To understand the complex structure of magmatic plumbing systems beneath volcanoes, one needs to study the different textures shown in the igneous rocks produced by the volcano in question. By doing this, one can get a clue of the processes that resulted in the final rock. One of the most important methods to use for studying rock samples is the Crystal Size Distribution (CSD), which can reveal a great amount of information about the history of the rock and give an insight in the journey of the crystals during their time in the magma. An extinct volcano named Chachahuén, located in Argentina, South America, was chosen for this study. Samples of rock were collected from one of its laccoliths named Cerro Bayo and was identified as hornblende-bearing dacite. The difference in crystal size was very significant in these samples, with both larger and smaller crystals embedded in the same matrix. This is interesting considering the fact that large crystals form by slow cooling of the magma while smaller crystals form as the magma cools rapidly. By studying the CSD and interpreting other textures found in samples of igneous rock, one may interpret different processes which affected the crystals, indicating what the structure of the magma chamber once looked like. / För att kunna förstå den komplexa strukturen hos magmatiska system under vulkaner måste man studera olika texturer som påträffas i de magmatiska bergarter producerade av vulkanen i fråga. Genom att göra detta kan man få en inblick i de processer som resulterade i den slutgiltiga bergarten. En av de viktigaste metoderna att använda sig av för att studera stenprov är kristallstorleksfördelningen (CSD), som kan avslöja en mängd viktig information om bergarten och kristallernas historia under sin färd i magman. En slocknad vulkan vid namn Chachahuén belägen i Argentina, Sydamerika, valdes ut för denna studie. Stenprover samlades från en av dess lakkoliter med namnet Cerro Bayo, och identifierades som hornblände-bärande dacit. Skillnaden i kristallstorleken var mycket markant, med både större och mindre kristaller inbäddade i samma matrix. Detta är intressant med tanke på att stora kristaller bildas under en långsam nedkylning av magma medan mindre kristaller bildas när magma kyls ner snabbt. Genom att studera CSD och tolka andra texturer som finns hos magmatiska stenprover kan man tolka olika processer som har påverkat kristallerna, vilket i sin tur indikerar hur strukturen av magmakammaren en gång såg ut.

abstract: The infrastructure is built in Unsaturated Soils. However, the geotechnical practitioners insist in designing the structures based on Saturated Soil Mechanics. The design of structures based on unsaturated soil mechanics is desirable because it reduces cost and it is by far a more sustainable approach. The research community has identified the Soil-Water Characteristic Curve as the most important soil property when dealing with unsaturated conditions. This soil property is unpopular among practitioners because the laboratory testing takes an appreciable amount of time. Several authors have attempted predicting the Soil-Water Characteristic Curve; however, most of the published predictions are based on a very limited soil database. The National Resources Conservation Service has a vast database of engineering soil properties with more than 36,000 soils, which includes water content measurements at different levels of suctions. This database was used in this study to validate two existing models that based the Soil-Water Characteristic Curve prediction on statistical analysis. It was found that although the predictions are acceptable for some ranges of suctions; they did not performed that well for others. It was found that the first model validated was accurate for fine-grained soils, while the second model was best for granular soils. For these reasons, two models to estimate the Soil-Water Characteristic Curve are proposed. The first model estimates the fitting parameters of the Fredlund and Xing (1994) function separately and then, the predicted parameters are fitted to the Fredlund and Xing function for an overall estimate of the degree of saturation. Results show an overall improvement on the predicted values when compared to existing models. The second model is based on the relationship between the Soil-Water Characteristic Curve and the Pore-Size Distribution of the soils. The process allows for the prediction of the entire Soil-Water Characteristic Curve function and proved to be a better approximation than that used in the first attempt. Both models constitute important tools in the implementation of unsaturated soil mechanics into engineering practice due to the link of the prediction with simple and well known engineering soil properties. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2011

