Philosophiae Doctor - PhD / Coal combustion accounts for 95% of electricity generation in South Africa while globally coal combustion for energy generation stands at 42%. It has been predicted that coal utilization for energy generation will continue due to its low cost and availability in huge quantities in different parts of the world. Additionally brine and gaseous emissions are produced in the power generation and coal combustion processes. In fact, it has been established that CO2 emissions from power plants are the main cause of the green-house effect leading to global warming. Mitigation of the effects of disposal of fly ash, brine and CO2 emissions is critical for sustainable energy generation from coal and environmental protection. The study investigated whether South African coal fly ash could be used for brine remediation and CO2 capture using fly ash based hydrotalcites and zeolites. Four main objectives were investigated. These were; firstly, to compare the natural CO2 capture potential of a power station ash dam with an accelerated ex-situ mineral carbonation process. Secondly, to probe the effect of accelerated ex-situ mineral carbonation on brine quality with regards to major, minor and trace elements concentration. Furthermore, the study investigated the feasibility of synthesizing hydrotalcites from fly ash by optimizing the synthesis parameters such as acid concentration, aging time, aging temperature, pH during aging, crystallization time and crystallization temperature. Finally the study compared the CO2 adsorption capacities of the fly ash based hydrotalcites with fly ash based zeolites NaA, and NaX. The natural carbonation potential of the wet disposed ash dam at Secunda was investigated by coring a 20 year old dam. Three cores (SI, S2 and S3) were obtained by air flush coring the dam along a geophysical line and establishing the geophysical profile of the three cores. The surface of the three cores was of medium resistivity with values between 9.3 and 12.2 nm while the midsections were of low resistivity with values ranging between 4 and 7 nm. The base section of core SI had a resistivity of 28.3 nm, that of S2 was between 16.2 and 21.4 nm and that of S3 between 12.2 and 16.2 nm; implying that SI had the lowest salt load while S3 had the highest salt content. Moisture content was observed to be high deeper down the profiles of S2 and S3 with samples appearing water logged while SI had the highest moisture content at the surface showing the inhomogeneity of the ash dam. The morphology of fresh fly ash taken from the ash collection hoppers at Secunda was observed to be spherical. Weathered ash from the ash dam showed irregularly agglomerated particles while accelerated ex-situ mineral carbonation resulted in the formation of acicular particles of calcite. Fresh ash, weathered ash and the accelerated carbonated ash were all class F with a sum total of silica, alumina and iron oxide totaling more than 70%. A reduction in silica and alumina content with instability of fly ash. Dumping of spent iron catalyst (resulting from the petrochemical operations as Sasol) on the ash dam led to an increase in Fe203 content of the weathered ash. Enrichment of Nb, Sr, Y, Th, Na, Cl, S04, K and S with natural carbonation as well as during accelerated ex-situ mineral carbonation was observed and was due to the contact of ash with brine during these two processes. Reduction of Zr, Rb, Pb, Ni, Co and V content of ash was observed with weathering. Mineralogically, all the ash samples had main phases of mullite, quartz, magnetite and hematite, with weathered and accelerated carbonated ash having additional phases of calcite. The aluminosilicious nature of the three ashes was identified by structural evaluation using Fourier transform infrared analysis which revealed that, bands associated with C-O in-plane and out of plane bending of carbonates was only visible in weathered and carbonated ash.

