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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Water Flow Through Geotextiles Used to Support the Root Zone of Turfgrass on Sports Fields

Rose-Harvey, Keisha M. 14 January 2010 (has links)
A sports field construction method that uses a geotextile to support the root zone atop a synthetic drainage structure is an alternative to the common design that uses gravel drainage material to support the root zone. A study was conducted to address the concern that fine particles in the root zone may migrate under the influence of percolating water, clog geotextile pores, and restrict the amount of water drained from a sports field. In test columns, six root zone mixtures with different particle size distributions were combined with ten geotextiles with different opening sizes to produce 60 replicated treatments. Water flow through the root zone mixture-geotextile combinations in the test columns was evaluated over a six-month period. Change in permeability was assessed by monitoring the temporal distribution of drainage from a 25-mm pulse of water applied to 300-mm deep root zone mixture in the test column. Particles in drainage water were analyzed for size distribution. The study revealed that drainage rates were affected more by drainage trough the root zone mixture than through the geotextile. The amount and particle size distribution of particles in drainage water were influenced more by root zone mixture than by geotextile. It appeared that in the establishment phase of a sports field that fine particles in the root zone may present more of a problem to clogging of the root zone pores than clogging of the geotextile pores.
22

Effects of Fines on the Undrained Behaviour of Christchurch Sandy Soils

Rees, Sean David January 2010 (has links)
Liquefaction of sandy soil has been observed to cause significant damage to infrastructure during major earthquakes. Historical cases of liquefaction have typically occurred in sands containing some portion of fines particles, which are defined as 75μm or smaller in diameter. The effects of fines on the undrained behaviour of sand are not however fully understood, and this study therefore attempts to quantify these effects through the undrained testing of sand mixed with non-plastic fines sourced from Christchurch, New Zealand. The experimental program carried out during this study consisted of undrained monotonic and cyclic triaxial tests performed on three different mixtures of sand and fines: the Fitzgerald Bridge mixture (FBM), and two Pinnacles Sand mixtures (PSM1 and PSM2). The fines content of each host sand was systematically varied up to a maximum of 30%, with all test specimens being reconstituted using moist tamping deposition. The undrained test results from the FBM soils were interpreted using a range of different measures of initial state. When using void ratio and relative density, the addition of fines to the FBM sand caused more contractive behaviour for both monotonic and cyclic loadings. This resulted in lower strengths at the steady state of deformation, and lower liquefaction resistances. When the intergranular void ratio was used for the interpretation, the effect of additional fines was to cause less contractive response in the sand. The state parameter and state index were also used to interpret the undrained cyclic test results – these measures suggested that additional fines caused less contractive sand behaviour, the opposite to that observed when using the void ratio. This highlighted the dependency on the parameter chosen as a basis for the response comparison when determining the effects of fines, and pointed out a need to identify a measure that normalizes such effects. Based on the FBM undrained test results and interpretations, the equivalent granular void ratio, e*, was identified from the literature as a measure of initial state that normalizes the effects of fines on the undrained behaviour of sand up to a fines content of 30%. This is done through a parameter within the e* definition termed the fines influence factor, b, which quantifies the effects of fines from a value of zero (no effect) to one (same effect as sand particles). The value of b was also determined to be different when interpreting the steady state lines (bSSL) and cyclic resistance curves (bCR) respectively for a given mixture of sand and fines. The steady state lines and cyclic resistance curves of the FBM soils and a number of other sand-fines mixtures sourced from the literature were subsequently interpreted using the equivalent granular void ratio concept, with bSSL and bCR values being back-calculated from the respective test data sets. Based on these interpretations, it was concluded that e* was conceptually a useful parameter for characterizing and quantifying the effects of fines on the undrained behaviour of sand, assuming the fines influence factor value could be derived. To allow prediction of the fines influence factor values, bSSL and bCR were correlated with material and depositional properties of the presented sand-fines mixtures. It was found that as the size of the fines particles relative to the sand particles became smaller, the values of bSSL and bCR reduced, indicating lower effect of fines. The same trend was also observed as the angularity of the sand particles increased. The depositional method was found to influence the value of bCR, due to the sensitivity of cyclic loading to initial soil fabric. This led to bSSL being used as a reference for the effect of fines, with specimens prepared by moist tamping having bCR > bSSL, and specimens prepared by slurry deposition having bCR < bSSL. Finally the correlations of the fines influence factor values with material and depositional properties were used to define the simplified estimation method – a procedure capable of predicting the approximate steady state lines and cyclic resistance curves of a sand as the non-plastic fines content is increased up to 30%. The method was critically reviewed based on the undrained test results of the PSM1 and PSM2 soils. This review suggested the method could accurately predict undrained response curves as the fines content was raised, based on the PSM1 test results. It also however identified some key issues with the method, such as the inability to accurately predict the responses of highly non-uniform soils, a lack of consideration for the entire particle size distribution of a soil, and the fact the errors in the prediction of bSSL carry through into the prediction of bCR. Lastly some areas of further investigation relating to the method were highlighted, including the need to verify the method through testing of sandy soils sourced from outside the Christchurch area, and the need to correlate the value of bCR with additional soil fabrics / depositional methods.
23

