Dissertations / Theses on the topic 'Sand'
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1
Robinson, R. B. "Piles in sand and in sand overlying clay." Thesis, University of South Wales, 1989. https://pure.southwales.ac.uk/en/studentthesis/piles-in-sand-and-in-sand-overlying-clay(8c43e7a9-c869-4a1f-a044-30741f2964bc).html.
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This thesis examines the behaviour of single 60mm and 114mm segmented tubular steel piles driven and placed into loose sand and loose sand overlying clay. The soil was placed and instrumented under controlled conditions in a 3.0m diameter by 3.0m deep concrete tank. The 60mm pile was dynamically driven using a pneumatically controlled driving rig, whilst the 114mm pile was driven at a constant rate of penetration via a hydraulic jack. The static and dynamic axial load distributions were monitored for the 60mm pile. The variation in local shaft friction and radial effective stress were monitored along the pile shaft of the 114mm pile, together with the distribution of axial load within the pile. The pore water pressure was continuously monitored at selected points in the clay from the placement of the overburden to the final stages of the experiment. The density of the sand was carefully controlled during placement and was subsequently measured at the relevant point in the experiment. Vertical and radial displacements were monitored within the sand. For the two soil profiles radial shear and vertical effective stresses were recorded at a defined level within the strata. Data from both the pile and soil instrumentation was recorded throughout the pile installation and load testing programme by an Orion Data Logger which was interfaced with a Commodore PET micro computer. The results show: (i) During pile installation the major principal stress acting at depth within a soil profile, appears to emanate from the face of the active wedge driven ahead of the pile. (ii) The boundary of the sand/clay interface has a considerable effect on the development of soil displacements and the effective vertical stress developed within the overlying sand. (iii) The radial displacement during pile installation is directly related to the pile diameter. Within a sand profile the peak radial displacement can be predicted using an empirical compaction factor adjustment to a theoretical representation of radial soil movement. (iv) In sand, the local unit shaft friction and the radial effective stress are practically constant along the pile shaft for a given pile embedment and increases at a diminishing rate with pile embedment. (v) At full pile embedment and ultimate applied load, the local coefficient of earth pressure KZ, for a driven pile may approach or exceed the value of Kp near the top of the pile and tend to a lower limit of 0.6 near the pile base. (vi) For a placed insitu pile at ultimate applied load, the local coefficient of earth pressure Kz may be less than Kp near the top of the pile and tend to Ka near the pile base. (vii) Adjacent to the pile shaft the radial effective stress is the major stress. (viii) The development of shaft friction is directly related to displacements within the surrounding sand and on the sand/clay interface. (ix) The influence of the underlying clay layer affects the development of shaft friction to varying limits above and below the sand/clay interface. (x) For shallow pile penetrations into the clay layer the drawdown of sand and sand plug driven ahead of the pile significantly reduces the pore water pressure generated at the soil/pile interface. (xi) The development and radial distribution of pore water pressure within the clay can be represented be a logarithmic expression. (xii) The maximum compressive strain due to pile installation in a sand profile radiates from below and around the pile base. These results are compatible with and extend previous research work at the Polytechnic of Wales. They illustrate how soil behaviour and soil/pile interaction are influenced by the method of pile installation and the boundary effects of an incompatible underlying layer.
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Livingston, Kimberly S. "Sand Beach." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1041889.
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This project consisted of a series of short stories which worked together creating a larger fictional piece in the form of a non-continuous narrative. This non-continuous narrative is in the tradition of Sherwood Anderson's Winesburg, Ohio, and Louise Erdrich's Love Medicine. The stories in this type of fiction are connected by similar themes and settings, allowing the reader to participate directly in the creative process. The reader helps create the fiction by drawing his or her own conclusions about the characters and places from between the individual stories. By involving the reader more directly in the outcome, this type of narrative creates a more emotional response to the work. Each of the stories in this project were set in a town called Sand Beach, Michigan, and involved four generations of women in a single family. The major themes of the stories were mother/daughter relationships, healing, and redemption. Common images in the stories presented were, Lake Huron, the town of Sand Beach, and a rock in the local region bearing Native American petroglyphs Each of these images participated in the development of the common themes.Department of English
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Yu, Jie 1966. "Generation of sand ripples and sand bars by surface waves." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/17485.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, February 2000.Includes bibliographical references (p. 234-244).
Part I Generation of Sand Ripples by Surface Waves In Chapter 1, we study the sand ripple instability under partially standing surface waves in constant water depth. For gently sloped ripples, the approximate flow field is· worked out. By invoking an empirical formula of sediment transport rate, an eigenvalue problem is obtained, which gives rise to the equation for initial ripple growth with coefficients depending on local wave conditions. It is found that the wave-induced steady streaming has no effect on ripple growth. Thus, ripple instability is locally similar to the cases for oscillatory flows and for purely progressive waves, and is driven by ripple-induced flow. But the intensity of this process varies spatially with the period of half the surface wavelength due to the reflection. The results show that beneath the envelope minima (nodes) ripples grow the fastest and are the longest; under the envelope maxima (antinodes) ripples are unlikely. Part II Generation of Sand Bars and Sediment/Wave Interaction In this part we study the formation mechanism of sand bars under reflected surface waves and the mutual influence of the waves and bars through Bragg resonance. In Chapter 2, we first give an analysis of the effects of shoreline reflection on Bragg resonance by considering rigid bars, aiming at acquiring a deeper understanding of the physical processes of the Bragg resonance mechanism. We show that finite reflection by the shoreline can increase the wave energy arriving at the shore, in contrast to the result from most previous studies, suggesting that the mechanism can enhance the attack of the incident sea on the beach. The phase relation of the rigid bars and the shoreline reflection is found to be a key to the qualitative change of wave response. In Chapter 3, we develop a quantitative theory to describe the formation mechanism of sand bars by coupling sediment dynamics and wave hydrodynamics. Assuming that the slopes of waves and bars are comparably gentle and sediment motion is dominated by the bedload, an approximate evolution equation of bar height is derived. This equation shows that sand bars grow and evolve via a forced diffusion process rather than instability. Both the forcing and diffusivity depend on the flow field above the current bed. In Chapter 4, the coupled evolution of sand bars and waves is investigated, in which the Bragg scattering mechanism has been understood as two concurrent physical processes: energy transfer between two wave-trains propagating in opposite directions and change of their wavelength. Both effects are found to be controlled locally by the position of bar crests relative to wave nodes. In the absence of shoreline reflection, it is found that pre-existing sand bars cannot be maintained by their own Bragg scattered waves and the formation of sand bars offshore by Bragg scattering is at best a transient phenomenon. Comparison with experimental data supports the description of bar formation as a forced diffusion process. In Chapter 5, we examine the effects of horizontal variation of eddy viscosity on the evolution of bars. This variability arises because (1) the intensity of wave oscillation at the bottom changes in space due to the reflection; (2) the bottom roughness is not uniform due to the formation of ripples. While the forced diffusion mechanism is not changed qualitatively, it is found that the variable turbulent intensity inside the wave boundary layer strongly enhances the spatial fluctuation of the sand flux induced by wave stresses, thus causes stronger forcing to the bar growth.
by Jie Yu.
Ph.D.
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Walker, Thomas M. "Shifting sand : the palaeoenvironment and archaeology of blown sand in Cornwall." Thesis, University of Reading, 2014. http://centaur.reading.ac.uk/78304/.