Indiana University-Purdue University Indianapolis (IUPUI)

[EN] This research work constitutes a first approximation to the study of the viability of carbonic fertirrigation in citrus fruits as a CO2 drain potential. To that effect, carbonic fertirrigation experiments were carried out with citrus fruits of the Nadarcott variety from the year 2010 to the year 2015. The study required the monitoring of parameters related to the leaf surface, the phenological state of the trees, the ground, the leaves and the fruits of the tested trees. The analysis of the results obtained showed there were no significant differences in the size and quality of the fruits irrigated with CO2. Differences were neither observed in the trees' vegetative development nor in the advance or delay of the blooming and formation of fruits. The analysis of the grounds revealed that the content in organic matter of the grounds irrigated with CO2 was higher than in the grounds used as reference in at least two tenths of a percentage. Similarly, it was noted that the content in iron in the leaves of the trees irrigated with CO2 was significantly higher than in the trees used as reference. The statistical analysis carried out confirmed these conclusions, noting a 24% increase over the average value in the case of the organic matter in the ground and of a 16% in the case of the iron content in the leaves. Both factors indicate that carbonic fertirrigation does have relevant agronomic repercussions, especially on the organic fraction of the ground and on the iron soluble fraction. Various authors confirm the mobilisation of the iron produced by the decrease in the pH of the irrigation water - this study confirms this fact and strengthens the usage of carbon dioxide as a potential substitute of strong acids normally used for this purpose. The increase in the content of the ground's organic matter is an especially interesting result, as it was not expected, even though some authors have related the decrease of soil respiration to different cultural practices that improve the ground's texture. The interaction between the CO2 of the irrigation water and the content in organic matter in the ground and, therefore, soil respiration must be studied in further detail in a future, with experiences specially aimed at valuing the repercussions of this practice on both parameters. / [ES] Este trabajo de investigación constituye una primera aproximación al estudio de viabilidad de la fertirrigación carbónica en cítricos como potencial sumidero de CO2. A tal efecto, se llevaron a cabos experimentos de fertirrigación carbónica con cítricos de la variedad Nadarcott desde el año 2010 hasta el año 2015. El estudio requirió la monitorización de parámetros relacionados con la superficie foliar, los estados fenológicos de los árboles, el suelo, las hojas y los frutos de los árboles ensayados. El análisis de los resultados obtenidos mostró que no había diferencias significativas en el tamaño y calidad de los frutos regados con CO2. Tampoco se observaron diferencias en el desarrollo vegetativo de los árboles ni en el avance o retraso de la floración y formación de los frutos. Los análisis de los suelos revelaron que el contenido en materia orgánica de los suelos regados con CO2 era más alto que los suelos tomados como referencia en al menos dos décimas porcentuales. De la misma manera, se observó que el contenido en hierro en las hojas de los árboles regados con CO2 era significativamente más alto que en los árboles tomados como referencia. Los análisis estadísticos realizados confirmaron estas conclusiones, observándose un incremento del 24% sobre el valor promedio en el caso de la materia orgánica del suelo y del 16% en el caso del contenido en hierro de las hojas. Ambos factores indican que la fertirrigación carbónica sí que tiene repercusiones agronómicas relevantes, especialmente sobre la fracción orgánica del suelo y sobre la fracción soluble de hierro. Diversos autores confirman la movilización del hierro producido por la disminución del pH del agua de riego; este estudio confirma este hecho y refuerza la utilización del dióxido de carbono como potencial sustituto de los ácidos fuertes normalmente utilizados para este cometido. El aumento en el contenido de materia orgánica del suelo es un resultado especialmente interesante, pues no era esperado pese a que algunos autores han relacionado la disminución de la respiración edáfica con diferentes prácticas culturales que mejoran la textura del suelo. La interacción entre el CO2 del agua de riego y el contenido en materia orgánica del suelo y, por tanto, la respiración edáfica deben de ser estudiados con más detalle, en un futuro con experiencias especialmente dirigidas a valorar las repercusiones de esta práctica sobre ambos parámetros. / [CA] Aquest treball d'investigació constitueix una primera aproximació a l'estudi de la viabilitat de la fertirrigació carbònica en cítrics com a potencial embornal de carboni. Amb aquesta finalitat es dugueren a terme experiments de fertirrigació carbònica amb cítrics de la varietat Nadorcott des de l'any 2010 fins l'any 2015. L'estudi va requerir la monitoratge de paràmetres relacionats amb la superfície foliar, els estat fenològics del arbres, el sòl, les fulles i el fruits dels arbres assatjats. L'anàlisi dels resultats obtinguts mostrà que no hi havia diferències significatives en el tamany i qualitat del fruits regats amb CO2. Tampoc es varen observar diferències en el desenvolupament vegetatiu dels arbres ni en l'avanç o retard de la floració i formació dels fruits. Les anàlisis dels sòls revelaren que el contingut de matèria orgànica dels sòls regats amb CO2 era més alt que els sòls considerats com a referència en, almenys, dues dècimes percentuals. De la mateixa manera, s'observà que el contingut de ferro en les fulles dels arbres