abstract: Most stars form in groups, and these clusters are themselves nestled within larger associations and stellar complexes. It is not yet clear, however, whether stars cluster on preferred size scales within galaxies, or if stellar groupings have a continuous size distribution. I have developed two methods to select stellar groupings across a wide range of size-scales in order to assess trends in the size distribution and other basic properties of stellar groupings. The first method uses visual inspection of color-magnitude and color-color diagrams of clustered stars to assess whether the compact sources within the potential association are coeval, and thus likely to be born from the same parentmolecular cloud. This method was developed using the stellar associations in the M51/NGC 5195 interacting galaxy system. This process is highly effective at selecting single-aged stellar associations, but in order to assess properties of stellar clustering in a larger sample of nearby galaxies, an automated method for selecting stellar groupings is needed. I have developed an automated stellar grouping selection method that is sensitive to stellar clustering on all size scales. Using the Source Extractor software package on Gaussian-blurred images of NGC 4214, and the annular surface brightness to determine the characteristic size of each cluster/association, I eliminate much of the size and density biases intrinsic to other methods. This automated method was tested in the nearby dwarf irregular galaxy NGC 4214, and can detect stellar groupings with sizes ranging from compact clusters to stellar complexes. In future work, the automatic selection method developed in this dissertation will be used to identify stellar groupings in a set of nearby galaxies to determine if the size scales for stellar clustering are uniform in the nearby universe or if it is dependent on local galactic environment. Once the stellar clusters and associations have been identified and age-dated, this information can be used to deduce disruption times from the age distribution as a function of the position of the stellar grouping within the galaxy, the size of the cluster or association, and the morphological type of the galaxy. The implications of these results for galaxy formation and evolution are discussed. / Dissertation/Thesis / Ph.D. Astrophysics 2011

Si l’Inde est un pays majoritairement rural, sa population urbaine est plus grande que la population totale des États-Unis. Ainsi, à la fin du 20ème siècle, le phénomène urbain indien est déjà bien développé, d’autant plus qu’il possède une histoire plurimillénaire. La présence de deux perturbations ayant modifié les logiques urbaines au cours du 20ème siècle, nous a amené à nous questionner sur la résilience du système urbain indien. Afin d’en présenter les principaux mécanismes, nous avons retracé l’évolution du système urbain indien au cours du 20ème siècle. Pour ce faire, nous avons utilisé une approche géographique par la population, qu’une approche qualitative et davantage historique est venue compléter. Nous nous sommes ainsi intéressés à l’évolution de la hiérarchie urbaine et à celle des rythmes de croissance des villes. Après avoir mis en lumière l’existence de mécanismes de rééquilibrage de la trame urbaine au cours du 20ème siècle, nous nous sommes penchés sur la stabilité organisationnelle et structurelle du système urbain. Cela nous a permis de mettre en évidence l’existence de classes dynamiques au sein de la hiérarchie urbaine. Leur évolution met en exergue le dynamisme du système urbain durant la seconde moitié du siècle dernier et nous présente les étapes de sa résilience. / If India is a predominantly rural country, its urban population is larger than the total population of the United States. Thus, at the end of the 20th century, the Indian urban phenomenon is already well developed, especially as it has a plurimillenary history. The presence of two disturbances have changed the urban logic in the 20th century and led us to question the resilience of the Indian urban system.To present the main mechanisms, we traced the evolution of the Indian urban system across the 20th century. To do this, we used a geographical approach by the population and a more historical one in complement. We emphasized the evolution of the urban hierarchy and that of the cities growth rates.After showing the existence of balancing mechanisms of the urban framework in the 20th century, we focused on the organizational and structural stability of the urban system. This allowed us to highlight the existence of dynamic classes in the urban hierarchy. Their evolution highlights the dynamism of the urban system in the second half of the last century and shows us the stages of its resilience.

