The thesis project aims to investigate a Form Finding process as a design tool as well as the generator of a structural system, in this case a process of intersecting cones to create surface network logic, for a sailing school at Lidingö, Stockholm. Specifically the research aims at the blurring of the cone shape and the diffusion of a cellular logic by a process that increases the complexity and definition of the whole system. And as a result, a design method that generates and shapes the space.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This article describes consolidated Direct Cut tests not drained in the laboratory, carried out on samples of volcanic sand from Arequipa, Peru. The samples were tested for maximum dry density and optimal moisture content; Furthermore, they were reinforced with polypropylene fibers and cement. The samples were reinforced with 0.5% cement with respect to the dry weight of the sample soil and tested at 3 days. The added polypropylene fiber has dimensions of 48 mm wide with 1.2855 mm long and 0.3325 mm thick, and they were used in different percentages regarding the dry weight of the soil sample (0.25% -0.75% -1.00% -1.25%). The results of the tests indicated that the addition of polypropylene fibers together with the cement increases the resistance to cut proportionally to the amount of fiber up to 1% of fiber, this being the best result obtained, decreasing the resistance as the percentage of polypropylene fiber.

3D and 2D trajectory data of sand grains saltating over a bed are presented from highspeed camera measurements. They were obtained at Zingst peninsula and in laboratory using a wind tunnel. Trajectories, calculated with a Runge-Kutta procedure, using values of the mean wind profile and the air flow were fitted to the measured ones. The trajectory with the lowest RMSE against the measured one was used to estimate the grain diameter of the saltating grain. Also ejection and impact angle, ejection and impact speed of the grain were determined. The results confirm earlier findings that ejection angles decreases with increasing grain diameter. Ejection angles between 57° and 27° for fine (63-200 μm) and middle (200-630 μm) ejecta and between 38° and 20° for coarse grains (630-2000 μm) were found. The impact angle β increases with increasing grain diameter. Impact angles between 8° and 15° for fine impactors and between 12° and 36° for middle and coarse grains were found. Additionally the ratio between the mean ejection angle α and mean impact angle β, which decrease with increasing grain diameter (Rice et al., 1995), could be confirmed. The ration between the ejection speed ue and impact speed ui was found nearly the same for all determined grain sizes, but the grains ejected from the bed had an average speed of one order of magnitude less than the impact speed.

Traditional sand analysis is labor and cost-intensive, entailing specialized equipment and operators trained in geological analysis. Even a small step to automate part of the traditional geological methods could substantially improve the speed of such research while removing chances of human error. Digital image analysis techniques and computer vision have been well developed and applied in various fields but rarely explored for sand analysis. This research explores capabilities of remote sensing digital image analysis techniques, such as object-based image analysis (OBIA), machine learning, digital image analysis, and photogrammetry to automate or semi-automate the traditional sand analysis procedure. Here presented is a framework combining OBIA and machine learning classification of microscope imagery for use with unconsolidated terrigenous beach sand samples. Five machine learning classifiers (RF, DT, SVM, k-NN, and ANN) are used to model mineral composition from images of ten terrigenous beach sand samples. Digital image analysis and photogrammetric techniques are applied and evaluated for use to characterize sand grain size and grain circularity (given as a digital proxy for traditional grain sphericity). A new segmentation process is also introduced, where pixel-level SLICO superpixel segmentation is followed by spectral difference segmentation and further levels of superpixel segmentation at the object-level. Previous methods of multi-resolution and superpixel segmentation at the object level do not provide the level of detail necessary to yield optimal sand grain-sized segments. In this proposed framework, the DT and RF classifiers provide the best estimations of mineral content of all classifiers tested compared to traditional compositional analysis. Average grain size approximated from photogrammetric procedures is comparable to traditional sieving methods, having an RMSE below 0.05%. The framework proposed here reduces the number of trained personnel needed to perform sand-related research. It requires minimal sand sample preparation and minimizes user-error that is typically introduced during traditional sand analysis. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Crustacean spermatozoa are among the most peculiarly modified germ cells in the animal kingdom. Many of their striking cytological specializations may be observed in the sperm cells or Emerita analoga, the so-called sand crab. This animal has been used by the writer for studies on spermatogenesis and on spermatozoan behavior during the summer or 1951, 1952, and 1953 at the Pacific Marine Station.

No description available.

Bedding angle is a fundamental property of a particulate system that describes the resistance to rolling motion of a single grain. Mean trends of the bedding angle of sand have been described in the literature. This research expands upon the work to date by investigating the distribution of bedding angle for sands. Experimental measurements of bedding angle distributions are made for eight sands. Additionally, a theoretical description of the variability of bedding angle as a function of random grain size is developed and implemented numerically. The shape of the bedding angle distribution is found to be simulated well from the numerical simulations; the mean value of bedding angle is best predicted from particle roundness and empirical relationships. Together, these procedures provide a means of predicting the complete distribution of bedding angle for any given sand.

No description available.