regats amb CO2 era significativament més alt que en els arbres referència. Les anàlisis estadístiques realitzades confirmaren aquestes conclusions, observant-se un increment del 24% sobre el valor mitjà en el cas de la matèria orgànica del sòl i del 16% en el cas del contingut en ferro de les fulles. Tots dos factors indiquen que la fertirrigació carbònica sí que té repercusions agronòmiques rellevants, especialment, sobre la fracció orgànica del sòl i la fracció soluble de ferro. Diferents autors confirmen la mobilització del ferro produit per la disminució del pH de l'agua de reg; aquest estudi confirma aquest fet i reforça l'ús del diòxid de carboni com a potencial subsutitut dels àcids forts normalment gastats per a aquesta tasca. L'augment en el contingut de matèria orgànica del sòl és un resultat especialment interessant, ja que no era esperat, malgrat que alguns autors han relacionat la disminució de la respiració edàfica amb diferents pràctiques culturals que milloren la textura del sòl. La interacció entre el CO2 de l'aigua de reg i el contingut en matèria orgànica del sòl i, per tant, la respiració edàfica han de ser estudiats amb més detall en un futur amb experiències especialment dirigides a valorar les repercussions d'aquesta pràctica sobre tots dos paràmetres. / Tarazona Díez, JV. (2015). ANÁLISIS DEL POTENCIAL DE LA FERTIRRIGACIÓN CARBÓNICA EN CÍTRICOS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59405

Final draft report presented to the Graduate School of Business Leadership, University of South Africa / The main purpose of this study is to ascertain the major service quality variables that determine customer satisfaction for the Carbonated Soft Drink market which is dynamic and is also part of the highly competitive impulse beverage industry in South Africa. Amalgamated Beverages Industry (aka Coca Cola) still holds the lion’s share of the market although its share has fallen in the last 5 years presumably due to the growth in the consumption of substitutes such as bottled water, 100% fruit juices, energy drinks and dairy juice blends. The proliferation of “diet conscious” consumers has exacerbated the situation. These alternatives are the primary growth areas in the impulse beverage market. This has obviously threatened the viability and profitability of major players in this industry. To date the performance of Carbonated Soft Drinks (CSDs) has been less than satisfactory. There are other key players which have penetrated this market namely Pepsi, trading as Pioneer Foods, Royal, Pioneer Foods, California Cola, Pick ‘n Pay and Quality Beverages. For purposes of this study the three key players were chosen namely ABI, Pepsi and Quality Beverages. These key players have made huge investments in this industry at the level of production and distribution. In addition heavy investments go towards advertising and promotional campaigns. This research is exploratory in nature and makes way for further research in order to reach a more logical conclusion. This study is conducted within the confines of Gauteng region and more specifically Johannesburg North and Central. These two regions were chosen because the researcher resides close to these regions and wanted to minimize the costs involved in this study. The researcher also assumed the findings are a true representation of the broader picture of the South African scenario. Before collecting information the researcher initially consulted recent articles, books, magazines, company reports and even the internet in order to develop a clear understanding of the industry. This also helped the researcher to make logical decisions in the course` of undertaking the research. To that effect the researcher adopted the service quality SERVQUAL and the Gaps models in coming up with a measurement instrument for the research. The CSD companies have two broad categories of customers namely the trader and the end user or consumer. The trader purchases the product for purposes of research whilst the end user buys for consumption. This research focused on the trade customer. According to research experts a sample of more than 5% of the total population does not compromise validity. However the researcher opted for more than 10% of the total population in order to increase reliability of the results. Thus from the population size of 965 trade outlets the researcher arrived at a sample of 100. The traders were classified into four major categories namely retail outlets, wholesalers, restaurants and service stations. Information was collected from these 100 traders using personal interviews. The researcher is the one who conducted all the interviews. Information was gathered from buyers, managers and owners. The researcher took advantage of the Statistical Package for Social Scientists in order to make a meaningful analysis of the data collected. Many service oriented recommendations have been promulgated by this research. They are neither exhaustive nor prescriptive given the time constraint within which this research was conducted.

