Relevant bibliographies by topics / Sand retention

Academic literature on the topic 'Sand retention'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Sand retention"

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Wang, Dongmei, Chunxiao Li, and Randall S. Seright. "Laboratory Evaluation of Polymer Retention in a Heavy Oil Sand for a Polymer Flooding Application on Alaska's North Slope." SPE Journal 25, no. 04 (May 14, 2020): 1842–56. http://dx.doi.org/10.2118/200428-pa.

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Summary For a polymer flooding field trial in a heavy oil reservoir on Alaska's North Slope, polymer retention is a key parameter. Because of the economic impact of retention, this parameter was extensively studied using field core material and conditions. In this paper, multiple types of laboratory measurements were used to assess hydrolyzed polyacrylamides (HPAM) polymer retention, including a brine tracer, effluent viscosity, total effluent organic carbon, and effluent chemiluminescent nitrogen. Retention tests were conducted in different Milne Point Schrader Bluff sands, with extensive permeability, grain size distribution, X-ray-diffraction (XRD), and X-ray fluorescence (XRF) characterizations. Several important findings were noted. Polymer retention based on effluent viscosity measurements can be overestimated unless the correct (nonlinear) relation between polymer concentration and viscosity is used. Polymer degradation (either mechanical or oxidative) can also lead viscosity-based measurements to overestimate retention. Inaccessible pore volume (PV) (IAPV) can be overestimated if insufficient brine is flushed through the sand between polymer banks. Around 100 PVs of brine may be needed to displace mobile polymer to approach a true residual resistance factor and properly measure IAPV. Even for a sandpack with kwsor = 20 md, IAPV was zero for HPAM with a molecular weight (Mw) of 18 MM g/mol. Fine-grained particles (<20 µm) strongly impacted polymer retention values. Native NB#1 sand with a significant component of particles <20 µm exhibited 290 µg/g, while the same sand exhibited 28 µg/g after these small particles were removed. Polymer retention did not necessarily correlate with mineral composition. The NB#1, NB#3, and OA sands had similar elemental and clay compositions, but the NB#1 sand exhibited ∼10 times higher retention than the NB#3 sand. Polymer retention did not necessarily correlate with permeability. NB#1 sand exhibited much higher retention than OA sand, even though NB#1 sand was twice as permeable as OA sand. No evidence of chromatographic separation of HPAM molecular weights was found in our experiments. Although retention tended to be greater without a residual oil saturation (than at Sor), the effect was not strong. Aging a core (with high oil saturation) at 60°C reduced HPAM retention by a factor of two. Under similar conditions, polymer retention was greater for a higher Mw HPAM (18 MM g/mol) than for a lower Mw HPAM (10 to 12 MM g/mol). In many cases with high polymer retention values (e.g., 240 µg/g), polymer arrival at the end of the core was relatively quick, but achieving the injected concentration occurred gradually over many PVs. This effect was not caused by chromatographic separation of polymer molecular weights. Results from modeling of this behavior were consistent with concentration-dependent polymer retention. The form assumed for the retention function in a simulator can have an important impact on the timing and magnitude of the oil response from a polymer flood. Field-based observations can underestimate polymer retention, depending on when the tracer and polymer concentrations were measured and the assumptions made about reservoir heterogeneity.
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Feng, Yuqing, Xavier Choi, Bailin Wu, Qinggong Wang, Chong Yau Wong, Seng Lim, Bahrom Madon, et al. "A numerical assessment of the effect of particle size distribution and operation parameters on sand retention over sand screens." APPEA Journal 55, no. 2 (2015): 476. http://dx.doi.org/10.1071/aj14111.

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Sand screens are often installed in sanding prone wellbores to control sand production. A selection of optimal sand screen apertures is required to minimise sand production and maximise fluid production. This has been accomplished historically on empirical correlations, rules of thumb and laboratory sand retention experiments. These methodologies have a number of limitations that can lead to different screen types and sub-optimal screen apertures to be selected. Using discrete element models (DEMs), many design/operating parameters similar to a specific wellbore condition can be simulated and tested in parallel. Most importantly, the detailed particle scale information helps to give a detailed understanding of the underlying mechanisms controlling the sand retention process. This extended abstract presents an investigation of the sand production problem from wire wrapped screens and slotted liners through the use of a DEM for the solid flow with fluid flow coupling using computational fluid dynamics (CFD). Information about particle sizes and distributions incorporated in the DEM model are based on measurement data from reservoir sands. The focus is on the effect of particle size distributions, particle concentration, and the slot width on sand retention across a slotted sand screen.
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Hunt, H. W., A. M. Treonis, D. H. Wall, and R. A. Virginia. "A mathematical model for variation in water-retention curves among sandy soils." Antarctic Science 19, no. 4 (October 1, 2007): 427–36. http://dx.doi.org/10.1017/s0954102007000703.

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AbstractEquations were developed to predict soil matric potential as a function of soil water content, texture and bulk density in sandy soils. The equations were based on the additivity hypothesis - that water-retention of a whole soil depends on the proportions of several particle size fractions, each with fixed water-retention characteristics. The new model is an advancement over previously published models in that it embodies three basic properties of water-retention curves: a) matric potential is zero at saturation water content, b) matric potential approaches -∞ as water content approaches zero, and c) volumetric water content in dry soil is proportional to bulk density. Values of model parameters were taken from the literature, or estimated by fitting model predictions to data for sandy soils with low organic matter content. Most of the variation in water-release curves in the calibration data was explained by texture, with negligible effects of bulk density and sand particle size. The model predicted that variation in clay content among soils within the sand and loamy sand textural classes had substantial effects on water-retention curves. An understanding of how variation in texture among sandy soils contributes to matric potential is necessary for interpreting biological activity in arid environments.
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Rahayu, Rahayu, Yang Geun Mo, and Choi Joon Soo. "Amendements on Salinity and Water Retention of Sand Base Rootzone and Turfgrass Yield." SAINS TANAH - Journal of Soil Science and Agroclimatology 16, no. 1 (June 30, 2019): 103. http://dx.doi.org/10.20961/stjssa.v16i1.28132.

