Les reaccions de metàtesi de diens i d'enins catalitzades per espècies carbèniques de ruteni constitueixen poderoses eines àmpliament utilitzades per a la síntesi d'una gran diversitat de productes. La importància de la reacció de metàtesi s'ha posat de manifest amb la concesió del premi Nobel de Química 2005 a Chauvin, Grubbs i Schrock. La recerca de catalitzadors més estables i actius i la preparació de catalitzadors reciclables han merescut els esforços d'un gran nombre de grups durant els últims anys. Grubbs i Hoveyda han introduït carbens N-heterocíclics (NHC) i lligands estirènics quelatants per a la millora dels sistemes catalítics. Una de les estratègies utilitzades per a la recuperació i reciclatge d'aquests sistemes catalítics és l'ancoratge de l'espècie homogènia a un suport polimèric insoluble, sent els polímers orgànics els més comuns. Dins dels inorgànics els treballs són menys nombrosos i corresponen a l'ancoratge a síliques comercials, a sistemes monolítics o a síliques mesoestructurades. La major estabilitat tèrmica, química i mecànica dels polímers inorgànics i les seves elevades àrees superficials els fan alternatives atractives per a la incorporació covalent de lligands orgànics i complexes metàlics. Com a alternativa a l'ancoratge, la part orgànica pot incorporar-se a la matriu inorgànica mitjançant el procés sol-gel. Els híbrids orgànico-inorgànics derivats de sílice obtinguts han experimentat un gran creixement durant la última dècada, amb el desenvolupament de sistemes organitzats en presència de tensioactius. En la present tesi doctoral s'han sintetitzat cinc monòmers diferents de tipus Hoveyda que presenten grups trietoxisilil. El primer és un equivalent del lligand quelatant original de Hoveyda que inclou una cadena espaiadora i un grup trietoxisilil. Altres monòmers són variacions on la cadena espaiadora inclou una urea enlloc d'un carbamat. Un d'ells conté a la seva estructura un grup nitro que ha de potenciar la seva activitat com a catalitzador, mentre que un altre es tracta d'un derivat bisililat, el qual permet la preparació de materials pel procés sol-gel sense que sigui necessària l'addició de tetraetoxisilà (TEOS). A partir dels diferents monòmers s'han sintetitzat materials híbrids orgànico-inorgànics per diversos procediments: procés sol-gel amb diferents quantitats deTEOS i fluorur com a catalitzador, en presència de dodecilamina, que actua com a agent estructurant i com a catalitzador a la vegada i, en el cas del derivat bisililat, també pel procés sol-gel en absència de TEOS. Els mateixos monòmers s'han ancorat a gel de sílice mesoestructurat MCM-41 i a gel de sílice comercial. Tots els materials s'han caracteritzat gràcies a la col·laboració amb el grup de Michel Wong Chi Man de la "Ecole Nationale Superieure de Chimie de Montpellier" mitjançant diferents tècniques: Ressonància magnètica nuclear de silici-29 en estat sòlid (que permet comprovar la unió covalent entre el lligand orgànic i la matriu sililada), mesures d'adorció-desorció de nitrogen pel mètode BET (amb les quals es determina la superfíce específica del material i la distribució dels diàmetres de porus), difracció de raigs X en pols (determinació de la possible estructuració del material), anàlisi elemental (quantitat de matèria orgànica incorporada) i microscopia electrònica de transmissió (TEM). S'observa que els materials presenten superfices específiques majors quan s'han utilitzat agents estructurant i quan la dilució de la part orgànica és major. El tractament dels materials híbrids amb els carbens de Grubbs de primera i/o segona generació ha donat lloc als corresponents catalitzadors suportats. Aquests s'han assajat en reaccions de metàtesi de diens per tal d'obtenir olefines di-, tri- i tetrasubstituides, i també en la metàtesi d'un ení.Dels resultats obtinguts es desprèn que els materials tractats amb el catalitzador de segona generació són els més eficaços i que els catalitzadors heterogènis que provenen de sol-gel són més actius i es reciclen millor que els corresponents a l'ancoratge a MCM-41 o a sílica comercial. En la síntesi de l'1-(4-toluensulfonil)-2,5-dihidro-1H-pirrole s'han realitzat fins a cinc cicles consecutius amb la majoria dels catalitzadors. Aquells materials que contenen el monòmer més semblant al lligand quelatant original de Hoveyda són els que donen una millor capacitat de reciclatge, mentre que els més actius són els que contenen el grup electroatraient nitro. Entre els catalitzadors preparats per sol-gel resulten ser més actius aquells que presenten una major superfície específica i una major dilució del lligand al seu interior. Els materials preparats a partir del monòmer bisililat sense la addició de TEOS presenten, malgrat tenir una superfície nula, una activitat comparable als altament porosos. En la síntesi de l'1-(4-toluensulfonil)-2,5-dihidro-3-metil-1H-pirrole s'han pogut realitzar fins a cinc cicles de catàlisi. Aquests resultats són millors que els descrits a la literatura amb catalitzadors suportats per a aquesta reacció. En la síntesi del 3,4-dimetil-1-(4-toluensulfonil)-2,5-dihidro-1H-pirrole s'han aconseguit realitzar fins a tres cicles amb un dels catalitzadors, i dos amb la majoria. Aquests resultats constitueixen el primer exemple reeixit de preparació d'aquesta olefina tetrasubstituida amb un catalitzador suportat i el primer cas on s'aconsegueix reutilitzar el catalitzador amb un cert èxit. En la metàtesi de l'ení 