In this work the objective was to develop a method that would make it easier to quantitatively evaluate different quality parameters in pasta. This was done with the assistant of a texture analyzer from TexVol Instruments. The quality parameters that were investigated were hardness, resilience, elasticity and adhesiveness. Two different types of measurements were used to measure three different pasta brands. These were single cycle and hold until time. Before this was done the main parameters in the texture analyzer were tested and adjusted to suite the method. Most of the steps in the developed method worked satisfactorily but more studies have to be done to make the method useful in the daily work with pasta production and pasta development. With all tests in mind it could be said that the De Cecco pasta was the one with the best texture parameters. It had the highest hardness, elasticity and resilience and the lowest adhesiveness. The other two brands, Kungsörnen and Tomadini had lower but similar results. Further important studies to look into is if there`s a possibility to get a computer software that are more targeted on pasta measurement. Another important thing is if these pasta measurements can be done in a different way, perhaps just using a few spaghetti straws. It would also be interesting to study the protein network in an electron microscope because then it´s easier to understand what´s happening when pasta is prepared. Last but not least I think it´s important to do a organoleptic test to see if it´s possible to taste the measured results. / Detta examensarbete gick ut på att ta fram en metod med hjälp av en texturmätare där olika kvalitetsparametrar såsom hårdhet, elasticitet och spänst kunde mätas på pasta. Dessa mätningar gjordes på tre olika spaghettimärken. Dessa var Kungsörnen, Tomadini samt De Cecco. Mätningarna på de olika pastamärkena gjordes med hjälp av en texturmätare från TexVol som är ett svenskt företag. Deras olika instrument är främst framtagna för att fungera inom bageribranchen och köttindustrin. Detta gjorde att det var spännande att se om detta instrument även kunde användas med framgång för att mäta olika kvalitetsegenskaper på kokt pasta. Först gjordes mätningar på Kungsörnens spaghetti vid olika koktider. Dessa var mellan 5 och 14 minuter. Dessa mätningar gjordes främst för att se vad som händer med de olika kvalitetsegenskaperna från det att pastan är underkokt till kraftigt överkokt. Utifrån resultaten från dessa mätningar är det svårt att dra några tydliga slutsatser då de varierade kraftigt. Därefter gjordes mätningar på de tre olika pastamärkena med två olika mätmetoder, dels single cycle och dels hold until time. Med single cycle menas att proben(mätstången) går ner i pastan och sen direkt upp igen medan vid hold until time metoden så går proben ner för att sen stanna nere tills en förinställd tid passerat innan den går upp igen. På detta sätt kan olika kvalitetsegenskaper mätas med de olika mätmetoderna. För att dessa mätmetoder ska fungerar har olika parametrar på texturmätaren utvärderats och på detta sätt har en metod/tillvägagångssätt tagits fram. De flesta av stegen i denna metod verkar fungera bra men ett stort problem är att mätningarna skiljer sig mycket åt. Detta beror troligtvis på att pastan lägger sig olika inför varje mätning vilket gör att mätningarna blir långt ifrån identiska vilket leder till att resultaten blir svårtolkade. Vissa tendenser kan dock ändå ses. Om alla mätningar tags i beaktande kan det sägas att De Cecco pastan är den pasta av högst kvalité. De Cecco pastan är den som är mest "al dente", mest elastisk, mest spänst samt lägst klibbighet. Vad detta beror på är svårt att säga då det kan finnas många förklaringar som är mer eller mindre relevanta. En trolig förklaring kan vara att De Cecco pastan har ett högre proteininnehåll än de båda andra märkena. I litteraturen står det att ett högre proteininnehåll ger en bättre kokt pasta och detta verkar rimligt då protein nätverket blir starkare vilket håller ihop pastan på ett bättre sätt. En annan möjlig orsak kan vara att fördelningen av de olika proteinerna är bättre i De Cecco pastan än i de andra märkena vilket leder till en bättre kvalitet. De två andra, Kungsörnen och Tomadini hade snarlika resultat. Vad som behöver göras för att denna metod eventuellt ska kunna användas i den dagliga produktionen av pasta och utveckling av ny pasta är att ta bort så många felkällor som möjligt så att standardavvikelsen i alla mätningar blir avsevärt mindre. Detta kan kanske avhjälpas av att ha en mjukvara som är mer anpassad till pastamätningar än den som var används nu som är anpassad till bageribranchen. En annan viktig sak kan vara att mäta på bara några få pasta strå till skillnad mot nuvarande "spaghettinystan". Ytterligare en intressant sak är att göra en organoleptisk undersökning av de olika pastamärkena för att se om de uppmätta resultaten är smakbara. Även att titta i elektronmikroskåp för att se de olika spaghettis proteinnätverk kan vara intressant för att få en förståelse för hur pastan ändrar sig under kokning.

Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Pasta manufacturing is a process whereby wheat flour is converted into a shelf-stable food that is more desirable than native wheat flour. It can be fortified and may serve as a valuable source of nutrition in developing countries. Quality measures are of importance in the production process to ensure a consistent and acceptable finished product. Literature provides information on many aspects of wheat types, milling techniques and processing of pasta. Protein content and quality of cultivated wheat varieties is of major importance to produce quality pasta products. Wheat types of lower protein content are more readily available than traditionally used durum wheat. As in all food products, the cost of final products is of major importance. Bread wheat is generally less expensive than durum wheat. However, product quality (and thus acceptability) may be lower. Direct measurements of product quality are currently limited to protein content, moisture content, colour analyses and certain other characteristics measurable in a laboratory, for example mechanical strength and firmness. Direct measurements of defects that may affect final product quality, such as cracks and fissures on the strands of spaghetti, different types of spots and lines on the strands, broken units, units sticking together and odd shapes are not well documented. During the first part of this study, spaghetti quality evaluation techniques were reviewed, improved or developed and thereafter standardised. This developmental research was conducted to establish valid and reliable measures (with a high degree of repeatability) for the evaluation of dry and cooked pasta quality characteristics. A wide variety of available products on the South African market were evaluated for different quality characteristics. From this evaluation standards were drawn up, tested for validity and reliability by means of repeatability. Minimum sample sizes for the evaluation of different quality characteristics were calculated and presented in the study, together with reference photographs that can be used to evaluate spaghetti. This study found that colour evaluation by means of commercially available apparatus needs revision. This study suggests the use of multiple layers when evaluating translucent food products for colour. The occurrence of fissures and flour spots are of importance for the quality of the final product. This study provides a set of valid and reliable measurements for measuring the quality of dry and cooked spaghetti. Simple techniques can therefore be used to detect the presence or absence of these defects. Thereafter an empirical study was conducted to describe the differences between spaghetti prepared from durum and non-durum wheat, dried at different temperatures and at different relative humidity. Spaghetti samples of diverse perceived quality, from different manufacturers, were purchased and evaluated. Standard methods and the newly developed testing methods were used to test whether these methods effectively distinguish between spaghetti of diverse quality, reflecting on the validity of the methods. Correlations were calculated between dependent and independent variables in an attempt to find possible explanations for certain defects or quality differences, and to test certain theories in the literature. Certain relationships between quality characteristics were found, while others were questioned. The most important proven relationships were between protein content and its effects on reducing quality defects such as fissures, breakages and cooking losses. The relationship between ash content and spaghetti colour could not be confirmed in this study. This study confirmed that protein remains one of the most important variables to ensure consistent quality spaghetti. / AFRIKAANSE OPSOMMING: Pastavervaardiging is ‘n proses waartydens koring meel omskep word in a produk met ‘n stabiele en lang rakleeftyd wat meer gewens is as die oorspronklike koring meel. Pasta kan gefortifiseer word and kan dien as a waardevolle voedingsbron in ontwikkelende lande. Om ‘n konstante en aanvaarbaare finale produk te verseker