A theoretical and experimental examination into the dynamics of granular solids has been completed which covers aspects of flow and failure within this material. The investigation is divided into three natural sections; each section being devoted to a different type of failure. As indicated by the title, the subject of the study was cohesionless soil, and thus the basic tenets of soil mechanics and the failure of granular media are applicable. The first section deals with gravity flow of non-cohesive granular material in both axial and rectangular geometry. Traditional plasticity theory is used to establish characteristics of stress and strain, also stress sliplines within a wedge. From these, two relationships between the angle of internal friction and the bound to a radial flow field are established. A minimum energy theory of flow is discussed and then used to determine mass flow rates. From this theory a velocity profile is deduced an by use of either the entire profile or the vertical ray or the extreme angular ray three relationships between the bound tot he radial flow field and the mass flow rate are established. The limits to piping in axial symmetry are defined. It is shown that gravity flow in rectangular geometry must always result in pipes. Experiments were devised to substantiate these findings and they show that, dependent upon the assumptions that were made, the devised relationships bracket, within reasonable limits, the radial bound and the mass flow rate. Work of two other investigators is compared wit the presented experimental results. The definitions of pipe are shown to have validity. Section Two was the result of an attempt to measure a parameter that was relevant to the investigation in Section Three. The possibility of the passive rather than the active lateral earth pressure acting upon a shifting retaining wall was discovered while attempting the measurement of the coefficient of friction of sand on mild steel. The third section is concerned with an investigation into the factors that affect the forces on a horizontally propelled model that is immersed in sand. The parameters of depth, speed, projected model area, and other model characteristics were varied, and experimental relationships between the force and these parameters determined. Also, pressure measurements were made within the sand as the model passed to determine the extent of the failure region. Several other experiments, such as the effect of false walls on the force level, were made in order to determine the limits of validity of the main experiment. It was found that the force on the model varied as the 2.3 power of the depth, linearly with the projected model area, and not at all with model surface, model length, or speed in the range 0-15 feet per minute. The pressure measurements and false-walls studies showed that failure occurred within the sand and not at the walls of the tank; also that failure took the form of successive shear dislocation of pyramidally shaped wedges of sand.

Video imaging data generated from the Naval Postgraduate School Imaging System (NAPSIS) during November 2004 to June 2006 was analyzed to determine the location of rip channels and track their morphology. During the study period, the rip fields constantly changed in shape, size, and location. Rip channels were found to have a mean migration southward at a rate of 0.16 meters per day with a standard deviation of 7.6 meters per day and maximum rates varying between approximately 30 meters per day north and 30 meters per day south. The migration exhibited a strong seasonal variation with southerly shifts in the fall and winter months, northerly shifts in the late winter and early spring months, and no significant shift in the late spring and summer months. Directional wave spectra measured every hour at the offshore NOAA buoy were refracted to the 10 meter depth contour at Marina and Sand City and compared with measured spectra at these locations. The significant wave heights at both locations exhibited a correlation of 0.94. Mean wave directions for Marina and Sand City were found to have correlations of 0.83 and 0.34, respectively. These refracted data were then used to calculate sediment transport rates at Stillwell Hall, Fort Ord. Rip channel migration and calculated sediment transport rates were correlated at 0.8, qualitatively confirming the hypothesis that the migration rate of rip channels is a function of modeled alongshore sediment transport. The sometimes rapid migration of these large scale morphological features is critical to the successful planning and execution of U.S. Navy and Marine Corps beach assaults and the operation of mine warfare. Because amphibious and special forces operate mainly in shallow areas, the modeling of rip current direction and magnitude contributes greatly to effective mission organization and accomplishment. In addition to causing mines to drift, rip currents transport sediment that can cause the underlying morphology to change, possibly covering bottom mines and creating a potential hazard for military forces operating in the area. Being able to predict where mines may be drifting and how much sediment has concealed them is a necessity in securing a littoral battlespace.

