This thesis describes an investigation of how techniques of modelling, estimation and control can be used to improve regulation of pH. A novel mathematical model of neutralization is used which explicitly accounts for two separate sources of non-linearities in pH systems: the inherent non-linearity of the pH measurement and the variable and uncertain non-linearity of the neutralization chemistry. A detailed interactive simulation package was developed. It has been used to study: <ul><li>1. The application of a Bayes' non-linear estimator to a noisy pH measurement. The estimator is used in conjunction with an Extended Kalman Filter in order to generate estimates for use in combined feedforward/feedback controllers. A novel version of the Bayes' estimator is developed which successfully estimated jumping and drifting bias on the pH measurement.</li><li>2. A novel cautious stochastic control law which uses the generated estimates and allows for their uncertainty. Reduced quality of estimation forces the controller to regulate the pH at an optimally tuned target value where control is easier.</li><li>3. Comparisons of a variety of modern and conventional control algorithms. The modern algorithms include three self-tuners, the non-linear estimators and the cautious controller. The conventional algorithms include a PID controller, analytical linearisation of the pH measurement and the use of estimated or measured feedforward signals. Twenty-five pH control laws are simulated.</li></ul> The quality of regulation which can be achieved depends on what prior information is available about the neutralisation process. A strategy is proposed which matches controller structure to available information. This strategy provides guidelines to the control configurations that can be implemented as well as their relative limitations. It is shown that improvement in performance over a PID regulator is possible if one uses more complex controllers. This improvement is investigated by simulation because it varies from one process to another. It is also shown how the resulting simulation package has been used for computer aided design of pH control systems in the chemical industry.

Thesis (Ph. D.)--Murdoch University, 1995. / Thesis submitted to the School of Mathematical and Physical Sciences. Includes bibliographical references (leaves 274-288).

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 63 p. : ill. Includes abstract. Includes bibliographical references (p. 57-63).

acase@tulane.edu / The objective of this research is to study the surface/interfacial phenomena via video-microscopic observation and quantification inside a micro-channel or microcapillary, which can mimic the operating conditions of practical problems, such as ink-jet, lubricant oil neutralization and enhanced oil recovery. In the second chapter, a micropipette-in-microcapillary method is described for the surface tension measurement at high temperatures, which mimics the dimension and working environment of ink-jet print head. Temperature control within the confined space of a capillary was achieved by coating the outer surface of the housing microcapillary with an electrically conductive, transparent, tin-doped indium oxide (ITO) thin film as a heating jacket. The precision of this technique was discussed according to the comparisons of our results with published reference data for water, n-hexadecane, and n-decane at both room and elevated temperatures. Traditionally, the neutralization of sulfuric acid by engine oils has been the major focus, however, due to the introduce of biofuel or ethanol the acetic acid has become an important concern. In the third chapter, based on micropipette-in-square-channel video-microscopy setup, the neutralization reaction mechanism and reaction kinetics of acetic acid by fully formulated lubricant oil is discussed. It was found that the neutralization exists simultaneously on the oil-acid-interface and bulk-oil phase during the droplet shrinkage. Besides, FTIR and NMR analysis show the neutralization of acetic acid as an instantaneous process, and almost all of the dissolved acetic acid in the bulk is eventually neutralized. Due to the minor role of acetic acid dissolution compared to the interfacial reaction, an interface-reaction-rate-controlled kinetic mechanism is proposed as approximation to describe the neutralization process at different conditions. When glacial and diluted acetic acid droplets were neutralized in fully formulated lubricant oil, the experimentally measured shrinking radius agreed very well with the mathematical model. According to Arrhenius equation, the activation energy of neutralization reaction was determined to be constant and its range (Ea>21 kJ/mol) further validated the assumption of interface-controlled reaction kinetics. In the final chapter, an oil-soluble surfactant prepared by Eni S.p.A. was studied to enhance crude oil mobilization in cryolite-packed miniature bed, which provided a transparent porous media at the microscopic level. When the porous media was imbued with crude oil, the presence of the surfactant in the oil phase was able to improve the mobilization performance of crude oil by flushing. In order to deliver the oil-soluble surfactant and apply it to the removal of crude from porous media, an SDS solution was used to solubilize the surfactant, and the formation of SDS/Eni-Surfactant micellar solution was confirmed by Cryo-SEM images. Using the prepared micellar solutions in oil-removal tests on the packed bed, a very high effectiveness was demonstrated by image binarization, thus confirming the possibility to deliver liposoluble surfactants to the porous-media-trapped crude oil by means of hydrosoluble carriers. / 1 / Yufei Duan

