Laboratory scale activated sludge experiments were conducted on primary effluent municipal wastewater to evaluate the effects of anoxic selectors on controlling activated sludge bulking and foaming. These experiments were conducted with two pilot plants; a three stage anoxic selector preceding a complete mix system (experimental unit) and a complete mix system (control unit). Successful selector operation requires balancing two conflicting requirements; obtain a high substrate concentration in the selector while achieving a high substrate removal efficiency in the selector. The high substrate concentration enables rapid substrate uptake to occur predominately by floc forming microorganisms while the high substrate removal efficiency ensures that a feed-starve cycle is created whereby filamentous microorganisms are selected against. The reported metabolic mechanisms responsible for substrate uptake in the selector are the formation of internal storage products and high rate metabolism. As presented by Jenkins et al., (1993) small amounts of substrate are oxidized in the selector during the formation of internal storage products. Hence, large quantities of substrate can be removed while reducing only small amounts of the terminal electron acceptor. The internal stores are metabolized in the main biological reactor only after the exogenous substrate has been exhausted. High rate metabolism in the selector results in larger amounts of substrate oxidation. Consequently, for successful selector operation large quantities of the terminal electron acceptor must be reduced. The anoxic selector pilot unit successfully reduced activated sludge settleability and biological foams relative to the control unit. Results from this study indicate that the mode of substrate removal was influenced by the initial selector floc load. This is in general agreement with the findings by Goel and Gaudy (1968) and Gaudy and Gaudy (1988) on oxidative assimilation in activated sludge treatment. The floc load depicts the instantaneous organic loading in the selector irrespective of hydraulic retention time. Results from this study further indicate that for lower floc loadings substrate storage is predominate. Alternatively, at higher floc loadings high rate substrate metabolism is predominate. Therefore, it is hypothesized that for selector zones with high enough F/M ratios to promote rapid substrate uptake, the mechanism predominately responsible for substrate removal is influenced by the floc loading. / Master of Science

There has been extensive research done in the area of Semiparametric Regression. These techniques deliver substantial improvements over previously developed methods, such as Ordinary Least Squares and Kernel Regression. Two of these hybrid techniques: Model Robust Regression 1 (MRR1) and Model Robust Regression 2 (MRR2) require the choice of an appropriate bandwidth for smoothing and a mixing parameter that allows a portion of a nonparametric fit to be used in fitting a model that may be misspecifed by other regression methods. The current method of choosing the bandwidth and mixing parameter does not guarantee the optimal choices in either case. The immediate objective of the current work is to address this process of choosing the optimal bandwidth and mixing parameter and to examine the behavior of these estimates using 3D plots. The 3D plots allow us to examine how the semiparametric techniques: MRR1 and MRR2, behave for the optimal (AVEMSE) selection process when compared to data-driven selectors, such as PRESS* and PRESS**. It was found that the structure of MRR2 behaved consistently under all conditions. MRR2 displayed a wider range of "acceptable" values for the choice of bandwidth as opposed to a much more limited choice when using MRR1. These results provide general support for earlier fndings by Mays et al. (2000).