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Coastal sand dunes are common in Britain, especially along western Atlantic coasts, and archaeological sites are well preserved under blown sand. One of the questions is how Holocene palaeoclimate variation influences patterns of settlement establishment and abandonment. Few studies of coastal sites have included palaeoenvironmental evidence, and even fewer include securely dated stratigraphy. This study uses a multi proxy approach to investigate two main and five minor coastal sites in Cornwall, with molluscs analyses being the principal analytical method. Chronology is established by radiocarbon dating and optically stimulated luminescence so that episodic human activity can be related to periods of sand blow and instability. Evidence is sought concerning the history of mineral mining in the Red River catchment area. Twenty three cores and a test pit were examined along a transect at the multi period site at Gwithian on the north Cornish coast. Mollusc columns were obtained at Strap Rocks near the main Gwithian site, and from five trenches excavated at the early medieval site of Gunwalloe on the Lizard peninsula. The study establishes that initial sand deposition was about 3000 BC, with further marked periods of sand blow in the early and late Bronze Age, the Iron Age and the mid-medieval period. Some, but not all, sand blow correlates with periods of settlement occupation and abandonment, and with known palaeoclimate episodes such as the Little Ice Age. Difficulty in establishing periods of sand conflation and deflation and how this may lead to errors in chronology are discussed. There is weak evidence for mining activity in the Bronze Age, but strong evidence from c 1050 AD. The chronology of mollusc extinctions and introductions is refmed, e.g. Xerocrassa geyeri did not become extinct until the end of the early Bronze Age and Cochlicella acuta was present from the late Neolithic, about 2400 BC.
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Faulkender, DeWayne J. "Source of sand for An Nafud sand sea, Kingdom of Saudi Arabia." Thesis, Kansas State University, 1986. http://hdl.handle.net/2097/14009.
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Eisa, Khalid Osman Gafar Mohamed. "Compensation grouting in sand." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611262.
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Gallo, Federico. "Dynamics of sand injections." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613651.
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Hasan, Faisal S. "Upflow sand-roughing filtration." Thesis, Loughborough University, 1994. https://dspace.lboro.ac.uk/2134/34972.
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Slow sand filtration requires low turbidity water for effective operation. In most cases this means pretreating the raw water to reduce its turbidity. Lately horizontal gravel filters have become very popular as a means of pretreatment. They are simple to operate, have a large mass storage capacity, and can cope with high turbidity shock loads. However, cleaning them can be a problem. An alternative pretreatment, which this study is concerned with, is upflow sand roughing filtration. It has the potential advantages of simple design, ease of operation and cleaning, and low area requirements. A study of upflow versus downflow was done using two small filter columns. The results showed that although downflow exhibited a better turbidity removal than upflow, upflow allowed longer filter runs and better utilisation of bed depth. This was in agreement with earlier findings. The effect of backwash water quality was also investigated. Both filters were run in upflow direction; one was washed with tap water, the other with polluted raw water. The results suggested, unexpectedly, that a filter washed repeatedly with polluted water produced slightly better turbidity removal than one washed with tap water. This indicated some form of maturation, which could be biological in nature, taking place. Experiments with horizontal gravel filters clearly showed the importance of biological mechanisms in maturation. Four new filter columns, 50mm in diameter, were constructed. These allowed further investigation of the effect of bed depth. Backwash rate and duration were investigated to find an optimum. Very little of the wash water was required to clean the filters, the majority being required to flush the turbidity out of the system. The long-term effect of backwash on filters was investigated, as was the effect of wash water quality. Tap water, raw water and raw water polluted with settled sewage were used to wash the filters. The results indicated that the filters washed with raw water and polluted water proved to be as good as regards turbidity removal as those washed with tap water. This suggested that raw water backwash could be used effectively for washing upflow roughing filters.
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van, Arragon Lukas. "Livelihoods Built on Sand: Exposing the Precarity of Labour in Cambodia’s Sand Extraction Industry." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42454.
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Although Cambodia banned sand exports in 2017, under-regulated sand extraction in rivers across the country continues, driven by demand from rapid urbanization and land reclamation around Phnom Penh. In the last decade, the sand extraction industry has come under intense scrutiny for its role in riverbank erosion and degradation of aquatic ecosystems, with some activists and scholars highlighting how this damages livelihoods and displaces rural Cambodians. At the same time, the sand boom in Cambodia has created a demand for labour, offering opportunities to rural Cambodians who have few other livelihood options in their home provinces. However, the vast majority of wealth from sand extraction does not accrue to sand labourers. Using qualitative data gathered from various sand extraction and transportation sites along the Mekong River in and around Phnom Penh, this thesis reveals new insights into the sand extraction industry. This thesis draws upon sustainable livelihoods approaches to reveal the difficult trade-offs that rural Cambodians must make when leaving their homes to enter the sand extraction industry. The thesis then uses the concept of precarity to show that sand labour in Cambodia is characterized by precarious employment conditions, including work in remote and isolated locations, separation of families when men leave for sand related labour, a lack of formal work contracts or rights, an inability to diversify income sources, and unpredictable cycles of intermittent work. The thesis then follows the approach used in political ecology literature, examining the power relations that help explain why sand labourers have little choice but to pursue precarious livelihoods, while business and government elites amass great wealth from resource extraction in Cambodia. In doing so, this thesis helps to broaden the understanding of the implications of a little understood yet hugely important resource extraction industry.
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Thapa, Bhola. "Sand Erosion in Hydraulic Machinery." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-302.
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The topic of this thesis is damage of hydraulic machinery due to sand erosion. This is a very broad topic in which all the aspects of design of hydraulic machinery namely material selection; mechanics of material and hydraulics are involved. The issue of sand erosion is equally important for operation and maintenance of hydropower plants.
The erosion damage of turbines of hydropower plants in Himalayan Rivers, in particular in Nepal, due to high sediment contents in river is a motivating factor for this research. The findings of this study are believed to help to reduce erosion of turbine components, increase their life time and improve maintenance procedure.
The objectives of this study are to:
1. Study the erosion process on different materials and compare lifetime of turbine material with hard surface coating.
2. Study the flow in the turbine and identify the region of highest velocity and acceleration where most serious sand erosion occurs.
3. Study erosion rate of turbine as a function of operating parameters (head and speed), particle characteristics and turbine material.
4. Assess loss of efficiency and to analyze repair method and repair interval that gives optimal economy of the hydropower plants.
The goals laid out in the objectives are achieved by understanding the theory of erosion of material through literature, investigating the nature of turbine damage from field observation and finally by experiments to study effect of variables of erosion rate and investigation of particle separation process in rotational flow.
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Berg, Joris van den. "Non-linear sand wave evolution." Enschede : University of Twente [Host], 2007. http://doc.utwente.nl/57884.
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Alhajraf, Salem. "Numerical simulation of drifting sand." Thesis, Cranfield University, 2000. http://hdl.handle.net/1826/3502.
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Two-phase flows are involved in many industrial and natural flow phenomena
varying from as specific as the transport of crude oil in pipelines to as general
as the dispersion of pollutants in the atmosphere. Numerical modelling based
on Computational Fluid Dynamics (CFD), has attracted the attention of
scientists and engineers from a wide range of backgrounds over recent
decades during which these models have been extensively developed, analysed
and applied to many practical applications.
Wind blown particles such as sand or snow and their resulting accumulation
around buildings, roads, oil field installations and security fences causes
severe structural and design problems. These are traditionally addressed
based on previous experience, full-scale field investigation or using scale
model wind tunnel experiments, all of which incur high cost.
In this study, wind blown particles are considered as a two-phase flow system.
A finite volume based CFD code is developed using two-phase flow theory and
is employed to numerically simulate the drifting of sand and snow around
obstacles of different geometry. The model solves the governing transport
equations in three dimensional space. Three different approaches are
investigated to represent and solve the secondary flow phase, particles, within
the flow field; a particle tracking model, based on a Lagrangian reference
frame and the homogenous and the mixture models, based on an Eulerian
reference frame. The capabilities and limitations of each of these models are
investigated for flow fields involving drifting particles around obstacles of
different geometry.