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This research was column pot experiment with turfgrass was Kentucky bluegrass (<em>Poa pratensis</em>) plant irrigated saline irrigation and the column soaked in saline water. Rootzone profile consisted of 20 cm using saline lake dredged up sand. The sand amendments of the root zone were soil, zeolite, bottom ash, and peat. The mixtures of topsoil were; 90% sand + 10% peat moss, 80% sand + 10% soil + 10 % bottom ash, 80% sand + 20% soil, 90% sand + 5% peat + 5% zeolite, and 80% sand + 20% bottom ash. Interruption layer with coarse sand with diameters over 2 mm of 20 cm and 10 cm loamy soil as the bottom layer of the column. The result showed that Kentucky bluegrass could grow in sand based growing media amended by peat, sandy loam soils, bottom ash and zeolite being irrigated by 2 dS m<sup>-1</sup> saline water. Sand-based growing media amended by peat resulted in the highest clipping weigh but showed the highest salt accumulations. Sand amended by bottom ash and applied gypsum decreased clipping weigh, decreased SAR and increased calcium (Ca) when compared to the soil + peat (SP). Sand amended by zeolite and gypsum decreased clipping weight, decreased sodium adsorption ratio (SAR) and higher Ca. Higher soil moisture retention of growing media promoted the growth of Kentucky bluegrass in spring, and lower moisture content promoted the growth in summer and fall season.
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Wei, Wenjun, Bing Wang, and Xiang Niu. "Soil Erosion Reduction by Grain for Green Project in Desertification Areas of Northern China." Forests 11, no. 4 (April 22, 2020): 473. http://dx.doi.org/10.3390/f11040473.

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The Grain for Green Project (GGP) encompasses most desertification areas in northern China where fragile soils are susceptible to erosion given the arid and semi-arid climate, low vegetation cover, and strong winds. We collected relevant data through ecological surveys and literature review to quantify total sand fixation and dust retention in 2015 based on different restoration methods, forest types, ecological function zones, and key desertification areas. Our results showed that cropland and wasteland afforestation increased sand fixation and dust retention, whereas facilitate afforestation was less effective in doing so. Further, sand fixation and dust retention values were higher in ecological and shrub forests compared with economic forests, as well as in wind erosion zones compared with wind-water erosion and water erosion zones. Moreover, 43.28% and 44.75% of total sand fixation and dust retention, respectively, were concentrated in important windbreak and sand fixation areas. Similarly, 60% and 30% of total sand fixation and dust retention, respectively, occurred in sandstorm paths and sources. Lastly, policy factors primarily influenced the spatial distribution patterns of both sand fixation and dust retention. Based on these results, enhancement of GGP efficacy into the future will rely on increased restoration efforts specifically aimed at planting more drought-resistant shrubs and native vegetation as doing so will enhance sand fixation, dust retention, and thus, the ecological integrity of these valuable and fragile desert ecosystems in northern China.
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Murdoch, Charles L., and David L. Hensley. "Physical Properties of Hawaiian Golf Course Sands." HortTechnology 4, no. 2 (April 1994): 150–53. http://dx.doi.org/10.21273/horttech.4.2.150.

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Physical properties (particle size distribution, bulk density, capillary pore space, non-capillary pore space, hydraulic conductivity, and water retention) of three imported silica sands (Perth, Malaysian, and Newcastle), a man-made sand product (Mansand), and coral sand alone and in peatmoss mixtures were determined to evaluate their suitability as golf-green substrates. Based on laboratory evaluation of physical properties, the silica sands amended with peatmoss (15%) were superior to coral sand or crushed basalt (Mansand) amended with 15% peatmoss for use in high-traffic turfgrass areas.
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Carpenter, Chris. "Evaluating Sand-Screen Performance With Sand-Retention Tests and Numerical Modeling." Journal of Petroleum Technology 68, no. 10 (October 1, 2016): 76–78. http://dx.doi.org/10.2118/1016-0076-jpt.

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Ismail, Noor Ilyana, Shibo Kuang, Mengmeng Zhou, and Aibing Yu. "Numerical investigation of non-uniform sand retention behavior in sand screens." Powder Technology 395 (January 2022): 604–17. http://dx.doi.org/10.1016/j.powtec.2021.10.016.

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Wulandari, Lies Kurniawati, and Munasih Munasih. "Blackwater Purification Using Sand Filter." Journal of Applied Philosophical Management and Innovation 1, no. 1 (December 9, 2018): 35. http://dx.doi.org/10.26805/japmai.v1i1.19.

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This study aimed to determine the effect of the thickness of the sand filter and the best residence time for water purification. The type of sand used in this study was concrete sand, and the observation was focused on turbidity (NTU) parameter. Measurements of turbidity were performed before treatment, as well as at each retention time from 1 to 9 days. The method of data analysis was Linear Regression analysis on SPSS 21 program. Blackwater was collected in the morning and afternoon, and the turbidity of each sample was 1000 and 800 NTU, respectively. Wastewater turbidity was continued to decreased along with the longer retention time. The best results were obtained from the treatment 3 (sand filter 20 cm) with 9 days retention time, in which the turbidity levels decreased to 90 NTU (morning sample), and 105 NTU (afternoon sample).
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Nguyen, Lam Quoc Cuong, and Mau Dang Nguyen. "Evaluating the screen performance in sand control design by laboratory sand retention test." Petrovietnam Journal 11 (December 16, 2022): 43–49. http://dx.doi.org/10.47800/pvj.2022.11-04.

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To produce oil and gas from unconsolidated sandstone reservoirs, sand screens are necessary to control sand flowing from the formation into the wells, causing well pluggings. In open hole completion, stand-alone sand screen is an essential component to prevent sand production, thus, selection of suitable sand screens is critical to minimize sand production and optimize the well’s production life. Nowadays, premium screens with steel meshes make the openings of the screen slots complex in shape, resulting in a very different effect of sand retention compared to the traditional screens. The sand retention test is considered a standard and must be conducted to select screen opening and size, which decides the sand prevention capacity of the screen. The paper presents the factors affecting the results of laboratory sand retention tests and proposes solution in the direction of considering the data trend rather than relying completely on the output results. The paper also brings about the evaluation method through the change the screen’s permeability to have better qualitative results compared to the traditional methods.
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Dissertations / Theses on the topic "Sand retention"

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Khaddour, Ghonwa. "Multi-scale charaterisation of the hydro-mechecanical behaviour of unsaturated sand : water retention and triaxial responses." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI051/document.