This thesis describes development of the DRACO plasma simulation code. DRACO is an electro-static (ES) code which uses the particle-in-cell (PIC) formulation to track plasma particles through a computational domain, and operates within the Air Force COLISEUM framework. The particles are tracked on a non-standard mesh, which combines the benefits of a Cartesian mesh with the surface-resolving power of an unstructured mesh. DRACO contains its own mesher, called VOLCAR, which is also described in this work. DRACO was applied to a fully kinetic simulation of an ion-beam neutralization. The thruster configuration and running parameters were based on the NASA's 40cm NEXT ion thruster. The neutralization process was divided into three steps. Electron dynamics was studied by assuming an initial beam neutralization, which was accomplished by injecting both electrons and ions from the optics. Performing the simulation on a full-sized domain with cell size much greater than the Debye length resulted in a formation of a virtual anode. Decrease of the cell size to match the Debye length was not feasible, since it would require a million-fold increase in the number of simulation nodes. Instead, a scaling scheme was devised. Simulations were performed on thruster scaled down by a factor of 100, but its operating parameters were also adjusted such that the produced plasma environment did not change. Loss of electrons at the boundary of the finite simulation domain induced a numerical instability. The instability resulted in a strong axial electric field which sucked out electrons from the beam. It was removed by introducing an energy based particle boundary condition. Combination of surface scaling and energy boundary resulted in physically sound simulation results. Comparison were made between the Maxwellian and polytropic temperatures, as well as between simulation electron density and one predicted by the Boltzmann relationship. The cathode was modeled individually from the beam by introducing a positively charged collector plate at a distance corresponding to the beam edge. The local Debye length at the cathode tip was too small to be resolved by the mesh, even if mesh-refinement was incorporated. Since the simulation was not concerned with the near-tip region, two modifications were performed. First, the a limiting value of charge density at the tip was imposed. Second, the cathode potential was allowed to float. These two modifications were necessary to prevent development of a strong potential gradient at the cathode tip. The modified cathode model was combined with ion injection from the optics to model the actual beam neutralization. Three configurations were tested: a single thruster, a 2x2 cluster with individual cathodes and a similar cluster with a single large neutralizer. Neither of the cases achieved neutralization comparable to one in the base-line pre-neutralized case. The reason for the discrepancy is not known, but it does not seem to be due a loss of electrons at the walls. The difference could be due to limited extent of the modeled physics. An additional work is required to answer this question. / Master of Science

Due to societal and economic costs caused by compulsive consumption behavior, specifically problem drinking and overeating, a search has been launched for a cognitive explanation for the ‘deviant’ behaviors and the motivations that cause these behaviors to continue. This dissertation attempted to develop a better understanding of continued compulsive consumption behavior by investigating consumers’ use of the techniques of neutralization theory. Based on methodological concerns in neutralization research, the development of reliable and valid measures of the five techniques of neutralization theory were described and used to examine their moderation of compulsive consumption behavior and its relationship with social norm commitment and guilt. The dissertation resulted in developing four reliable and valid neutralization technique scales. The results of the structural model suggested a negative relationship between social norms and compulsive consumption behavior and a multiple regression indicated a partial moderation of certain neutralization techniques of this relationship. This dissertation has provided a better understanding of the cognitive process surrounding a consumer’s compulsive consumption behavior, the techniques used to allow the behavior to continue, and marketing applications to entice consumers to stop the behavior.

