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Verma, Vishash. "Improved Slope Estimation in Organic Field-Effect Transistor Mobility Estimation." Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1618703169092189.
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SepuÌlveda, Sergio AndreÌs. "The effect of topographic amplification on seismic rock slope instability." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405772.
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Rodrigues, Afonso Dias Ana Sofia. "The effect of vegetation on slope stability of shallow pyroclastic soil covers." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG002/document.
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L'effet de la végétation locale, composée de Castanea sativa cultivé, sur la stabilité des pentes a été étudié sur un site d'essai au Mont Faito (Campanie, Italie). En Campanie, les sols pyroclastiques peu profonds sont sensibles aux glissements de terrain provoqués par les précipitations. Des périodes de pluies prolongées suivies de précipitations extrêmes à court terme déclenchent des glissements de terrain rapides et destructeurs au niveau des coupes routières et des escarpements pyroclastiques sur les falaises rocheuses dans les régions autour du volcan Vésuve.Des échantillons de sol pyroclastiques non perturbés contenant des racines de C. sativa matures ont été utilisés pour la caractérisation hydraulique par le biais d'un ensemble d'expériences en laboratoire. La perméabilité saturée, la réponse à l’évaporation et l’imbibition, la teneur en eau pour les fortes valeurs de succion et la biomasse sèche des racines ont été déterminées.La présence de racines a augmenté la perméabilité d'un ordre de grandeur dans les sols les plus superficiels (10-7 à 10-6 m s-1) et diminué la valeur d'entrée d'air des courbes de rétention (6 à 4 kPa). La variabilité de la perméabilité entre les couches de sol a été identifiée comme conditionnant l'écoulement de l'eau souterraine par rapport à la vitesse du mouvement du front de mouillage et à la génération de pressions positives de l'eau interstitielle dans le profil. L'étalonnage du modèle hystérétique pour caractériser les sols pyroclastiques naturels a fourni une méthode plus approximative de modélisation des réponses hydrauliques. Une bonne concordance entre le modèle et les observations a été obtenue.L’étude sur le terrain a permis de montrer que la distribution des racines de C. sativa est associée au régime des eaux souterraines. Les distributions spatiales et verticales de la densité et des traits des racines ont été quantifiées pour les racines de C. sativa prélevées dans des forages réalisés au Mont Faito. La succion minimale, la teneur minimale en eau et la pente minimale (indiquant un débit d'eau descendant) ont été surveillées tout au long de l'année et confrontées avec la distribution des racines et à la distribution spatiale des arbres. Une densité racinaire croissante était associée à des valeurs de succion plus faibles et à des gradients d'infiltration plus élevés, ce qui peut avoir une influence négative sur la stabilité de la pente.La modélisation du renforcement mécanique du sol par les racines des arbres a permis de comprendre l'importance des composantes hydrauliques et mécaniques sur la stabilité d'une pente. Les racines augmentent la résistance au cisaillement (jusqu'à 25,8 kPa) grâce à un renforcement mécanique et donc le facteur de sécurité de la pente augmente. L'examen du renforcement dû aux racines dans l'estimation du facteur de sécurité des surfaces de rupture potentielles a montré que la surface de rupture la plus faible a été trouvée à 2,2 m, où le renforcement dû aux racines était de 1,3 kPa, au lieu de 0,9 m sans le renforcement de 13,8 kPa. La surface de rupture la plus faible correspond aux surfaces de rupture observées lors de glissements de terrain antérieurs. Le site d'essai ne présentait pas les caractéristiques d'une zone de déclenchement d'un glissement de terrain. L'angle de pente des zones de déclenchement des glissements de terrain (35° à 45°) peut dépasser l'angle de frottement du sol (36,5° à 38,5°) et l'effet hydraulique ne serait pas suffisant pour garantir la stabilité de la pente pendant la saison humide (0 à 10 kPa). On estime que le renforcement dû aux racines peut maintenir les pentes jusqu'à un angle de 42°.On a donc constaté que la présence de racines d'arbres affectait la stabilité hydraulique et mécanique des couvertures de sol pyroclastiques. Ces conclusions peuvent être étendues aux autres zones de plantations de C. sativa. L'effet hydraulique de la végétation a été largement compensé par le renforcement mécanique dû aux racinesThe effect of the local vegetation, composed of cultivated Castanea sativa, on slope stability was investigated on a test site in Mount Faito (Campania, Southern Italy). In Campania, shallow pyroclastic soil covers are susceptible to landslides triggered by rainfall. Prolonged rainfall periods followed by extreme short-term rainfall events trigger fast moving and highly destructive landslides in road cuts and pyroclastic scarps on rocky cliffs in the areas surrounding the Vesuvius volcano.Undisturbed