Particles transported by wind both in suspension and saltation are modelled
based on the physical characteristic and the threshold condition of the
particle. Their effect on the flow field is incorporated through separate source
terms contributing to the particle transport equation.
The Eulerian based models are coupled with the Fractional Area/Volume
Obstacle Representation (FAVOR) as a mean of representing the solid boundary formed by deposited particles separating the flow field from the
accumulation zones. The FAVOR treatment allows the flow field to respond to
the changes in the geometry of the deposition regions and further calculations
take into account the erosion and deposition processes that have previously
occurred.
The model can be calibrated to match specific flow conditions through several
controlling parameters. These controlling parameters are identified and
analysed for four distinct case studies. Model results are compared with field
and wind tunnel observations available in the literature and with field
measurements conducted as a part of this study in the desert of the State of
Kuwait. Qualitatively good agreement between the model and the
observations is obtained in two as well as three dimensions.
Although the mixture and particle tracking models show the potential
capability to simulate such flow systems, the homogenous model is found to
be the most appropriate model due to its relative simplicity compared to the
mixture model and its lower computational cost compared to the Lagrangian
particle-tracking model.
In conclusion, a practical CFD tool has been developed and validated,
incorporating novel physical and numerical models. The tool can be utilised
by scientists and engineers to further understand the real world problem of
drifting sand and snow in urban and industrial environments.
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Yan, Wei. "Sand transport in multiphase pipelines." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/8074.
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Over the life of an oil and gas reservoir, it is likely to encounter sand production. In offshore production fields, as there are lack of processing facilities nearby, gas, liquid and sand are often transported together in long distance pipelines. The existence of sand could accumulate in the pipelines under inappropriate operation condition and eventually will lead to a blockage. Thus, to design such systems requires knowledge on how sand is transported, when and where it will accumulate.
This thesis summarizes the experimental work undertaken using the 2 inch, 3 inch and 4 inch multiphase facilities. Generally, the main objectives of the experiments were to i) observe and enhance the understanding of sand transport characteristics in water and air-water flows; ii) investigate sand concentration effect and pipe diameter effect on sand minimum transport condition (MTC); iii) investigate the effect of pipeline orientation (0, +5, +10 and +20 degrees) and viscosity effect (Carboxy Methyl Cellulose (CMC) solution with viscosity of 7, 20cP; Oil with viscosity of 105, 250 and 340cP) on sand MTC; iv) validate the equivalent pressure drop concept for predicting sand MTC in sand-air-water flow and v) extend current MTC prediction model for sand-water flow to account for different sand concentrations .
Similar sand behaviour was observed in horizontal sand-water flow in all pipe sizes tested. At minimum transport velocity, sand particles were observed transporting in form of sand streaks. For horizontal sand-air-water flow, sand transport characteristics and MTC were strongly dependent on the air-water flow regime. Sand was found to be transported more efficiently within slug or roll wave body, where turbulence is generated intensively.
Parametric studies were conducted to investigate the factors affecting sand MTC in water and air-water flows in pipeline. It was found that the MTC will increase as sand concentration and pipe diameter increase. Pipeline orientation was found having little effect on sand behaviours and MTC in upwardly inclined water flow. However, in upwardly inclined air-water flow, although sand particles were observed sometime moving backward with the liquid film, the superficial gas and liquid velocities required to transport sand were less than those in the horizontal pipeline due to the fact that slug flow regime was found more prevailing in inclined pipeline. In addition, the liquid viscosity effect on sand MTC in single phase liquid flow was investigated due to the increase of concerns relating to solids transport in high viscosity crudes. It appeared that, in turbulent flow, sand MTC increased slightly as the fluid viscosity increased. However, when the bulk flow became laminar, the MTC decreased as the fluid viscosity increased.
After visually obtained the sand MTC in air-water flow, the measured pressure gradients were compared between MTC condition for sand-water flow for different sand concentrations, the results indicate that the equivalent pressure gradients concept is a valid approach to extend the sand MTC prediction from water flow to air-water flow conditions for the purpose of pipeline design.
Two concentration correction correlations (dual range and single range) were proposed. The modified model could account for a wider range of sand concentration (from 0.000005 to 0.3 volume fraction) in water flow. The predicted MTC velocities showed good agreement with the experimental results.
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Ventouras, Konstantinos. "Engineering behaviour of Thanet sand." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424787.
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Johansson, Rebecca. "George Sand : une femme moderne ?" Thesis, Högskolan Dalarna, Franska, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:du-10264.
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A travers des œuvres de George Sand (1804-1876), le mémoire étudie la littérature champêtre, l'exotisme et l’écriture féminine. Dans un deuxième temps il montre les relations avec des personnes célèbres qui ont influencé l’auteur et les correspondances entretenues entre George Sand et elles. Enfin le mémoire se termine par une étude de la femme moderne qu'était George Sand.
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Yonan, Shafik J. "Pipe jacking forces in sand." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/15343.
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In this research work, a comprehensive review of investigations into pipe jacking operations, and in particular the forces generated during the process, is presented. The factors affecting these forces were examined and their influence was studied in order to give a clear indication on the their magnitude and behaviour. A model scale testing facility, based on a 1.8m X 1.5m X 1.5m high steel tank, has been developed together with hydraulic jacking facilities and scale model pipes of 200mm diameter having both steel and concrete surfaces. In this facility the actual pipe jacking operation can be simulated, so that a study of the jacking forces could be made with the use of appropriate instrumentation techniques and computerised data recording. A series of tests was conducted to examine the influence of several parameters on the jacking forces, such as overcut ratio, type of soil, type of pipe surface, overburden pressure, and the rate of jacking. These parameters were in relation to the distance jacked. Two granular soils, uniformly graded Leighton Buzzard sand and well-graded River sand, were used as the material surrounding the pipeline, that is the material through which the pipes were jacked. Laboratory analysis on the soil materials was conducted and the relationship between results obtained from these tests and scale model testing were established. The interface friction between the surface of the pipeline and the surrounding soil was determined. The results show a peak in the jacking forces at the start of the jacking process, followed by a decrease and leveling off as the jacking continued. The graph is very similar to the stress/strain relationship of a typical granular soil. Both steel and concrete pipes were used in the tests to detennined the influence of pipe surface, and to a lesser degree pipe joint, characteristics. Higher forces were recorded for concrete pipes. The jacking rate was kept constant and consistent for all tests. It was found to have little effect on the magnitude of the jacking forces. The jacking forces were measured automatically using a computer. The results show a clear trend of increase in the jacking forces when the overburden pressure and jacking length were increased. Tests using different overcut ratios have indicated that a minimum jacking force might be achieved at a specific overcut ratio. The results of this research show that the jacking forces are influenced by a number of parameters. These include the overburden pressure, overcut ratio, pipe diameter, jacking length and the influence of the surrounding material. This is fully demonstrated by establishing a method of jacking forces prediction, termed herein the Loughborough Method.
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Gajo, Alessandro. "Instability phenomena in sand samples." Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399938.
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Wagner, Richard A. "Sand modeling of crustal extension." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/59038.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1985.Microfiche copy available in Archives and Science.
Vita.
Bibliography: leaf 53.
by Richard A. Wagner, Jr.
M.S.
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Hamon, Bernard. "George sand et la politique." Versailles-St Quentin en Yvelines, 1998. http://www.theses.fr/1998VERS1008.
