As the global climate changes, understanding short-term variations in water storage is increasingly important. Continuously operating Global Positioning System (cGPS) stations in Iceland record annual periodic motionthe elastic response to winter accumulation and spring melt seasonswith peak-to-peak vertical amplitudes over 20 mm for those sites in the Central Highlands. Here for the first time for Iceland, we demonstrate the utility of these cGPS-measured displacements for estimating seasonal and shorter-term ice cap mass changes. We calculate unit responses to each of the five largest ice caps in central Iceland at each of the 62 cGPS locations using an elastic half-space model and estimate ice mass variations from the cGPS time series using a simple least squares inversion scheme. We utilize all three components of motion, taking advantage of the seasonal motion recorded in the horizontal. We remove secular velocities and accelerations and explore the impact that seasonal motions due to atmospheric, hydrologic, and nontidal ocean loading have on our inversion results. Our results match available summer and winter mass balance measurements well, and we reproduce the seasonal stake-based observations of loading and melting within the 1 sigma confidence bounds of the inversion. We identify nonperiodic ice mass changes associated with interannual variability in precipitation and other processes such as increased melting due to reduced ice surface albedo or decreased melting due to ice cap insulation in response to tephra deposition following volcanic eruptions, processes that are not resolved with once or twice-yearly stake measurements.

Ter dentes brancos é cada vez mais uma exigência estética. A indicação do tratamento clareador dental, bem como da técnica empregada, deve ser criteriosa. Os agentes clareadores mais utilizados para dentes vitalizados são peróxido de hidrogênio e peróxido de carbamida, em diferentes concentrações. Duas técnicas são mais utilizadas, clareamento em consultório e clareamento caseiro, cujas indicações devem estar embasadas na segurança do paciente, no que diz respeito à manutenção da integridade de seus órgãos dentais, bem como de sua saúde bucal e geral. A finalidade deste estudo, a cerca do tratamento clareador dental é trazer resultados que permitam ao profissional de Odontologia, indicar o melhor tratamento visando segurança. Avaliando quanto à facilitação do desgaste de dentes humanos, submetidos in vitro às duas técnicas e aos dois principais agentes clareadores, ambulatorial e caseira, peróxido de hidrogênio, 35% (Whiteness HP MAXX FGM) e peróxido de carbamida a 10% (Whiteness Perfect - FGM), respectivamente, e à ação mecânica de um ensaio de escovação simulada. Ambos os tratamentos foram realizados sob a técnica recomendada pelo fabricante. A escovação simulada foi realizada diariamente (10 dias, 500 ciclos). Corpos-de-prova (cp) foram divididos em 5 grupos (N=8) sendo um controle (sem clareamento) e 4 experimentais (um grupo recebeu a técnica ambulatorial e três a técnica caseira). Ainda foi avaliado o tempo de espera para a realização da escovação após o tratamento clareador caseiro (15, 30 e 60 minutos). A variação de massa foi aferida por peso, inicial e final dos cp (antes e depois do clareamento e escovação), em balança analítica, após a desidratação destes em sílica gel. Análise estatística (ANOVA Oneway e Student-Newman-Keuls) foi realizada e os resultados permitiram concluir que: 1- Ocorreu perda de massa nos dentes humanos após serem submetidos a ambos os tratamentos clareadores propostos e no grupo controle (sem clareamento), seguido de ensaio de escovação; 2- Peróxido de hidrogênio a 35%, técnica ambulatorial, ocasionou a menor perda de massa do esmalte dentário após o ensaio de escovação, embora sem diferença estatística; 3- Os grupos submetidos ao clareamento com peróxido de carbamida apresentaram a maior perda de massa, mas não houve diferença entre os tempos de espera para a realização do ensaio de escovação. / White teeth are more and more the aesthetic demand. The indication makes whitening teeth and the employed technique being of criterious use. Hydrogen peroxide and Carbamide peroxide are the whitening agents more used to vitalized teeth in different concentrations. There are two whitening teeths techniques: in office and at home, whose indications should be based on patients safety, concerning to the maintenance of the teeths integrity, as well as oral and general health. The aim of this study is to bring results to allow the professional of Dentistry to indicate the best treatment in order to give safety, evaluating facilitation to wear and tear in humans' teeth, submitted in vitro to the two techniques and the two main whitening agents, Hydrogen peroxide, 35% (Whiteness HP MAXX - FGM) and Carbamide peroxide, 10% (Whiteness Perfect - FGM), respectively, and to a mechanical action of a simulated brushing essay. Both whitening teeths treatments were accomplished by a technique recommended by the manufacturer. Simulated brushing was accomplished daily, 500 cycles, for 10 days. The specimens were divided in 5 groups (N=8), one control (without whitening teeth) and 4 experimental (one group received in office technique and the others received at home technique). It was still evaluated the waiting time in accomplishing the simulated brushing after the treatment at home (15, 30 and 60 minutes). The mass variation among the specimens was checked by initial and final weight (after and before the whitening teeth and the simulated brushing), in analytical scale and after the dehydration in silica gel of them. The statistical analysis (ANOVA Oneway and Student-Newman-Keuls) was accomplished and the results allowed concluding that: 1- It occurred loss of mass in the human teeth after they were submitted to both whitening treatments proposed, followed by simulated brushing essay, and on control group (without whitening teeth treatment); 2- Hydrogen peroxide 35% caused the smallest loss of mass in the enamel, after simulated brushing essay, with statistical difference; 3- There was no significant difference in the weight loss occurred with any waiting times proposed between the whitening teeth treatment with carbamide peroxide 16% and the simulated brushing essay, maybe this treatment caused the biggest loss of mass in enamel.