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Avec les récents développements des mesures de champs, il est devenu possible deréaliser des expériences sur un échantillon de sol en effectuant des mesures simultanémentaux différentes échelles pertinentes : celle de l'échantillon, et celle des grains, et ceci en3D volumique. Ces progrès ont permis une meilleure compréhension des processus qui seproduisent dans le sol, en les observant au cœur même des échantillons.Cette thèse vise à caractériser les comportements de rétention d'eau et hydro-mécaniquedu sable d'Hostun non saturé à l'échelle du grain. Pour ce faire, des essais de rétentiond'eau et des essais triaxiaux ont été effectués, qui ont nécessité le développement d'outils detraitement d'image et des montages expérimentaux spécifiques. L'installation de tomographie à rayons X du Laboratoire 3SR de l'Université des Grenoble a été utilisée pour générer des images en 3D de la microstructure du sol non saturé. Une technique de trinarization a été mise en œuvre pour permettre la séparation des phases (les grains, l'eau et l'air) dans les images 3D, et d'effectuer différentes mesures à l'échelle du grain. La porosité et le degré de saturation ont été mesurées macroscopiquement en utilisant les images segmentées, et microscopiquement en utilisant un code de cartographie spécialement développé. Les mesures microscopiques ont été réalisées sur un volume élémentaire représentatif (VER), dont la taille a été déterminée en utilisant une analyse développée sur la base d'outils statistiques. Plusieurs analyses discrets ont été développées pour étudier l'évolution de la phase fluide (l'eau et l'air) avec le chargement (succion, et chargement mécanique). La corrélation d'images numérique 3D volumique a été mise en œuvre systématiquement pour ces deux types d'essais.Pour analyser le comportement de rétention d'eau du sable d'Hostun pendant les processus de séchage et de mouillage, une cellule spécifique a été développée. La succion a été appliquée en utilisant la technique de tensiomètre. L'échantillon (cylindrique 1x1cm) a été préparé en utilisant la technique de la pluviation sous l'eau et scanné avec une résolution de 7,5micron. La courbe de rétention d'eau, surface et les domaines hydriques ont été obtenus et le phénomène d'hystérésis et la cohésion du sol ont été analysés à l'échelle du grain.Pour le comportement hydro-mécanique des sols non saturés, des essais triaxiaux ontété effectué sous trois conditions: saturé drainé, non saturé drainé et non saturé non drainé. Un appareil triaxial que l'on peut placer à l'intérieur de la cabine du tomographe à rayons X a été développé afin de permettre le suivi des changements dans la microstructure du sable et la distribution de l'eau lorsque l'on soumet l'échantillon à chargement mécanique. L'échantillon (cylindre de dimensions hxd=2x1cm) a été préparé en utilisant la technique de la pluviation sous l'eau (complétement saturé au début des trois tests), amené ensuite au niveau de saturation désiré (dans le cas des essais non saturés), puis chargé par étapes successives avec scan à chaque étape avec une résolution de 13micron, jusqu'à arriver à 21% de déformation axiale pour les trois types d'essai. Les courbes contrainte-déformation, la réponse volumétrique et les déformations ont été obtenus et le profil de déformation, l'hétérogénéité de l'échantillon, la cohésion et la distribution de l'eau ont été analysés
With the recent developments of full field measurements, it has become possible to do experiments on a soil specimen, and perform measurements at different scales. This progress has allowed greater understanding for all the processes that occur within the soil, and also created better environment to observe these mechanisms in 3D. This PhD work aims to characterize water retention and hydro-mechanical behaviours of unsaturated Hostun sand at the grain scale. To achieve this goal, water retention and triaxial tests were performed and a set of experimental and image processing tools was developed and used for the two series of tests. X-ray computed tomography set up available at 3SR Laboratory in Grenoble University was used to generate 3D images of the unsaturated soil microstructure non-destructively. A developed region growing systematic technique (trinarization technique) was used to allow the separation of the phases (i.e., grains, water and air) in the 3D images, and performing different measurements at the grain scale. Porosity and degree of saturationwere measured macroscopically using the trinarized images and microscopically using a developed mapping code. The microscopic measurements were performed over an REV, whose size was determined using a developed analysis based on statistical tools. Several microscopic-discrete analyses were developed to investigate the evolution of fluid phase (water and air) with loading (suction and mechanical loading). Digital Image Correlation was performed for the two tests.To analyze water retention behaviour of Hostun sand during drying and wetting processes, a pressure plate apparatus was developed. Suction was applied using tensiometry technique. The specimen (cylindrical 1x1cm) was prepared using water pluviation technique and scanned with a resolution 7.5micron. As a result, water retention curve, surface and domains were obtained and hysteresis phenomenon and soil cohesion were analyzed at the grain scale.For the mechanical behaviour of unsaturated soils, triaxial test were performed at three conditions: saturated drained, unsaturated drained and unsaturated undrained. A triaxial apparatus that can be placed inside the x-ray cabinet was developed in order to facilitate monitoring the changes in sand microstructure and water distribution when subjecting the soil specimen to loading. The specimen (cylinder of hxd=2x1cm) was prepared using water pluviation technique (completely saturated at the beginning of the three tests), loaded then scanned with a resolution 13micron, repeatedly till reaching 21% axial strain forthe three tests.Consequently, stress-strain curves, volumetric response and deformations measurements were obtained and deformation pattern, specimen heterogeneity, cohesion and water distribution were analyzed
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Forbes, Margaret G. "Phosphorus Retention and Fractionation in Masonry Sand and Light Weight Expanded Shale Used as Substrate in a Subsurface Flow Wetland." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3183/.