1-al·liloxi-1,1-difenil-2-propí s'han realitzar fins a cinc cicles amb la majoria dels catalitzadors. Els resultats constitueixen el primer exemple de recuperació d'un catalitzador en una reacció de matàtesi d'enins. / The diene and enyne metathesis reactions catalyzed by ruthenium carbene species are powerful tools widely used by organic chemists for the synthesis of a great diversity of compounds. The great importance of the metathesis reaction has been made clear with the award of the Nobel Prize of Chemistry 2005 to Chauvin, Grubbs and Schrock. In the metathesis field a considerable number of groups in the last years have dedicated their efforts to the search of more stable and active carbene complexes and to the preparation of recoverable catalysts. Grubbs and Hoveyda have introduced N-heterocyclic carbenes (NHC) and chelating styrenic ligands for the improvement of catalytic systems. One of the strategies used for the recovery of the mentioned ruthenium and palladium catalytic systems is the anchorage of the homogeneous species to an insoluble polymeric support, organic polymers being the most commonly used. In the case of inorganic polymers the precedents are scarce and correspond to the anchoring to commercial silicas, monolithic systems or mesostructured silicas. The better thermal, chemical and mechanical stability of inorganic polymers and their high surface areas make them attractive alternatives for the covalent incorporation of organic ligands and metallic complexes. As an alternative to the anchoring method, the organic moiety can be incorporated to the inorganic matrix by the sol-gel process. The silica-based organic-inorganic hybrids obtained by sol-gel have experienced a great boom in the last decade, with the development of organized systems in the presence of surfactants. In this doctoral thesis five Hoveyda-type monomers have been synthesized containing a triethoxysilil group. The first one is equivalent to the original Hoveyda quelating ligand, and includes a spacing chain and a triethoxysilil group. Other monomers have a urea instead of a carbamate as the spacing chain. One of them contains a nitro group which is expected to improve the catalyst activity, whereas another one is a bisililated derivative, which can be used to prepare materials through the sol-gel process without addition of TEOS being necessary. These monomers have been used to prepare organic-inorganic hybrid materials through several strategies: sol-gel process with different TEOS amounts and fluoride as catalyst, dodecilamine acting both as structurating agent and catalyst and, in the case of the bisililated monomer, through the sol-gel process without TEOS being added. The same monomers have been anchored to commercial and to mesostructurated MCM-41 silica gel. All of them have been characterized in collaboration with Michel Wong Chi Man, from the "Ecole Nationale Superieure de Chimie de Montpellier" through several techniques: Solid state 29Si-NMR (in order to verify the covalent bond between the organic moiety and the sililated matrix), BET nitrogen adsorption-desorption measures (specific surface area and pore size distribution of the material) X ray diffraction (possible material structuration), elemental analysis (amount of incorporated organic moiety) and transmission electron microscopy (TEM). Higher surface areas are observed when structurating agents have been used and with the higher dilution of the organic moiety. Treatment of the hybrid materials with Grubbs first and/or second generation carbenes has produced the corresponding supported catalysts. They have been used in diene metathesis reactions leading to di-, tri- and tetrasubstituted olefins, and in an enyne metathesis reaction, too. The results show that the materials treated with the second generation catalyst are the most efficient and that those synthesized by the sol-gel process are more active and more reusable than those obtained by anchoring either to MCM-41 or to commercial silica gel. In the synthesis of 1-(4-toluensulfonyl)-2,5-dihidro-1H-pirrole five consecutive runs have been performed with most of the catalysts. Those materials containing the most similar monomer to the Hoveyda quelating ligand show the best recycling capacity, whereas the more active ones are those with the electron withdrawing nitro group. Among the catalysts prepared by sol-gel, those with higher surface areas and higher dilution of the ligand in the sililated matrix are the more active. The materials prepared with the bisililated monomer without TEOS addition, although having no surface area at all, show a similar activity than the highly porous ones. In the synthesis of 1-(4-toluensulfonyl)-2,5-dihidro-3-methyl-1H-pirrole five consecutive runs have been performed. The results are better than those described in the literature with supported catalysts for this reaction. In the synthesis of 3,4-dimethyl-1-(4-toluensulfonyl)-2,5-dihidro-1H-pirrole three runs have been performed with one of the catalysts, and two with most of the other. These results are the first successful example for the preparation of this tetrasubstituted olefin with a supported catalyst and the first where it has been reused with a certain success. In the metathesis of 1-allyloxi-1,1-diphenyl-2-propyne five runs have been performed with most of the catalysts. The results obtained constitute the first example of recycling of a catalyst in an enyne metathesis reaction.