Ter dentes brancos é cada vez mais uma exigência estética. A indicação do tratamento clareador dental, bem como da técnica empregada, deve ser criteriosa. Os agentes clareadores mais utilizados para dentes vitalizados são peróxido de hidrogênio e peróxido de carbamida, em diferentes concentrações. Duas técnicas são mais utilizadas, clareamento em consultório e clareamento caseiro, cujas indicações devem estar embasadas na segurança do paciente, no que diz respeito à manutenção da integridade de seus órgãos dentais, bem como de sua saúde bucal e geral. A finalidade deste estudo, a cerca do tratamento clareador dental é trazer resultados que permitam ao profissional de Odontologia, indicar o melhor tratamento visando segurança. Avaliando quanto à facilitação do desgaste de dentes humanos, submetidos in vitro às duas técnicas e aos dois principais agentes clareadores, ambulatorial e caseira, peróxido de hidrogênio, 35% (Whiteness HP MAXX FGM) e peróxido de carbamida a 10% (Whiteness Perfect - FGM), respectivamente, e à ação mecânica de um ensaio de escovação simulada. Ambos os tratamentos foram realizados sob a técnica recomendada pelo fabricante. A escovação simulada foi realizada diariamente (10 dias, 500 ciclos). Corpos-de-prova (cp) foram divididos em 5 grupos (N=8) sendo um controle (sem clareamento) e 4 experimentais (um grupo recebeu a técnica ambulatorial e três a técnica caseira). Ainda foi avaliado o tempo de espera para a realização da escovação após o tratamento clareador caseiro (15, 30 e 60 minutos). A variação de massa foi aferida por peso, inicial e final dos cp (antes e depois do clareamento e escovação), em balança analítica, após a desidratação destes em sílica gel. Análise estatística (ANOVA Oneway e Student-Newman-Keuls) foi realizada e os resultados permitiram concluir que: 1- Ocorreu perda de massa nos dentes humanos após serem submetidos a ambos os tratamentos clareadores propostos e no grupo controle (sem clareamento), seguido de ensaio de escovação; 2- Peróxido de hidrogênio a 35%, técnica ambulatorial, ocasionou a menor perda de massa do esmalte dentário após o ensaio de escovação, embora sem diferença estatística; 3- Os grupos submetidos ao clareamento com peróxido de carbamida apresentaram a maior perda de massa, mas não houve diferença entre os tempos de espera para a realização do ensaio de escovação. / White teeth are more and more the aesthetic demand. The indication makes whitening teeth and the employed technique being of criterious use. Hydrogen peroxide and Carbamide peroxide are the whitening agents more used to vitalized teeth in different concentrations. There are two whitening teeths techniques: in office and at home, whose indications should be based on patients safety, concerning to the maintenance of the teeths integrity, as well as oral and general health. The aim of this study is to bring results to allow the professional of Dentistry to indicate the best treatment in order to give safety, evaluating facilitation to wear and tear in humans' teeth, submitted in vitro to the two techniques and the two main whitening agents, Hydrogen peroxide, 35% (Whiteness HP MAXX - FGM) and Carbamide peroxide, 10% (Whiteness Perfect - FGM), respectively, and to a mechanical action of a simulated brushing essay. Both whitening teeths treatments were accomplished by a technique recommended by the manufacturer. Simulated brushing was accomplished daily, 500 cycles, for 10 days. The specimens were divided in 5 groups (N=8), one control (without whitening teeth) and 4 experimental (one group received in office technique and the others received at home technique). It was still evaluated the waiting time in accomplishing the simulated brushing after the treatment at home (15, 30 and 60 minutes). The mass variation among the specimens was checked by initial and final weight (after and before the whitening teeth and the simulated brushing), in analytical scale and after the dehydration in silica gel of them. The statistical analysis (ANOVA Oneway and Student-Newman-Keuls) was accomplished and the results allowed concluding that: 1- It occurred loss of mass in the human teeth after they were submitted to both whitening treatments proposed, followed by simulated brushing essay, and on control group (without whitening teeth treatment); 2- Hydrogen peroxide 35% caused the smallest loss of mass in the enamel, after simulated brushing essay, with statistical difference; 3- There was no significant difference in the weight loss occurred with any waiting times proposed between the whitening teeth treatment with carbamide peroxide 16% and the simulated brushing essay, maybe this treatment caused the biggest loss of mass in enamel.