Plan de lanzamiento de un servicio para la asociación sin fines de lucro "Construye Identidad"

Flores Cueto, Nataly Amanda 12 1900 (has links)
Muchas organizaciones sin fines de lucro en el país se han visto perjudicadas por la disminución progresiva de financiamiento a organizaciones sociales desde que Perú es declarado internacionalmente como país de renta media. Este hecho se suma a la difícil situación interna que viven estas organizaciones, las cuales en su mayoría no poseen los conocimientos de gestión para desarrollar proyectos de alto impacto que puedan mantenerse en el tiempo. El presente trabajo tiene como objetivo el desarrollar un plan de implementación de un nuevo modelo de negocio para la organización peruana sin fines de lucro “Construye Identidad”, organización que trabaja por promover un el habitar responsable del planeta poniendo en valor los conocimientos ancestrales de las comunidades indígenas del mundo. Para obtener el modelo de negocio propuesto, se recurrió al uso de herramientas de Design Thinking y, posteriormente, para promover el servicio de “Ruta por el Perú” del modelo de negocio, se utilizaron estrategias de Marketing Digital.
24

Sobre los fines de la pena privativa de libertad : una mirada crítica a la situación chilena

Pastén López, Catalina Anakena January 2019 (has links)
Memoria de Prueba para optar al grado de Licenciada en Ciencias Jurídicas y Sociales / Esta tesis pretende hacer un recorrido desde el problema del concepto de la pena, con el devenir histórico respecto de las modalidades concretas de penalidad que los ordenamientos recogieron, para continuar con el análisis de los discursos propuestos para justificar los fines de la misma. Se dedica también a analizar el auge y posterior crisis mundial que atraviesan las teorías de la prevención especial, con énfasis en la cuestionada meta resocializadora. Todo esto con el propósito de poder resolver si existe un fin para la pena privativa de libertad en Chile y, de ser así, cuál es su contenido. / 31 julio de 2020
25

A model system for understanding the distribution of fines in a paper structure using fluorescence microscopy / Ett modellsystem för att förstå fördelningen av fines i en pappersstruktur med hjälp av fluorescensmikroskopi

Jansson Rådberg, Weronica January 2015 (has links)
Fines have a very important role in paper chemistry and are a determinant in retention, drainage and the properties of paper. The purpose of this project was to be able to label the fines with fluorophores and study their Brownian motion with fluorescence microscopy. When succeeded this could then be used to study fines, fibers and other additives in a suspension thus giving the fundamental knowledge of why fines have this important role. Due to aggregation of the fines no Brownian motion could be detected. Instead the fines were handled as a network system and small fluorescence labeled latex particles were then studied in this system. This approach yields information about the fines when the obstacle with sedimentation of the network is resolved. / Fines har en viktig roll i papperskemin och har en avgörande roll när det gäller retention, dränering och papprets egenskaper. Syftet med detta projekt var att kunna färga in fines med fluoroforer och sedan följa deras brownska rörelse med hjälp av ett fluorescensmikroskop. Denna metod skulle sedan kunna användas för att observera interaktionerna mellan fines, fibrer och andra additiver i en suspension. Det skulle göra de underliggande mekanismerna kända för varför fines utgör en så viktig del i processen. På grund av att fines aggregerade så fick man istället behandla dem som ett nätverk där man tillsatte redan fluorescerande prober vars rörelser studerades. Att studera fines indirekt på detta vis kommer att ge information när sedimenteringen av nätverket är löst.
26