is kwaliteitmetings gedurende die produksie proses belangrik. Die literatuur voorsien heelwat inligting rakende aspekte van belang vir pastakwaliteit, byvoorbeeld koringtipes, maaltegnieke en die vervaardigingsproses. Proteïninhoud en die kwaliteit daarvan is van groot belang tydens die produksie van hoë kwaliteit pasta. Koringtipes met ‘n laer proteïninhoud is meer geredelik beskikbaar as tradisionele durumkoring. Soos met alle voedselprodukte, is die koste van die finale produk van groot belang. Oor die algemeen verhandel broodkoring teen laer pryse as durumkoring. Die produkkwaliteit en aanvaarbaarheid van pasta vervaardig van broodkoring kan egter laer wees as dié van durumkoring. Direkte metings van produkkwalitiet is tans beperk tot proteïninhoud, voginhoud, kleuranalise en sekere eienskappe meetbaar in ‘n laboratorium, byvoorbeeld meganiese sterkte en fermheid. Die direkte meting van defekte wat finale produkkwaliteit kan beïnvloed, byvoorbeeld barste, krake, meel kolletjies, strepe op spaghetti-eenhede, gebreekte eenhede, eenhede wat aan mekaar kleef en ongewone vorms, is nie goed gedokumenteer nie. Gedurende die eerste gedeelte van hierdie studie, is ‘n oorsig van spaghetti evaluasie tegnieke beskikbaar in die literatuur gdoen, waarna sekeres verbeter is, ander ontwikkel is en finaal gestandariseer is. Hierdie navorsing is uitgevoer om geldige en betroubare metings (met ‘n hoë graad van herhaalbaarheid) vir die evaluasie van droë- en gaar pastakwalitietseienskappe vas te stel. ‘n Wye verskeidenheid van produkte beskikbaar op die Suid-Afrikaanse mark is ge-evalueer ten opsigte van verskillende kwaliteitseienskappe. Vanuit hierdie evaluasies is standaarde saamgestel en getoets vir geldigheid en betroubaarheid deur middel van herhaalbaarheid. ‘n Minimum steekproefgrootte per kwaliteitseienskap is bereken en word vermeld in hierdie studie. Daarmeesaam word verwysingsfoto’s aangebied wat gebruik kan word tydens die evaluasie van spaghetti. Hierdie studie bied a stel geldige en betroubare meting vir die kwaliteit van droe en gaan spaghetti. Eenvoudige tegnieke kan dus gebruik word om die voorkoms van hierdie defekte te meet. Met afloop van die verkennende studie, is ‘n empiriese studie gedoen om die verskille te beskryf tussen pasta vervaardig van durum en brood koring, gedroog teen verskillende temperature en relatiewe humiditeit. Spaghettimonsters met oënskynlike diverse kwaliteit, vervaardig deur verskillende maatskappye, is aangekoop en ge-evalueer. Standaardmetings en nuutontwerpte metings is gebruik om te bevestig of die metings kan onderskei tussen spaghetti met uiteenlopende kwaliteit, wat reflekteer op die geldigheid van die metingsmetodes. Korrelasies is bereken tussen afhanklike en onafhanklike veranderlikes in ‘n poging om moontlike verklarings vir sekere defekte of kwaliteitsverskille te vind, en ook om sekere teoriëe in die literatuur te toets. Die verband tussen sekere kwaliteitseienskappe is bevestig en bewys, terwyl ander bevraagteken was. Die mees belangrike verband was proteïninhoud en die effek daarvan om die voorkoms van defekte, soos barste, gebreekte eenhede en kookverliese te verlaag. Die verband tussen asinhoud en spaghettikleur kon nie in hierdie studie bevestig word nie. Hierdie studie het bevestig dat proteïn die mees belangrike veranderlike is wat oorweeg moet word wanneer ‘n konstante hoë kwaliteit spaghettiproduk vervaardig word. Kleurevaluasie met behulp van kommersieel-beskikbare apparaat vereis hersiening. Hierdie studie stel voor dat tydens kleur evaluasie van voedsel wat lig deurlaatbaar is, dit in veelvoudige lae evalueer moet word. Die voorkoms van defekte soos barste, krake of meel kolletjies is van belang ten opsigte van finale produkkwaliteit. Hierdie studie bied riglyne vir die evaluasie van die genoemde defekte. Die voorkoms van hierdie defekte is van groter belang as die graad waarteen die defek voorkom. Eenvoudige tegnieke kan vervolgens gebruik word om die teenwoordigheid of afwesigheid van hierdie defekte te bepaal.