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Objet: etudier et suivre l'evolution des idees politiques de george sand tout au long de sa vie. Est politique. Tout ce qui touche au gouvernement des societes humaines, etat, regimes, economie organisations, ecoles de pensees, religions et relations entre les etats. Sources utilisees: principalement sa correspondance et son oeuvre - romans, articles de revues et journaux, agendas-, et celles qui concernent les relations avec ses contemporains, leroux, lamennais, flaubert, le prince napoleon. . . Son eveil politique,est provoque par michel de bourges, puis surtout pierre leroux dont elle adopte avant 1840 tes idees philosophiques et politiques. Apres avoir rompu avec la revue des deux mondes elle fonde avec leroux la revue independante ou elle professe jusqu'en 1845 des theories resolument egalitaires. Admire robespierre, s'intitule communiste mais se montre plus evolutionniste que revolutionnaire. En 1848 elle defend les idees des republicains avances. Compromise le 15 mai elle se refugie a nohant d'ou elle n'interviendra plus qu'episodiquement. Durant l'empire apres avoir lutte pour sauver les republicains condamnes en 1852, elle demeure une opposante discrete proche du prince napoleon, anticlericale et hostile au pouvoir temporel du pape. Opposee a la guerre et a sa poursuite en 70, attachee au suffrage universel (mais contre son extension aux femmes qui doivent d'abord conquerir l'egalite civile ) et a la republique elle condamnera tout ce qui peut les menacer, la guerre a outrance et la commune. Hostile au jeu politique des individus et des partis, favorable a une republique moderee, elle renie la terreur, preche la tolerance la libre discussion et soutient thiers. Persuadee de la necessite d'une remise en cause prealable de la societe pour mettre en oeuvre ses idees, sceptique sur l'action de l'etat elle pronera pour y parvenir l'action individuelle et le reoli sur la sur la famille.
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Naser, Tim, and Stavros Ntouvas. "Gobi : Automatic sand-spreading robot." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296306.
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The purpose of this report was to research through the construction of a prototype the technical challenges associated with creating a robot that distributes sand on patios after snowfall. A robot that could complete this task should be able to know its position in an unknown terrain and traverse it in a predictable manner that allows for the even spread of the sand. In order to achieve stability and predictability of movement, stepper motor driven wheels were chosen as the steering method. The sand-spreading mechanism consists of a DC Motor connected to a 3D-printed disc with rectangular extrusions at its base. The wheels and chassis of the robot were likewise 3D-printed. Lastly, an Arduino MEGA board was the controller of choice.Syftet med denna rapport var att genom konstruktionen aven prototyp undersöka de tekniska utmaningarna för att skapa en robot som distribuerar sand på uteplatser efter snöfall. En robot som kan slutföra denna uppgift bör kunna känna till sin position i en okänd terräng och färdas på den på ett förutsägbart sätt som möjliggör en jämn spridning av sanden. För att uppnå stabilitet och förutsägbarhet för rörelse valdes stegmotordrivna hjul som styrmetod. Sandspridningsmekanismen består av en likströmsmotor ansluten till en 3D-utskriven skiva med rektangulära extruderingar vid basen. Robotens hjul och chassi var också 3D-utskrivna. Slutligen var ett Arduino MEGA-kort den valfriastyrenheten.
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Alaei, Ebrahim. "Hydrodynamic-plastic modelling of sand." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/25046.
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This thesis focuses on proposing a novel comprehensively predictive modelling framework for granular materials which builds on the hydrodynamic procedure to satisfy the principles of thermodynamics, mass, momentum and energy conservations. In developing our physical arguments we recognise that complexity of the macroscopic mechanical response of granular media is mainly a result of kinematic degrees of freedom in granular scale. We therefore employ the original concept of two-stage irreversibility by Jiang and Liu (2009) and consider an energy sink from the mesoscopic granular entropy level to the microscopic thermal entropy level. In stark contrast from previous hydrodynamic formulations for granular materials, we establish a clear passage from the granular temperature to calibrate instead our model based on the measurable kinetic pressure.
We introduce a novel coupling between the hydrodynamic formulation and plasticity theory by directly defining the evolution equations for state variables and imposing restrictions to ensure the non-negativity of the mechanical dissipation. Within our hydrodynamic-plastic framework, we construct two constitutive model variants. The first simpler model demonstrates remarkable capability to predict comprehensive rate-independent and rate-dependent phenomena, all while relying on only five previously defined mechanical constants.
We enhanced the first model to capture particle breakage effects through integration with the breakage mechanics theory (Einav 2007). This more advanced model readily maintains all the rate-independent capabilities of the first one, and demonstrates remarkable agreement with elaborated experimental breakage data from monotonic and cyclic compression and shear tests.
This thesis provides a foundation to explore and further model granular materials, as well as materials with complex internal heterogeneous mesoscopic structure, such as weakly cemented granular rocks, silts and clays.
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Owsiany, Dana Lynn 1969. "Sand stabilization using waste plastics." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/291370.
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A study on the possible use of melted waste thermoplastics to stabilize soils, and produce plastic-soil structural composites is presented. Specifically, the effects of melted thermoplastics on the shear strength, and creep characteristics of sands are examined. An extensive experimental program was conducted to examine the strength and creep characteristics of different plastic-sand compositions. It was found that increasing plastic content in the sand results in stronger, and stiffer soils with negligible creep deformations for loads which are at least 50% of the strength of the composite. It is expected that injection of melted waste thermoplastics in sands can improve significantly the engineering characteristics of foundation, and slope stability of sands. Other potential applications include construction of structural elements, bricks, etc.
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Al-Rkaby, Alaa H. J. "Anisotropic Characterisation of Reinforced Sand." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/69352.
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Soil reinforcement is widely used in many geo-structures that induce complex anisotropic conditions, i.e. principal stresses with different directions α, different intermediate principal stress parameters b and/or cyclic rotation of the principal stress direction. The Results of this thesis improve the understanding of anisotropic three-dimensional stress states, σ1 ≠ σ2 ≠ σ3, on the characterization of reinforced sand so that solid designs and analyses of reinforced geostructures can be achieved.
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Abbasalizadeh, Rajbari Majid. "Investigation of three-phase nozzle flow (water-sand-air) in an innovative sand-blasting system." Thesis, Anglia Ruskin University, 2011. http://arro.anglia.ac.uk/702999/.
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The study presented herewith was mainly focused on the numerical analysis of air-sand-water three-phase turbulent flow through converging-diverging nozzle. For this purpose dispersed flow of air-sand-water by various air inlet pressures, ambient air inlet temperature, sand particles and water droplets by different mass flow rates and temperature were considered. This study puts emphasis on sand blasting nozzle which is employed in Farrow abrasive system. Two-way turbulence coupling between particles/droplets and air flow as well as interference between the incident stream of particles and rebounded from the wall were applied in the numerical model. In addition, the shock wave which is produced in supersonic flow at diverging part of nozzle was considered. In order to capture the turbulent flow features accurately, Standard, RNG and Realizable k-e models as well as Spalart-Allmaras and Reynolds Stress turbulence models were tested. Meanwhile, Eulerian Model and Discrete Phase Model were employed for simulating of multi-phase flow through the nozzle. Eventually, Realizable k-ε Discrete Phase model was utilized in the present study. Since there is not any experimental or analytical result on three-phase flow through the nozzle, for validation of model, the same turbulent and multi-phase models were utilized on air-water two-phase flow. The obtained results were in good agreement with the experimental data. According to the results of three-phase flow simulation, the averaged exhaust momentum of sand particles had inverse proportion with water mass flow rate. The increasing of air inlet pressure had significant effect on mean exhaust velocity of sand particles. Moreover, the air exhaust velocity had direct proportion with inlet temperature of water droplets and sand particles. This investigation may be used in further studies related to the optimisation of sand blasting nozzle in different working conditions.
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Abbasalizadeh, Rajbari Majid. "Investigation of three-phase nozzle flow (water- sand -air) in an innovative sand-blasting system." Thesis, Anglia Ruskin University, 2011. https://arro.anglia.ac.uk/id/eprint/702999/1/Abbasalizadeh%20Rajbari_2011.pdf.