Denna rapport har undersökt några av de vattenreningsmetoder som används vid fordonstvättar i Sverige. Fokus har lagts vid kemisk-, biologisk-, elektrokemisk-, hydrocyklon-, jonbytar-, filter- och membranrening. Arbetet syftade till att finna en billig och miljövänlig metod som med lite underhåll skulle kunna användas, vid lastbilstvätten på Arla Foods mejeri i Kallhäll, för att möjliggöra recirkulering av tvättvattnet. Ett kolonnförsök med filtermaterialen natursand, Petrit E och ZinkStop utfördes för att undersöka materialens lämplighet att användas vid fordonstvättar. Ur reningssynpunkt utmärkte sig Petrit E som den enda filtermassan som klarade av att sänka tungmetallkoncentrationerna i vattnet under de befintliga gränsvärdena. Materialet bedömdes dock ha kortare livslängd än ZinkStop vilket gör att dess miljömässiga och ekonomiska hållbarhet därför inte bedömdes vara lika god som ZinkStopens. ZinkStop uppvisade god rening av de flesta problematiska metaller som släpps ut från fordonstvättar. Dock gav materialet ett högt initialt kromutsläpp då vatten pumpades genom det. Detta gör att materialet riskerar att överskrida anläggningens gränsvärden. Natursanden uppvisade betydligt lägre reningsgrad för de uppmätta parametrarna. För att Arla Foods ska uppnå en låg driftkostnad och minska kemikalieförbrukningen för sin fordonstvätt rekommenderas ett biologiskt reningssystem. / This thesis investigates some of the wastewater treatment methods that exist at car washes in Sweden. The main treatment methods that have been described are chemical, biological, electrochemical, hydrocyclone, ion exchange, filter and membrane treatment. The report aimed to find a cheap and environmentally friendly treatment option that requires little maintenance and could be used, at the truck wash at Arla Foods´ dairy in Kallhäll, to enable recirculation of water. A column experiment was also carried out in which the filter materials natural sand, Petrit E and ZinkStop were tested to determine their suitability to be used at vehicle washes. The experiment showed that Petrit E was the only material which managed to reduce the heavy metal concentrations below the current legal limits. However, the material was not believed to last as long as ZinkStop, which makes it less suitable than ZinkStop from an environmental and economic standpoint. ZinkStop also showed a good removal of most metals but did result in a high initial chromium emission. The sand had lower removal rates of most metals. To achieve low operational costs at Arla Foods’ dairy and to lower the consumption of chemicals a biological treatment system is recommended.

Titan is an important planetary body for aeolian research because of the vast equatorial sand seas that span 20% of its surface. Previous studies have determined the general margins of sand and sand seas on Titan, and have speculated about the source of Titan's sand. Little research has been done concerning where sand collects in the sand seas. Additionally, the relationships be-tween material distributions as observed by the Cassini Visual and Infrared Mapping Spectrometer (VIMS) and the history of erosion and transportation of sediments across equatorial latitudes is not fully understood. This work focuses on an in depth evaluation of sand distribution and abundance across the sand seas, and presents evidence for an alternative sand source. This work also addresses a potential stratigraphy for the equatorial regions based on the excavation of materials from impact craters. We mapped the extent of relative sand abundances by comparing different Cassini image datasets, largely by mapping where the Imaging Science Subsystems (ISS) regions were darkest, in-dicating the presence of more sand. Our results revealed that greater abundances of sand accumu-late near the eastern margins of sand seas. This is in agreement with previous studies that demon-strated general W to E transport, and fits a general model of sand transport across the sand seas to collect at the downwind margins, perhaps ahead of topographic obstacles that mark the eastern ends of the sand seas. Additionally, we found that the largest continuous expanse of abundant sand de-posits lie across Belet, a large sand sea that occupies a broad equatorial lowland. Another sand sea of interest is Shangri-La, which has a recessed SE margin adjacent to the broad, albedo-bright de-pression Xanadu. We also found abundant sand deposits within Shangri-La across a corridor be-tween highlands and along the SE boundary of the sand sea. Dune crest orientations across eastern Shangri-La indicate WNW to ESE transport in the region. We propose that the low topography of Xanadu, coupled with the strong gradient in albedo between Shangri-La and Xanadu would gener-ate atmospheric disturbances similar to those responsible for transporting sand across positive changes in elevation on Mars, and may be responsible for the distinct boundary. VIMS-blue materials are generally associated with water ice mixed with organic com-pounds. We found that VIMS-blue surfaces across equatorial latitudes tend to be directly adjacent to and upwind of sand seas. This, coupled with geomorphological observations of erosional charac-teristics and examination of material properties, suggests that sand could at least in part be derived from VIMS-blue materials. We propose 3 environments (alluvial fans, dry lakebeds, and ejecta from impact craters) for sand production using this interpretation and making comparisons with SAR, ISS, and VIMS imagery. Modeling suggests that Titan's lithosphere significantly thickened 500 m.y. ago. We inter-pret an elongate exposure of VIMS-blue materials adjacent to Aztlan to be a rift caused by a thick-ening of the lithosphere, similar to many of the other icy bodies of the solar system. Our interpreta-tion is further supported by the distribution of cryovolcanic features alongside the proposed rift. Anomalous VIMS-blue and bright regions within eastern Xanadu are distributed in a pattern that resembles a multi-ringed impact basin. Additionally, when a value threshold was applied to ISS imagery, a bright circular feature was revealed within western Xanadu. These observations suggest two large impacts may have been significantly responsible for creating Xanadu. Comparisons of impact crater models with VIMS imagery of Paxsi, Menrva, Sinlap, Selk, and other craters suggest alternating layers of VIMS-bright and VIMS-blue cover much of the equatorial latitudes of Titan. We completed ground penetrating radar (GPR) and global positioning system (GPS) surveys across margins of the Kelso Dunes to evaluate the effects of fluvial interaction on sand depth. Our terres-trial model was compared to sand seas on Titan that appear to also have interactions with fluvial channels. Distributions of sand suggest that in both the Kelso Dunes and on Titan, fluvial obstruc-tion is temporary and on Titan isolated across small regions. This work leads to a better understanding of sand production, accumulation and transport on Titan and in sand seas in general, and reveals a basic stratigraphy of the equatorial regions of Titan. This region is of particular interest because it is the landing site of the Dragonfly mission, now in design.