Final draft report presented to the Graduate School of Business Leadership, University of South Africa / The main purpose of this study is to ascertain the major service quality variables that determine customer satisfaction for the Carbonated Soft Drink market which is dynamic and is also part of the highly competitive impulse beverage industry in South Africa. Amalgamated Beverages Industry (aka Coca Cola) still holds the lion’s share of the market although its share has fallen in the last 5 years presumably due to the growth in the consumption of substitutes such as bottled water, 100% fruit juices, energy drinks and dairy juice blends. The proliferation of “diet conscious” consumers has exacerbated the situation. These alternatives are the primary growth areas in the impulse beverage market. This has obviously threatened the viability and profitability of major players in this industry. To date the performance of Carbonated Soft Drinks (CSDs) has been less than satisfactory. There are other key players which have penetrated this market namely Pepsi, trading as Pioneer Foods, Royal, Pioneer Foods, California Cola, Pick ‘n Pay and Quality Beverages. For purposes of this study the three key players were chosen namely ABI, Pepsi and Quality Beverages. These key players have made huge investments in this industry at the level of production and distribution. In addition heavy investments go towards advertising and promotional campaigns. This research is exploratory in nature and makes way for further research in order to reach a more logical conclusion. This study is conducted within the confines of Gauteng region and more specifically Johannesburg North and Central. These two regions were chosen because the researcher resides close to these regions and wanted to minimize the costs involved in this study. The researcher also assumed the findings are a true representation of the broader picture of the South African scenario. Before collecting information the researcher initially consulted recent articles, books, magazines, company reports and even the internet in order to develop a clear understanding of the industry. This also helped the researcher to make logical decisions in the course` of undertaking the research. To that effect the researcher adopted the service quality SERVQUAL and the Gaps models in coming up with a measurement instrument for the research. The CSD companies have two broad categories of customers namely the trader and the end user or consumer. The trader purchases the product for purposes of research whilst the end user buys for consumption. This research focused on the trade customer. According to research experts a sample of more than 5% of the total population does not compromise validity. However the researcher opted for more than 10% of the total population in order to increase reliability of the results. Thus from the population size of 965 trade outlets the researcher arrived at a sample of 100. The traders were classified into four major categories namely retail outlets, wholesalers, restaurants and service stations. Information was collected from these 100 traders using personal interviews. The researcher is the one who conducted all the interviews. Information was gathered from buyers, managers and owners. The researcher took advantage of the Statistical Package for Social Scientists in order to make a meaningful analysis of the data collected. Many service oriented recommendations have been promulgated by this research. They are neither exhaustive nor prescriptive given the time constraint within which this research was conducted.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-19T18:26:23Z No. of bitstreams: 1 2016 - Denise Rosane Perdomo Azeredo.pdf: 2006973 bytes, checksum: 610e1499e6733b78ee2eb47034198a7d (MD5) / Made available in DSpace on 2017-05-19T18:26:23Z (GMT). No. of bitstreams: 1 2016 - Denise Rosane Perdomo Azeredo.pdf: 2006973 bytes, checksum: 610e1499e6733b78ee2eb47034198a7d (MD5) Previous issue date: 2016-08-25 / Nowadays consumer desired healthy foods that promote benefits and free from food additives. The chemical composition of soft drinks, artificial colors and preservative, may pose a risk to consumer health due to the possibility of benzene formation, a recognized carcinogenic agent in humans and the association between artificial colors, allergic reactions and DNA damage. In this study, an orange soda formula containing the preservatives sodium benzoate and potassium sorbate with carrot and apple concentrate was developed. In parallel, we developed a standard formula containing tartrazine and sunset yellow. Physicochemical, microbiological and sensory analysis of formulas were carried out during the storage period of 150 days. It was observed that there were no changes in physicochemical parameters. However, the colorimetric analysis revealed a short shelf life in the sample containing the carrot and apple concentrate. Regarding microbiology, both formulations were according to regulation by public health agencies. The yeasts and molds counts presented 1 log cycle growth in the formula containing the carrot and apple concentrate, suggesting that the robustness of the developed matrix may be affected, if the hygiene conditions of processing line sanitation are not observed. It was found that the color was the sensory characteristic that most influenced consumers regarding the acceptability of the samples, signaling that this parameter interfered significantly in evaluating flavor and appearance The results obtained by microbiological challenge test and determination of growth potential (?) indicated that yeast and lactic acid bacteria are able to multiply in the formula containing carrot and apple concentrate without preservatives (? ? 0.5 log10), indicating that the formula is sensitive. Acid acetic bacteria, in these conditions, were inhibited. A preserved formula with the addition of carrot and apple concentrate and other formula with the addition of artificial colors were prepared. The results referring to the growth potential (?) indicated that yeast and lactic acid bacteria were inhibited (? ? 0.5 log10) in both formulas. However, the preservative resistant yeasts presented growth ability (? ? 0.5 log10). In the apple and carrot concentrate, it was observed that yeast, lactic acid bacteria and fungus Penicillium citrinum were inhibited, indicating that this ingredient should not be considered a nutrient source for microbial multiplication that would affect the formula robustness. It was verified the growth of the preservative resistant yeasts (growth potential ? ? 