foi empregado o modelo UNIQUAC. Os parâmetros de interação binária entre os compostos foram estimados através do método dos mínimos quadrados. O sistema ternário formado por biodiesel metílico de girassol – metanol – glicerina, foi analisado à 25ºC, 35ºC e 45ºC e foi observado que o efeito da temperatura foi pouco expressivo, havendo uma pequena redução da região de imiscibilidade à 45ºC. Foram estudados os sistemas pseudo-quaternários formados por biodiesel metílico de girassol – metanol – glicerina – água destilada/ácido sulfúrico diluído, o sistema ternário de biodiesel etílico de girassol – etanol – glicerina e também os sistemas pseudo-quaternários formados por biodiesel etílico de girassol – etanol – glicerina – água destilada/ácido sulfúrico diluído. Em todos os sistemas pseudo- quaternários foi observado que a presença de água/ácido diluído: aumenta a região de separação de fases, não havendo alteração expressiva no comportamento da curva ao aumentar a quantidade de água destilada/ácido diluído de 50% para 75% em relação à massa da glicerina; e diminui a solubilidade do biodiesel na fase rica em glicerina+água destilada/ácido diluído. Na modelagem termodinâmica do ELL, os dados experimentais foram comparados com os valores calculados pelo modelo UNIQUAC, onde obteve-se uma boa concordância entre os dados experimentais e os valores calculados, uma vez que o maior desvio apresentado foi de 0,27%. Isso mostra que, no estudo no ELL dos sistemas analisados, podem ser utilizados os parâmetros calculados. Observou-se que é satisfatório o uso do modelo UNIQUAC para tais sistemas. / The search for alternative sources of energy has been increasingly intense. In this context, it appears the biodiesel, biofuel that has the following characteristics: it emits less pollutant than petroleum diesel, biodegradable, renewable, non-toxic, among others. biodiesel is produced through the transesterification reaction, where vegetable oil or animal fat reacts with short chain alcohol in the presence of a catalyst. Sunflower oil is an oleaginous with potential use for the production of biodiesel, since it can be planted in the Brazilian Northeast during the rainy season. After the transesterification reaction, the reaction product contains impurities that need to be removed and, for this, the wash and purification of the reaction product must be carried out. To carry out the washing and the purification it is necessary to know the liquid-liquid equilibrium of mixtures formed by water, glycerine, biodiesel and alcohol. And for that, it may be necessary to have possession of the thermodynamic data. The objective of this work is to perform the thermodynamic study on the phase equilibrium of ternary systems (sunflower biodiesel - alcohol - glycerin) and pseudo - quaternaries (sunflower biodiesel - glycerine - water / diluted acid). The Gibbs energy minimization method was used at constants temperature and pressure. To represent the phases formed in each system, the UNIQUAC model was used. The parameters of binary interaction between the compounds were estimated using the least squares method. The ternary system formed by sunflower methyl biodiesel - methanol - glycerin was analyzed at 25ºC, 35ºC and 45ºC and it was observed that the effect of the temperature was not very expressive, with a small reduction of the region of immiscibility at 45ºC. We studied the pseudo quaternary systems formed by sunflower methyl biodiesel - methanol - glycerol - distilled water / diluted sulfuric acid, the ternary l system of ethyl biodiesel of sunflower - ethanol – glycerin and also the pseudo - quaternary systems formed by sunflower ethyl biodiesel - ethanol - glycerin - distilled water / diluted sulfuric acid. In all pseudo-quaternary systems it was observed that the presence of diluted water / diluted acid: increases the region of phase separation, with no significant change in the behavior of the curve by increasing the amount of distilled water / diluted acid from 50% to 75% relative to the glycerol mass; and decreases the solubility of biodiesel in the rich phase at glycerin + distilled water / dilute acid. In the thermodynamic modeling of the LLE, the experimental data were compared with the values calculated by the UNIQUAC model, where a good agreement was obtained between the experimental data and the calculated values, since the largest deviation was 0.27%. This shows that, in the LLE study of the analyzed systems, the calculated parameters can be used. It was observed that the use of the UNIQUAC model for such systems is satisfactory.