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The study presented herewith was mainly focused on the numerical analysis of air-sand-water three-phase turbulent flow through converging-diverging nozzle. For this purpose dispersed flow of air-sand-water by various air inlet pressures, ambient air inlet temperature, sand particles and water droplets by different mass flow rates and temperature were considered. This study puts emphasis on sand blasting nozzle which is employed in Farrow abrasive system. Two-way turbulence coupling between particles/droplets and air flow as well as interference between the incident stream of particles and rebounded from the wall were applied in the numerical model. In addition, the shock wave which is produced in supersonic flow at diverging part of nozzle was considered. In order to capture the turbulent flow features accurately, Standard, RNG and Realizable k- models as well as Spalart-Allmaras and Reynolds Stress turbulence models were tested. Meanwhile, Eulerian Model and Discrete Phase Model were employed for simulating of multi-phase flow through the nozzle. Eventually, Realizable k-ε Discrete Phase model was utilized in the present study. Since there is not any experimental or analytical result on three-phase flow through the nozzle, for validation of model, the same turbulent and multi-phase models were utilized on air-water two-phase flow. The obtained results were in good agreement with the experimental data. According to the results of three-phase flow simulation, the averaged exhaust momentum of sand particles had inverse proportion with water mass flow rate. The increasing of air inlet pressure had significant effect on mean exhaust velocity of sand particles. Moreover, the air exhaust velocity had direct proportion with inlet temperature of water droplets and sand particles. This investigation may be used in further studies related to the optimisation of sand blasting nozzle in different working conditions.
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Jackson, Colin. "The moult and migration strategies of Lesser Sand Plover, Greater Sand Plover and Terek Sandpiper." Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/27908.
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Moult in birds is a critical yet often underrated component of a birds' annual life cycle together with breeding and migration. A good understanding of the moult strategy of a species is important for its conservation because key moulting grounds must be protected to allow this component of the life cycle to be undertaken. Lesser Sand Plovers, Greater Sand Plovers and Terek Sandpipers are among the least known of the commonly encountered long-distance migrant waders in Africa and Australasia. This is particularly true for the populations which spend the non-breeding season on the East African coast. This study aims to describe the primary moult strategies for the three species from five locations at different latitudes: south-eastern India, Kenya, South Africa, north-western Australia and southeastern Australia. Differences in moult strategy between species, age and latitude are highlighted and explanations are proposed for the differences in the light of the breeding behaviour, migration time and routes, food availability and local climatic conditions. Results from this study are combined with other moult studies on migrant waders to present hitherto undescribed patterns in wader moult strategies at a global scale. A synthesis is presented of published and available unpublished information about the different populations for the three study species, their distribution, status and migration strategies with a focus on those visiting the East African coast. The three species follow a similar basic moult strategy in adults where primaries are moulted soon after arriving on the non-breeding grounds. Immature moult strategies are more complex and differ between species and latitude. In general adults in all three species at the more northern nonbreeding sites start moult earlier than those travelling farther south probably as a result of greater proximity to breeding grounds. Lesser Sand Plovers have a relatively long duration of moult (152- 154 days) across all locations where data were sufficient; Greater Sand Plovers have a short duration (80 days) in India and similar, comparatively longer durations (132-134 days) at the other latitudes. The Indian site is used mainly by this species as a site to stopover and moult while on migration to more southerly non-breeding grounds. Terek Sandpipers in Kenya have a relatively short duration of moult (99 days) when compared to India and Australia (121-130 days) and tend to have a rapid start to moult which then slows down after the first few primaries are moulted. Young Lesser Sand Plovers in India mostly undergo a complete primary moult while in Kenya and Australia birds generally do not moult in their first year. First year Greater Sand Plovers mostly all undergo a complete primary moult irrespective of latitude. Terek Sandpipers in their first year do not moult in India in the north, mostly undergo a partial moult of outer primaries in Kenya on the equator, and do a complete moult in south-eastern Australia. The north-west Australian population was divided into two almost equal groups: those that undergo a complete primary moult, and those that only moult a few outer primaries. A difference in winglength between these two groups suggests that there may be two distinct populations involved, most likely originating from distinct breeding grounds. In-depth study is needed to confirm this. The overarching picture of moult in adult migrant waders is that at high latitudes moult starts early and is kept short. With decreasing latitude, the timing of moult is delayed with increasing distance from breeding grounds. In the tropics the lack of constraints of approaching harsh winter weather and long distances from breeding grounds allow species to adapt a wide range of moult strategies. As birds migrate farther south before they moult, constraints on time available to moult due to large distances travelled mean duration is reduced in order to fit it in. An upper limit in duration of moult in migrant waders irrespective of the size of the bird appears to be set at c. 160 days. Small birds have a wide variation in duration while as body size increases over 100 g, moult duration is necessarily longer. With harsh winters in the north, large waders are forced to migrate south in order to moult. This study suggests that irrespective of body size the 'gold standard' for duration of moult is around 120 days (four months). While timing of migration is relatively well-known for the three species in Australia, it was hitherto unknown that juvenile Lesser Sand Plovers delay in reaching Australia until February or March in contrast to all other migrant wader species where first years arrive in September/October. It is unknown where they stop en route or indeed why they delay in this way. All three species in Kenya peak at a maximum population in November and early December after which numbers reduce as birds start to depart for the breeding grounds. Resightings of colour-flagged Lesser and Greater Sand Plovers confirmed the north-western coast of India as an important stopover site for migrants heading to western China and Mongolian breeding grounds from Kenya. A review of country population estimates for the three species suggested non-breeding populations in Africa of 200,000 Lesser Sand Plovers, 25,000-35,000 Greater Sand Plovers and 115,000-200,000 Terek Sandpipers. Mida Creek is shown to be a key stronghold for non-breeding waders in Kenya and its importance for their continued conservation is thus confirmed.
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Caors, Marielle. "George Sand et le Berry : paysages champêtres et romanesques /." Paris : Royer, 1999. http://catalogue.bnf.fr/ark:/12148/cb37702961q.
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Grimard, Elise. "Le féminisme de George Sand : engagement individuel ou collectif?" Sherbrooke : Université de Sherbrooke, 1998.
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Wiedemann, Kerstin. "Zwischen Irritation und Faszination : George Sand und ihre deutsche Leserschaft im 19. Jahrhundert /." Tübingen : G. Narr, 2003. http://catalogue.bnf.fr/ark:/12148/cb38839976c.
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Lewis, Corbin Robert. "Linear Dune Morphometrics in Titan’s Belet Sand Sea and a Comparison with the Namib Sand Sea." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7688.
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Despite atmospheric and compositional differences on Titan and Earth, the similarity in the shape and spacing of linear dunes of the Belet Sand Sea of Titan and the Namib Sand Sea of Earth suggests that comparisons will yield a better understanding of the dictating factors of duneforming processes. We present a methodology for the collection of dune width and spacing measurements representative of the Namib and Belet sand seas. 94,304 locations in Belet from Cassini SAR images and 5,563 locations in the Namib from IKONOS images are used for measurements. The average width and spacing of linear dunes in Belet are 1,235 m and 2,776 m, respectively, with a standard deviation of 422 and 859 respectively. In the Namib, the average linear dune width and spacing is 736 m and 2,203 m, with a standard deviation of 204 and 592. We also analyze these morphometrics according to potential dictating factors such as elevation and distance to sand sea margins. We establish significant trends according to distance to margin, which confirms that the largest and most widely spaced dunes are generally found in the center of the sand sea. We also observe increasing dune width with increasing elevation. The strongest trend we observe is distance to the western margin in the Namib Sand Sea. In Belet, none of these trends were found to be significant. Analysis of width vs. spacing is significant in both sand seas. The disparity in results of the two sand seas suggests factors such as age, sand sea size, or proximity to source may influence linear dune morphometrics.