0,5 log10) in all the evaluated formulas and ingredient. The data obtained, in this study, indicate that the development of more natural foods still represents a challenge for the food industry. / Atualmente o consumidor anseia por alimentos mais naturais, saud?veis, que promovam benef?cios ? sa?de e que sejam isentos de aditivos. Nesse sentido, a composi??o qu?mica dos refrigerantes, especialmente no que concerne aos corantes artificiais e conservadores pode representar riscos ? sa?de do consumidor, devido a possibilidade de forma??o de benzeno, reconhecido agente carcinog?nico ao homem, e a associa??o entre corantes artificiais, rea??es al?rgicas e efeitos delet?rios ao DNA. Nessa pesquisa, inicialmente, desenvolveu-se uma formula??o de refrigerante de laranja, contendo os conservadores benzoato de s?dio e sorbato de pot?ssio, na qual os corantes artificiais ? amarelo tartrazina e amarelo crep?sculo foram substitu?dos por concentrado de cenoura e ma??. Em paralelo, desenvolveu-se uma formula??o controle. Foram realizadas an?lises f?sico-qu?micas, microbiol?gicas e sensorial das formula??es durante o per?odo de armazenamento de 150 dias. Observou-se o atendimento ao padr?o de identidade e qualidade e estabilidade das formula??es em rela??o aos par?metros f?sico-qu?micos. Entretanto, na an?lise colorim?trica observou-se uma degrada??o de cor percept?vel ao consumidor na amostra contendo o concentrado de cenoura e ma??. Em rela??o as an?lises microbiol?gicas, ambas as formula??es atenderam aos par?metros preconizados pela legisla??o. Entretanto, a contagem de bolores e leveduras apresentou crescimento de 1 ciclo log na formula??o contendo o concentrado de cenoura e ma??, sugerindo que a robustez da matriz desenvolvida pode ser afetada, se as condi??es de higieniza??o da linha de processamento n?o forem observadas. Em rela??o a an?lise sensorial, verificou-se que a cor foi a caracter?stica sensorial que mais influenciou os consumidores com rela??o a aceitabilidade das amostras, sinalizando que esse par?metro interferiu, de forma significativa na avalia??o do sabor e apar?ncia. Os resultados referentes a aplica??o do teste desafio e a determina??o do potencial de multiplica??o microbiana (?) indicaram que as leveduras e bact?rias l?cticas s?o capazes de se multiplicar na formula??o adicionada de concentrada de cenoura e ma?? sem conservadores (? ? 0,5 log10), sinalizando que a formula??o ? sens?vel. As bact?rias ac?ticas, nessas condi??es, foram inibidas. Nas formula??es preservadas quimicamente com adi??o de concentrado de cenoura e ma?? e a adicionada de corantes artificiais, os resultados referentes ao potencial de multiplica??o microbiana (?) indicaram que as leveduras e bact?rias l?cticas foram inibidas (? ? 0,5 log10) em ambas as formula??es. Entretanto, as leveduras resistentes a conservadores apresentaram habilidade de crescimento (? ? 0,5 log10). No ingrediente concentrado de cenoura e ma??, observou-se que as leveduras, bact?rias l?cticas e o fungo Penicillium citrinum foram inibidos, indicando que o concentrado n?o deve ser considerado uma fonte de nutriente para a multiplica??o microbiana que afetaria a robustez da formula??o. Constatou-se a multiplica??o das leveduras resistentes a conservadores, com potencial de multiplica??o ? ? 0,5 log10 em todas as formula??es e ingrediente avaliados. Os dados obtidos no presente estudo sinalizam que o desenvolvimento de alimentos mais naturais ainda representa um desafio para a ind?stria de alimentos.

Nous étudions les comportements dynamiques de solutions aqueuses de dioxyde de carbone, pures ou sous forme de boissons gazeuses. Nous observons les façons dont des solutions carbonatées, initialement à l'équilibre de Henry, répondent à une perturbation, qui peut être un changement brusque de pression ou une agitation mécanique. Ces questions sont examinées expérimentalement, à l'aide de dispositifs construits pour cette étude. Ceux ci permettent de visualiser les champs de vitesse et les fronts de dissolution dans le fluide, dans des conditions variées de pression, taille et forme de système. Une partie importante est consacrée à la chemi-convection provoquée par la déstabilisation d'une couche diffuse de CO2 dissout. Nous présentons une caractérisation complète du phénomène, et une interprétation basée sur une théorie de l'instabilité de Rayleigh-Taylor correspondante. L'autre partie de notre travail concerne des systèmes fermés, dont la bouteille de champagne est l'exemple type. Nous montrons que l'agitation de la bouteille provoque une légère baisse transitoire de la pression interne, et expliquons le phénomène à l'aide d'un modèle basé sur la théorie d'Epstein-Plesset de la dynamique des bulles. / This work is about dynamical phenomena of water-carbon dioxide solutions, either pure binary mixtures or carbonated beverages. We address the general problem of how such solutions, initially at Henry's equilibrium, respond to a perturbation. The latter may be a sudden change in pressure, or mechanical shaking. These problems are investigated with the help of especially designed experimental hardware that allows us to visualize the velocity field and the concentration front inside solutions, in diverse conditions of pressure, system size and shape. An important part of the work is dedicated to chemi-convection, i.e. the fluid motion induced by destabilisation of the diffuse layer of dissolved CO2. Both experimental characterization and interpretation through a theory of the corresponding Rayleigh-Taylor instability are presented. The other part of the work is related to closed systems, representative of a bottle of champagne and of sodas in general. A key observation is that shaking produces a small transient drop of the internal pressure, which we explain through a dedicated modelbuilt on Epstein-Plesset's theory of bubble dynamics.