Vindtunneln som drivs av Sports Tech Research Centres   är en unik anläggning för att bedriva forskning på både atletiska utövare och   utrustning. Vindtunnelns avancerade system möjliggör för forskning och tester   på material och produkter kan utföras i en verklighetstrogen miljö. Det finns   även sedan byggnationen ett regnsystem installerat i vindtunneln. Detta   system är inte uppmätt efter viktiga faktorer och ingen vetskap om det   simulerade regnets egenskaper eller likhet med naturligt förekommande regn   finns. Syftet med arbetet var att utföra mätningar på det   befintliga regnsystemet med avseende på storlek och fallhastighet för   dropparna. Arbetets syfte var även att jämföra de uppmätta regn egenskaperna   mot vetenskapliga modeller som beskriver ett naturligt regn. Där målet med   arbetet var att ta fram ett underlag på det befintliga regnet i vindtunneln. Testerna utfördes med en optisk distrometer som   mätte de fallande vattendropparna med en laser. Distrometern användes för att   mäta storlek samt fallhastighet på vattendropparna. Distrometer placerades   vid tester på olika höjder i vindtunneln, regnet undersöktes även vid   varierande vattenflöde och vindhastigheter. Resultatet visade på att simulerade regnet hade en   lägre hastighet i förhållande till den uppmätta droppstorleken högt i   tunneln. Hastigheten på dropparna lågt i tunneln visade mer följa modellernas   beskrivning av en naturligfallhastighet. Droppstorleksfördelningen visades   inte överstämma mot naturligt regn utan visar på en högre mängd stora droppar   än vad som är naturligt förekommande. Intensiteten i vindtunneln var som   lägst 62 mm/h vilket väldigt högt sett från naturligt regn. Utifrån dessa   parametrar följer inte det simulerade regnet ett naturligt förekommande regn. / The wind tunnel operated by Sport Tech Research Centres,   are a unique facility to conduct research on athletic practitioners and their   equipment. The advanced systems in the wind tunnel allows for research and   testing of materials and product in a realistic environment. Since the   construction of the wind tunnel a rain system was fitted. This system is not   measured for important factors and no knowledge of the simulated rainfall   properties or similarities to naturally occurring rain exists. The aim of this work was to perform measurements of   the existing rainfall system with regards to size and falls speed of the   droplets. The purpose was also to compare the measure rain properties to   scientific models describing natural rainfall. The goal of the work was to   get a foundation of the existing rain in the wind tunnel. The tests were performed with an optic disdrometer   that measured the falling water particles with a laser. The disdrometer   measured size and fall speed of the droplets. The tests were carried out on   different heights in the wind tunnel, the rain was also investigated at   varying water pressure and wind speeds. The result shows that the simulated rainfall had   lower speed relative to the measured drop size high in the tunnel. Fall speed   of droplets low in the tunnel showed more according to the model’s   description of a natural rain fall speed. Drop size distribution was shown   not to be consistent with natural rainfall. The distribution shows a higher   amount of large drops than is naturally occurring. Rainfall intensity was   measured to 62 mm/h as lowest which is very high compared to natural rain.   Based on these parameters the simulated rain is not a naturally occurring   rainfall. / <p>Betyg: 180803</p>

Com a crescente diminuição de recursos minerais e o alto custo envolvido na construção da estrutura de uma mina, a recuperação máxima possível de uma jazida vem se tornando fundamental. Para isso além da escolha do método de lavra ter a necessidade de ser feito cautelosamente, é possível lançar mão de métodos adicionais de recuperação, como por exemplo, a recuperação de pilares. Essa pesquisa foi baseada na determinação da caracterização do enchimento (backfill cimentado) utilizado nas câmaras vazias que possibilita a posterior recuperação dos pilares. A caracterização do enchimento é composta da determinação da resistência simples do backfill necessária para que o enchimento cumpra com seu objetivo, desenvolvimento da classificação granulométrica ótima para os agregados e dosagem de cimento e água para alcançar a resistência proposta. A metodologia desenvolvida para obter a nova caracterização é composta de várias etapas que incluem