El presente trabajo de tesis tuvo como objetivo titular anticuerpos neutralizantes contra una cepa endémica del virus Chikungunya que circula en la costa norte peruana. Para desarrollar esta investigación, se empleó la prueba de neutralización por reducción en placas (PRNT), la cual se realizó en el Instituto Nacional de Salud (INS)– Laboratorio de Aislamiento y Cultivo Celular perteneciente al área de Metaxénicas Virales. La justificación de la investigación se basa en la necesidad de comprobar que los anticuerpos detectados por la prueba de ELISA son neutralizantes y logran inhibir la dispersión del CHIKV en el cuerpo humano. Además, la prueba es necesaria para evaluar drogas antivirales y futuras vacunas que lleguen al Perú. El diseño metodológico utilizado fue analítico y experimental. La cepa y las muestras fueron proporcionadas por el INS y provinieron del departamento de Tumbes. Las muestras positivas fueron previamente diagnosticadas con ELISA utilizando IgM e IgG y las muestras negativas fueron de individuos sanos sin contacto previo con arbovirus. La prueba de PRNT se realizó en 24 horas usando la línea celular VERO CCL-81 en monocapa. La valoración de la prueba se realizó al 50% de neutralización. Se obtuvo como resultado títulos de anticuerpos en el rango de 1/8 y 1/16. Ésta variación responde a una relación inversa con el inicio de los días de síntomas. Por lo tanto, se concluye que la población de la costa norte del Perú sí está desarrollando anticuerpos neutralizantes para contrarrestar el virus Chikungunya endémico en la región.The present thesis aims to titrate neutralizing antibodies against an endemic strain of the Chikungunya virus that circulates in the northern coast of Peru. In order to develop this research, the plaque reduction neutralization test (PRNT) has been used, which has been carried out at the National Institutes of Health (INS) - Isolation and Cell Culture Laboratory belonging to the Viral Metaxenics area. The justification of the investigation is based on the need to verify that the antibodies detected by the ELISA test are neutralizing and manage to inhibit the dispersion of CHIKV in the human body. In addition, the test is necessary to evaluate antiviral drugs and future vaccines that arrive in Peru. The methodological design used was analytical and experimental. The strain and samples were provided by the INS. The strain is endemic to the department of Tumbes. The positive samples were previously diagnosed with ELISA using IgM and IgG and the negative samples were from individuals that had not had contact with any arbovirus. The PRNT test was performed in 24 hours using the VERO CCL-81 cell line in monolayer. The titration of the test was performed at 50% neutralization. Antibody titres were obtained in the range of 1/8 and 1/16. This variation responds to an inverse relationship with the onset of symptom days. Therefore, it is concluded that the population of the northern coast of Peru is developing neutralizing antibodies to counteract the endemic Chikungunya virus in the region.

Esta tese tem por objeto a neutralização das vogais átonas no Português Brasileiro. Um dos objetivos principais é desenvolver uma proposta que consiga, além de capturar a neutralização das vogais médias a favor das médias-altas, como observado em dialetos do sul/sudeste (WETZELS, 1992), também capturar os fatos acerca dos dialetos do norte/nordeste, nos quais o contraste das vogais médias é perdido a favor das médias-baixas (SILVA, 2009). Para tanto, primeiramente argumenta-se que uma proposta desenvolvida por meio da Teoria da Otimalidade (PRINCE & SMOLESNKY, 1993) é capaz de não só formalizar o modo pelo qual a neutralização se dá, mas também explicar o porquê de isso acontecer. Em TO, argumenta-se que a neutralização pode ter duas motivações distintas, i.e., que há dois tipos de neutralização, a neutralização como um mecanismo de aprimoramento de contrastes (FLEMMING, 1995, 2004; PADGETT, 1997), e a neutralização como alinhamento de proeminências (CROSSWHITE, 1999, 2004). Nesta tese, argumenta-se que o Português Brasileiro é uma língua que possui ambos os tipos de neutralização e que por meio da interação entre as restrições que as motivam, é possível capturar os fatos observados tanto em dialetos do sul/sudeste, quanto é dialetos do norte/nordeste. A fim de testar a hipótese de neutralização via