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Su, Dong. "Centrifuge investigation on responses of sand deposit and sand-pile system under multi-directional earthquake loading /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202005%20SU.
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Roberts, Tiffany. "Natural and Anthropogenic Influences on the Morphodynamics of Sandy and Mixed Sand and Gravel Beaches." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4216.
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Beaches and coastal environments are dynamic, constantly shaped and reshaped by natural processes and anthropogenic modifications. The morphodynamics and influence of natural and anthropogenic factors of two different coasts at various temporal and spatial scales are discussed.
To quantify the performance of several beach nourishment projects at annual temporal and kilometer spatial scales on three adjacent microtidal low-wave energy barrier islands in west-central Florida, a total of 5,200 beach and nearshore-profiles spaced at 300 m were surveyed monthly to bi-monthly from 2006-2010. Beach nourishment performance is most significantly influenced by the interruption of longshore sediment transport by complex tidal-inlet processes. More specifically, the tidal-inlet processes influencing adjacent beach nourishment performance includes longshore transport interruption resulting from divergence induced by wave refraction over an ebb-tidal shoal, flood-tidal currents along the beach, and total littoral blockage by structured inlets. A morphologic indicator of a large longshore transport gradient within the study area is the absence of a nearshore sandbar. These non-barred beaches are characterized by persistent shoreline erosion and were almost exclusively located in areas with a large longshore transport gradient. The more typical beach state along the three barrier islands was one exhibiting a migratory bar and relatively stable shoreline. The presence of a sandbar indicates the dominance of cross-shore processes, with onshore migration during calm wave conditions and offshore migration during energetic wave conditions. The onshore and offshore migration of the sandbar is closely related to non-stormy summer and stormy winter seasonal beach changes, respectively.
The morphodynamics of a mixed sand and gravel beach in Delaware were investigated based on 740 beach profiles surveyed almost monthly from 2009 to 2011, 60 sediment cores, and 550 surface sediment samples collected at various alongshore and cross-shore transects. Inter-seasonal temporal scales of storm-induced beach changes and post-storm recovery were examined based on a hurricane, a typical energetic winter storm, and an extremely energetic storm resulting from the rare collision of a hurricane and winter storm ("Nor'Ida") occurring within a 3-month period in 2009. The mixed sand and gravel beaches in Delaware are characterized by monotonically increasing water depths lacking a sandbar under all wave conditions. A distinctive beach cycle was identified consisting of a built-up berm profile and depleted nearly-planar storm profile, with a time-scale related to the frequency and intensity of storm impact and duration of intra-storm recovery instead of simple seasonality. The sedimentological characteristics of the storm deposit associated with Nor'Ida demonstrated substantial cross-shore variation ranging from sandy-gravel and gravelly-sand within the storm swash zone (near the pre-storm dune edge) to well-sorted medium to coarse sand seaward of the storm swash zone, suggesting that storm deposits along mixed beaches demonstrate a variety of sedimentological characteristics. A new dynamic beach cycle model is proposed for the non-barred mixed sand and gravel beach with temporal variability controlled by storm occurrence and inter-storm duration.
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Kålås, Øystein Heden. "Patternless direct moulding of sand castings." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for produktutvikling og materialer, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12957.
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Emilsson, Inga-Lill. "Sand, småbarn och intra-aktiv lek." Thesis, Karlstads universitet, Avdelningen för utbildningsvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-13143.
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I förskolans utemiljö är det vanligt att det finns en sandlåda på gården. Den är centralt placerad och barnen är där och leker. Enligt den nya Skollagen och förskolans reviderade läroplan ska verksamhetens innehåll vila på vetenskaplig grund och beprövad erfarenhet. Detta gäller även den verksamhet som pågår i sandlådan. Men vad är det som sker när sanden, barnen och lekredskapen möts i sandlådan? Detta är en kvalitativ studie som utifrån ett intra-aktivt perspektiv syftar till att synliggöra hur sanden i sandlådan, lekredskap och de yngsta barnen (1-3 år) skapar möjligheter och villkor för lek och meningsskapande. Utifrån fotografier, anteckningar och videofilm har nya begrepp skapats för att kunna beskriva och förklara det som sker i sandlådan. Resultaten visar på en ständig rörelse där sand, barn och lekredskap förflyttas, förändras och förvandlas. Barn, sand och lekredskap leker tillsammans i ömsesidiga och sammanvävda intra-aktioner. Studiens resultat bidrar till att visa på dessa komplexa processer och hur små barn, med hela sin kropp och alla sinnen, medvetet tillsammans med sanden och lekredskapen skapar ny mening och nya möjligheter.In the preschool outdoor environment, it is common that there is a sandbox. It is centrally located and the children are there and play. According to the new Education act and Curriculum for the Preschool Lpfö 98 (Revised 2010) the content should be based on scientific evidence and proven experience. This also applies to the activities being performed in the sandbox. But what is happening in the sand, when the children and play equipment come together in the sandbox? This is a qualitative study based on an intra-active perspective, whose purpose is to visualize how the sand in the sandbox, the playground equipment and the youngest children (1-3 years) create opportunities and conditions for play and meaning. Based on photographs, notes and video, new concepts are created to describe and explain what happens in the sandbox. The results show a continuous movement in which sand, children, and playground equipment is moved, changed and transformed. Children, sand and playground equipment play together in mutual and intertwined intra-actions. The findings in the study help to demonstrate how these complex processes and young children, with the whole body and the senses, consciously together with the sand and play equipment create new meaning and new possibilities.
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Muir, Robert James. "Zooarchaeology of Sand Canyon Pueblo, Colorado." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0026/NQ51905.pdf.
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Hock, Kuah Teng. "Numerical simulation of sand casting process." Ohio : Ohio University, 1987. http://www.ohiolink.edu/etd/view.cgi?ohiou1183046313.
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Bolouri-Bazaz, Jafar. "Sand subject to biaxial cyclic loading." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391711.
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Mollins, Lee Hamilton. "The design of bentonite-sand mixtures." Thesis, University of Leeds, 1996. http://etheses.whiterose.ac.uk/4122/.
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One-dimensional and isotropic swelling tests, hydraulic conductivity tests and triaxial compression tests have been performed at applied stresses up to 450kPa on sodium bentonite powder, sand and compacted sodium bentonite-sand mixtures (5, 10, and 20% bentonite by dry weight). This was done to investigate the use of bentonite improved soils for waste containment, and study the fundamental geotechnical properties of bentonite-sand mixtures using a classical soil mechanics approach. It was found that air dried bentonite powder swells to reach a state described by a single straight line on a plot of void ratio against the logarithm of vertical effective stress, regardless of preparation technique. The gradient of this line was intermediate between a normal consolidation and rebound line for the same material indicating a different sample fabric when allowed to reach equilibrium from an initially dry state rather than the conventional fully saturated state. Swelling of bentonite-sand mixtures expressed in terms of the clay void ratio show a deviation from bentonite behaviour above a threshold stress which depends on the bentonite content. From this behaviour, a modified principle of effective stress has been proposed. Similar swelling relationships were found for samples under an isotropic confining stress. Hydraulic conductivity data for bentonite and mixtures indicate an approximately linear relationship between the logarithm of hydraulic conductivity and the logarithm of void ratio. Observed differences in hydraulic conductivity between bentonite and mixtures, when represented in terms of the clay void ratio, are attributed to the sand porosity and tortuosity. From a stress-dilatancy analysis of triaxial data, the peak strength of mixtures has been shown to depend on the sand relative density. This parameter indicates how the material will behave during shear. A threshold sand relative density has been postulated, which is dependent on the axial strain. Below the threshold value, it is likely that the stress-strain behaviour will be characteristic of the bentonite alone. A design model based on the clay void ratio, sand porosity and tortuosity, and sand relative density is presented, enabling the hydraulic conductivity or strength of a mixture to be estimated.