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Constructed wetlands are considered an inefficient technology for long-term phosphorus (P) removal. The P retention effectiveness of subsurface wetlands can be improved by using appropriate substrates. The objectives of this study were to: (i) use sorption isotherms to estimate the P sorption capacity of the two materials, masonry sand and light weight expanded shale; (ii) describe dissolved P removal in small (2.7 m3) subsurface flow wetlands; (iii) quantify the forms of P retained by the substrates in the pilot cells; and (iv) use resulting data to assess the technical and economic feasibility of the most promising system to remove P. The P sorption capacity of masonry sand and expanded shale, as determined with Langmuir isotherms, was 60 mg/kg and 971 mg/kg respectively. In the pilot cells receiving secondarily treated wastewater, cells containing expanded shale retained a greater proportion of the incoming P (50.8 percent) than cells containing masonry sand (14.5 percent). After a year of operation, samples were analyzed for total P (TP) and total inorganic P (TIP). Subsamples were fractionated into labile-P, Fe+Al-bound P, humic-P, Ca+Mg-bound P, and residual-P. Means and standard deviations of TP retained by the expanded shale and masonry sand were 349 + 169 and 11.9 + 18.6 mg/kg respectively. The largest forms of P retained by the expanded shale pilot cells were Fe+Al- bound P (108 mg/kg), followed by labile-P (46.7 mg/kg) and humic-P (39.8). Increases in the P forms of masonry sand were greatest in labile-P (7.5 mg/kg). The cost of an expanded shale wetland is within the range of costs conventional technologies for P removal. Accurate cost comparisons are dependent upon expansion capacity of the system under consideration. Materials with a high P sorption capacity also have potential for enhancing P removal in other constructed wetland applications such as stormwater wetlands and wetlands for treating agricultural runoff.
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Henderson, Elizabeth. "A KINETICS STUDY OF SELECTED FILTRATION MEDIA FOR NUTRIENT REMOVAL AT VARIOUS TEMPERATURES." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2344.

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In recent years the nutrient levels of the Upper Floridan aquifer have been increasing (USGS, 2008). An example of this is found in Ocala, Florida where Silver Springs nitrate concentrations have risen from 0.5 mg/L in the 1960 s to approximately 1.0 mg/L in 2003 (Phelps, 2004). Because stormwater is a contributor to surficial and groundwater aquifer recharge, there is an increasing need for methods that decrease nitrogen and phosphorus levels. A laboratory column study was conducted to simulate a retention pond with saturated soil conditions. The objectives of the column studies reported in this thesis were to investigate the capabilities of a natural soil and soil augmentations to remove nitrogen and phosphorus for a range of concentrations at three different temperatures. An analytical attempt to model the columns through low order reaction kinetics and derive the corresponding temperature conversion constant to relate the rate constants is also presented. The Media Mixes were selected through a process of research, preliminary batch testing and then implemented in column studies. Three columns measuring three feet in length and 6 inches outer diameter were packed with a control and two media mixes. Media Mix 1 consisted of 50% fine sand, 30% tire crumb, 20% sawdust by weight and Media Mix 2 consisted of 50% fine sand, 25% sawdust, 15% tire crumb, 10% limestone by weight. The control column was packed with natural soil from Hunter s Trace retention pond located in Ocala, Florida. The reaction rates for nitrate are best modeled as first order for Media Mix 1, and zero order for the Control and Media Mix 2. The reaction rates for orthophosphate are best modeled as zero order, second order and first order for the Control, Media Mix 1, and Media Mix 2 respectively. The best overall media for both nitrate and orthophosphate removal from this study would be Media Mix 1. Media Mix 2 does have the highest average orthophosphate removal of all the mixes for all of the temperatures; however Media Mix 1 outperforms Mix 2 for the other two temperatures. The best column for Nitrate removal is the Media Mix 1 column. The temperature conversion factors for nitrate were found to be 1.11, 1.1, and 1.01 for Media Mix 1, the Control and Media Mix 2 respectively. The temperature conversion factors for orthophosphate were found to be 1.02, 0.99, and 0.95. As well as temperature conversion factors, the activation energies and frequency factors for the Arrhenius Equation were investigated. Average values corresponding to each column, species, and temperature would be inaccurate due to the large variation in calculated values.
M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engr MSEnvE
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Rothhardt, Steffi [Verfasser], Reinhard [Akademischer Betreuer] Gaupp, and Gerd [Akademischer Betreuer] Gleixner. "Influence of the white-rot fungus Schizophyllum commune on organically coated sand grains and their heavy metal retention / Steffi Rothhardt. Gutachter: Reinhard Gaupp ; Gerd Gleixner." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2013. http://d-nb.info/1033670243/34.

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Dikinya, Oagile. "The effects of self-filtration on saturated hydraulic conductivity in sodic sandy soils." University of Western Australia. School of Earth and Geographical Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0051.

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[Truncated abstract] Self-filtration is here defined as particle detachment and re-deposition causing re-arrangement of the particles and therefore pore space which affects water flow in soil by decreasing hydraulic conductivity. This is of particular important in soils which are susceptible to structural breakdown. The objective of this thesis was to examine the dynamics of the self-filtration process in sodic sandy soils as affected by ionic strength and soil solution composition. The temporal changes of hydraulic conductivity and the elution of fine particles from soil columns were used as the main criteria to assess selffiltration. Two porous media exhibiting significantly different structural cohesion were examined, one a loamy sand (Balkuling soil) from agricultural land use and the second a mining residue from mineral sands operations . . . The effects of the composition of mixed calcium (Ca) and sodium (Na) ions in solution (sodium adsorption ratio (SAR)) on the exchange behaviour and saturated hydraulic conductivity were examined by carrying out batch binary exchange and saturated column transport experiments. A strong preference for Ca2+ ions in the exchange complex was observed for both soils. Generally K/Ko was found to decrease with increasing sodium adsorption ratio with the more structured Balkuling soil maintaining K/Ko for SARs 3 and 5 at an electrolyte concentration of 100 mmol/L. However measurements at the critical threshold and turbidity concentrations at a SAR of 15 revealed structural breakdown of the pore matrix system attributed to various extents of slaking, swelling, dispersion and decreases of pore radii as a result of selffiltration during leaching. These experiments illustrate the wide range of complex interactions involving clay mineralogy, solution composition and structural factors which can influence the extent of mobilization, transport and re-deposition of colloidal particles during the leaching process in soil profiles.
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Eid, Naglaa Mahmoud. "Electro-kinetic concentration and retention of nitrate in sandy soil." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187265.