pesquisas em campo e trabalhos em laboratório. Primeiramente, foram obtidos através de análise em campo os parâmetros de dosagem de cimento e classificação granulométrica dos agregados já utilizados na planta de fabricação do enchimento, bem como sua resistência correspondente. Em seguida definições teóricas da dosagem de cimento ideal e classificação granulométrica ótima foram realizadas com base na resistência à compressão simples que foi identificada como necessária para cumprir com as solicitações geomecânicas do maciço rochoso, então posteriormente, a nova caracterização definida teoricamente foi posta à prova através da confecção de corpos de prova de backfill, seguido de execuções de ensaios de compressão. Durante a primeira etapa da metodologia, já se pôde identificar que os agregados possuíam um alto índice de partículas tamanho argila que estavam afetando os resultados de resistência obtidos com a caracterização empregada inicialmente. A partir disso se optou por construir a curva granulométrica ótima sem essa fração. A resistência à compressão simples calculada de 2,69 MPa, foi obtida com base no planejamento de longo prazo que prevê a total recuperação dos pilares existentes na mina. Dessa maneira toda a área que será minerada foi considerada como um único bloco. Finalmente, foi identificada a dosagem de cimento sendo de 4% em peso, que juntamente com a granulometria ótima é capaz de alcançar os valores esperados de resistência. Para que o planejamento da produção da mina durante os próximos anos de vida útil seja efetivamente cumprido, o enchimento deverá prover à mina estabilidade geomecânica local a nível de câmaras abertas com paredes verticais de backfill estáveis e também estabilidade global a nível de contato entre níveis e galerias de acesso. Isso somente será alcançado se a nova caracterização for corretamente aplicada. / As a consequence of the ongoing reduction of mineral resources and the high cost involved in the construction of a mine, the maximum recovery of a mineral deposit becomes a fundamental issue. Therefore, besides the need of caution on the choice of the mining method, it is possible to make use of additional recovery methods, such as the recovery of pillars. This research was based on the determination of the characterization of the fill (cemented backfill) used in avoid stopes that allows the subsequent recovery of adjacent pillars. The characterization of the fill consists of determining the uniaxial compressive strength of the backfill required for an efficient filling, developing an optimal particle-size distribution for the aggregates and finding the cement-water ratio necessary to reach the desired resistance. The methodology developed to obtain the new characterization is comprised of several steps which include field work and laboratory tests. First, cement dosing parameters and particle size of the aggregates (already used at the filling manufacturing plant), as well as their corresponding strength, were obtained through analyses in the field work. Then, theoretical definitions of the ideal cement dosing and optimal particle-size analysis were carried out based on the uniaxial compressive strength that has been identified as necessary to comply with the geomechanical requests from the rock mass, and then later, the new theoretical characterization was tested by making backfill samples, followed by execution of compression tests. During the first stage of this methodology, it has been identified a high proportion of clay particle size for the aggregates, that have affected the strength results obtained from the characterization used initially. From this point, we decided to build the optimal particle-size curve without this fraction. Uniaxial compressive strength, calculated as 2.69 MPa, was obtained from the long-term planning that determines the full recovery of the existing pillars in the mine. In this way, the entire area to be mined was considered as a single block. Finally, the cement dosing has been identified as 4% by weight, which together with the optimal particle size, is able to achieve the expected strength values. In order to effectively fulfill the mine production planning over the next years of lifespan, the filling should provide the mine local geomechanical stability at open stopes level, with vertical walls of stable backfill, and also global stability at the contacts between levels and access galleries. This will only be achieved if the new characterization is correctly applied.