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Promputthangkoon, Panu. "Liquefaction of Sand-Tyre Chip Mixtures." Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515469.
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Ní, Dhúill Gráinne Bríd. "Autobiography and fiction in George Sand." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627442.
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Börjesson, Sanna. "Virtuell lek med sand och vatten." Thesis, Linnéuniversitetet, Institutionen för design (DE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-43552.
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‘Virtuell lek med sand och vatten’ är ett projekt i samarbete med HAGS Aneby AB. Syftet med lekredskapet är att reducera barns stillasittande vardag. Genom att koppla samman fysiskt stimulerande lek med möjligheterna inom de virtuella leksaksvärldarna är målet att underlätta övergången mellan de digitala, passiva spelaktiviteterna och mer fysiskt stimulerande aktiviteter. Med utgångspunkt i den klassiska sandlådan ville jag undersöka och utveckla sandlådans potential. Med lekredskapets möjligheter till varierad aktivitet och rörelse, samt ramen och sandens höjdanpassning är målet att bjuda in en större bredd av besökare och bland annat öka tillgängligheten för vuxna och besökare med funktionshinder.Virtuell lek med sand och vatten
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Jansson, Adam. "Further development of Sand Bed Burner." Thesis, Karlstads universitet, Science, Mathematics and Engineering Education Research (SMEER), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-33657.
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To determine whether a weapon system meets the requirements set for insensitivity, the system is getting exposed for special tests. One of these tests shows how the system reacts when it ends up in a fire. This test is called the "Fast Cook-Off (FCO) Test", called FCO-test, and performed with a Sand Bed Burner (SBB). According to primary testing provision, the fuel for this test is used of jet fuel such as Jet A-1. A project at Bofors Test Center (BTC) is in progress to use an alternative fuel of Liquefied Petroleum Gas (LPG). This fuel is very advantageous compared to jet fuel in terms of environmental impact, work environment and testing costs. The aim of this thesis is to improve the existing test equipment considering fire over the entire surface and solve the problems with dropped gas flow and freezing of gas bottles. SBB works in the sense that the new petrol LPG streams into the SBB and expands in the free space below the sand bed before the gas will diffuse through the bed of sand and the fire engulfs the object. LPG is a condensable gas that requires oxygen. LPG exceed from liquid to gas phase and needs a large lateral surface to take up more energy which results in better evaporationto the phase transfer. Reaction products from complete combustion of LPG are only water vapor and carbon dioxide, the same as in your exhaled air. To solve these problems it was needed to change P11 composite bottles to P45 steel bottles to get a longer evaporation and larger lateral surface. Four flow inlets instead were used of one into SBB for a better stream in the free space under the sand bed. Propane regulators used to get a lower and more constant flow to avoid freezing. Compressed airconnected tothe SBB to geta mix between oxygen and LPG. The result shows in higherheat radiation efficiency even though the flow was settled down to 1/3 with the new propane regulators. In test 2 the value was 37 kW/m2 and in test 7 it was around 57 kW/m2. Because of a smaller flow and bigger steel bottles the freezing disappeared. Smaller grain of sand together with four inlets and compressed air gave a more complete combustion.
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Crawford, Adrian C. "The deformation of channel sand bodies." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326973.
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QUARESMA, HELENA DAHIA. "CUBICAL TRIAXIAL TESTS IN SATURATED SAND." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1997. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2068@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOEste trabalho apresenta um estudo experimental detalhado do comportamento tensão-deformação-resistência de uma areia saturada submetida a uma condição tridimensional de carregamento. Os ensaios foram realizados nos equipamentos triaxiais cúbico e convencional. O equipamento triaxial cúbico apresenta a vantagem de controlar a magnitude das três tensões principais independentemente ( sigma 1 , sigma 2 , sigma 3 ) sob condições drenada e não drenada. Para o desenvolvimento do trabalho foi utilizada uma amostra de areia calcárea. Os corpos de prova utilizados foram moldados por pluviação submersa. No programa experimental foram realizados ensaios especiais, seguindo diferentes trajetórias de tensão. Este programa foi elaborado de modo a verificar a influência de cada parâmetro de tensão individualmente e os efeitos da anisotropia inicial de areias preparadas por pluviação submersa. Verifica-se através dos resultados de ensaios drenados que as deformações cisalhante e volumétrica são maiores na condição axissimétrica do que na de deformação plana. Tal observação equivale, em solicitações não drenadas, a um acréscimo de poropressão mais acentuado na condição axissimétrica. O comportamento anisotrópico de areias também é revelado com base em ensaios com diferentes direções ( alfa ) da tensão principal maior. Nos ensaios onde alfa = 90 graus Celsius (direção do carregamento perpendicular à de deposição do solo), ocorrem variações de deformação volumétrica e cisalhante bem mais acentuadas do que para alfa = 0 . O programa experimental mostrou ainda que areias calcáreas não cimentadas não apresentam comportamento tensão-deformação acentuadamente diferente do comportamento de areias de quartzo, mais usuais no Brasil.
The subject of this dissertation is a detailed experimental study of the stress-strain-strength behavior of saturated sand under three-dimensional loading condition.The investigation was carried out in a cubic triaxial and a conventional apparatuses. The cubic triaxial apparatus has the advantage of independently controlling the magnitude of the three principal stresses (sigma1, sigma2, sigma3 ) under drained and undrained conditions. Reconstituted specimens of calcareous sand were used in all tests reported in this thesis.The specimens were prepared by pluviation of the sand in destilled water. Special tests were performed following different 3D stress paths. The experimental program was designed for checking the influence of each stress parameter individually. The effects of the inicial anisotropy of sands, caused by the water pluviation method, were also investigated.The results of the drained tests show that the shearing and volumetric strains are larger under axysimmetric than under plane strain condition. In undrained tests this observation would be equivalent to obtaining larger porepressure under axysimmetric conditions. The anisotropic behavior of sands is also noted in tests with different directions (alfa) of the major principal stress. In tests where alfa = 90 Celsius degrees ( direction of load perpendicular to pluviation) the variations in volumetric and shearing strains are much more accentuated than for alfa = 0.The experimental program also shows that the stress-strain behavior of uncemented calcareous sands is not significantly different from the behavior of quartz sands, which are more common in Brazil.
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Svensson, Andreas, and Mattias Johansson. "Klimatkompensering : Guldet som blev till sand?" Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18849.