This project is a Master's Thesis which extent is 30 credits in the specialization Soil and Rock Construction within Civil Engineering at the Technical University of Luleå. The project is a laboratory study, which has been executed at the Technical University of Brunswick in Ger-many.The project has looked into how uniaxial strength of stabilised soil is affected when the mate-rial has been exposed for ground frost. The study also checked whether there is a recovering effect in the material after thaw. The study was performed in laboratory by studying two soils and two stabilisation agents. The materials were a clay stabilised with lime and a silty sand stabilised with cement. Both soils where taken from the Stockholm area in Sweden. In total 108 samples were manufactured with different combinations of content of stabilization agent, hardening time, number of freeze-thaw-cycles and curing time. This resulted in 18 combinations of samples for each soil. The questions the project answered are:impact of freeze-thaw-cycles on the uniaxial compressive strengthif the curing after freeze-thaw can repair the material with respect to its uniaxial compressive strength.The results show that the uniaxial compressive strength of the lime-stabilised clay is reduced by about 40 to 80 %. The magnitude depends on the amount of stabilizer, hardening time and freeze-thaw-cycles. The cement-stabilised sand gets a change of its uniaxial compressive strength by ±10 %. Consequently there is no evidence that the freezing has an impact on the uniaxial compressive strength in this case. After curing of the stabilised clay samples exposed to freezing and thawing the uniaxial compressive strength was found to be 20 to 115% of the original value. Therefore, there is only a small actual recovery in the clay samples. For the ce-ment-stabilised sand a more continuous growth of strength was found rather than recovery during the after curing. This was in the range of about 0 to 25%.The cement-stabilised sand has shown to be brittle and sensitive to deformations. This makes its limitation not to be carrying capacity. The limitations are rather deformation and move-ment.

Once the characteristics of the study area have been defined within the context of desert environments the theory of sediment accumulation in such a setting will be critically reviewed. The processes and products of aeolian sand transport and deposition that dominate the region will be discussed in Chapter Four and illustrated with contemporary examples from the study area and ancient equivalents from the Permian-age Clipper Field of the Southern North Sea. Once the primary building blocks of aeolian bedforms have been considered, the relationship between aeolian bedforms and the wind will be addressed in Chapter Five. The basis for the classification of aeolian bedforms on the grounds of morphology and morphometry will be examined, as will the possible controls on bedform size and spacing and the concept of draas as equilibrium bedforms. The apparent relationships that exist between bedform morphology, alignment and wind regime in a number of the world's desert areas will be critically considered in this section. The concepts of bounding surfaces, bedform accumulation and preservation will be considered in Chapter Six. The roles of sand supply and subsidence will be addressed, as will the significance of interdune sequences. Once the factors controlling the evolution, distribution, and the accumulation of aeolian sediments in aeolian bedforms have been considered, the dynamics of sand-sea systems and the significance of regional bounding surfaces will be critically assessed in Chapter Seven. In Chapter Eight the application of ground penetrating radar (GPR) as a means to determine the internal sturcutre of modern aeolian bedforms will be considered in conjunction with the results of a survey conducted on the Al Liwa area. The theories and principles discussed to date will then be applied to the study area. In Chapter Nine observed patterns of present-day dune morphology and morphometry across the region will be described in detail and the question of bedform morphology and alignment with respect to the contemporary wind regime addressed.

This thesis interprets and maps some key stratigraphic and structural elements of Garden Bank (GB) Block 191 applying both geological and geophysical techniques. The area is located in the Gulf of Mexico 160 miles southwest of Lafayette. Threedimensional seismic data and some well logs were integrated and analyzed to construct a reasonable geological subsurface image. GeoFrame software from Schlumberger was used in this research. A spatial attention was given to salt diapers. Their influence on sand accumulations and hydrocarbon traps were investigated. Two Pleistocene sands accumulations (4500-ft & 8500-ft) were examine thoroughly in this research. Time and amplitude maps were produced. In addition, a wave-theoretical model that describes salt tectonic activities within the area was reconstructed in order to understand the influence of these dynamical forces on the overlaying strata.