Com a crescente diminuição de recursos minerais e o alto custo envolvido na construção da estrutura de uma mina, a recuperação máxima possível de uma jazida vem se tornando fundamental. Para isso além da escolha do método de lavra ter a necessidade de ser feito cautelosamente, é possível lançar mão de métodos adicionais de recuperação, como por exemplo, a recuperação de pilares. Essa pesquisa foi baseada na determinação da caracterização do enchimento (backfill cimentado) utilizado nas câmaras vazias que possibilita a posterior recuperação dos pilares. A caracterização do enchimento é composta da determinação da resistência simples do backfill necessária para que o enchimento cumpra com seu objetivo, desenvolvimento da classificação granulométrica ótima para os agregados e dosagem de cimento e água para alcançar a resistência proposta. A metodologia desenvolvida para obter a nova caracterização é composta de várias etapas que incluem pesquisas em campo e trabalhos em laboratório. Primeiramente, foram obtidos através de análise em campo os parâmetros de dosagem de cimento e classificação granulométrica dos agregados já utilizados na planta de fabricação do enchimento, bem como sua resistência correspondente. Em seguida definições teóricas da dosagem de cimento ideal e classificação granulométrica ótima foram realizadas com base na resistência à compressão simples que foi identificada como necessária para cumprir com as solicitações geomecânicas do maciço rochoso, então posteriormente, a nova caracterização definida teoricamente foi posta à prova através da confecção de corpos de prova de backfill, seguido de execuções de ensaios de compressão. Durante a primeira etapa da metodologia, já se pôde identificar que os agregados possuíam um alto índice de partículas tamanho argila que estavam afetando os resultados de resistência obtidos com a caracterização empregada inicialmente. A partir disso se optou por construir a curva granulométrica ótima sem essa fração. A resistência à compressão simples calculada de 2,69 MPa, foi obtida com base no planejamento de longo prazo que prevê a total recuperação dos pilares existentes na mina. Dessa maneira toda a área que será minerada foi considerada como um único bloco. Finalmente, foi identificada a dosagem de cimento sendo de 4% em peso, que juntamente com a granulometria ótima é capaz de alcançar os valores esperados de resistência. Para que o planejamento da produção da mina durante os próximos anos de vida útil seja efetivamente cumprido, o enchimento deverá prover à mina estabilidade geomecânica local a nível de câmaras abertas com paredes verticais de backfill estáveis e também estabilidade global a nível de contato entre níveis e galerias de acesso. Isso somente será alcançado se a nova caracterização for corretamente aplicada. / As a consequence of the ongoing reduction of mineral resources and the high cost involved in the construction of a mine, the maximum recovery of a mineral deposit becomes a fundamental issue. Therefore, besides the need of caution on the choice of the mining method, it is possible to make use of additional recovery methods, such as the recovery of pillars. This research was based on the determination of the characterization of the fill (cemented backfill) used in avoid stopes that allows the subsequent recovery of adjacent pillars. The characterization of the fill consists of determining the uniaxial compressive strength of the backfill required for an efficient filling, developing an optimal particle-size distribution for the aggregates and finding the cement-water ratio necessary to reach the desired resistance. The methodology developed to obtain the new characterization is comprised of several steps which include field work and laboratory tests. First, cement dosing parameters and particle size of the aggregates (already used at the filling manufacturing plant), as well as their corresponding strength, were obtained through analyses in the field work. Then, theoretical definitions of the ideal cement dosing and optimal particle-size analysis were carried out based on the uniaxial compressive strength that has been identified as necessary to comply with the geomechanical requests from the rock mass, and then later, the new theoretical characterization was tested by making backfill samples, followed by execution of compression tests. During the first stage of this methodology, it has been identified a high proportion of clay particle size for the aggregates, that have affected the strength results obtained from the characterization used initially. From this point, we decided to build the optimal particle-size curve without this fraction. Uniaxial compressive strength, calculated as 2.69 MPa, was obtained from the long-term planning that determines the full recovery of the existing pillars in the mine. In this way, the entire area to be mined was considered as a single block. Finally, the cement dosing has been identified as 4% by weight, which together with the optimal particle size, is able to achieve the expected strength values. In order to effectively fulfill the mine production planning over the next years of lifespan, the filling should provide the mine local geomechanical stability at open stopes level, with vertical walls of stable backfill, and also global stability at the contacts between levels and access galleries. This will only be achieved if the new characterization is correctly applied.