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En ny trend inom flyg- och resebranschen är ett system som tillåter flygresenärerna attkompensera för de utsläpp som resan medför. Det har dykt upp en rad olika organisationersom flyg- och resebolagen använder sig av som återför de pengar som flygresenären betalar iavgift, till projekt som verkar för att skapa en bättre miljö. Det omfattar åtgärder från attplantera regnskog till forskningsprojekt som ska verka för att förbättra miljön. Avgiften somresenären betalar räknas ut med hjälp av en kalkylator där resenären fyller i var resan ska gå,därefter räknar kalkylatorn ut hur mycket koldioxid som kommer att släppas ut perpassagerare. Charterresebolaget Apollo, som vi valt att studera, har erbjudit sina kunderklimatkompensering genom företaget GreenSeat i drygt ett år. Produkten har inte fått detgenomslag som förväntades av företagen i branschen.Syftet med uppsatsen är att undersöka varför inte fler konsumenter väljer attklimatkompensera när de reser med flyg. Vi ska också ta reda på vad som krävs för att fåkonsumenterna att klimatkompensera oftare vid resor med flyg. I uppsatsen har vi både ettpositivistiskt och hermeneutiskt förhållningssätt. Vi har gjort en kvantitativenkätundersökning med totalt 122 respondenter som valts ut genom ett bekvämlighetsurval.Resultatet av enkätundersökningen har legat till grund för arbetet med analysen ochslutsatserna. Resultatet har därefter tolkats av oss i avsikt att ge Apollo rekommendationer omhur de ska få fler konsumtenter att klimatkompensera i framtiden. I uppsatsen har vi använtoss av en induktiv ansats. Vi använde primärdata i form av en enkätundersökning ochsekundärdata i form av litteratur och tidigare gjorda studier.Slutsatserna i vår undersökning är att de konsumenter som känner till vadklimatkompensering innebär är positiva till produkten. Vår enkätundersökning visar att cirka80 % av de 122 respondenterna har en positiv inställning till klimatkompensering. Detindikerar på att det finns en stor potential för klimatkompensering men att det idag saknaslättillgänglig information för konsumenterna att ta del av. Apollo lyckas inte övertygakonsumenterna att klimatkompensering är ett bra sätt att stödja miljön, vilket leder till attkonsumenterna inte vill betala för något som de inte tror på eller känner till.För att få fler konsumenter att klimatkompensera måste informationen som ges ut till deminnehålla starka argument för att locka deras intresse och den bör också visa konkretaexempel på effekter som klimatkompensering bidrar med. Tillgången till produkten måsteockså bli enklare än vad den är idag. Det ska vara lätt och smidigt att klimatkompenseraannars är risken att konsumenten väljer bort det på grund av bekvämlighetsskäl.Uppsatsnivå: C
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Ahmed, Naif Baker. "The stabilization of Aeolian sand dunes." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/1099/.
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Barr, A. D. "Strain-rate effects in quartz sand." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/15989/.
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Soil-filled wire and geotextile gabions are commonly used to construct defensive infrastructure in military bases, where the attenuating properties of soil are used to protect personnel and key assets from the effects of blast and fragmentation. The behaviour of soils in these extreme loading regimes is not well understood, and so designers require data at these high pressures and strain rates in order to develop robust soil constitutive models and adapt to new threats. The one-dimensional compression of three sandy soils was compared under quasi-static loading to axial stresses of 800 MPa. Trends in behaviour were identified with respect to the particle size distributions of the soils, and were found to correspond to the relationships observed at lower stresses. Split Hopkinson pressure bar (SHPB) experiments were used to investigate the strain rate dependence of this behaviour. Measurements of radial stress indicated that an increase in the axial stiffness of the soils between strain rates of 10^-3 s^-1 and 10^3 s^-1 was likely due to radial inertial effects. Potential sources of error were identified in the SHPB experiments, leading to the implementation of a dispersion-correction algorithm, which improved the measurement of axial stresses. Analysis of the electromagnetic activity around the specimen isolated the cause of erroneous radial stress measurements. Quasi-static experiments were used to investigate the effect of moisture content on soil stiffness at high pressures, and SHPB experiments at the same moisture contents were used to consider the effect of strain rate on the quasi-static behaviour. Recovery SHPB experiments were designed to enable reliable post-test particle size analyses to be performed, and the range of moisture contents was expanded to investigate the change in soil behaviour on reaching full saturation. Reduced triaxial compression experiments were used to define the yield surface of a sand to a mean stress of 400 MPa. The high-pressure compression and yield strength data was used to calibrate LS-DYNA soil models, and the performance of the models was assessed through modelling of the SHPB experiments.
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Martin, Sophie. "George Sand et les milieux picturaux." Paris 4, 1999. http://www.theses.fr/1998PA040142.
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Ce travail de recherches sur George Sand et les milieux picturaux a pour ambition de présenter une mise au point précise, des influences et évènements qui ont fait naitre chez George Sand l'amour de la peinture et des peintres passion dont elle s'est nourrie et a nourri son œuvre : la présence constante de l'art pictural dans la vie et l'œuvre de la romancière s'impose comme une évidence. Trois axes d'étude différents, et pourtant liés, permettent de faire lumière sur la personnalité riche et complexe de George Sand. La première partie étudie le contexte artistique familial et sensible qui porta la jeune fille vers la peinture ainsi que la place déterminante et omniprésente de la création picturale dans sa vie. Sa propre production artistique et l'inspiration de la peinture dans son œuvre littéraire y sont, de même, analysées. La seconde partie, établit l'influence qu'elle exerça sur les peintres et comment elle fut perçue par ces artistes et examine, en particulier, son amitié avec Delacroix. Enfin, la dernière partie fait l'objet de l'étude de sa perception picturale et son rôle au sein des différents mouvements picturaux de son siècle : le romantisme, la peinture de paysage et l'école de Barbizon.
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Tarouilly, Patricia. "George Sand, la cause du peuple." Brest, 1993. http://www.theses.fr/1993BRES1008.
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Etude de l'oeuvre (romans ; contes ; nouvelles ; pièces de theatre, récits autobiographiques ; articles) et de la correspondance de George Sand (1804-1876), infatigable défenseur du peuple, avocat d'une cause sociale et politique. Première partie : le personnage sandien, au service d'une nouvelle conception de l'humanité, généreuse et aimante. Deuxième partie : un univers propice à l'unité sociale (réhabilitation du peuple dans un décor qui a les couleurs d'un monde meilleur, mise en valeur de sa langue, de ses coutumes, de sa musique, de ses croyances). Troisième partie : analyse d'une pensée très personnelle (idées politiques, religieuses, sociales, philosophiques)The aim of this thesis is to show how essential is the part of the lower classes in the whole George Sand's works. The first part is given over to analyze the idealized pictures of proletarians, peasants, workers, servants, given by the writer and the meaning of these generous, virtuous, just men and women who represent the ideal human type. George Sand loves people, and "her" people carries hope of a better world. The second chapter shows the characteristics of sandian world. This ideal world is a rustic and romantic one, it's a world where knowledges, education and progress are at social justice service. This chapter studies too the litterary art the writer -who is exclusively read by the upper classes- uses to bring out the lower classes'way of life and cultural patrimony. The last chapter is the study of george sand's fight for justice and equality through the analyses of her social, political and philosophical ideas, ideas sprang from her own personnal story and from the litterary and philosophical influences of great thinkers like Rousseau, Lamennais, Saint-Simon. It studies too her attitude in front of the great social events of her century
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Türk, Serhat, and Kristoffer Müller. "Kinetic Art Table : Polar sand plotter." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296307.
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CNC machines are used with plenty of different implementations, one of which is in this project where a polar CNC machine was used to draw mesmerizing patterns on a table with fine sand. This construction read G-code and converted it to polar coordinates. The capabilities of what the plotter could draw were tested, everything from ODE plots to custom-made patterns and drawings with the help of Sandify. Although the patterns were drawn properly with small errors the ODE was too difficult to draw because it required a smaller magnetic ball and an even more precise system than what was used. This machine also generated noise at roughly 33 dB when it was in use.CNC-maskiner används med massor av olika implementationer, en av dem är i det här projektet där en polar CNC maskin användes för att rita fascinerande mönster på ett bord fylld med fin sand. Denna konstruktion läste in G-kod och konverterade det till polära koordinater. Förmågan av vad maskinen kunde rita testades, allt från ODE grafer till specialtillverkade mönster och ritningar med hjälp av Sandify. Aven om de olika mönstren ritades ordentligt men med mindre små fel var ODE för svårt att rita på grund av att det krävde en mindre magnetisk kula och ännu mer noggrannhet jämfört med detta system. Denna maskin alstrade också ljud på cirka 33 dB under användning.