<p>Značajan porast prevalence dentalnih erozija u savremenom dru&scaron;tvu, zahteva sve vi&scaron;e pažnje ka&nbsp; istraživanju njihove etiologije i preventivnih mera koje se mogu preduzeti. Cilj ove studije bio je da se ispita erozivni potencijal gaziranih napitaka i njihov uticaj na zubna tkiva, tokom različitih vremenskih intervala.<br />Stepen kiselosti izražen pH vrednostima za svaki ispitivani napitak (gaziranu vodu &bdquo;Knjaz Milo&scaron;&ldquo;, Coca-Cola-u i Schweppes Bitter Lemon), određen je odmah po otvaranju ambalaže sa napitkom, nakon 5 i 60 minuta kao i nakon 12 i 24 sata od potapanja zubnih uzoraka. U ovoj studiji posmatrane su mikroskopske promene proučavanjem skening elektronske mikrofotografije spolja&scaron;nje povr&scaron;ine gleđi, kao i uzdužni presek gleđi i dentina zuba nakon izlaganja gore navedenim napicima 5 i 60 minuta,12 i 24 sata kao i 7 i 30 dana, ali i makroskopske promene boje i strukture gleđi u svim navedenim vremenskim intervalima. Za određivanje stepena nastalih mikroskopskih i makroskopskih promena primenjene su individualno prilagođene skale.<br />Početna pH vrednost svih ispitivanih napitaka je niža od kritične pH vrednosti za demineralizaciju gleđi. Sa porastom vremena od potapanja zubnih uzoraka u napitke, njihova pH vrednost značajno raste. Na SEM mikrofotografijama gleđi i dentina se uočavaju promene u morfologiji, čiji intenzitet zavisi od vrste napitka i vremena koje je uzorak u njemu proveo. Centralni tip demineralizacije prisutan je kod uzoraka potopljenih u kiselu vodu i Coca Cola napitak a periferni kod Schweppes Bitter Lemon. Intenzitet promena zubnih tkiva raste u funkciji vremena, ali statistički značajna razlika ne postoji između svih vremenskih intervala. Zubi koji su bili izloženi delovanju gazirane vode &bdquo;Knjaz Milo&scaron;&ldquo; ne pokazuju izmene u makroskopskom izgledu, za razliku od zuba koji su tretirani Coca-Cola-om i Schweppes Bitter Lemon-om čiji intenzitet izmenjenosti raste u funkciji vremena, s tim da je statitički značajna razlika prisutna između pojedinih vremenskih intervala. S obzirom na erozivni potencijal i promene koje gazirani napitci izazivaju u in vitro условима, potrebno je preduzeti odgovarajuće preventivne mere kako bi se smanjio njihov uticaj na zube u in vivo uslovima.</p> / <p>Značajan porast prevalence dentalnih erozija u savremenom dru&scaron;tvu, zahteva sve vi&scaron;e pažnje ka&nbsp; istraživanju njihove etiologije i preventivnih mera koje se mogu preduzeti. Cilj ove studije bio je da se ispita erozivni potencijal gaziranih napitaka i njihov uticaj na zubna tkiva, tokom različitih vremenskih intervala.<br />Stepen kiselosti izražen pH vrednostima za svaki ispitivani napitak (gaziranu vodu &bdquo;Knjaz Milo&scaron;&ldquo;, Coca-Cola-u i Schweppes Bitter Lemon), određen je odmah po otvaranju ambalaže sa napitkom, nakon 5 i 60 minuta kao i nakon 12 i 24 sata od potapanja zubnih uzoraka. U ovoj studiji posmatrane su mikroskopske promene proučavanjem skening elektronske mikrofotografije spolja&scaron;nje povr&scaron;ine gleđi, kao i uzdužni presek gleđi i dentina zuba nakon izlaganja gore navedenim napicima 5 i 60 minuta,12 i 24 sata kao i 7 i 30 dana, ali i makroskopske promene boje i strukture gleđi u svim navedenim vremenskim intervalima. Za određivanje stepena nastalih mikroskopskih i makroskopskih promena primenjene su individualno prilagođene skale.<br />Početna pH vrednost svih ispitivanih napitaka je niža od kritične pH vrednosti za demineralizaciju gleđi. Sa porastom vremena od potapanja zubnih uzoraka u napitke, njihova pH vrednost značajno raste. Na SEM mikrofotografijama gleđi i dentina se uočavaju promene u morfologiji, čiji intenzitet zavisi od vrste napitka i vremena koje je uzorak u njemu proveo. Centralni tip demineralizacije prisutan je kod uzoraka potopljenih u kiselu vodu i Coca Cola napitak a periferni kod Schweppes Bitter Lemon. Intenzitet promena zubnih tkiva raste u funkciji vremena, ali statistički značajna razlika ne postoji između svih vremenskih intervala. Zubi koji su bili izloženi delovanju gazirane vode &bdquo;Knjaz Milo&scaron;&ldquo; ne pokazuju izmene u makroskopskom izgledu, za razliku od zuba koji su tretirani Coca-Cola-om i Schweppes Bitter Lemon-om čiji intenzitet izmenjenosti raste u funkciji vremena, s tim da je statitički značajna razlika prisutna između pojedinih vremenskih intervala. S obzirom na erozivni potencijal i promene koje gazirani napitci izazivaju u in vitro uslovima, potrebno je preduzeti odgovarajuće preventivne mere kako bi se smanjio njihov uticaj na zube u in vivo uslovima.</p> / <p>Due to the fact that prevalence of dental erosion significantly increased in modern society, it is important to investigate its etiological factors and all available preventive measures. The aim of this study was to investigate erosive potential of carbonated beverages and their influence on dental hard tissues, during different intervals.