This thesis is a hermeneutic phenomenological investigation of the phenomenon of addiction, particularly alcohol addiction. My thesis draws heavily from the phenomenological school of hermeneutic phenomenology, in particular Max Van Manen’s (2006) text, Researching Lived Experience: Human Science for an Action Sensitive Pedagogy as a frame of reference for my inquiry into and analysis of the lived experience of addiction and recovery. The Van Manen text is used as a research handbook, guiding my approach, my analysis, and the project more generally. My thesis found that, using the existential of lived time, temporality, in recovery the present is essentially different than the past, and that recovering addicts necessarily rethink and reorient themselves to the past to heal.

Purpose: To investigate the differential effects of solutions providing varying concentrations of carbohydrate and/or protein ingested between 200-meter sprints on sprint time. Subjects: Recruitment was from the Georgia State University track and field team. Methods: The study protocol was approved by the Georgia State University IRB. Ten subjects, 18 to 21 years of age, consented to be included in the study. Nine subjects (7 females; 2 males) completed trial 1, six subjects (5 females; 1 male) completed trial 2, and three subjects (2 females; 1 male) completed the final trial. Each trial consisted of a 200-meter sprint followed by the immediate ingestion of a post-exercise recovery beverage within the first fifteen minutes of a one-hour recovery period. Following the one-hour of recovery, subjects sprinted a second 200-meter sprint. Beverage solutions were formulated to contain 1.2 g of protein (PRO), 1.2 g carbohydrate (CHO), or 1.2 g carbohydrate with protein (CHO/PRO) per kg of subject body weight. Using a single blind, non-randomized design, subjects received the same recovery beverage in each trial. Each trial consisted of either PRO (trial 1), CHO (trial 2), or CHO/PRO (trial 3), with one week separating trials. Sprint times were recorded in seconds and ten hundredths of a second using a manual, digital stopwatch. Results: During PRO, two subjects sprinted faster (x= -.25 sec), three subjects saw no change in sprint time, and four subjects sprinted slower (x= +.98 sec). During CHO, two female subjects sprinted faster between sprints (x= -.85 sec); and all other subjects (n=4) sprinted slower (x= +.73 sec). During CHO/PRO, no subjects sprinted faster from sprint 1 to sprint 2 (x= +.33 sec) Conclusions: Post-exercise nutritional supplementation effects varied among subjects, with some subjects performing better following PRO, while others experiencing improvements with CHO. In general, subjects performed better following consumption of the CHO beverage. Of those who ran faster between sprints, the CHO beverage resulted in an average improvement of -.85 sec, while the PRO beverage resulted in an average improvement of -.25 sec. On average, CHO resulted in faster 2nd sprints (x= +.20 sec) than the PRO beverage (x= +.47 sec) or the CHO/PRO beverage (x= +.33 sec). Continued research in this population is necessary for elucidation of study results. This investigation may serve as the foundation for future, related studies.

This study explores how middle-aged homeless persons in Atlanta, GA, who have harmful, self-identified addictive behaviors come to make positive material and psychological changes, while constrained by urban poverty and structural violence. This study is divided into two parts. In part one, I examine the interaction between individual, social, and material factors that promote recovery from addiction in a poor, urban context. I argue that recovery occurs through a process, initiated by a decision and realized through practice. Recovery is enhanced by a stable community and consistent material access. In part two, I examine how pain associated with homelessness can create a strong drive to intensify substance usage as a means to seek relief. I then describe how alienation, pain and corresponding addictive behaviors among homeless persons can be lessened through intentioned, empowering acts, which I call “symbolic love”. Finally, I offer policy recommendations based on my findings.