relaxamento (i.e., de que a neutralização das vogais médias favorece as médias-baixas), elaborou-se um experimento de leitura de palavras trissílabas paroxítonas inseridas em uma frase veículo, que foram produzidas por 20 indivíduos, nascidos e criados em São Luís-MA, ou seja, falantes de uma dialeto representativo dos dialetos do norte/nordeste. Os resultados obtidos pela análise estatística do corpus constituído por 4800 dados corroboraram a hipótese de neutralização via relaxamento enquanto as vogais médias-baixas e altas em sílabas pretônicas em início absoluto de palavras são previsíveis por serem restritas a contextos mais específicos, a produção de vogais médias-baixas nesse contexto não é completamente previsível, o que evidencia que sua produção deve resultar da própria neutralização, e não de outros processos fonológicos. Argumenta-se, ainda, que propostas anteriores como a de Wetzels (1992) consegue capturar a totalidade dos fatos acerca dos dialetos do sul/sudeste, mas não pode ser estendida a fim de prever o que ocorre em dialetos do norte/nordeste. Por sua vez, a análise de Nevins (2012) consegue formalizar os fatos acerca da produção de vogais médias-baixas em sílabas pretônicas, mas faz previsões incorretas acerca da produção de vogais médias-baixas em sílabas postônicas não-finais, contexto no qual não há indícios de que a neutralização via relaxamento ocorra (SILVA, 2010; SANTANA, 2014). Desse modo, é crucial que a proposta de neutralização para o Português Brasileiro consiga capturar que a neutralização via relaxamento ocorre em sílabas pretônicas iniciais, mas não em sílabas postônicas não-finais. Argumenta-se que essa distinção se dá pelas diferenças de proeminência contextual em dialetos do norte/nordeste, a neutralização das vogais médias favorece médias-baixas (vogais mais proeminentes dentre as vogais médias) em contextos átonos proeminentes (sílabas em início absoluto de palavra), e que as vogais médias-altas (formas menos proeminentes dentre as vogais médias) são favorecidas em contextos com baixa proeminência relativa (sílaba postônica não-final). Por meio da formalização via ranqueamento de restrições, mostra-se que as restrições que motivam o aprimoramento de contrastes são responsáveis por eliminar o contraste entre as vogais médias e que as restrições acerca do alinhamento de proeminências é responsável pela seleção de qual das vogais deve ocupar a pauta medial: médias-baixas em contextos átonos mais proeminentes e médias-altas em contextos átonos menos proeminentes. A fim de estender essa análise para outros contextos pretônicos, que não somente as sílabas pretônicas em início absoluto de palavra, elaborou-se um segundo experimento que buscou observar a produção de vogais médias em sílabas pretônicas não-inicias portadoras ou não de acento secundário. O corpus de 2400 dados, provenientes das produções de 20 indivíduos, nascidos e criados em São Luís, mostram que vogais médias-baixas em contextos nãoharmônicos foram produzidas em sílabas pretônicas que poderiam portar acento secundário, mas evitadas em contextos em que o acento secundário não poderia ser produzido. Desse modo, é possível estender a propostas desenvolvida também para outros contextos pretônicos para além das sílabas em início absoluto de palavra, de modo que a previsão feita para os dialetos do norte/nordeste é a de que a neutralização favorece vogais médias-baixas em contextos átonos proeminentes (sílabas pretônicas em início absoluto de palavras e portadoras de acento secundário) e favorece médias-altas em contextos átonos nãoproeminentes (sílabas postônicas não-finais e sílabas pretônicas não-iniciais e não portadoras de acento secundário). Os fatos acerca dos dialetos do sul/sudeste, na qual a neutralização sempre favorece as vogais médias-altas em contextos átonos, independente de suas proeminências relativas, são capturadas por meio de um ranqueamento diferente das mesmas restrições utilizadas para formalizar o padrão observado em dialetos do norte/nordeste. / This dissertation focuses on unstressed vowel neutralization in Brazilian Portuguese. One of its main goals is to develop an analysis that is able to capture besides the pattern of mid vowel neutralization that favors high-mid vowels, as observed in southern dialects (WETZLES, 1992) what is observed in northern dialects, in which the contrast of mid vowels is lost