<br />The acidity or pH level was measured for each beverage (carbonated water &bdquo;Knjaz Milos&ldquo;, Coca-cola and Schweppes Bitter Lemon), on opening of the bottle, after 5 minutes and 60 minutes, and after 12 hours and 24 hours immersion of tooth samples in adequate beverage. In this study, microscopic changes of dental tissues were examined using a scanning electron microphotography of outer surface of enamel and longitudinal section of enamel and dentin, after exposure to beverages during 5 and 60 minutes, 12 and 24 hours, and 7 and 30 days, as well as macroscopic changes of tooth color and structure at same intervals. Individually adopted scales were used for grading of the severity of microscopic and macroscopic changes.<br />Initiated pH value of each tested beverage was lower than critical pH for enamel demineralisation. SEM images of enamel and dentin showed different morphology changes, which intensivity depended on type of beverages and time that sample were stored. Central type of demineralisation was visible on samples treated with carbonated water and Coca-Cola, while peripheral type of demineralisation was detected on samples treated with Schweppes Bitter Lemon. The intensity of alterations of dental tissues increased during time, but there was not statistically significant difference between all intervals. There wasn&rsquo;t detected macroscopic changes on teeth stored in carbonated water, while teeth treated with Coca-Cola and Schweppes Bitter Lemon showed changes which intensity increased during time, but statistically significant difference between all intervals wasn&rsquo;t detected. Due to erosive potential and changes influenced by carbonated beverages in vitro, preventive measures are necessary for reducing their effect on teeth in vivo.</p>

Submitted by JOSÉ VARELA DONATO DONATO (jvarela@superig.com.br) on 2011-08-03T20:10:39Z No. of bitstreams: 1 TESE - Empreendedorismo e Estratégia.pdf: 2040306 bytes, checksum: ec0f87dee77d5c0f7e15ae6920a28565 (MD5) / Approved for entry into archive by Vera Lúcia Mourão (vera.mourao@fgv.br) on 2011-08-03T20:28:08Z (GMT) No. of bitstreams: 1 TESE - Empreendedorismo e Estratégia.pdf: 2040306 bytes, checksum: ec0f87dee77d5c0f7e15ae6920a28565 (MD5) / Approved for entry into archive by Vera Lúcia Mourão (vera.mourao@fgv.br) on 2011-08-03T20:31:43Z (GMT) No. of bitstreams: 1 TESE - Empreendedorismo e Estratégia.pdf: 2040306 bytes, checksum: ec0f87dee77d5c0f7e15ae6920a28565 (MD5) / Made available in DSpace on 2011-08-04T13:40:05Z (GMT). No. of bitstreams: 1 TESE - Empreendedorismo e Estratégia.pdf: 2040306 bytes, checksum: ec0f87dee77d5c0f7e15ae6920a28565 (MD5) Previous issue date: 2011-06-30 / This research aims to describe how the process of creating two companies and their competitive strategies have developed in the carbonated soft drinks sector in the State of Ceará. It is a qualitative and descriptive research, in which interpretation plays a crucial role in data analysis, that consisted mainly of texts originated from interviews with the founders and general managers of two companies studied and managers of three supermarket chains as well as documents, articles, studies and statistics from the carbonated soft drinks sector. The research revealed that the entrepreneurial processes occured in a disordely way, the discovery of an opportunity resulted of a set of conditions, the entrepreneurs did not compare opportunities and used rational and non-rational criteria for evaluating opportunities, they didn’t have a long-term goal or vision at the beginning of their companies and exhibited confidence and optimism about the success of their business. Regarding the creation of competitive strategy, the results show that competition occurred in all segments of the value chain of companies, a cost leadership strategy was effective for entry into the market, but an obstacle to growth in face of changes in the economic profile and lifestyle of consumers; the intangible assets (brand reputation, knowledge, education for entrepreneurship, for example) and capabilities to effectively perform the activities in the value chain are more sustainable and valuable competitive advantages to business performance. Finally, the research results suggest that the development and evaluation of business creation projects must incorporate variables such as increasing the number of firms and their survival and mortality rates, entry costs, capacity utilization, and competitive movements in broader geographic areas. / Esta pesquisa tem por objetivo principal descrever como se desenvolveram, no setor de refrigerantes no Estado do Ceará, os processos de criação de duas empresas e de suas estratégias competitivas. Trata-se de pesquisa qualitativa, de natureza descritiva, em que a