A la present Tesi Doctoral s'ha dut a terme la síntesi de derivats de cel·lulosa, amilosa i quitosà amb l'objectiu d'avaluar-los com a selectors quirals en separacions d'enantiòmers per cromatografia de repartiment centrífug. Segons la metodologia sintètica desenvolupada anteriorment en el grup de recerca, s'han preparat els tris(3,5-dimetilfenilcarbamats) i tris(3,5-diclorofenilcarbamats) de cel·lulosa, amilosa i quitosà, compostos de reconeguda enantioselectivitat quan s'apliquen en fases estacionàries quirals d'HPLC. El mètode s'ha extès cap a la preparació d'altres derivats, incloent derivats mixtes dodecanoïl/dimetilfenilcarbamat de cel·lulosa. L'objectiu d'aquesta diversificació ha estat d'una banda estudiar l'efecte dels diferents substituents sobre l'enantioselectivitat i d'altra banda incrementar la solubilitat dels polisacàrids en dissolvents orgànics. A partir dels compostos preparats, s'han buscat les condicions experimentals adequades per la seva utilització en cromatografia de repartiment centrífug (CPC). Aquesta és una tècnica cromatogràfica sense suport sòlid on el procés de separació té lloc entre dues fases líquides immiscibles. Quan es consideren separacions d'enantiòmers, cal solubilitzar en una de les fases un compost que actui com a selector quiral. La selecció dels sistemes de dissolvents que donin lloc a les dues fases immiscibles esdevé de gran importància, doncs ha de permetre la distribució de l'analit, garantir la retenció del selector quiral en una de les fases i permetre que el selector quiral manifesti enantioselectivitat en dissolució. Amb aquest objectiu, en el present treball s'han utilitzat sistemes binaris formats per un dissolvent orgànic (metil isobutil cetona, MIBK i metil tert-butil eter, MTBE) on s'han dissolt els selectors derivats de polisacàrids, i una dissolució aquosa tamponada (dissolució de fosfat sòdic i dissolució d'acetat amònic) que ha actuat com a fase mòbil. S'ha estudiat la solubilitat dels derivats de polisacàrids i la viscositat de les dissolucions. S'ha seleccionat un ventall d'analits racèmics de caràcter àcid, bàsic i neutre i s'ha examinat la seva distribució en els sistemes bifàsics. En les condicions determinades, s'han dut a terme amb èxit les primeres separacions d'enantiòmers utilitzant derivats de polisacàrids com a selectors quirals en CPC. Els experiments de separació s'han realitzat en el mode clàssic d'elució, comparable a un mode isocràtic en HPLC, i en el mode de cromatografia de desplaçament de pH-zone-refining. Dels resultats en mode clàssic se'n desprèn que el camp d'aplicació dels derivats de polisacàrids és notablement més reduït en CPC que en HPLC. Tot i així, s'han aconseguit resolucions parcials d'enantiòmers per analits com la warfarina i el pindolol. La menor enantioselectivitat es podria atribuir a la pèrdua de part de l'estructura supramolecular dels polisacàrids quan aquests s'utilitzen en dissolució i també a l'elevat grau d'ionització dels analits en les condicions de pH de fase mòbil utilitzades, que dificultaria la interacció amb el selector derivat de polisacàrid. A fi de superar aquesta limitació i promoure interaccions més efectives entre selector i enantiòmers s'ha utilitzat el mode de pH-zone-refining. En aquest mode de desplaçament aplicable a analits ionitzables s'ha aconseguit incrementar l'enantioselectivitat i la resolució de les separacions, així com la capacitat de càrrrega dels selectors. Un estudi comparatiu entre CPC i HPLC ha reflectit que les dades de capacitat de càrrega de dos derivats de cel·lulosa i amilosa front a determinats racèmics eren favorables a la CPC. La major accessibilitat del selector quiral en la fase estacionària líquida de CPC podria facilitar la interacció amb els enantiòmers. A fi de caracteritzar la densitat de llocs de reconeixement en el selector quiral polisacarídic, s'ha estudiat la interacció selector/enantiòmers a través de diferents tècniques, entre elles la ressonància magnètica nuclear utilitzant experiments de transferència de saturació (STD NMR). / The synthesis of cellulose, amylose and chitosan derivatives has been carried out, aimed at testing them as chiral selectors in enantiomer separations by CPC. After preparing the polysaccharide tris(3,5-dimethylphenylcarbamates) and tris(3,5-dichlorophenylcarbamates), compounds of proved enantioselectivity when applied in HPLC chiral stationary phases, the methodology was extended to the preparation of other derivatives including the heterogeneously substituted cellulose dodecanoyl/3,5-dimethylphenylcarbamate. Derivatization was aimed at studying the effect of the substituents on the enantioselectivity and increasing the solubility of polysaccharides in organic solvents. Subsequently, convenient experimental conditions were searched for applying polysaccharide derivatives in CPC. In this liquid chromatography technique without solid support, the separation process takes place between two immiscible liquid phases. When enantiomer separations are envisaged, one of them contains a chiral selector. The biphasic solvent system should allow a convenient distribution of the analyte and permit that the selector maintains its enantioselectivity in solution. In the present work binary systems have been used, formed by an organic solvent and a buffered aqueous solution which has acted as mobile phase. A range of acidic, neutral and basic analytes has been selected. In the conditions determined, the first application of polysaccharide derivatives as chiral selectors in CPC has been performed. The separation experiments have been carried out in the classical elution mode, which can be compared to isocratic HPLC mode, and in the pH-zone-refining displacement mode of chromatography. From the results in classical mode it can be observed that the application field of polysaccharide derivatives is significantly lower in CPC than in HPLC. Even so, partial enantiomer resolutions have been achieved. pH-Zone-refining CPC has allowed an increase in enantioselectivity and resolution, as well as higher loadability of the chiral selectors. With regards to loadability, a comparative study between HPLC and CPC has afforded better results for the latter. This could be favoured by a better accessibility of the selectors in the liquid stationary phase of CPC. In order to characterize the density of recognition sites in the polysaccharide chiral selector, the selector/enantiomer interaction has been studied, among other techniques, by means of saturation transfer difference NMR (STD-NMR) experiments.