in favor of low-mid vowels (SILVA, 2009). For this, it is firstly argued that a proposal developed through Optimality Theory (PRINCE & SMOLENSKY, 1993) is not only able to formalize how neutralization occurs, but also accounts for its motivation. It has been argued in OT that neutralization has two distinct motivations, the enhancement of contrast (FLEMMING, 1995, 2004; PADGETT, 1997) and the alignment of prominences (CROSSWHITE, 1999, 2004). In this dissertation, it is argued that Brazilian Portuguese is a language that presents both types of neutralization and that through the interaction of the restrictions that motivate them, it is possible to capture the facts that are observed in both southern and northern dialects. In order to test the hypothesis of neutralization via laxing (i.e., that mid vowel neutralization favors low-mid vowels), a reading experiment of trisyllabic words with pre-final stress in carrier sentences was designed. 20 participants, born and raised in São Luís-MA, a Brazilian capital in the northeast area of the country, participated in the experiment which resulted in a corpus of 4800 tokens. Statistical results corroborated the hypothesis of neutralization via laxing in northern dialects in word-initial pretonic syllables, high-mid vowels are predictable, restricted to specific contexts, while lowmid vowels are not, which serves as evidence that the production of low-mid vowels must result from neutralization, and not from other phonological processes, given that the contrast between high-mid and low-mid vowels is lost outside primary stress context. It is also argued that previous proposals, such as Wetzels (1992), formalize the patterns of neutralization observed in southern dialects, but cannot be extended to capture what occurs in northern dialects. By its turn, the account proposed by Nevins (2012) formalizes the facts regarding the production of low-mid vowels in pretonic syllables, but make incorrect predictions regarding mid vowels distribution in non-final post-tonic context, in which there is no evidence that neutralization via laxing occurs (SILVA, 2010; SANTANA,2014). Thus, an account for vowel neutralization in Brazilian Portuguese must formalize that neutralization via laxing occurs in word-initial pretonic syllables, but not in non-final post-tonic context. It is argued that this distinction is due to contextual prominence in northern dialects, mid vowel neutralization favors low-mid vowels (more prominent if compared to high-mid vowels) in unstressed contexts that have relative high prominence (such as wordinitial syllables), and that high-mid vowel (less prominent when compared to low-mid vowel) are favored in unstressed context with low relative prominence (such as non-final post-tonic syllables). Through constraints ranking, it is shown that the constraints that motivate contrast enhancement are the ones that trigger mid vowel neutralization, but the constraints on prominence alignment are the ones that select which of the mid vowels will get to be produced: high-mid vowel in less prominent contexts and low-mid vowels in more prominent contexts. In order to extend this analysis to formalize the pattern in other pretonic contexts besides word-initial syllables, a second experiment was designed. Results from a corpus of 2400 tokens, obtained from an experiment with 20 participants born and raised in São Luís-MA, showed that low-mid vowels in non-harmonic contexts were produced in pretonic syllables that could bear secondary stress, but were avoided in context where secondary stress could not be produced. Therefore, the analysis can be extended in a way that the predictions will be the same to all unstressed prominent and all the unstressed non-prominent contexts: in northern dialects, neutralization favors low-mid vowels in prominent contexts (pretonic word-initial and that bear secondary stress) while neutralization favor high mid-vowels in non-prominent contexts (non-final post-tonic syllables and pretonic syllables that are not in word-initial context and that cannot bear secondary stress). The facts regarding southern dialects, in which mid-vowel neutralization always favors high-mid vowels regardless of context prominence, are formalized through a different ranking of the same constraints that are used to formalize the pattern of mid vowel neutralization in northern dialects.

