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Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-01-16T20:42:05Z No. of bitstreams: 1 MicaelaDaSilvaPaulaDamasceno_DISSERT.pdf: 1692024 bytes, checksum: f455fce5146810245110703dd481309a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-01-22T16:08:39Z (GMT) No. of bitstreams: 1 MicaelaDaSilvaPaulaDamasceno_DISSERT.pdf: 1692024 bytes, checksum: f455fce5146810245110703dd481309a (MD5) / Made available in DSpace on 2018-01-22T16:08:39Z (GMT). No. of bitstreams: 1 MicaelaDaSilvaPaulaDamasceno_DISSERT.pdf: 1692024 bytes, checksum: f455fce5146810245110703dd481309a (MD5) Previous issue date: 2017-10-27 / O cozimento do pescado reduz o rendimento, causando perdas econ?micas e de qualidade no produto. O aditivo fosfato tem sido utilizado em produtos de pescado para aumentar a reten??o de ?gua, reduzir as perdas no rendimento e por fim melhorar sua qualidade final. A avalia??o da associa??o do uso do aditivo alimentar fosfato como pr?-tratamento ao processo de cozimento do camar?o Litopenaeus vannamei descascado em uma ind?stria de beneficiamento, foi realizada examinando-se os efeitos de diferentes tipos de fosfato (tripolifosfato de s?dio - TPF e mistura de fosfatos ? Blend formulada com difosfato tetrass?dio, difosfato tetrapot?ssio, trifosfato pentass?dio e trifosfato pentapot?ssio), concentra??o do aditivo (3 e 5%) e tempo de contato (por imers?o, 30 e 60 min) sobre o rendimento (ganho e perda de peso) e a qualidade f?sico-qu?mica do camar?o. As amostras imersas em ?gua (30 e 60 min) foram consideradas como controle. As an?lises laboratoriais (capacidade de reten??o de ?gua, umidade, prote?na, textura, cor e pH) foram realizadas ap?s o cozimento e ap?s o descongelamento. As an?lises de fosfato e s?dio foram realizadas apenas ap?s o descongelamento. O uso do aditivo fosfato mostrou efeito satisfat?rio na redu??o da perda de peso e no aumento da capacidade de reten??o de ?gua da carne de camar?o, quando comparado as amostras controle (tratadas com ?gua). A efic?cia do fosfato nas propriedades de reten??o de ?gua reflete em melhoria da qualidade do produto e depende do tipo, da concentra??o do aditivo e do tempo de contato. O tratamento com TPF e Blend (5% por 60 minutos) apresentou fosfato residual acima do limite legal permitido (1%) e esse ?ltimo tratamento tamb?m apresentou pH acima do permitido (7,85). Os resultados indicaram o alto potencial de uso de fosfato antes do cozimento em situa??es reais de produ??o para melhorar a qualidade do produto (camar?o cozido), desde que esteja de acordo com a legisla??o vigente. / The seafood cooking reduces the yield, causing economic and quality losses in the product. The phosphate additive has been used in seafood products to increase water retention, reduce yield losses and ultimately improve final quality. The evaluation of the association of the use of the feed additive phosphate as a pre-treatment to the cooking process of the shrimp Litopenaeus vannamei peeled in a processing industry was carried out by examining the effects of different types of phosphate (sodium tripolyphosphate - TPF and Blend - formulated with tetrasodium diphosphate, tetrapotassium diphosphate, pentasodium triphosphate and pentapotassium triphosphate), additive concentration (3 and 5%) and contact time (by immersion, 30 and 60 min) on yield (gain and weight loss) and the physical-chemical quality of the shrimp. Samples immersed in water (30 and 60 min) were considered as controls. The laboratory analyzes (water holding capacity, moisture, protein, texture, color and pH) were performed after cooking and after thawing. The phosphate and sodium analyzes were performed only after thawing. The use of the phosphate additive showed a satisfactory effect on the reduction of weight loss and on the increase of the water holding capacity of the shrimp meat when compared to the control samples (treated with water). The efficacy of the phosphates in the water retention properties reflects on the improvement of the quality of the product and depends on the type, the concentration of the additive and the time of contact. Treatment with TPF and Blend (5% for 60 minutes) presented residual phosphate above the legal limit allowed (1%) and the latter treatment also had a pH above that allowed (7,85). The results indicated the high potential of using phosphate before cooking in real production situations to improve the quality of the product (cooked shrimp), since is in accordance with the current legislation.