The design, synthesis and evaluation of chiral selectors that allow the determination of enantiomeric composition using electrospray ionization mass spectrometry are detailed herein. The enantiomers of the chiral selector were mass labeled at a distant site from the chiral recognition sites of the molecules. The mass-labeled enantiomers were mixed in a one-to-one ratio to form a quasi-racemate. Chiral recognition can be observed by comparing relative abundances of the pseudo-diastereomeric selector-analyte complexes in the mass spectrum. The observed sense of chiral recognition with mass spectrometry was consistent with that observed chromatographically using a corresponding chiral stationary phase in every case. The complex intensity fraction (CIF, intensity of one selector-analyte complex divided by the sum of the intensities for both selector-analyte complexes) is linear with the enantiomeric composition. The slope of this line is an indication of the extent of the enantioselectivity: the larger the slope, the more significant the enantioselectivity. In addition, this line can be used as a calibration curve for the quantitative determination of enantiomeric composition of the same analyte with unkown enantiomeric composition. Amide derivatives of DNB-amino acids were first used as pseudo-enantiomeric chiral selectors in the presence of added lithium chloride. The enantioselectivity values were smaller than those observed on chiral HPLC using the corresponding chiral stationary phase. The use of deprotonated DNB-amino acids as chiral selectors provides higher enantioselectivities, but with low ion abundances. Tertiary amine appended analogues of the chiral stationary phase DNB-Leucine were prepared. The amine was appended to provide a site for ready ionization (through protonation). The performance of chiral selectors of this type was compared to the original chiral selectors that lack this functional group. Chiral recognition was also observed in a reciprocal sense using proline-derived pseudo-enantiomeric chiral selectors and analytes similar to DNB-amino acid esters or amides. Optimization of the electrospray ionization conditions provided similar enantioselectivities to those from chiral HPLC. Libraries of tertiary amine appended derivatives of DNB-dipeptides, which were prepared through combinatorial peptide synthesis, were screened using electrospray ionization mass spectrometry. The use of electrospray ionization mass spectrometry as a discovery tool for new chiral selectors is discussed.

This work aims at studying the effect of word position in text on understanding and tracking the content of written text. In this thesis we present two uses of word position in text: topic word selectors and topic flow signals. The topic word selectors identify important words, called <i>topic words</i>, by their spread through a text. The underlying assumption here is that words that repeat across the text are likely to be more relevant to the main topic of the text than ones that are concentrated in small segments. Our experiments show that manually selected keywords correspond more closely to topic words extracted using these selectors than to words chosen using more traditional indexing techniques. This correspondence indicates that topic words identify the topical content of the documents more than words selected using the traditional indexing measures that do not utilize word position in text. The second approach to applying word position is through <i>topic flow signals</i>. In this representation, words are replaced by the topics to which they refer. The flow of any one topic can then be traced throughout the document and viewed as a signal that rises when a word relevant to the topic is used and falls when an irrelevant word occurs. To reflect the flow of the topic in larger segments of text we use a simple smoothing technique. The resulting smoothed signals are shown to be correlated to the ideal topic flow signals for the same document. Finally, we characterize documents using the importance of their topic words and the spread of these words in the document. When incorporated into a Support Vector Machine classifier, this representation is shown to drastically reduce the vocabulary size and improve the classifier's performance compared to the traditional word-based, vector space representation.