Orientador: Katia Denise Saraiva Bresciani / Resumo: A Leishmaniose Visceral (LV) apresenta uma ampla distribuição geográfica em todos os continentes, representando um sério problema de Saúde Pública. Os flebotomíneos (Diptera, Psychodidae, Phlebotominae) são importantes insetos vetores de microrganismos patogênicos como Leishmania spp., Bartonella spp. e arbovírus (Vesiculovirus, Phlebovirus, Orbivirus), porém, estes insetos apresentam grande importância para a transmissão das leishmanioses em várias regiões do mundo, incluindo as Américas do Sul e Central. No Brasil, há duas espécies, até o momento, relacionadas com a transmissão da Leishmania infantum: a Lutzomyia longipalpis e a Lutzomyia cruzi. Infecções por Leishmania spp. são potencialmente zoonóticas e acometem homens e diversas espécies de animais silvestres e domésticos. Os cães são importantes hospedeiros, fontes de infecções e potenciais reservatórios, não só pelo estreito relacionamento ou convívio com os seres humanos, mas também por sua incapacidade imunológica em responder à doença com sucesso. O Ministério da Saúde no Brasil, preconiza para o diagnóstico da Leishmaniose Visceral Canina (LVC), o teste imunocromatográfico, como exame de triagem e o ensaio imunoenzimático, como confirmatório. Também recomenda o diagnóstico precoce e tratamento adequado dos casos humanos, o controle dos vetores, a eutanásia dos cães e atividades de educação em saúde nas áreas endêmicas para esta doença. Por tanto, foram instituídas ações de prevenção e controle da LV canina, na áre... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Visceral leishmaniasis (VL) has a wide geographical distribution on all continents, representing a serious Public Health problem. Sand flies (Diptera, Psychodidae, Phlebotominae) are important insect vectors of pathogenic microorganisms such as Leishmania spp., Bartonella spp. and arboviruses (Vesiculovirus, Phlebovirus, Orbivirus), however, these insects are of great importance for leishmaniasis transmission in various regions of the world, including South and Central America. In Brazil, there are two species related to the transmission of Leishmania infantum: Lutzomyia longipalpis and Lutzomyia cruzi. Leishmania spp. infections are potentially zoonotic and affect men and various species of wild and domestic animals. Dogs are important hosts, sources of infections and potential reservoirs, not only for their close relationship or contact with humans, but also for their immunological inability to successfully respond to the disease. The Health Ministry of Brazil recommends for the diagnosis of canine visceral leishmaniasis (CVL), the immunochromatographic test as a screening test and the enzyme immunoassay as confirmatory. It also recommends early diagnosis and appropriate treatment of human cases, vector control, dog euthanasia and health education activities in endemic areas for this disease. Therefore, prevention and control actions of canine VL were instituted in the urban area of municipality of Araçatuba, São Paulo, Brazil. / Doutor

Basalts from Askja, Iceland have high MgO (5-18 wt %) and high Fe2O3 (5-18 wt %: Baratoux et al., 2011; Mangold et al., 2013, this study) similar to Martian basalts, which have Fe2O3 from 10-33 wt % McSween et al, 2006; Ming et al., 2008]) and MgO around 11 wt. % (McSween et al., 2009). Askja’s cold desert climate provides a good weathering analogueanalog (Mountney and Russell, 2004). Askja is located in the Northern Volcanic Zone of Iceland and basalts have been weathered to form mafic volcaniclastic deposits in a 40-km long sand sheet to the E-SE of the Askja caldera complex (Fig. 1; (Kuritani et al., 2011). The 2014-2015 Holuhraun eruption was emplaced onto the southeastern part of the sand sheet (Fig. 1) and altered the regional geomorphology and may have impacted the geochemistry of the sand sheet itself by addition of wind-blown ash and crystals, plus weathering of the lava flow (MgO content of ~7.1 wt % Geiger et al., 2016). Mangold et al. (2011) found that Icelandic sands show little chemical variations but that study was limited in the number of samples (12 sand samples and 12 rock seven rock, seven sand; Mangold et al., 2011). Here we expand on that study and we have created a morphological and geochemical database with the goal of identifying relevant trends to past and present Martian environments. The Askja sand sheet, between ~10 cm and ~10 m thick, covers 240 km2 (Mountney and Russell). Mountney and Russell described three distinct sections of the sand sheet. The southwest section is deflationary and defined by very fine to medium grained basaltic sand with cobbles and boulders of lithologies sourced from adjacent to and distal from the sand sheet. The central part is inflating and is dominated by very fine-grained sand, relict lava fields, and small to large sand ripples. The northeast portion is also inflating but that accumulation is limited to topographic depressions. The northeast, characterized by sand mostly composed of pumice from the 1875 Askja eruption and basalt clasts from local lava fields, was not studied in detail here due to the difference in chemistry. Martian basaltic eolian sediments may record a long history of local and global climate change and they may have been potential habitats where water, nutrients and organic carbon mixed below the surface (Blake et al., 2013; Fisk et al., 2013). Basaltic sand fields on Earth have not been characterized as well as felsic sands, but represent a unique analog to deposits such as the Stimson Fm. on Mars (Mangold et al., 2011; Banham et al., 2016; Gupta et al., 2016; Ming et al., 2016; Newsom et al., 2016; Yen et al., 2016) . Eolian dominated weathering prevalent at Askja volcano, Iceland, likely also occurred on Mars and Askja mafic volcaniclastic dunes could be the best morphological and compositional analogueanalog for Martian eolian dunes (Edgett and Lancaster, 1993).