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / There is an agreement that in dental treatments with incomplete rizogenese it is necessary an intracanal medication with high antibacterial effect because the use of files and standard protocol based on instrumentation must be avoided to protect the fragile dental element from extra hazard. Several endodontic dressings have been used with this purpose, alone or associated to a copious irrigation procedure. However, it is not yet standardized in the literature a unique medication with protracted and excellent antimicrobial effect, associated to a feasible handling and insertion into the duct. The purpose of this study was to evaluate the in vitro effectiveness of different antimicrobial pastes currently used as intracanal medication against the pathogen Enterococcus faecalis by means of agar disk diffusion method. Accordingly, it was created a polypropylene device to simulate the release characteristics of the main root canal. The efficacy tests were performed over a period of 30 days. The formulations studied were distributed in triplicate just as follows: Triantibiotic Paste (metronidazole, ciprofloxacin and minocycline); Biantibiotic Paste (metronidazole and ciprofloxacin); Ciprofloxacin Paste; Amoxilin Paste; Calcium hydroxide paste; 0.9% saline (control group). All pastes were still allotted into 2 categories: open and closed apex. The devices remained in the medium at 37ÂC over 30 days (static). Samples used for the measurement of biologic response were collected in pre-fixed times: H1(1st hour), H6(6th hour), H24(24th hour), D3(3rd day), D7(7th day), D14(14th day) and D30(30th day) in the course of thirty days. At every settled time, 20μL of solution was removed from each device and embedded on sterile paper discs with 6mm of diameter, being the equivalent volume replaced with fresh release medium. After, the discs were transferred with sterile tweezersg to the surface of agar-BHI medium previously inoculated with bacteria over petri plaques. From the devices with closed apex, it was removed 20μL of solution from above the paste surface, avoiding any directly touch on it. This collect aimed to evaluate the antimicrobial effect of different preparations inside the root canal. From the devices with open apex it was removed 20μL of the solution in which the plastic device was submerged, in order to measure the action of the diffused antibiotic to the periapical region through the apex. From the inhibition halos obtained in each case it was possible to rank the formulations in order of effectiveness. The Amoxicillin paste presented an initial antimicrobial effect more robust, keeping it throughout the experiment. However from the second week there was no more significant difference between this and the other antibiotic pastes (triantibiotic and biantibiotic). These pastes had an initial effect less representative than amoxicillin, however the effect became similar from the second week. Nevertheless, calcium hydroxide paste had a discreet effect initially and it was completely ceased already after the 3rd day. Even if Amoxicillin paste presented a superior result among the studied pastes, it was noticed color changes associated to degradation signs after two weeks. The findings show that these antibiotics pastes posed an excellent pharmacological effect, apart from calcium hydroxide. It can be concluded that all the antibiotics pastes, among them the pastes of amoxicillin, triantibiotic and biantibiotic were effective against E. faecalis. As a result its use as dressing for teeth with incomplete risogenesis in may be a good alternative. Among the advantages it is the microbial effectiveness, as well as the feasible manipulation during the clinical procedure. When comparing biantibiotic and triantibiotic pastes, the first showed to be almost equally effective, being a great choice for the clinical treatments of anterior teeth, where the pigmentation caused by minocycline antibiotic could present a drawback in the final result of the treatment. / Existe um consenso de que no tratamento de dentes com rizogÃnese incompleta à necessÃria uma medicaÃÃo intracanal com mÃximo efeito antibacteriano, pois o uso de limas e o protocolo convencional de instrumentaÃÃo devem ser evitados para que nÃo torne o elemento dental ainda mais frÃgil. Diversos