This work aims at studying the effect of word position in text on understanding and tracking the content of written text. In this thesis we present two uses of word position in text: topic word selectors and topic flow signals. The topic word selectors identify important words, called <i>topic words</i>, by their spread through a text. The underlying assumption here is that words that repeat across the text are likely to be more relevant to the main topic of the text than ones that are concentrated in small segments. Our experiments show that manually selected keywords correspond more closely to topic words extracted using these selectors than to words chosen using more traditional indexing techniques. This correspondence indicates that topic words identify the topical content of the documents more than words selected using the traditional indexing measures that do not utilize word position in text. The second approach to applying word position is through <i>topic flow signals</i>. In this representation, words are replaced by the topics to which they refer. The flow of any one topic can then be traced throughout the document and viewed as a signal that rises when a word relevant to the topic is used and falls when an irrelevant word occurs. To reflect the flow of the topic in larger segments of text we use a simple smoothing technique. The resulting smoothed signals are shown to be correlated to the ideal topic flow signals for the same document. Finally, we characterize documents using the importance of their topic words and the spread of these words in the document. When incorporated into a Support Vector Machine classifier, this representation is shown to drastically reduce the vocabulary size and improve the classifier's performance compared to the traditional word-based, vector space representation.

This study results of an empirical research which analyzes the life trajectories and work of a garbage selectors group in Maceió-Al, nowadays inserted directly in the productive chain of recycling. The objective of this work was to analyze the trash recycling process, as an environmental policy that reorients the production of new materials usinor those dismissable ones, detaching the role of the selectors, their insertion in the productive process, their work relationship and their life conditions. The research involved referring methodological procedures to the bibliographical research, the documentary one and the empirical research, being used the techniques of the participant observation to analysis of the daily one, and of the interview half-structuralized for the reconstruction of their histories of life. The development of the research made in possible for us to understand that the reality of the selecting in Maceió had not been modified. These selectors are the same abandoned of long ago that feed the production chain of the recycles. We conclude that the field work here realized in corroborate, in the theory of Gonçalves, who the perverse cycle is much more observed them the virtuous cycle and, still with more reason, than the anatomical cycle of recycling. In short, the activity of selecting doesn t foresee the social fairness and, therefore, don t foresee the sustainable development. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo resulta de uma pesquisa empírica que analisa as trajetórias de vida e trabalho de um grupo de catadores de lixo de Maceió-Al, hoje inseridos diretamente na cadeia produtiva da reciclagem, atividade considerada como meio para a preservação ambiental. O objetivo deste trabalho foi analisar o processo de reciclagem de lixo, enquanto política ambiental que reorienta a produção de novos materiais a partir da reutilização dos descartáveis, destacando o papel dos catadores, sua inserção no processo produtivo, suas relações de trabalho e suas condições de vida. A investigação envolveu procedimentos metodológicos concernentes à pesquisa bibliográfica, à documental e à pesquisa empírica, sendo que nela foram utilizadas as técnicas da observação participante para análise do cotidiano, e da entrevista semi-estruturada para a re-construção de suas histórias de vida. O desenvolvimento da investigação possibilitou-nos compreender que a realidade dos catadores de lixo em Maceió não foi alterada. Esses catadores são os mesmos desvalidos de outrora que alimentam a cadeia de produção dos recicláveis. Conclui-se que o trabalho de campo aqui realizado corrobora, à luz da teoria de Gonçalves, que o ciclo perverso é muito mais observado do que o ciclo virtuoso e, ainda com mais razão, que o ciclo atômico da reciclagem. Em suma, a atividade de catação não provê a eqüidade social e, portanto, não provê o Desenvolvimento Sustentável.