Orientador: Estevão Tomomitsu Kimpara / Banca: Alvaro Della Bona / Banca: José Henrique Rubo / Banca: Mário Alexandre Coelho Sinhoreti / Banca: Guilherme de Siqueira Ferreira Anzaloni Saavedra / Resumo: Testou-se o efeito de diferentes formas de tratamento da superfície cerâmica após condicionamento com ácido hidrofluorídrico (HF) na resistência à fratura de coroas cerâmicas à base de dissilicato de lítio. Quarenta terceiros molares humanos receberam um preparo convencional para coroa total. Após escaneamento digital dos preparos, blocos cerâmicos foram usinados pelo sistema CAD/CAM para obtenção das coroas. A espessura da película de cimento das coroas ao preparo foi verificada com silicone de adição. As coroas foram distribuídas nos 4 grupos conforme o tratamento da superfície cerâmica (n=10): (HF)- HF à 4.9% por 20s + spray ar-água por 30s; (HFN)- HF + agente neutralizador por 5 min (N); (HFU) - HF + banho sônico por 5 min (U); e (HFNU)- HF + N + U. Após aplicação de uma camada de silano (60s), as coroas foram cimentadas com cimento resinoso dual. Uma carga compressiva de 1000Kg foi aplicada no centro da face oclusal da coroa com velocidade de 1 mm/min até a fratura. Os dados foram analisados por ANOVA e Tukey (α=0,05). A carga média de fratura (Kgf) foi: HF = 169,92 ± 21,37; HFN = 187,34 ± 34,79; HFU = 166,63 ± 40,22 e HFNU = 175,26 ± 40,22. O tratamento da superfície cerâmica após condicionamento ácido não influenciou significativamente (p>0.05) na resistência à fratura das coroas cerâmicas testadas, sugerindo que é desnecessário qualquer tratamento adicional para remoção de resíduos após o uso de HF e lavagem com jato de água-ar / Abstract: The effect of different ceramic surface post hydrofluoric acid (HF) etching cleaning protocols in the fracture strength of lithium dissilicate glass ceramic crowns were evaluated. Forty maxillary third human molars received a conventional full preparation. Crowns were obtained from the digital scanning of the preparations and CAD/CAM blocks machining. Crown cement film thickness was evaluated with vinyl polysiloxane. The crowns were allocated in 4 groups according to the ceramic surface treatment (n=10): (HF)- 4.9% HF for 20s + water spray for 30s; (HFN)- HF + neutralizing agent for 5 min (N); (HFU) -: HF+ sonic bath for 5 min (U) and (HFNU): HF + N + U. After a silane coat (60s), crowns were cemented with dual cure cement. A compressive load of 1000Kg was applied in the occlusal surface center at crosshead speed of 1mm/min until the fracture. Data were analyzed by one-way ANOVA and Tukey tests (α = 0.05). Fracture strength mean for each group was (Kgf): HF = 169.92 ± 21.37; HFN = 187.34 ± 34.79; HFU = 166.63 ± 40.22 e HFNU = 175.26 ± 40.22. There was no statistical difference as the surface treatment (p>0.05) suggesting that it is not necessary any additional ceramic surface treatment in order to remove debris after using of HF and air-water spray rinsing / Doutor

Clostridium difficile is a leading cause of nosocomial infection in North America and a considerable challenge to healthcare professionals in hospitals and nursing homes. The Gram-positive bacterium produces two exotoxins, toxin A (TcdA) and toxin B (TcdB), which are the major virulence factors responsible for C. difficile-associated disease (CDAD) and are targets for CDAD therapy. In this work, recombinant single-domain antibody fragments (VHHs) which target the cell receptor binding domains of TcdA or TcdB were isolated from an immune, llama phage display library and characterized. Four VHHs (A4.2, A5.1, A20.1, and A26.8) were potent neutralizers of the cytopathic effects of TcdA in an in vitro assay and the neutralizing potency was enhanced when VHHs were administered in combinations. Epitope mapping experiments revealed that some synergistic combinations consisted of VHHs recognizing overlapping epitopes, an indication that factors other than mere epitope blocking are responsible for the increased neutralization. Binding assays revealed TcdA-specific VHHs neutralized TcdA by binding to sites other than the carbohydrate binding pocket of the toxin. The TcdB-specific VHHs failed to neutralize TcdB, as did a panel of human VL antibodies isolated from a synthetic library. To enhance the stability of the C. difficile TcdA-specific VHHs for oral therapeutic applications, the VHHs were expressed with an additional disulfide bond by introducing Ala/Gly54Cys and Ile78Cys mutations. The mutant VHHs were found to be well expressed, were non-aggregating monomers, retained low nM affinity for TcdA, and were capable of in vitro TcdA neutralization. Digestion of the VHHs with the major gastrointestinal proteases, at biologically relevant concentrations, revealed a significant increase in pepsin resistance for all mutants and an increase in chymotrypsin resistance for the majority of mutants without compromising inherent VHH trypsin resistance. Collectively, the second disulfide not only increased VHH thermal stability at neutral pH, as previously shown, but also represents a generic strategy to increase VHH stability at low pH and impart protease resistance. These are all desirable characteristics for the design of protein-based oral therapeutics. In conclusion, llama VHHs represent a class of novel, non-antibiotic inhibitors of infectious disease virulence factors such as C. difficile toxins.