Orientador: Liliane Maria Ferrareso Lona / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-07T08:12:19Z (GMT). No. of bitstreams: 1 Bufo_MoacirJose_D.pdf: 987875 bytes, checksum: 8fa242d4879a20b9592f76cbbb4e5681 (MD5) Previous issue date: 2006 / Resumo: Águas residuárias urbanas e industriais, cujo destino final em nível mundial é o rio, sempre apresentam imiscíveis na forma de película e gotas, sejam de óleos comestíveis ou óleos lubrificantes ou solventes petroquímicos. A grande dificuldade em separar estes imiscíveis está no diâmetro de gotas inferior a 40 microns. A melhor tecnologia, hoje, produz água tratada ainda com gotas de 20 microns e com teor de imiscível igual a 10 mg/litro. O autor do presente trabalho, em 1984, acidentalmente criou um coalescedor a filme, e realizou ensaios numa instalação em escala piloto, para encontrar uma solução para um problema de imiscível em água, de uma indústria petroquímica. Os ensaios qualitativos realizados mostraram que a tecnologia é eficiente para separar imiscíveis em água. Os estudos, naquela época, não tiveram continuidade. O regime de operação da instalação piloto era contínuo. A aparelhagem da piloto era totalmente em vidro. O controle destes ensaios foi por meio visual que é bastante significativo pelo fato de ser um controle simnão, isto é, ou tem turbidez ou não tem turbidez. A água residuária entrando no coalescedor era homogênea e na saída do coalescedor havia a formação de duas camadas distintas com uma interface de separação. A camada inferior apresentava uma turvação e a camada superior não apresentava turvação. Este fato mostra de forma inquestionável de que ocorreu um processo de aglutinação de partículas ou coalescência. Desta forma, o objetivo deste trabalho é dar continuidade ao trabalho iniciado em 1984, visando desenvolver uma metodologia para explicar o fenômeno da coalescência neste tipo de coalescedor e também desenvolver um modelo para o seu dimensionamento, visto que o fluxograma do processo já está estabelecido. Este trabalho é assim definido como teórico, uma vez que já existe o trabalho experimental realizado em 1984. A consulta em literatura tem três enfoques: O primeiro é conhecer o fenômeno da coalescência em termos científico. O segundo enfoque foi conhecer o estado da arte da tecnologia de coalescedor. O terceiro foi uma compilação de todos aqueles conhecimentos científicos e tecnológicos julgados pertinentes para a condução deste estudo. Adotouse, neste trabalho, o método de dedução indutiva e a antiga técnica da equação da proporcionalidade para propor um mecanismo e uma equação cinética da coalescência em filme de líquido. Também foi usada a equação da continuidade de NavierStokes para determinar o perfil de concentração das gotas ao longo do filme, visando gerar um modelo de dimensionamento para o coalescedor proposto. Foi constatado que o comportamento de imiscível em água é específico para cada espécie química e também depende da intensidade de energia aplicada ao meio. Por este motivo, a consolidação da tecnologia de separação de gotas de imiscível proposta só poderá ser realizada mediante um estudo numa instalação em escala industrial. Qualquer estudo em escala piloto vem somente confirmar o que já foi realizado e no máximo fornecer valores isolados de concentração de gotas de imiscível / Abstract: Urban and industrial wastewaters always have immiscible chemicals. These immiscibles are chemicals such as edible oils, lubricant oil and petrochemical solvents. The final destinations of these wastewaters is the river. It is very difficult to separate immiscibles with diameter drop less than 40 µm from the wastewater. The best separation technology available today still produces clean water with drops below 20 microns and with immiscible content of 10 mg/l. In 1984 the author of this work accidentally created one coalescence film equipment. The pilot scale test results were successful in separating immiscibles from wastewater in a petrochemical plant. The glass pilot plant operated continuously. The kind of control plant it is visual to detect the turbidity. The homogenous liquid wastewater is fed to the top of the coalescence equipment. The liquid issue. the bottom of equipment had two phases. The lower phase was turbid and the upper phase was not. Unfortunately the investigation was stopped at the time. Based on the research developed in 1984, the objective of this work is to study the phenomena of coalescence of the liquid film and to develop a kinetic coalescence model and a design model for a coalescence equipment. This present work is theoretical based on the experimental date (process flowsheet and design