This diploma thesis deals with the application of two permanently positively charged monosubstituted β-cyclodextrin derivatives (PEMEDA-β-CD, PEMPDA-β-CD) as chiral selectors in capillary electrophoresis. Use of PEMPDA-β-cyclodextrin in capillary electrophoresis has not been reported in literature. Properties of PEMEDA-β- cyclodextrin are already known, but its application for separation of amino acid enantiomers has not been published yet. Cyclodextrin derivatives were tested as additives in different buffers of different pH and with eventual addition of organic modifier. As suitable background electrolyte 15 mmol·l-1 borate buffer, pH = 9.5 without organic modifier was chosen. Furthermore the influence of chiral selector on separation and eventual enantioseparation of chosen analytes was evaluated. Addition of cyclodextrin derivatives in concentration range 0.0 - 5.0 was tested. Fourteen anionogenic analytes, including native amino acids, N- blocked amino acids and profens, were detected with UV-VIS detector at optimal wavelength 214, 254 or 280 nm. Both chiral selectors were suitable for enantioseparation of N-boc-D,L-tryptophan, which was baseline separated at concentration of selector as low as 0.5 mmol·l-1 . Tested amino acids blocked with terc-butoxycarbonyl and D,L-ketoprofen were partially...

Uma das questões mais importantes nas linguagens e arcabouços orientados a aspectos atuais é a expressividade da linguagem ou mecanismo de definição de pointcuts. A expressividade de uma linguagem de pointcuts impacta diretamente a qualidade dos pointcuts, uma propriedade que pode ser decisiva para a eficácia das implementações de aspectos. Neste trabalho, propomos os seletores de pontos de junção como um mecanismo de extensão simples para enriquecer linguagens de pointcut atuais com elementos que fazem o papel de \"novos pointcuts primitivos\". Os seletores de pontos de junção permitem a criação de pointcuts com maior valor semântico. Apesar de existirem mecanismos similares em algumas abordagens existentes, o conceito subjacente não foi claramente definido ou completamente explorado. Apresentamos também uma arquitetura simples para a adição de seletores de pontos de junção a um arcabouço orientado a aspectos existente, e mostramos exemplos do uso de seletores para melhorar a qualidade de pointcuts e facilitar o desenvolvimento de aspectos. / One of the main issues in modern aspect-oriented programming languages and frameworks is the expressiveness of the pointcut language or mechanism. The expressiveness of pointcut languages directly impacts pointcut quality, a property that can be decisive for the effectiveness of aspect implementations. In this work we propose join point selectors as a simple extension mechanism for enriching current pointcut languages with constructs that play the role of \"new primitive pointcuts\". Join point selectors allow the creation of pointcuts with greater semantic value. Although similar mechanisms can be found in some existing approaches, the underlying concept has not yet been clearly defined nor fully explored. We also present a simple architecture for adding join point selectors to an existing aspect-oriented framework, and show examples of usage of join point selectors to enhance the quality of pointcuts and make aspect development easier.

This thesis analyses the process of women&rsquo / s legislative recruitment in Turkey by focusing on the interaction among the certain features of the Turkish political system including the attitudes of the party elite toward the enhancement of women&rsquo / s political representation. It has been demonstrated in earlier studies that one of the reasons behind women&rsquo / s low level of parliamentary representation in Turkey is the fact that the selectors in the political parties fail to support women candidates adequately in the elections. Related to that, women&rsquo / s legislative recruitment is also likely to be impeded by the unsupportive nature of the main dynamics of political system such as political culture, party system and the v electoral system. Considering the fact that these institutional and attitudinal factors are highly inter-related with each other, the insufficient number of women candidates nominated by the major social democratic party, the Republican People&rsquo / s Party in the 1990s, including the latest national elections on November 3rd, 2002 calls for an analysis of not only the attitudes of the RPP selectors toward positive discrimination mechanisms such as the quotas for women but also of the relevant party institutional factors rooted in the Turkish political system. The study contends that the RPP&rsquo / s women-friendly party culture and selectors&rsquo / positive perspectives towards women&rsquo / s political integration are not sufficient factors for the promotion of women&rsquo / s legislative recruitment within the party. The weakness of the intra-party democracy in the RPP which is particularly the result of the oligarchic structure and the problems with institutionalization significantly impede women&rsquo / s legislative recruitment within the party. The study has found that the low level of women&rsquo / s legislative recruitment in the RPP is a consequence of the interaction between the institutional and attitudinal factors within the RPP which perpetuates patriarchal elite oligarchy in the nomination process. The documented gap between the RPP&rsquo / s party rhetoric and practice in this study is found as the reflection of the party&rsquo / s problems in internalizing social democratic values.