curativos endodÃnticos tÃm sido utilizados com este objetivo, bem como o uso de uma irrigaÃÃo mais copiosa e com irrigante mais efetivo. No entanto, ainda nÃo està padronizada na literatura uma medicaÃÃo com efeito antibiÃtico prolongado e efetivo, alÃm de fÃcil manipulaÃÃo e inserÃÃo no conduto. O objetivo deste trabalho foi avaliar in vitro a eficÃcia de diferentes pastas antimicrobianas utilizadas como medicaÃÃo intracanal sobre o patÃgeno Enterococcus faecalis utilizando o mÃtodo de disco - difusÃo em Ãgar. Para isso, foi confeccionado um dispositivo de polipropileno que possui caracterÃsticas semelhantes ao canal radicular principal. Os testes de eficÃcia foram realizados por um perÃodo de 30 dias. Foram analisadas as seguintes formulaÃÃes: Pasta triantibiÃtica (metronidazol, ciprofloxacino e minociclina); Pasta biantibiÃtica (metronidazol e ciprofloxacino); Pasta de Ciprofloxacino; Pasta de Amoxicilina; Pasta de hidrÃxido de cÃlcio; SoluÃÃo fisiolÃgica 0,9% (grupo controle). Todas as pastas foram ainda alocadas em duas categorias: Ãpice aberto e Ãpice fechado e ensaiadas em triplicata. Os dispositivos permaneceram em estufa a 37ÂC durante 30 dias (sem agitaÃÃo), sendo as coletas para aferiÃÃo da resposta biolÃgica realizadas em perÃodos preestabelecidos: H1(1 hora), H6(6 hora), H24(24 hora), D3(3 dia), D7(7 dia), D14(14 dia) e D30(30 dia) no decorrer de 30 dias. A cada coleta foram retirados de cada dispositivo 20ÂL de soluÃÃo e depositados sobre discos de papel de filtro estÃreis com 6 mm de diÃmetro. Em seguida, os discos de papel embebidos foram transferidos com pinÃa estÃril para a superfÃcie das placas de petri previamente semeadas com a bactÃria. Dos dispositivos com Ãpice fechado foram removidos 20ÂL da soluÃÃo que estava sobre a superfÃcie da pasta, tendo o cuidado para nÃo tocÃ-la. Este procedimento teve o intuito de medir a aÃÃo antimicrobiana direta dos diferentes preparados no interior do conduto radicular. A partir dos dispositivos com Ãpice aberto foram retirados 20ÂL da soluÃÃo na qual o dispositivo plÃstico encontrava-se imerso, com o intuito de medir a aÃÃo do preparado difundido à regiÃo periapical. A partir dos halos de inibiÃÃo obtidos, foi possÃvel observar quais preparados foram mais eficazes com respeito ao seu efeito antibacteriano. A pasta de amoxicilina apresentou o maior efeito antimicrobiano inicial, mantendo-o durante todo o experimento, no entanto, a partir da segunda semana nÃo houve mais diferenÃa estatÃstica entre as pastas antibiÃticas e o efeito tornou-se semelhante. As pastas triantibiÃtica e biantibiÃtica tiveram efeito inicial menor do que o da Amoxicilina, porÃm o efeito foi igualado a partir da segunda semana. Por outro lado, a pasta de hidrÃxido de cÃlcio teve um efeito discreto inicialmente, o qual foi totalmente cessado jà apÃs o 3 dia. Ainda que a pasta de Amoxicilina tenha apresentado os melhores resultados dentre as pastas estudadas, foi evidenciado o aparecimento de cor escurecida associada a sinais de degradaÃÃo apÃs duas semanas. Este estudo mostrou que as pastas antibiÃticas tiveram um excelente efeito farmacolÃgico, ao contrÃrio da pasta de hidrÃxido de cÃlcio. Pode-se concluir que as pastas antibiÃticas, dentre elas as pastas de Amoxicilina, triantibiÃtica e biantibiÃtica apresentaram um excelente efeito sobre o micro-organismo E. faecalis. Portanto, seu uso como medicaÃÃo intracanal nos casos de dentes com rizogÃnese incompleta pode ser uma Ãtima alternativa, estando ainda a facilidade de manipulaÃÃo durante o procedimento clÃnico atrelada à eficÃcia microbicida. Quando comparadas, a pasta biantibiÃtica mostrou-se quase que igualmente efetiva a triantibiÃtica, podendo ser uma Ãtima escolha em casos clÃnicos de tratamento de dentes anteriores, sempre e quando a pigmentaÃÃo causada pelo fÃrmaco Minociclina possa comprometer o resultado final do tratamento. PÃde-se concluir que as pastas antibiÃticas, dentre elas as pastas de amoxicilina, triantibiÃtica e biantibiÃtica apresentaram excelente efeito inibitÃrio sobre o micro-organismo E. faecalis. Portanto, o seu uso como medicaÃÃo intracanal nos casos de dentes com rizogÃnese incompleta pode ser uma excelente alternativa.