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Laboratory experiments utilizing closed and open system experiments were conducted in this study to evaluate the applicability of using an electro-kinetic process to concentrate and retain nitrate close to the anode. A finite difference model was developed to predict the pH gradient developed during the electro-kinetic process. Model results then were used with a derived regression equation between pH and N0₃- to predict the nitrate gradient developed during an electro-kinetic process. The results of this research revealed that an electro-kinetic method is an effective means for concentrating and retaining nitrate close to the anode in saturated sandy soil even under a strong hydraulic gradient. Results also support the validity of using a finite difference and regression equation model to predict the spatial and temporal distribution of N0₃- developed under an electro- kinetic process for both closed and open system configurations.
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Albarran, Ruth Maria, and Ranee Taechameena Sahachartsiri. "Foster parent satisfaction and retention." CSUSB ScholarWorks, 2008. https://scholarworks.lib.csusb.edu/etd-project/3399.

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This study proposed to explore several factors that promote foster parent satisfaction in order to preserve quality foster homes to serve the 532,000 displaced children currently in the child welfare system. A sample of 52 foster parents were surveyed to determine overall satisfaction with their foster care experience at Children's Way Foster Family Agency in San Bernardino, California. It was hypothesized that the higher the level of foster parent satisfaction, the higher rates of retention. A modified version of an existing instrument titled "Foster Parent Satisfaction Survey" was utilized in this study.
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Dai, Sheng. "Natural hydrate-bearing sediments: Physical properties and characterization techniques." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52186.

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An extensive amount of natural gas trapped in the subsurface is found as methane hydrate. A fundamental understanding of natural hydrate-bearing sediments is required to engineer production strategies and to assess the risks hydrates pose to global climate change and large-scale seafloor destabilization. This thesis reports fundamental studies on hydrate nucleation, morphology and the evolution of unsaturation during dissociation, followed by additional studies on sampling and pressure core testing. Hydrate nucleation is favored on mineral surfaces and it is often triggered by mechanical vibration. Continued hydrate crystal growth within sediments is governed by capillary and skeletal forces; hence, the characteristic particle size d10 and the sediment burial depth determine hydrate morphologies in natural sediments. In aged hydrate-bearing sand, Ostwald ripening leads to patchy hydrate formation; the stiffness approaches to the lower bound at low hydrate saturation and the upper bound at high hydrate saturation. Hydrate saturation and pore habit alter the pore size variability and interconnectivity, and change the water retention curve in hydrate-bearing sediments. The physical properties of hydrate-bearing sediments are determined by the state of stress, porosity, and hydrate saturation. Furthermore, hydrate stability requires sampling, handling, and testing under in situ pressure, temperature, and stress conditions. Therefore, the laboratory characterization of natural hydrate-bearing sediments faces inherent sampling disturbances caused by changes in stress and strain as well as transient pressure and temperature changes that affect hydrate stability. While pressure core technology offers unprecedented opportunities for the study of hydrate-bearing sediments, careful data interpretation must recognize its inherent limitations.
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El-Tayeb, El-Sayed Mohamed. "Rétention d'alpha-oléfinésulfonates de sodium dans un sable argilo-calcaire : étude expérimentale et modélisation du transport en présence de cations divalents et d'asphalte." Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL149N.

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L’utilisation de tensioactifs de type alpha-oléfinésulfonate dans les procédés de récupération améliorée du pétrole apparait comme une solution à des gisements pétroliers possédant une eau de gisement moyennement salée contenant des cations divalents. L’optimisation du procédé passe par l'élaboration d'un modèle de transport traduisant l'évolution de la concentration du tensioactif, donc de son efficacité, lors de son transit au sein du milieu poreux que constitue le gisement. La modélisation s'est appuyée sur une méthode expérimentale reposant sur la chromatographie réactive, qui permet à partir de l'analyse de la réponse d'un milieu poreux à un signal de concentration de déduire qualitativement et quantitativement les interactions qui contrôlent le transport de l'espèce étudiée. Les expériences ont été effectuées sur un sable argilo-calcaire, le sable de gue et sur un mélange artificiel de sable d'argile, imprégné par de l'asphalte. Le mélange de tensioactif utilisé est une alphaoléfinésulfonate de sodium commerciale en C14-C16. Trois phénomènes prépondérants contrôlent le transport de ce tensio-actif au-dessus de la concentration micellaire critique: (1) l'adsorption est essentiellement contrôlée par la concentration en magnésium qui n'est pas contrôlée par les équilibres calcocarboniques (ii) la séparation chromatographique du mélange en trois classes de produits lors de l'adsorption (iii) le partage du à la présence d'asphalte sur la surface qui augmente notablement la capacité de rétention du milieu. À partir de ces observations un modèle global a été développé pour simuler le comportement du tensioactif dans un large domaine (10-4 à 10-1 mole/l) et de quantité injectée. Ce modèle est utilisable pour évaluer à la fois le comportement des alphaoléfinésulfonates commerciaux en milieu poreux et la faisabilité du procédé
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Ogunniyi, Jumoke Esther. "Effects of clay and organic matter amendments on water and nutrient retention of sandy soils." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/101514/.