Optotracing for polysaccharide analysis / Optotracing för polysackaridanalys

Grånäs Jakobsson, Saga January 2022 (has links)
Det finns en växande efterfrågan på nya material från biomassa för produktion av nya och ersättning av befintliga kemikalier, bränslen och material. Genom att förstå den kemiska sammansättningen hos ett material och dess strukturella egenskaper kan vi enklare hitta lämpliga användningsområden. Optotracing är en ny metod för fluorescensbaserad visualisering av biopolymerer. I detta projekt användes optotracertekniken som metod för fluorescensbaserad visualisering av hemicellulosa, cellulosa och lignin. Detta examensarbete bestod av två delprojekt. Först undersöktes om optotracing kunde användas för att identifiera och differentiera hemicellulosa. Därefter studerade vi möjligheten att använda optotracing för att bekräfta provsammansättningen hos nanocellulosa och för att mäta de fysiska dimensionerna av cellulosananofibriller. Av hemicellulosaproverna som analyserades med optotracern Carbotrace680 detekterades xyloglukan och galaktomannan. Förekomsten av cellulosa i både kommersiellt tillgängliga prover och extrakt kunde bedömas av Carbotrace680. Spektroskopimetoden möjliggör även detektion av lignin. Fibrillära fina strukturer detekterades med konfokalmikroskop och med svepelektronmikroskop. I detta projekt kunde även möjligheten att använda optotracing-tekniken för anatomisk kartläggning och därmed ta reda på sammansättningen i förhållande till den fysiska platsen i växter bekräftas. / There is a growing demand for new materials from biomass to produce new and replacement of existing chemicals, fuels, and materials. By understanding the chemical composition of a material and its structural characteristics, we can more easily find suitable applications. Optotracing technology is a novel method for fluorescence-based visualization of biopolymers. In this project, the optotracer technology was used as a method for fluorescence-based visualization of hemicellulose, cellulose, and lignin. This thesis consisted of two sub-projects. First, it was investigated whether optotracing could be used to identify and differentiate hemicelluloses. Second, it was investigated whether optotracing could be used to analyze nanocellulose to confirm sample composition and to measure the physical dimensions of cellulose nanofibrils. Out of the hemicellulose samples that were analyzed with the optotracer Carbotrace680, xyloglucan and galactomannan were detected. The presence of cellulose in both commercially available samples and extracts could be assessed by Carbotrace680. Furthermore, the spectroscopy method also allowed us to detect lignin. Fibrillar fine structures were detected by confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM). In this project, the possibility of using the optotracing technology for anatomical mapping and thus finding out the composition in relation to the physical location in plants could also be confirmed.
27

The Effects Of Non-Plastic and Plastic Fines On The Liquefaction Of Sandy Soils

Polito, Carmine Paul 20 January 2000 (has links)
The presence of silt and clay particles has long been thought to affect the behavior of a sand under cyclic loading. Unfortunately, a review of studies published in the literature reveals that no clear conclusions can be drawn as to how altering fines content and plasticity actually affects the liquefaction resistance of a sand. In fact, the literature contains what appears to be contradictory evidence. There is a need to clarify the effects of fines content and plasticity on the liquefaction resistance of sandy soils, and to determine methods for accounting for these effects in engineering practice. In order to help answer these questions, a program of research in the form of a laboratory parametric study intended to clarify the effects which varying fines content and plasticity have upon the liquefaction resistance of sandy sands was undertaken. The program of research consisted of a large number of cyclic triaxial tests performed on two sands with varying quantities of plastic and non-plastic fines. The program of research also examined the applicability of plasticity based liquefaction criteria and the effects of fines content and plasticity on pore pressure generation. Lastly, a review of how the findings of this study may affect the manner in which simplified analyses are performed in engineering practice was made. The results of the study performed are used to clarify the effects of non-plastic fines content and resolve the majority of the inconsistencies in the literature. The effects of plastic fines content and fines plasticity are shown to be different than has been previously reported. The validity of plasticity based liquefaction criteria is established, the mechanism responsible for their validity is explained, and a new simplified criteria proposed. The effects of fines content and plasticity on pore pressure generation are discussed, and several recommendations are made for implementing the findings of this study into engineering practice. / Ph. D.
28