[pt] A partir da análise da trajetória do pintor paulista Paulo Pasta (1959-), o presente trabalho busca examinar as condições de sustentabilidade da pintura, como gênero, na contemporaneidade. Para tanto, vale-se das noções de memória e corpo, utilizando-as como eixos conceituais capazes de expressar a articulação, presente na obra do artista, da persistência da tradição moderna à identificação de aberturas estratégicas de vivências espaço-temporais mais afeitas à sensibilidade do sujeito contemporâneo. / [en] Through the analysis of the career of São Paulo painter Paulo Pasta (1959 -), this work aims to examine the conditions of sustainability of painting as a genre in contemporaneity. To that end, it uses the notions of memory and body as conceptual axes able to express the articulation - present in this artist work - of the modern tradition persistence in the identification of such strategic openings as to allow for space-time experiences more congruous to the contemporary sensitivity.

El objetivo de esta investigación fue evaluar y comparar la efectividad antibacteriana de la pasta Tri mix e hidróxido de calcio frente a las bacterias Porphyromona gingivalis y Actinomyces odontolyticus prevalentes en conductos radiculares necróticos de dientes jóvenes. Se utilizaron dos cepas ATCC® Actinomyces odontolyticus (bacteria anaerobia facultativa) y Porphyromona gingivalis (bacteria anaerobia estricta) y se empleó el Método de Difusión en Pozos (MDP) en condiciones de anaerobiosis. Se realizó el primer control a la semana en el caso de Actinomyces odontolyticus y a los 20 días en el caso de Porphyromonas gingivalis. La mayor actividad antibacteriana fue dada por la pasta Tri mix, la cual presentó un halo de inhibición de 38 mm. La bacteria Porphyromona gingivalis fue inhibida completamente. / --- The aim of this study was to evaluate and compare the antibacterial activity between the Tri mix and calcium hydroxide paste against the bacterias Porphyromona gingivalis y Actinomyces odontolyticus prevalent in inmature teeth with necrotic pulps. For this study were used two ATCC® strains Porphyromona gingivalis (stric anaerobic bacterias) and Actinomyces odontolyticus (facultative anaerobic bacterias) by Difussion method in wells in anaerobic conditions. The reading of results was made at one week to Actinomyces odontolyticus and twenty days to Porphyromona gingivalis. The biggest antibacterial activity was produced by Tri mix paste, it showed a halo of inhibition 38 mm. The Porphyromona gingivalis was inhibited complety.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-09-16T22:28:34Z No. of bitstreams: 1 474863 - Texto Completo.pdf: 113191714 bytes, checksum: 284055c8f9508bc0fbd7e2b9c7022e03 (MD5) / Made available in DSpace on 2015-09-16T22:28:34Z (GMT). No. of bitstreams: 1 474863 - Texto Completo.pdf: 113191714 bytes, checksum: 284055c8f9508bc0fbd7e2b9c7022e03 (MD5) Previous issue date: 2015-06-05 / The concrete, due to its high strength, low cost and moldability, is the most popular building material at the moment when compared with other materials used for the same purposes. In this context, with the continued growth of urban areas, the number of buildings and large roads structures has also increased. For this reason, many animal species have had to adapt themselves to these new environmental conditions and have started to use human buildings, which can often simulate nature conditions, as shelters. Thus, the metabolism waste resulting from these animals began to chemically interact with these building materials, causing substantially degradation. The main aim of this work is to show how the biological waste, in this case, bat guano, can promote chemical degradation of the cement paste. To that purpose, the chemical attack of cement hardened sampleswas realized in different exposition times in with aqueous solutions of nitric acid and sulfuric acid at pH 4.5, simulating the bat guano oxidation conditions, where these acids, among other substances, are formed. The results indicate that nitric acid is more aggressive to cement paste than the sulfuric acid as evidenced by electron microscopy images where there was a more intensive deterioration of the cement matrix on the surface of cement hardened samples. The images generated by the X-ray microtomographyshowed that there is a difference