Made available in DSpace on 2016-12-12T20:12:31Z (GMT). No. of bitstreams: 1 PGEF15MA039.pdf: 2330601 bytes, checksum: 436c70ad150933024e19e47188c03d1d (MD5) Previous issue date: 2015-02-19 / Evaluation of erros from non-destructive volumetric estimates takes fundamental importance, as well the establishment of trusted relations between solid volume and mass units, whereas the wood quantification is directly linked to eficiente planning in forestry companies. This way, the aim of this study was to evaluate the accuracy of volumetric estimates by the non-destructive method comprinsing diferente ages and horizontal distance measurement (HD) and, establish relations between solid volume and mass units considering diferente ages, assortments and storage time in stands of Pinus taeda l.. the experiments were conducted in themunicipality of Ponte Alta do Norte SC. The non-destructive measurements were performed using dendrometer Criterion RD1000, and they were compared to the destrucrtive and xylometer methods. The method used both volumetric estimates was Hohenadl with 10 sections, in stands of 13 and21 years old, considereing three HD s (10; 14 and 18 m). the results were assessed at the level of mean absolute and relative erros, taking as reference the xylometer values. In the study of relations between solid volume and mass units were considered stands of nine and 21 years old, where in the first age had assortments in fine point of 8 18 cm (S1) and 18 24 cm (S2), while in the second, in addition of these, there were two more assortments, 25 35 cm (S3) andaboce 35 cm (S4). Theexperiment was conducted in a randomized block expedrimental design, considering the a factorial scheme with three replications, each of these being composed of five logs. The logs had their estimated volume (Smalian method) and heavy, at 0; 7; 14; 21; 28; 60 and 90 days of storage in the open. Statistical diferences were evaluated according to analysis of variance followed of Scott-Knott test for factors age and assortment and regression analysis to storage time. The volumetric estimates through non-destructive volumetric estimates demonstrate satisfactoey results in all HD s studied at age 21 years. While in the age of 13 years it s observed that only the HD 0f 18 m showed similar results with destructive volumetric estimate, demonstrating overestimation mean erros of 1.32% aboce the same. Relations between solid volume and mass presented statistical diferences when considering assortments and ages, and there is, intersction between these factors. For the storage time, there were diferences in the case of S1 and S2 at both ages, whereas for S3 and S4 at the age of 21 years significant changes weren t observed. Thus, it can be concluded that the non-destructive estimates proved promising, reaching acceptable erros, especially in the HD 0f 18 m at both ages and, the adoption of mean conversion s factors of solid volume and mass units by the forestry companies, can lead to large erros in estimates, when they showed diferences in age, assortment and storage time / A avaliação de erros oriundos de cubagens não-destrutivas assume fundamental importância, assim como o estabelecimento de relações confiáveis entre unidades de volume sólido e massa, considerando que a quantificação de madeira tem ligação direta a planejamentos eficientes nas empresas florestais. Desta forma, o objetivo do presente trabalho foi avaliar a exatidão de estimativas volumétricas pelo método não-destrutivo englobando diferentes idades e distâncias horizontais de medição (DH) e, estabelecer relações entre unidades de volume sólido e massa analisando diferentes idades, sortimentos e tempos de estocagem em povoamentos de Pinus taeda L.. Os experimentos foram conduzidos no município de Ponte Alta do Norte SC. As cubagens não-destrutivas foram realizadas utilizando o dendrômetro Criterion RD1000, sendo que as mesmas foram comparadas ao método destrutivo e xilometria dos fustes. O método empregado em ambas às cubagens foi o de Hohenadl 10 seções, em povoamentos de 13 e 21 anos de idade, considerando três DH s (10; 14 e 18 m). Os resultados foram avaliados ao nível de erros absolutos e relativos médios, tomando-se como referência os valores da xilometria. No estudo das relações entre unidades de volume sólido e massa foram considerados povoamentos de nove e 21 anos de idade, sendo que na primeira idade tinham-se sortimentos na ponta fina de 8 18 cm (S1) e 18 24 cm (S2), já na segunda, além desses, existiam mais dois sortimentos, 24 35 cm (S3) e acima de 35 cm (S4). O experimento foi analisado no delineamento em blocos ao acaso, considerando o esquema fatorial, com três repetições, sendo cada uma dessas, composta por cinco toras. As mesmas foram cubadas (método de Smalian) e pesadas, aos 0; 7; 14; 21; 28; 60 e 90 dias de estocagem a céu aberto. As diferenças estatísticas foram avaliadas segundo análise de variância seguidas do teste de Scott-Knott para idade e sortimento e, análise de regressão para tempo de estocagem. As