Ruling of al-gharāmah (the fine) as ta'zīr punishment (discretionary punishment) in comparative Islāmic jurisprudence

Kailani, Osaid January 2009 (has links)
No description available.
29

Dynamic Characteristics and Evaluation of Ground Response for Sands with Non-Plastic Fines

Arefi, Mohammad Jawad January 2014 (has links)
Deformational properties of soil, in terms of modulus and damping, exert a great influence on seismic response of soil sites. However, these properties for sands containing some portion of fines particles have not been systematically addressed. In addition, simultaneous modelling of the modulus and damping behaviour of soils during cyclic loading is desirable. This study presents an experimental and computational investigation into the deformational properties of sands containing fines content in the context of site response analysis. The experimental investigation is carried on sandy soils sourced from Christchurch, New Zealand using a dynamic triaxial apparatus while the computational aspect is based on the framework of total-stress one-dimensional (1D) cyclic behaviour of soil. The experimental investigation focused on a systematic study on the deformational behaviour of sand with different amounts of fines content (particle diameter ≤ 75µm) under drained conditions. The silty sands were prepared by mixing clean sand with three different percentages of fines content. A series of bender element tests at small-strain range and stress-controlled dynamic triaxial tests at medium to high-strain ranges were conducted on samples of clean sand and silty sand. This allowed measurements of linear and nonlinear deformational properties of the same specimen for a wide strain range. The testing program was designed to quantify the effects of void ratio and fines content on the low-strain stiffness of the silty sand as well as on the nonlinear stress-strain relationship and corresponding shear modulus and damping properties as a function of cyclic shear strains. Shear wave velocity, Vs, and maximum shear modulus, Gmax, of silty sand was shown to be significantly smaller than the respective values for clean sands measured at the same void ratio, e, or same relative density, Dr. However, the test results showed that the difference in the level of nonlinearity between clean sand and silty sands was small. For loose samples prepared at an identical relative density, the behaviour of clean sand was slightly less nonlinear as compared to sandy soils with higher fines content. This difference in the nonlinear behaviour of clean sand and sandy soils was negligible for dense soils. Furthermore, no systematic influence of fines content on the material damping curve was observed for sands with fines content FC = 0 to 30%. In order to normalize the effects of fines on moduli of sands, equivalent granular void ratio, e*, was employed. This was done through quantifying the participation of fines content in the force transfer chain of the sand matrix. As such, a unified framework for modelling of the variability of shear wave velocity, Vs, (or shear modulus, Gmax) with void ratio was achieved for clean sands and sands with fines, irrespective of their fines content. Furthermore, modelling of the cyclic stress-strain behaviour based on this experimental program was investigated. The modelling effort focused on developing a simple constitutive model which simultaneously models the soil modulus and damping relationships with shear strains observed in laboratory tests. The backbone curve of the cyclic model was adopted based on a modified version of Kondner and Zelasko (MKZ) hyperbolic function, with a curvature coefficient, a. In order to simulate the hysteretic cycles, the conventional Masing rules (Pyke 1979) were revised. The parameter n, in the Masing’s criteria was assumed to be a function of material damping, h, measured in the laboratory. As such the modulus and damping produced by the numerical model could match the stress-strain behaviour observed in the laboratory over the course of this study. It was shown that the Masing parameter n, is strain-dependent and generally takes values of n ≤ 2. The model was then verified through element test simulations under different cyclic loadings. It was shown that the model could accurately simulate the modulus and the damping simultaneously. The model was then incorporated within the OpenSees computational platform and was used to scrutinize the effects of damping on one-dimensional seismic site response analysis. For this purpose, several strong motion stations which recorded the Canterbury earthquake sequence were selected. The soil profiles were modelled as semi-infinite horizontally layered deposits overlying a uniform half-space subjected to vertically propagating shear waves. The advantages and limitations of the nonlinear model in terms of simulating soil nonlinearity and associated material damping were further scrutinized. It was shown that generally, the conventional Masing criteria unconservatively may underestimate some response parameters such as spectral accelerations. This was shown to be due to larger hysteretic damping modelled by using conventional Masing criteria. In addition, maximum shear strains within the soil profiles were also computed smaller in comparison to the values calculated by the proposed model. Further analyses were performed to study the simulation of backbone curve beyond the strain ranges addressed in the experimental phase of this study. A key issue that was identified was that relying only on the modulus reduction curves to simulate the stress-strain behaviour of soil may not capture the actual soil strength at larger strains. Hence, strength properties of the soil layer should also be incorporated to accurately simulate the backbone curve.
30