on density of the cement matrix in the region chemically attacked, in particular when the sulfuric acid was used, which can be associated with the corrosion product properties formed due the sulfuric acid reaction with the cementitious matrix. The hardened cement paste samples showed mass increase with exposition time, probably due to the respective calcium salts deposition on the surface formed as products of chemical attack. / O concreto ? o material mais usado na constru??o de edifica??es na atualidade, devido a sua grande resist?ncia, moldabilidade, durabilidade e baixo custo, entre outras caracter?sticas, quando comparado com outros materiais utilizados para os mesmos fins. Neste contexto, com o cont?nuo crescimento das ?reas urbanas, o n?mero de edifica??es e grandes obras de arte da malha vi?ria tamb?m cresceram. Desta forma, muitas esp?cies animais necessitaram se adaptar a essas novas condi??es, devido ? modifica??o de seu ambiente natural e passaram a utilizar as edifica??es humanas, que muitas vezes simulam condi??es encontradas na natureza, como abrigos. Assim, os res?duos resultantes do metabolismo desses animais, passaram a interagir com os materiais constituintes dessas edifica??es, agredindo substancialmente este material. Este trabalho tem como principal objetivo mostrar como os res?duos da atividade de agentes biol?gicos, neste caso o guano dos morcegos, podem promover a degrada??o qu?mica na pasta ciment?cia. Para tal, realizou-se o ataque qu?mico,em diferentes de exposi??o, em corpos de prova com dois tipos de solu??es aquosas de ?cido n?trico e ?cido sulf?rico com pH 4,5, simulando as condi??es da oxida??o do guano dos morcegos, onde estes ?cidos, entre outras subst?ncias, est?o presentes. O ?cido n?trico mostrou-se mais agressivo do que o sulf?rico, sendo isso evidenciado pelas imagens de microscopia eletr?nica onde se observou uma deteriora??o maior da matriz ciment?cia na superf?cie dos corpos de prova. Nas imagens geradas no microtom?grafo de raios X verificou-se diferen?a de densidade na matriz ciment?cia, especialmente com o ataque de ?cido sulf?rico, devido aos produtos da rea??o deste ?cido com a matriz ciment?cia. Os corpos de prova apresentaram aumento de massa em fun??o tempo provavelmente devido ? deposi??o dos respectivos sais de c?lcio formados pelo ataque ?cido.

Estágio realizado na Horquim - Representações, Ldª. e orientado pelo Eng.ª Helena Veiga e Eng.ª Rita Gouveia / Tese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto. 2009

Tese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto. 2010

Yellow pigment (YP) concentration is an important quality trait in durum wheat (<i>Triticum turgidum</i> L. var <i>durum</i>) and is comprised primarily of carotenoids. The main objective of our study was to measure the accumulation of carotenoids during the grain fill period to improve our understanding of the physiological basis for differences among durum wheat cultivars. Thirteen cultivars and breeding genotypes with large variation in total YP concentration (<6 µg g-1 to >15 µg g-1) were studied. Spikes were sampled from replicated field plots in 2007 and 2008 near Saskatoon and Swift Current, Saskatchewan, Canada, at 14, 21, 28 and 35 days after heading (DAH). The remainder of each plot was combined at grain maturity for YP and carotenoid analysis. Carotenoids were extracted with 1:1 methanol:dichloromethane (0.1% BHT) and quantified with HPLC. <i>Trans</i> (E)-lutein was the predominant carotenoid at maturity and was detected at 14 DAH in all genotypes. The rate and duration of E-lutein accumulation was variable among genotypes expressing high, intermediate and low YP. The accumulation of all carotenoids was lowest in genotypes expressing low YP, and suggests rate limitations early in the carotenoid biosynthetic pathway. E-zeaxanthin concentrations were highest in mature grain, but no significant differences were detected among genotypes. However, the ratio of E-zeaxanthin to E-lutein was inversely correlated with total YP, suggesting that the â,å branch of lycopene cyclization is favoured over the â,â branch in high-YP genotypes. These results provide insights to the regulation of the carotenoid biosynthetic pathway during grain fill stage in durum wheat and will facilitate breeding for higher carotenoid concentration.

No description available.