estimativas volumétricas por meio das cubagens não-destrutivas demonstram resultados satisfatórios em todas as DH s estudadas na idade 21 anos. Enquanto na idade de 13 anos observa-se que apenas a DH de 18 m apresentou resultados similares à cubagem destrutiva, demonstrando erros médios de superestimativa de 1,32% superior à mesma. As relações entre volume sólido e massa apresentaram-se diferentes estatisticamente quando se consideraram sortimentos e idades, existindo ainda, interação entre esses fatores. Para o tempo de estocagem, observaram-se diferenças nos caso dos S1 e S2 em ambas as idades, enquanto para S3 e S4 na idade de 21 anos não foram observadas variações significativas. Desta forma, pode-se concluir que as estimativas não-destrutivas se mostraram promissoras, atingindo erros aceitáveis, principalmente na DH de 18 m em ambas as idades e, a adoção de fatores de conversão médios entre unidades de volume sólido e massa por parte das empresas florestais, pode acarretar em erros nas estimativas, sendo que os mesmos apresentaram diferenças a nível de idade, sortimento e tempo de estocagem

Seafloor compliance is a non-intrusive geophysical method sensitive to the shear modulus of the sediments below the seafloor. A compliance analysis requires the computation of the frequency dependent transfer function between the vertical stress, produced at the seafloor by the ultra low frequency passive source-infra-gravity waves, and the resulting displacement, related to velocity through the frequency. The displacement of the ocean floor is dependent on the elastic structure of the sediments and the compliance function is tuned to different depths, i.e., a change in the elastic parameters at a given depth is sensed by the compliance function at a particular frequency. In a gas hydrate system, the magnitude of the stiffness is a measure of the quantity of gas hydrates present. Gas hydrates contain immense stores of greenhouse gases making them relevant to climate change science, and represent an important potential alternative source of energy. Bullseye Vent is a gas hydrate system located in an area that has been intensively studied for over 2 decades and research results suggest that this system is evolving over time. A partnership with NEPTUNE Canada allowed for the investigation of this possible evolution. This thesis describes a compliance experiment configured for NEPTUNE Canada’s seafloor observatory and its failure. It also describes the use of 203 days of simultaneously logged pressure and velocity time-series data, measured by a Scripps differential pressure gauge, and a Güralp CMG-1T broadband seismometer on NEPTUNE Canada’s seismic station, respectively, to evaluate variations in sediment stiffness near Bullseye. The evaluation resulted in a (- 4.49 x10-3± 3.52 x 10-3) % change of the transfer function of 3rd October, 2010 and represents a 2.88% decrease in the stiffness of the sediments over the period. This thesis also outlines a new algorithm for calculating the static compliance of isotropic layered sediments.

Seafloor compliance is a non-intrusive geophysical method sensitive to the shear modulus of the sediments below the seafloor. A compliance analysis requires the computation of the frequency dependent transfer function between the vertical stress, produced at the seafloor by the ultra low frequency passive source-infra-gravity waves, and the resulting displacement, related to velocity through the frequency. The displacement of the ocean floor is dependent on the elastic structure of the sediments and the compliance function is tuned to different depths, i.e., a change in the elastic parameters at a given depth is sensed by the compliance function at a particular frequency. In a gas hydrate system, the magnitude of the stiffness is a measure of the quantity of gas hydrates present. Gas hydrates contain immense stores of greenhouse gases making them relevant to climate change science, and represent an important potential alternative source of energy. Bullseye Vent is a gas hydrate system located in an area that has been intensively studied for over 2 decades and research results suggest that this system is evolving over time. A partnership with NEPTUNE Canada allowed for the investigation of this possible evolution. This thesis describes a compliance experiment configured for NEPTUNE Canada’s seafloor observatory and its failure. It also describes the use of 203 days of simultaneously logged pressure and velocity time-series data, measured by a Scripps differential pressure gauge, and a Güralp CMG-1T broadband seismometer on NEPTUNE Canada’s seismic station, respectively, to evaluate variations in sediment stiffness near Bullseye. The evaluation resulted in a (- 4.49 x10-3± 3.52 x 10-3) % change of the transfer function of 3rd October, 2010 and represents a 2.88% decrease in the stiffness of the sediments over the period. This thesis also outlines a new algorithm for calculating the static compliance of isotropic layered sediments.