Discrete element modelling of iron ore pellets to include the effects of moisture and fines

Morrissey, John Paul January 2013 (has links)
Across industry the majority of raw materials handled are particulate in nature, ranging in size and properties from aggregates to powders. The stress regimes experienced by the granular solids vary and the exhibited bulk behaviours can be complex and unexpected. The prevalence of granular solids makes them an area of interest for industry and researchers alike as many challenges still remain, such as dealing with complex cohesive behaviour in materials, which often gives rise to handling difficulties. Storage and transportation are an important part of the process chain for industries where particulate solids are commonplace. Failure to properly account for the cohesive nature of a particulate solid can be costly as it can easily lead to blockages in a silo such as ratholing or arching near the outlet during discharge. The cohesive strength of a bulk material depends on the consolidation stress it has experienced. As a result, the stress history in the material leading up to a handling scenario needs to be considered when evaluating its handling behaviour. The Discrete Element Method (DEM) has been extensively used to simulate the behaviour of granular materials, however the majority of the focus has been on noncohesive systems. For cohesive solids, it is crucial that the stress history dependent behaviour is adequately captured. Many of the contact models commonly used in DEM simulations to simulate cohesive granular materials such as the JKR model or liquid bridge models are elastic in nature and may not capture the stress history dependent behaviour observed in cohesive particulate solids. A comprehensive study on the effect of cohesion arising from the addition of moisture on the behaviour of two types of LKAB iron ore fines (KPBO and KPRS) has been carried out. The addition of moisture to the sample has been found to have a significant effect on both kinds of fines. KPRS fines were found to have a much higher unconfined strength and flow function at higher moisture contents, and also show a greater increase in cohesion with the addition of moisture, while at moisture contents of less than 2% the KPBO fines demonstrate higher unconfined yield strength. The KPBO fines were also found to achieve a significantly looser initial packing at much lower moisture content when compared to the KPRS fines. The lateral pressure ratio has also been evaluated. In this study a mesoscopic adhesive contact model that accounts for contact plasticity and stress history dependency in the bulk solid, the Edinburgh Elasto-Plastic Adhesion (EEPA) mode, has been presented and mathematically verified. A parametric study of the DEM contact model parameters was conducted to gain a deeper understating of the effect of input parameters on the simulated cohesive bulk behaviour. The EEPA contact model has been used to predict an experimental flow function of KPRS iron ore fines. The contact model has demonstrated the ability to capture the stress history dependent behaviour that exists in cohesive granular solids. The DEM simulations provide a very close match to the experimental flow functions, with the predicted unconfined strengths found to be within the standard deviations of the experimental results. Investigations into the failure mode predicted by the DEM simulations show that the samples are failing from the development of shear planes similar to those observed experimentally. The effect of increasing levels of adhesion has been explored for a flat bottomed silo where the level of adhesion has been varied. The DEM simulations were found to capture the major phenomena occurring in silo discharge including the various flow zones associated with a flat bottomed silo. Funnel flow, the effective transition and mass flow which are associated with a mixed flow pattern were observed in the model silo. The location of the effective transition height was identified: above this was mass flow. The velocity determined from the discharge rate was found to be in excellent agreement with the velocity profiles found in the zones of mass flow. A high velocity core flow zone was observed above the outlet where velocities were greater than 1.25 times the mass flow velocity, VMF. The level of adhesion in the silo was found to affect the discharge rate - a reduced flow rate was found until the eventual blockage of the silo at a high level of adhesion was found. As the level of adhesion increased the probability of arching also increased, and the formation of intermittent arching behaviour was noted in the cases with higher levels of adhesion in the system. The development of both temporary and permanent cohesive arches over the silo outlet were also observed with stopped flow from the silo.

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