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Sandy soils are one of the most widely distributed soils in the world. However, crop production on these soils can be problematic especially in terms of water and nutrient retention. In the face of climate change and a projected reduction in water availability, food production is likely to be particularly affected. The aim of this research is to examine if amending soils with clay and organic matter can improve their water and nutrient retention. The research approach employed laboratory column leaching experiments, rainfall simulation, Computed Tomography (CT) scanning and field trials to investigate the potential of two types of clay, Kaolin (K) and Bentonite (B), and peat (Pt), as well different combinations of clay and peat, to act as effective soil amendments. The influence of amendment materials was assessed by examining water retention, nutrient retention, soil organic carbon and changes in soil properties. Laboratory analysis was supported by field trials to examine the productivity of spring wheat. The results showed that the amendment materials increased soil water retention and availability, reduced water infiltration, increased nutrient uptake, increased spring wheat growth and yield, and improved soil carbon storage compared to an unamended control. The findings provide a further understanding of how the addition of clay and OM can affect ecological function of sandy soils and elucidate the mechanisms involved in controlling water retention and availability, as well as nutrient retention in the amended soils.
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Books on the topic "Sand retention"

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Greg, Ridgeway, ed. Strategies for improving officer recruitment for the San Diego Police Department. Santa Monica, CA: RAND Corporation, 2008.

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(Firm), LaFrance Associates. Building the field that builds the future: A comprehensive evaluation of San Francisco CARES and WAGES plus. [San Francisco, CA]: LaFrance Associates, 2004.

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Terry, K. W. Retention and excretion of thorium by mineral sands industry employees: Results of research carried out as MERIWA Project No. M211 at the Department of Minerals and Energy, WA. East Perth, WA: Minerals and Energy Research Institute of Western Australia, 1993.

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Al-Shankiti, Abdullah. Phosphorus Forms and Retention in a Sandy Soil Receiving Dairy Waste Effluent. Dissertation Discovery Company, 2019.

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Al-Shankiti, Abdullah. Phosphorus Forms and Retention in a Sandy Soil Receiving Dairy Waste Effluent. Dissertation Discovery Company, 2019.

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Greg, Ridgeway, ed. Strategies for improving officer recruitment in the San Diego Police Department. Santa Monica, CA: RAND Corporation, 2008.

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Book chapters on the topic "Sand retention"

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Yao, Shuxia, Chuancheng Zhao, Suyun Wang, Yongli Liu, and Mansheng Li. "Study of Soil Water Retention in Horqin Sand Land." In Geo-Informatics in Resource Management and Sustainable Ecosystem, 374–80. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49155-3_38.

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Bettles, C. J., and M. S. Dargusch. "Creep and Bolt-load Retention of Sand Cast Elektron MEZ." In Magnesium Alloys and their Applications, 705–10. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/3527607552.ch111.

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Muto, Yasunori, and Ryo Yokokawa. "Wetland Paddy Fields as Green Infrastructure Against Flood." In Ecological Research Monographs, 135–59. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-6791-6_9.

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AbstractInundation simulation was carried out for an inland depression mainly covered by paddy fields to estimate its flood retention volume. In addition to surface water flooding, river flooding combined with it was also explored in a wide range of precipitation including a 1000-year return period. The results showed that the paddy fields in the studied area can retain approximately 60% of the total inundation volume. Judging from the relationship between the flood retention volume in the paddy fields and the number of inundated buildings above floor level, we could estimate two reference values regarding the potential volume of floodwater retention in paddy fields: one at which damage to the buildings starts to appear and the other where damage seriously expands in the main residential area. By using these reference values, we demonstrated the importance of land-use strategies in flood alleviation. In other words, by transferring buildings inundated between these levels to safer places, the potential volume of floodwater retention in paddy fields can be increased to a higher level, which well agrees with the concept of green infrastructure. The idea of flood alleviation deduced from this study can be applied to similar near-shore depressions cut off by sand dunes, which are common in Japan.
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Strauss, J. M., M. A. Bues, and L. Zilliox. "Retention of Mercury II on a Natural Quartz Sand: Non Linear Behaviour at Very Low Concentrations." In Contaminated Soil ’90, 351–58. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-011-3270-1_76.

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Singh, Kanwar, Satyendra Mittal, P. S. Prasad, and Kishor Kumar. "Critical Evaluation on Retention of Fine Sand Through Soil Nailing for Construction of Rail Underpass by Box Jacking—A Case Study." In Lecture Notes in Civil Engineering, 325–39. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6713-7_26.

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Fukuhara, Haruo, Fumiko Nemoto, Yoko Takeuchi, and Nobushige Toda. "Nitrate dynamics in a reed belt of a shallow sand dune lake in Japan: Analysis of nitrate retention using stable nitrogen isotope ratios." In Shallow Lakes in a Changing World, 49–58. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6399-2_5.

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McEwan, Margaret A., Tom A. van Mourik, Mihiretu C. Hundayehu, Frezer Asfaw, Sam Namanda, Issahaq Suleman, Sarah Mayanja, Simon Imoro, and Prince M. Etwire. "Securing Sweetpotato Planting Material for Farmers in Dryland Africa: Gender-Responsive Communication Approaches to Scale Triple S." In Root, Tuber and Banana Food System Innovations, 353–88. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92022-7_12.

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AbstractTriple S (Storage in Sand and Sprouting) is a root-based system for conserving and multiplying sweetpotato planting material at the household level. In sub-Saharan Africa, farmers predominantly source planting material by cutting vines from volunteer plants that sprout from roots left in the field from a previous crop. However, it takes 6 to 8 weeks after the rains start to produce enough vines for planting material, and normally these vines are infected by sweetpotato diseases and pests carried over from previous crops. Where rainfall is unpredictable, farmers can use Triple S to take advantage of the whole growing season, planting and harvesting early to obtain food, higher yields, and income. Triple S facilitates household retention and adoption of new sweetpotato varieties, notably the beta-carotene-rich, orange-fleshed varieties. Triple S PLUS is the combined innovation package of core Triple S components and complementary components used to scale the innovation. These included good agricultural practices, different storage containers, local multiplication and sales of planting material, and a multimedia communication strategy for training and extension to encourage the uptake of Triple S. Components were at different levels of scaling readiness. This chapter explores evidence from Ethiopia and Ghana (2018–2019) on the extent to which exposure to different communication channels and their combinations influenced the uptake of Triple S PLUS by male and female farmers, the partnering arrangements that supported this, and the resulting changes in food security. We discuss implications for future scaling initiatives.
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Kikan, Jitendra, and W. H. Somerton. "Retention Behavior of Dilute Polymers in Oil Sands." In ACS Symposium Series, 241–56. Washington, DC: American Chemical Society, 1989. http://dx.doi.org/10.1021/bk-1989-0396.ch012.