This thesis is a hermeneutic phenomenological investigation of the phenomenon of addiction, particularly alcohol addiction. My thesis draws heavily from the phenomenological school of hermeneutic phenomenology, in particular Max Van Manen’s (2006) text, Researching Lived Experience: Human Science for an Action Sensitive Pedagogy as a frame of reference for my inquiry into and analysis of the lived experience of addiction and recovery. The Van Manen text is used as a research handbook, guiding my approach, my analysis, and the project more generally. My thesis found that, using the existential of lived time, temporality, in recovery the present is essentially different than the past, and that recovering addicts necessarily rethink and reorient themselves to the past to heal.

Intensive swine operations produce large amounts of manure that must be dealt with responsibly. Liquid swine manure (LSM) collected in storage units is applied to cropland as a nutrient source. Maximizing crop utilization of the nitrogen (N) added in manure is important to achieve economic and environmental benefits. The objectives of this research were to evaluate the effect of 1) adding a nitrification inhibitor and 2) using supplemental phosphorus (P) and sulfur (S) fertilizers as means of enhancing crop recovery of LSM-N.<p>Field experiments were conducted at two long-term manure management sites in Saskatchewan; 1) Dixon (Black Chernozem) and 2) Melfort (Dark Grey Luvisol). At the Dixon site, plant and soil samples were collected throughout the 2005 and 2006 growing season, and ammonium-N (NH4+-N) and nitrate-N (NO3--N) concentration in soil, and total N content in plant were measured. Plant root simulator (PRSTM) probes were used to measure NH4+-N and NO3--N supply rates at the Dixon site to determine the effectiveness of a nitrification inhibitor dicyandiamide (DCD) added to LSM. Crop recovery of N applied through LSM application was assessed by measuring seed and straw yield and total N content. The effect of adding supplemental P fertilizer at 6.5 kg P ha-1 to swine manure amended soil on N recovery was also evaluated at the Dixon site. At the S deficient Melfort site, the effect of supplemental S fertilizer added at 40 kg S ha-1 as ammonium sulfate and elemental S was evaluated.<p>The addition of DCD (0.275 mL kg-1) to LSM in 2005 and 2006 at Dixon did not significantly affect the proportion of LSM-N recovered or the seed yield. However, measurements of available NH4+-N and NO3--N concentrations and supply rates at the beginning of the growing season in 2005 indicated that the nitrification inhibitor was effective in keeping more of the LSM-N in the NH4+ form for approximately 14 days after LSM application. <p> The addition of supplemental P fertilizer to plots fertilized with LSM at the Dixon site, generally did not produce any significant increase in crop N recovery or seed yield. However, increase in crop N recovery and seed yield in 100 kg N ha-1 urea treatments indicates that there was insufficient P available in the soils to maximize crop N recovery and seed yield. It appears that LSM is able to provide sufficient amounts of available P when applied annually at rates of 37,000 L ha-1 or higher. <p>At the Melfort site, the addition of supplemental S fertilizer did not significantly affect crop N recovery or seed yield in LSM treatments. Annual applications of the low rate of LSM of 37,000 L ha-1 supplied sufficient amounts of N and S to maximize seed yield and crop N recovery. However, large significant increases in seed yield and crop N recovery with supplemental S fertilizers were observed in the 80 kg N ha-1 urea treatment.<p>The use of a nitrification inhibitor added to LSM was effective at maintaining N in NH4+ form longer; however there was no significant effect on final yield, grain N or %N recovery. This may be due to the low N loss potential on prairies. Supplemental S and P fertilizer may be required with liquid swine manure. Supplemental commercial fertilizers with LSM are dependant on: the crop nutrient requirements, soil nutrient status and manure nutrient composition.