equipment) obtained in 1984. There are three main objectives: the first objective is to understand the coalescence phenomena; the second is to understand the development of coalescer technology; the third is to compile all relevant scientific and technological knowledge for this research. The investigation used the inductive deduction method and the old proportional equation technique to suggest a mechanism and kinetic equation to describe the film coalescence phenomenon. The NavierStokes equation was used to determine the drop concentration profile in the film, in order to produce a way to design the equipment. One conclusion is that each immiscible chemical behave differently in water. The applied energy also plays a role. Another pilot plant will only confirm what has been done and give isolated immiscible products drop concentration / Doutorado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

The present study deals with the physical characterization of macrodefect free cements produced by ICI. These materials are made through a specialized mixing technique which incorporates an organic polymer into the cement/water system. The high mechanical strength and low porosity of this class of hardened cement paste had been well documented, however, a detailed characterization of the physical nature of the microstructure had not previously been attempted. Two classes of macrodefect free material were studied, based on Ordinary Portland cement and High Alumina cement, respectively. The porosities of these two materials were determined in their original state and after various forms of heat treatment and conditioning. Samples based on Ordinary Portland cement had a well defined narrow pore size distribution, even after heat treatment, while the High Alumina cement samples displayed a very low total pore volume in their original state, but subsequent heat treatment led to the developement of porosity over a wide range of pore sizes. These fundamental differences in the pore size distributions had significant effects on the homogeneity and reproducibility of the microstructures of the samples. The porosity generated by heat treatment was found to be unstable in the presence of water. In general, reductions in the porosities and permeabilities were observed. This was due to the formation of fresh cement hydrate gel within the pore structure, which caused a shift in the pore size distributions towards smaller pores.

The most speciose group of fishes in the Gulf of Mexico is the dragonfishes (Family: Stomiidae). These fishes are dominant mesopelagic predators occurring throughout the world’s oceans, including the Antarctic seas. Little is known regarding their reproductive ecology, a consequence attributed to insufficient sample sizes of mature adults due to inadequacies of sampling gear; larger, sexually mature stomiid adults are more adept at net avoidance, thereby obfuscating synoptic reproductive biology studies. Between 2010-2011, the Offshore Nekton Sampling and Analysis Program was initiated in the northern Gulf of Mexico over all four seasons using a discrete-depth sampling system (MOCNESS) and a large, commercial-sized midwater trawl (Irish herring trawl). Gonads were dissected from 714 individuals belonging to 47 species of stomiids, of which the most 12 abundant species were subjected to detailed analysis. Female ovaries possessed an asynchronous oocyte development, suggesting that females are iteroparous. Males exhibited a similar pattern. Chauliodus sloani had an overall sex ratio that favored females, and was the only species in which the overall sex ratio significantly differed from the expected 1:1 ratio (male:female) (P < 0.05). Considering just mature specimens, Aristostomias xenostoma, Malacosteus niger, Eustomias fissibarbis, and Eustomias schmidti had sex ratios that favored males, and were the only species in which the sex ratio significantly differed from even (P < 0.05). Eustomias hypopsilus was the only species in which mean biomass significantly differed between sexes. Histological analysis and binomial regression indicated that females of the 12 most abundant species matured at larger lengths than males. Generally, only females were present in the larger size classes, suggesting that females also become larger than males. Size distribution plots by gear type to assess gear selectivity revealed two patterns: the MOCNESS caught fewer specimens per species than the Irish herring trawl, and the MOCNESS caught predominantly smaller specimens. These data are essential for ecosystem-based modeling of global deep-pelagic ecosystems, which contain the overwhelming majority of Earth’s fish biomass.