Made available in DSpace on 2014-06-11T19:32:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-21Bitstream added on 2014-06-13T21:03:54Z : No. of bitstreams: 1 lazarini_ap_dr_rcla.pdf: 3581248 bytes, checksum: 818fcdd3b0cbfb1ec531c2766d6f5a2f (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

El pan es un alimento de gran consumo desde la antigüedad, obtenido de un proceso de panificación dinámico. Una de las innovaciones de mayor éxito en panificación ha sido el pan parcialmente cocido obtenido por la tecnología de panificación interrumpida que proporciona pan crujiente en cualquier momento del día. La crujibilidad es el atributo más demandado por los consumidores en el pan crujiente fresco. Desafortunadamente, la crujibilidad es percibida por corto tiempo después del horneado y la pérdida de ésta es uno de los atributos que causa rechazo en los consumidores. El objetivo de esta investigación fue la modulación de las propiedades físico-químicas y funcionales del pan mediante la aplicación de tratamientos de superficie con el fin de comprender las características de la corteza y el desarrollo de productos de pan con un valor agregado. Para abordar dicho objetivo se han realizado estudios para determinar el impacto de la adición de vapor, durante el horneado, sobre las propiedades mecánicas de la corteza y para evaluar la influencia de estas propiedades en los parámetros de calidad utilizando diferentes panes comerciales. Además se han realizado estudios para modular las propiedades de la corteza dirigidos a entender su microestructura y modificarla mediante tratamientos enzimáticos con amiloglucosidasa o con un recubrimiento funcional, con la finalidad de modificar la permeabilidad de la corteza u obtener panes probióticos. Los resultados mostraron que la cantidad de vapor utilizada durante la cocción (100, 200 y 400 ml) modificaron las propiedades físico-químicas y mecánicas así como la estructura de la corteza del pan. Los parámetros de calidad permitieron la diferenciación de variedades de pan parcialmente cocido, específicamente las propiedades mecánicas de la corteza junto con el volumen específico, dureza y estructura de la miga. Sin embargo, la textura de la corteza de pan fue significativamente dependiente de las condiciones de ensayo (velocidad y sección de la sonda). Los resultados mostraron que la velocidad más baja (0,5 mm / s) dio información acerca de la estructura celular de la corteza relacionada con la textura crujiente. Por otra parte, la estructura celular fue modificada por la amiloglucosidasa pulverizada sobre la superficie del pan antes de la cocción, lo que condujo a una disminución en el contenido de agua y actividad del agua de la corteza, lo cual se requiere para extender crujibilidad. La aplicación de recubrimientos comestibles con L. acidophilus microencapsulado sobre la superficie pan (disperso o en multicapa) garantizó la supervivencia del microorganismo después del tiempo de cocción y almacenamiento, a pesar de que estos disminuyeron la fuerza de fractura y actividad de agua de la corteza. El análisis de microestructura demostró la presencia de microcapsulas dispersas en la corteza de pan. Por lo tanto, L. acidophilus incluido en microcápsulas pueden ser incorporado en la superficie de pan a través de recubrimientos comestibles, abriendo la posibilidad de obtener panes funcionales. / Altamirano Fortoul, RDC. (2013). Modulation of the physico-chemical and functional properties of bread by applying surface treatments [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/33398 / TESIS