Infiltration of highly concentrated solutions into unsaturated sand is suspected to be affected by the liquid-gas interfacial tension between the resident water and that of the infiltrating solution. The wetting of non-porous solid surfaces by liquids is commonly quantified by contact angle measurements. However, it is well known that wettability of porous solids cannot be accurately obtained by optical inspection because the liquid is penetrating into the pores of the solid in question. The main objective of this investigation was to find an effective method to measure contact angle in coarse porous media such as sandy soils. In this study, we compare both static and dynamic methods to estimate the contact angle formed by solutions of varying surface tension on silica sands. In addition, the contact angle of the imbibing solutions is estimated in both dry and water-wetted sand. Experiments in this study employed three clear acrylic columns of known volume to determine contact angles using two methods, one static method and one dynamic method. The three acrylic columns were packed with the same mass of each grade of Accusand�� (40/50, 30/40, 20/30, and 12/20 grades respectively) for triplicate measurements. The solutions used in this study included (1) pure water and (2) 5 molal NaNO��� and (3) n-hexane as a reference. The static method estimated contact angles in initially dry sand of 23�� for 40/50 sand, and 30�� to 33�� for 12/20, 20/30, and 30/40 sands, with the same values obtained for both solutions. Contact angles of these solutions observed in the dynamic test, were twice those found in the static test (averaging 45�� and 62�� respectively). In the case of pre-wetted sands, dynamic imbibition with water provided an estimated contact angle of 2��, while the NaNO��� solution yielded 21�� contact. Based on relative surface tensions of water and the 5 molal NaNO���, the Young's equation predicts a contact angle of 25��. These results strongly support recent claims of effective contact angles between these miscible, but contracting, fluids. The observed data suggest that the zero contact angle assumption is a poor one even for clean dry silica sand. In a dynamic system, gravitational forces cannot be ignored in course porous media. An analytical method, used to model imbibition of the solutions into the silica sands, was both accurate and useful for estimating contact angle. / Graduation date: 2002

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

A robust understanding and planning of production enhancement and flow assurance is required as petroleum E&P activities are targeting deepwaters and long distances. Different flow assurance issues and their solutions are put together in this work. The use of multiphase pumps as a flow assurance solution is emphasized. Multiphase pumping aids flow assurance in different ways. However, the problem causing most concern is sand erosion. This work involved a detection-based sand monitoring method. Our objectives are to investigate the reliability of an acoustic sand detector and analyze the feasibility of gel injection as a method to mitigate sand erosion. Use of a sand detector coupled with twin-screw pumps is studied under varying flow conditions. The feasibility of gel injection to reduce slip and transport produced solids through twin-screw pump is investigated. A unique full-scale laboratory with multiphase pumps was utilized to carry out the experimental tests. The test results indicate that acoustic sand detection works in a narrow window around the calibration signature. An empirical correlation for predicting the twin-screw pump performance with viscous fluids was developed. It shows good agreement in the practical operational limits – 50% to 100% speed. The results indicate that viscous gel injection should be an effective erosion mitigation approach as it reduces slip, the principle cause of erosive wear. To correlate the performance of viscous fluid injection to hydroabrasive wear, further experimental investigation is needed.