interpretação desempenha papel crucial na análise dos dados, constituídos principalmente de textos, originados de entrevistas com os fundadores e gerentes gerais das duas empresas estudadas e gerentes de três redes de supermercados, além de documentos, estudos, artigos e dados estatísticos do setor de refrigerantes. A pesquisa revelou que os processos de empreender ocorreram de maneira desordenada; a descoberta de uma oportunidade resultou do atendimento de um conjunto de condições; os empreendedores não compararam oportunidades e usaram critérios racionais e não racionais para avaliação de oportunidades, não tiveram meta ou visão de longo prazo na implantação de suas empresas e exibiram confiança e otimismo quanto ao sucesso de suas empresas. Quanto à criação da estratégia competitiva, os resultados mostram que a competição ocorreu em todos os segmentos da cadeia de valor das empresas; uma estratégia de liderança em custo foi eficaz para a entrada no mercado, mas impeditiva ao crescimento diante das mudanças no perfil econômico e estilo de vida dos consumidores; os recursos intangíveis (reputação da marca, conhecimento, educação para o empreendedorismo, por exemplo) e capacidades de executar com eficiência as atividades na cadeia de valores foram vantagens competitivas mais sustentáveis e valiosas para o desempenho empresarial. Finalmente, os resultados da pesquisa sugerem que a elaboração e a avaliação de projetos de criação de empresas devem incorporar variáveis como aumento do número de firmas e suas taxas de sobrevivência e mortalidade, custos de entrada, utilização de capacidade e movimentos competitivos em espaços geográficos mais amplos.

Au Jurassique supérieur, la plateforme carbonatée jurassienne séparait le bassin de Paris du Bassin delphino-helvétique. Pauvres en fossiles biostratigraphiques, les dépôts du passage Oxfordien- Kimméridgien sont partiellement datés. L'organisation et la hiérarchie communes des séquences de dépôt observées dans le Jura franco-suisse et en Lorraine permettent d'établir des corrélations régionales haute résolution et montrent l'implication des cycles d'excentricité et de précession dans la formation des séquences. Les corrélations permettent de réviser le cadre bio-lithostratigraphique du Jura français et de contraindre l'évolution de la géométrie de la plateforme et de ses paléoenvironnements. Réalisées sur des huîtres et Trichites issus de niveaux de passage Oxfordien-Kimméridgien du Jura et de Normandie, des analyses isotopiques montrent une évolution climatique commune à tout le pourtour du bassin de Paris, intimement liée à la dynamique sédimentaire de la plateforme jurassienne. L'étude des entités coralliennes de l'Oxfordien terminal montre que leurs compositions et leurs morphologies sont fonction de leur position sur la plateforme et de l'évolution du niveau marin relatif. A la fin de la zone à Bimammatum, l'enregistrement de pistes de dinosaures dans les dépôts de la plateforme exprime une phase d'émersion. La position de celle-ci dans le cadre séquentiel montre que l'enregistrement des empreintes est lié à un contexte paléogéographique, paléoenvironnmental et séquentiel exceptionnel, favorisant le développement, puis l'induration et le recouvrement de laminites microbiennes et la migration des dinosaures sur la plateforme / The Upper Jurassic Jura platform separated the Paris basin and the delphino-helvetic basin. The scarcity of biostratigraphic fossils of the Oxfordian-Kimmeridgian platform deposits prevent from establishing accurate dating. The common organization and hieacrchy of depositional sequences observed in French and Swiss Jura and in Lorraine allow to establish high-resolution regional correlations, and show the involvement of eccentricity and precession cycles in the formation of sequences. Correlations allow revising the French Jura bio-lithostratigraphic framework and highlight the evolutions of platform geometry and palaeoenvironments. Isotopic analysis based on oyster and Trichites specimens, sampled in several beds from the Upper Oxfordian-Lower Kimmeridgian, in Jura and Normandie, show a similar climatic evolution, all around the Paris basin. This evolution seems closely linked to the Jura platform sedimentary dynamics. The study of the Upper Oxfordian reef entities shows that their compositions and morphologies depend on their position along the platform and the evolution of relative sea level. In the end of the Bimammatum zone, the record of dinosaur trackways, in the platform deposits, expresses an emersion phase. Its position in the sequential framework shows that the track record was abled by an exceptional palaeogeographic, palaeoenvironmental and sequential context that favored on the one hand the development, induration and covering of microbial laminites and on the other hand the migration of dinosaurs across the platform