The Saglek-Hebron Complex (SHC) in Northern Labrador represents one of the oldest terrains on Earth and it is closely related to the Archean Itsaq Gneiss Complex (IGC) in Greenland. The SHC is a typical granite-greenstone terrain that recorded over one billion years of magmatic history between ~3900 Ma and ~2700 Ma. Our geochronological and geochemical study shows that the SHC includes five generations of trondhjemite-tonalite-granodiorite suites (TTG): the ~3870 Ma Iqaluk gneiss, the ~3750 Ma Uivak I gneiss, the ~3600 Ma Uivak II gneiss, the newly described ~3300 Ma Iluilik gneiss, and the ~3220 Ma Lister gneiss. These granitoid units are mostly consist of trondhjemite and tonalite with only rare granodiorites that appear to define a distinct unit formed at ~3330 Ma and newly defined as the Iluilik gneiss. The Iluilik granodiorite appears to be derived from a Hadean mafic crust as supported by its combined whole-rock geochemical composition, its positive µ142Nd value of +6, and its low εHf= -6 and εNd= -3, at 3300 Ma. SHC granites were emplaced throughout the Archean, from 3800 to 2700 Ma, but are predominant in the Neoarchean. They appear to have been mainly formed from the reworking of the SHC TTG, as supported by their low εHf and εNd initial values of respectively -16 and -11 at 2700 Ma. The granitoids include numerous enclaves of supracrustal rocks from various size, up to a few kilometers in scale, consisting of metavolcanic metasedimentary rocks. Previous work has suggested that they were formed at two different ages, with the younger Upernavik supracrustal unit deposited around 3400 Ma and the older Nulliak supracrustal assemblage deposited at around 3750 Ma. We show that both units are comparatively geochemically homogeneous with no distinction between the mafic and ultramafic rocks from both supracrustal assemblages. They mainly consist of mafic metavolcanic amphibolites with tholeiitic affinities, consistent with more depleted mafic and more enriched compositions produced by magmatic differentiation. Their complementary Eu anomaly and whole-rock geochemistry suggest that they formed from fractional crystallization of gabbroic assemblage that derived from similar if not the same parental magma. The mafic metavolcanic rocks are also often associated with ultramafic rocks that we divided into two distinct units, respectively referred as the high-Fe and the low-Fe ultramafic rocks, characterized by different FeO contents and Al/Ti ratio. They both represent olivine-rich cumulative rocks derived from distinct parental komatiitic basalt magmas. Our interpretation contrasts with previous work suggesting that the SHC ultramafic rocks were komatiites and slivers of residual lithospheric mantle. Most SHC TTG exhibit a positive 142Nd anomaly, as high as µ142Nd = +15, suggesting a source formed by differentiation in the Hadean. This 142Nd isotopic composition is similar to the Nulliak supracrustal rocks that exhibit on average a µ142Nd of +10. TTG is generally considered to derive from a mafic precursor. This study therefore shows that mafic crustal source of the SHC Eoarchean TTG, potentially the Nulliak metabasalts, derives from an ancient highly depleted mantle, described as the Saglek mantle, sharing a similar early history as the mantle reservoir involved in the formation of the ancient Itsaq terrane of southwest Greenland. The Saglek depleted mantle is interpreted to have formed at ~4400 Ma, exhibit highly depleted signature with a 147Sm/144Nd ratio of 0.221-0.240.

abstract: Archean oxidative weathering reactions were likely important O2 sinks that delayed the oxygenation of Earth’s atmosphere, as well as sources of bio-essential trace metals such as Mo to the biosphere. However, the rates of these reactions are difficult to quantify experimentally at relevantly low concentrations of O2. With newly developed O2 sensors, weathering experiments were conducted to measure the rate of sulfide oxidation at Archean levels of O2, a level three orders of magnitude lower than previous experiments. The rate laws produced, combined with weathering models, indicate that crustal sulfide oxidation by O2 was possible even in a low O2 Archean atmosphere. Given the experimental results, it is expected that crustal delivery of bio-essential trace metals (such as Mo) from sulfide weathering was active even prior to the oxygenation of Earth’s atmosphere. Mo is a key metal for biological N2 fixation and its ancient use is evidenced by N isotopes in ancient sedimentary rocks. However, it is typically thought that Mo was too low to be effectively bioavailable early in Earth’s history, given the low abundances of Mo found in ancient sediments. To reconcile these observations, a computational model was built that leverages isotopic constraints to calculate the range of seawater concentrations possible in ancient oceans. Under several scenarios, bioavailable concentrations of seawater Mo were attainable and compatible with the geologic record. These results imply that Mo may not have been limiting for early metabolisms. Titanium (Ti) isotopes were recently proposed to trace the evolution of the ancient continental crust, and have the potential to trace the distribution of other trace metals during magmatic differentiation. However, significant work remains to understand fully Ti isotope fractionation during crust formation. To calibrate this proxy, I carried out the first direct measurement of mineral-melt fractionation factors for Ti isotopes in Kilauea Iki lava lake and built a multi-variate fractionation law for Ti isotopes during magmatic differentiation. This study allows more accurate forward-modeling of isotope fractionation during crust differentiation, which can now be paired with weathering models and ocean mass balance to further reconstruct the composition of Earth’s early continental crust, atmosphere, and oceans. / Dissertation/Thesis / Doctoral Dissertation Geological Sciences 2020