Resilience engineering first appeared as a new approach for both system design and system safety in the last decade. One of the first substantive publications on resilience as applied to engineering was Resilience Engineering: Concepts and Precepts [Hollnagel et al. 2006]. Hollnagel, Woods, and Leveson developed the basic concepts behind resilience engineering in order to understand and prevent tragedies such as the Columbia Challenger accident and the September 11 terrorist attack.<p> In its present stage, resilience engineering has several fundamental problems. 1. There is not an appropriate definition for resilience. 2. The differences between resilience and other similar concepts are not clarified. 3. There is no quantitative method which can measure resilience. The three questions need to be addressed in order to advance the concept of resilience engineering and form a theoretical concept to an applied science. These three issues then form the foundation of this thesis.<p> As a first step, a resilience definition is presented based on the concepts of system function and damage. Then, the differences between resilience and five similar concepts (reliability, robustness, repairing, redundancy, and sustainability) are clearly elaborated. As a last step, a method for quantifying resilience is proposed in the form of a resilience index. This method exclusively measures system resilience by analyzing the system recoverability from two points of view: reconfiguration and replacement of components.<p> In order to illustrate the approach to and definitions of resilience, an actual application is considered: a water pumping station operated by SaskWater in Saskatoon, Saskatchewan (the Clarence Booster Station). This pumping station is a complicated system consisting of mechanical electrical and chemical subsystems. The resilience of Clarence Booster Station is analyzed using the proposed definition of resilience and resilience index.<p> This thesis is just an initial step establishing a comprehensive definition (qualitatively and quantitatively) for resilience. The resilience index so defined in this work appears to have potential but much more scrutiny and refinement must be pursued to ensure that it is truly applicable to more universal engineering applications.

Digital resampling is a process that converts a digital signal from one sampling rate to another. This process is performed by means of interpolating between the input samples to produce output samples at an output sampling rate. The digital interpolation process is accomplished with an interpolation filter.<p> The problem of resampling digital signals at an output sampling rate that is incommensurate with the input sampling rate is the first topic of this thesis. This problem is often encountered in practice, for example in multiplexing video signals from different sources for the purpose of distribution. There are basically two approaches to resample the signals. Both approaches are thoroughly described and practical circuits for hardware implementation are provided. A comparison of the two circuits shows that one circuit requires a division to compute the new sampling times. This time scaling operation adds complexity to the implementation with no performance advantage over the other circuit, and makes the 'division free' circuit the preferred one for resampling.<p> The second topic of this thesis is performance analysis of interpolation filters for Quadrature Amplitude Modulation (QAM) signals in the context of timing recovery. The performance criterion of interest is Modulation Error Ratio (MER), which is considered to be a very useful indicator of the quality of modulated signals in QAM systems. The methodology of digital resampling in hardware is employed to describe timing recovery circuits and propose an approach to evaluate the performance of interpolation filters. A MER performance analysis circuit is then devised. The circuit is simulated with MATLAB/Simulink as well as implemented in Field Programmable Gate Array (FPGA). Excellent agreement between results obtained from simulation and hardware implementation proves the validity of the methodology and practical application of the research works.

Because of the high demand for hydrogen in the oil industries, new technologies for hydrogen production are being investigated. The thermochemical splitting cycle is one of them. Among the cycles that have been investigated, sulfur-iodine (S-I) water splitting is the most studied. In the S-I cycle, there are three reactions: H2SO4 decomposition, Bunsen reaction and HI decomposition. A new thermochemical cycle has been developed based on the S-I cycle, which is a H2S splitting cycle. In the H2S cycle, there are also three reactions. The only difference between S-I and H2S cycle is that the H2SO4 decomposition reaction is replaced by a reaction between hydrogen sulfide and sulfuric acid which produces sulfur dioxide, elemental sulfur and water. Research on this reaction has been done for many years, studying thermodynamic, kinetics and mass transfer. This reaction produces sulfur, sulfur dioxide and water. The SO2 produced is the used in the second reaction in the H2S cycle; the Bunsen reaction.<p> The main objective of this research was to find an operating condition to increase the production of SO2 from the reaction between H2S and H2SO4. This study investigated different conditions such as temperature, stirring rate and sulfuric acid concentration to maximize the production of SO2. The temperature and stirring rate range used in the reaction were from 120 to 160°C and from 0 to 400 rpm, respectively. The sulfuric acid concentrations were between 90 and 96 wt%. The results showed that increasing the temperature and the acid concentration in the reaction between H2S and H2SO4, the SO2 produced from this reaction will increase. There is no need to apply stirring in the reaction, because the stirring will increase the surface area which allows the produced sulfur dioxide in the gas phase to be dissolved more in sulfuric acid solution, which favors the unwanted side-reaction between SO2 and H2S. A model that was developed to predict the partial pressure change of SO2 in closed reactor. This model was used to compare the data between experimental and simulation through Matlab software. The simulated data was compared to the experimental data and the results indicated that the model fits the data satisfactorily. Additionally, study on the separation between the remaining sulfuric acid and produced elemental sulfur from the reaction between H2S and H2SO4 were performed. The mixture was placed in an oven at140°C of temperature for two hours. It was found that all small droplets of sulfur produced during the reaction between hydrogen sulfide and sulfuric acid agglomerated and the sulfuric acid solution became clearer.

No description available.