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Terleev, Vitaly, Wilfried Mirschel, Aleksandr Nikonorov, Viktor Lazarev, Roman Ginevsky, Alex Topaj, Kirill Moiseev, et al. "Models of Hysteresis Water Retention Capacity and Their Comparative Analysis on the Example of Sandy Soil." In Advances in Intelligent Systems and Computing, 462–71. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-19868-8_46.

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Desta, Yonas, Nigus Gabbiye, and Agegnehu Alemu. "Hydrothermal Synthesis of Na-P1 Zeolite from Pumice to Enhance Moisture Content and Water Retention Capacity of Sandy Soil." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 457–72. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-15357-1_38.

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Conference papers on the topic "Sand retention"

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Ballard, Tracey, Steve Beare, and Nicola Wigg. "Sand Retention Testing: Reservoir Sand or Simulated Sand - Does it Matter?" In SPE International Conference and Exhibition on Formation Damage Control. Society of Petroleum Engineers, 2016. http://dx.doi.org/10.2118/178966-ms.

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Agunloye, Ehimhen, and Erome Utunedi. "Optimizing Sand Control Design Using Sand Screen Retention Testing." In SPE Nigeria Annual International Conference and Exhibition. Society of Petroleum Engineers, 2014. http://dx.doi.org/10.2118/172488-ms.

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Wu, B., G. Lupton, T. Barton, R. Denke, C. Y. Wong, Y. Feng, J. Boulanger, and S. K. Choi. "Development of a Novel Sand Retention Cell." In SPE Asia Pacific Oil & Gas Conference and Exhibition. Society of Petroleum Engineers, 2016. http://dx.doi.org/10.2118/182494-ms.

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Wu, B., S. K. Choi, Y. Feng, R. Denke, T. Barton, C. Y. Wong, J. Boulanger, et al. "Evaluating Sand Screen Performance Using Improved Sand Retention Test and Numerical Modelling." In Offshore Technology Conference Asia. Offshore Technology Conference, 2016. http://dx.doi.org/10.4043/26434-ms.

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Pioli, B. C., A. M. S. Maximiano, and F. A. M. Marinho. "Soil-Gasoline Retention Curve for a Uniform Sand." In Second Pan-American Conference on Unsaturated Soils. Reston, VA: American Society of Civil Engineers, 2018. http://dx.doi.org/10.1061/9780784481684.005.

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Fattahpour, Vahidoddin, Morteza Roostaei, Mahdi Mahmoudi, Mohammad Soroush, Seyed Abolhassan Hosseini, and Mark Anderson. "Standalone Sand Control Evaluation: Developing a Large-Scale High Temperature Sand Retention Test Apparatus." In SPE Canada Heavy Oil Conference. Society of Petroleum Engineers, 2020. http://dx.doi.org/10.2118/199960-ms.

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Fuller, Michael, Terry Palisch, and Christine Fischer. "Sieve Distribution vs Sand Retention: The Impact of Mono-Sieved Gravel on Sand Control." In SPE Annual Technical Conference and Exhibition. Society of Petroleum Engineers, 2019. http://dx.doi.org/10.2118/196139-ms.

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Likos, William J., Masami Nakagawa, and Stefan Luding. "Pore-Scale Model for Water Retention in Unsaturated Sand." In POWDERS AND GRAINS 2009: PROCEEDINGS OF THE 6TH INTERNATIONAL CONFERENCE ON MICROMECHANICS OF GRANULAR MEDIA. AIP, 2009. http://dx.doi.org/10.1063/1.3180077.

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Samuel, Elvy Jose, Mohd Shah Redza Hanif, Muhd Syaiful Azman Mustapa, Merza Media Adeyosfi, Moet Moet Lwin, Samie Sok Foon Lee, Pascal Millot, and Fui Kent Wong. "Advance Nuclear Magnetic Resonance and Image Logs Application for Predicting Particle Sand Distribution." In IADC/SPE Asia Pacific Drilling Technology Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/209912-ms.

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Abstract The complexities of designing an effective sand control for unconsolidated gas reservoirs in a deepwater environment is exacerbated when the targeted formation sands are characterized by particle size distributions with poorly sorted and non uniform coeficients, and high fine concentrations. Managing these intricacies requires comprehensive sand retention studies developed to ascertain the effectiveness of the sand control performance of gravel and screen gauge opening combinations in the presence of selected formation sand ratios. To build a representative testing program, actual core samples from the targeted studied zones are desirable. However, for economical, technical or logistic contrains the availability of these cores is not always feasible. This paper covers a workflow to determine a synthetic Particle Size Distribution (PSD) of a targeted well in a development block where no core data is available. The data feeding the workflow is derived from wireline bore hole imagers and Non-Magnetic Resonance (NMR) logs obtained from six wells drilled in the exploration phase of the studied gas block. Results are calibrated with localized PSD from available side wall cores. Furthermore, data obtained from the process is used to interrogate sand retention testing Mastercurves built with formation samples from one of the fields in the studied block (Field I). The interrogation process takes the synthetic PSD from the targeted well and creates normalized formation testing ratios which are then compared to the results documented on the sand retention Mastercurves. This paper is intends to discuss the worklflow and results of its field application.
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Imre, E., K. Rajkai, T. Firgi, Q. P. Trang, and G. Telekes. "Closed-Form Functions for the Soil Water-Retention Curve of Sand Fractions and Sand Mixtures." In Fourth International Conference on Unsaturated Soils. Reston, VA: American Society of Civil Engineers, 2006. http://dx.doi.org/10.1061/40802(189)205.

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Reports on the topic "Sand retention"

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Kinikles, Dellena, and John McCartney. Hyperbolic Hydro-mechanical Model for Seismic Compression Prediction of Unsaturated Soils in the Funicular Regime. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, December 2022. http://dx.doi.org/10.55461/yunw7668.