Thesis advisor: Seth C. Kruckenberg / In the earth’s lithosphere there exists both homogeneous and heterogeneous deformation on a variety of scales. The lower crust specifically plays a critical role in lithospheric deformation; however, the lower crust does not deform homogenously but rather heterogeneously in space and time. One of the best avenues for addressing heterogeneous lower crustal deformation is through an integrated study of shear zones. While many studies have identified factors such as strain rate and temperature as key actors in lower crustal strain localization, more studies are needed to characterize the dominant grain-scale mechanisms that accommodate the development of lower crustal shear zones. The primary aim of this research is to investigate the dominant mechanisms that lead to strain localization in the lower crust. The Capricorn Ridge Shear Zone (CRSZ), Central Australia, is an ideal location for study because it is a lower crustal shear zone that contains discrete zones of strain localization, primarily adjacent to major lithological boundaries. Previous studies conclude that competency contrast caused strain to localize at the lithologic boundaries of the CRSZ, a hypothesis that is tested in this study. Using microstructural, textural, and rheologic analysis, as well as field-based mapping and grain size piezometry, this study finds that differential stresses in Capricorn Ridge range from 17-27 MPa for quartz, 31-42 MPa for plagioclase, and 2.8-7.6 MPa for enstatite. Monophase aggregate strain rates range from 1.6 x 10-15 to 1.7 x 10-14 s-1 for quartz, 4.5 x 10-15 to 3.3 x 10-14 s-1 for plagioclase, and 6.0 x 10-20 to 1.2 x 10-18 s-1 for enstatite; corresponding effective viscosities 0.3-1.7 x 1021 Pa.s, 0.3-1.5 x 1021 Pa.s, and 0.2-1.8 x 1025 Pa.s for quartz, plagioclase, and enstatite, respectively. Data across the CRSZ show that while strain rate (viscosity) in monophase aggregates of quartz and plagioclase are generally similar across the shear zone, they do decrease at lithologic boundaries. In contrast to a previous study’s finding that competency contrast caused strain to localize at these boundaries, both quartz and plagioclase appear to record strain accumulation through grain size reduction. However, the observations made in previous studies are not negated by this study, as it is possible that grain size reduction in the mylonite zones near the boundaries caused strain to accumulate over time and therefore produce the observed pattern of increasing fabric intensity with proximity to the lithologic boundaries. / Thesis (MS) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

<p> Nine rock samples from the mafic volcanics of Mamainse Point, Ontario were analysed for boron using Prompt Gamma Neutron Activation Analysis (PGNAA) and Alpha-Track Imaging (ATI). The mean concentration of boron in these rocks was 7.85 ppm with a maximum concentration of 15.5 ppm and a minimum concentration of 4.21 ppm. The Mamainse Point samples are therefore enriched in boron relative to fresh basalts (~ 2 ppm B) but depleted relative to basalts altered on the seafloor (30 - 60 ppm B). From ATI the boron was found to be most highly concentrated in iron oxides, chlorite, stilpnomelane and microscopic fractures throughout the rock. Plagioclase, clinopyroxene, quartz and calcite were all low in boron.</p> <p> These results led to the conclusion that the Mamainse Point Formation is of continental rather than marine origin. The addition of boron to the rock has resulted from penecontemporaneous burial and hydrothermal metamorphism in the zeolite and subgreenschist facies through the interaction of boron-bearing hydrothermal fluids. The source of the boron is thought to be from the surrounding Precambrian terrain (Canadian Shield), the lower continental crust and magmatic fluids associated with volcanism.</p> / Thesis / Bachelor of Science (BSc)

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