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A semi-empirical elasto-plastic constitutive model with a hyperbolic stress-strain curve was developed with the goal of predicting the seismic compression of unsaturated sands in the funicular regime of the soil-water retention curve (SWRC) during undrained cyclic shearing. Using a flow rule derived from energy considerations, the evolution in plastic volumetric strain (seismic compression) was predicted from the plastic shear strains of the hysteretic hyperbolic stress-strain curve. The plastic volumetric strains are used to predict the changes in degree of saturation from phase relationships and changes in pore air pressure from Boyle’s and Henry’s laws. The degree of saturation was used to estimate changes in matric suction from the transient scanning paths of the SWRC. Changes in small-strain shear modulus estimated from changes in mean effective stress computed from the constant total stress and changes in pore air pressure, degree of saturation and matric suction, in turn affect the hyperbolic stress-strain curve’s shape and the evolution in plastic volumetric strain. The model was calibrated using experimental shear stress-strain backbone curves from drained cyclic simple shear tests and transient SWRC scanning path measurements from undrained cyclic simple shear tests. Then the model predictions were validated using experimental data from undrained cyclic simple shear tests on unsaturated sand specimens with different initial degrees of saturation in the funicular regime. While the model captured the coupled evolution in hydro-mechanical variables (pore air pressure, pore water pressure, matric suction, degree of saturation, volumetric strain, effective stress, shear modulus) well over the first 15 cycles of shearing, the predictions were less accurate after continued cyclic shearing up to 200 cycles. After large numbers of cycles of undrained shearing, a linear decreasing trend between seismic compression and initial degree of saturation was predicted from the model while a nonlinear increasing-decreasing trend was observed in the cyclic simple shear experiments. This discrepancy may be due to not considering post shearing reconsolidation in the model, calibration of model parameters, or experimental issues including a drift in the position of the hysteretic shear-stress strain curve. Nonetheless, the trend from the model is consistent with predictions from previously- developed empirical models in the funicular regime of the SWRC. The developments of the new mechanistic model developed in this study will play a key role in the future development of a holistic model for predicting the seismic compression across all regimes of the SWRC.
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Litaor, Iggy, James Ippolito, Iris Zohar, and Michael Massey. Phosphorus capture recycling and utilization for sustainable agriculture using Al/organic composite water treatment residuals. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600037.bard.

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Objectives: 1) develop a thorough understanding of the sorption mechanisms of Pi and Po onto the Al/O- WTR; 2) determine the breakthrough range of the composite Al/O-WTR during P capturing from agro- wastewaters; and 3) critically evaluate the performance of the composite Al/O-WTR as a fertilizer using selected plants grown in lysimeters and test-field studies. Instead of lysimeters we used pots (Israel) and one- liter cone-tainers (USA). We conducted one field study but in spite of major pretreatments the soils still exhibited high enough P from previous experiments so no differences between control and P additions were noticeable. Due to time constrains the field study was discontinued. Background: Phosphorous, a non-renewable resource, has been applied extensively in fields to increase crop yield, yet consequently has increased the potential of waterway eutrophication. Our proposal impetus is the need to develop an innovative method of P capturing, recycling and reuse that will sustain agricultural productivity while concurrently reducing the level of P discharge from and to agricultural settings. Major Conclusions & Achievements: An innovative approach was developed for P removal from soil leachate, dairy wastewater (Israel), and swine effluents (USA) using Al-based water treatment residuals (Al- WTR) to create an organic-Al-WTR composite (Al/O-WTR), potentially capable of serving as a P fertilizer source. The Al-WTR removed 95% inorganic-P, 80% to 99.9% organic P, and over 60% dissolved organic carbon from the agro-industrial waste streams. Organic C accumulation on particles surfaces possibly enhanced weak P bonding and facilitated P desorption. Analysis by scanning electron microscope (SEM- EDS), indicated that P was sparsely sorbed on both calcic and Al (hydr)oxide surfaces. Sorption of P onto WW-Al/O-WTR was reversible due to weak Ca-P and Al-P bonds induced by the slight alkaline nature and in the presence of organic moieties. Synchrotron-based microfocused X-ray fluorescence (micro-XRF) spectrometry, bulk P K-edge X-ray absorption near edge structure spectroscopy (XANES), and P K-edge micro-XANES spectroscopy indicated that adsorption was the primary P retention mechanism in the Al- WTR materials. However, distinct apatite- or octocalciumphosphatelike P grains were also observed. Synchrotron micro-XRF mapping further suggested that exposure of the aggregate exteriors to wastewater caused P to diffuse into the porous Al-WTR aggregates. Organic P species were not explicitly identified via P K-edge XANES despite high organic matter content, suggesting that organic P may have been predominantly associated with mineral surfaces. In screen houses experiments (Israel) we showed that the highest additions of Al/O-WTR (5 and 7 g kg⁻¹) produced the highest lettuce (Lactuca sativa L. var. longifolial) yield. Lettuce yield and P concentration were similar across treatments, indicating that Al/O- WTR can provide sufficient P to perform similarly to common fertilizers. A greenhouse study (USA) was utilized to compare increasing rates of swine wastewater derived Al/O-WTR and inorganic P fertilizer (both applied at 33.6, 67.3, and 134.5 kg P₂O₅ ha⁻¹) to supply plant-available P to spring wheat (TriticumaestivumL.) in either sandy loam or sandy clay loam soil. Spring wheat straw and grain P uptake were comparable across all treatments in the sandy loam, while Al/O-WTR application to the sandy clay loam reduced straw and grain P uptake. The Al/O-WTR did not affect soil organic P concentrations, but did increase phosphatase activity in both soils; this suggests that Al/O-WTR application stimulated microorganisms and enhance the extent to which microbial communities can mineralize Al/O-WTR-bound organic P. Implications: Overall, results suggest that creating a new P fertilizer from Al-WTR and agro-industrial waste sources may be a feasible alternative to mining inorganic P fertilizer sources, while protecting the environment from unnecessary waste disposal.
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