pyroclastic soil samples containing roots of mature C. sativa were used for hydraulic characterization through an extensive set of laboratory experiments. Saturated permeability, evaporation and imbibition response, water content for high suction ranges, and the root dry biomass were determined.The presence of roots increased the hydraulic permeability by one order of magnitude in the most surficial soil (10-7 to 10-6 m s-1) and decreased the air-entry value of the water retention curves (6 to 4 kPa). The variability of soil permeability among soil layers was identified as conditioning of the groundwater flow with regard to the speed of the wetting front movement and generation of positive pore-water pressures within the soil profile. The calibration of hysteretic model to characterize natural pyroclastic soil provided a more approximate manner of modelling in situ hydraulic responses. A good agreement between the model and the field observations was obtained.Field monitoring was performed with the intent of showing that the distribution of roots of C. sativa is associated to the groundwater regime. The spatial and vertical distribution of root density and traits were quantified for C. sativa roots collected from several boreholes performed in Mount Faito. Minimum suction, minimum water content and minimum gradient (indicative of downward water flow), were monitored throughout the year and related to root distribution and spatial distribution of trees. An increasing root density was found to be associated to lower values of suction and higher gradients of infiltration, which can potentially have a negative influence of the slope stability.A modelling investigation on the mechanical reinforcement of soil by tree roots allowed us to understand the importance of hydraulic and mechanic components on the stability of a slope. Roots increase greatly the shear strength of soil (up to 25.8 kPa) through mechanical reinforcement and consequently, the safety factor of the slope increased significantly. Considering the root reinforcement in the estimation of potential failure surfaces safety factor showed that the weakest failure surface was found at 2.2 m, where the root reinforcement was 1.3 kPa, instead of 0.9 m without the root reinforcement of 13.8 kPa. The weakest failure surface found was in agreement with the failure surfaces observed from previous landslides. The test site did not present the characteristics of a landslide triggering area. The slope angle of the landslide triggering areas (35° to 45°) can easily exceed the soil friction angle (36.5° to 38.5°) and the hydraulic effect would not be enough to guarantee the stability of the slope during the wet season (0 to 10 kPa). However, the root reinforcement was estimated to be able to sustain the slopes until an angle of 42°.Therefore, the presence of tree roots was found to affect hydraulically and mechanically stability of pyroclastic soil covers. Such conclusions may be extended to the areas of Campania where C. sativa plantations are present. The hydraulic effect of vegetation was greatly compensated by the mechanical reinforcement of roots
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Ciliz, Serap. "The Effect Of Basin Edge Slope On The Dynamic Response Of Soil Deposits." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608206/index.pdf.
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The effects of basin edge slope on the dynamic response of soil deposits are assessed by using one-dimensional and two-dimensional numerical analyses. 24 basin models having trapezoidal cross section are generated to represent different geometries (basin depth, basin edge slope) and soil type. Harmonic base motions with different predominant periods (Tp) are used in the analyses.
The results indicate that, for a constant basin edge slope and a constant ratio of fundamental period of site to the predominant period of base motion (Tn/Tp), the response is almost the same for different soil types, basin depths and base motions.
In the sloping edge region, one-dimensional response analysis predictions are found to be conservative compared to two-dimensional analysis predictionshowever beyond this region they are unconservatively biased by a factor as high as 1.5. The sloping edge region and the horizontal region of the basin are denoted by normalized distance (ND) values varying from 0 to 1 and 1 to 2 respectively. The critical region where maximum amplification observed falls in the range of ND=1.0 to ND=1.5 for basins having slopes greater than 30o. The lower boundary of the critical region is shifted towards as low as ND=0.2 for basins having slopes less than 30o. For a constant value of Tn/Tp, the increase in the amplification is smooth for basins with gentle slopes as compared to basins with steep slopes for the region where ND~1. For a basin and earthquake couple approaching to resonance state (Tn/Tp=1), the amplification for the region where ND is greater than 1 is found to be as high as 100% of that is found for the region where ND~1.
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Yip, Tat-wing Francis. "The effect of water to the stability of man-made slope in Hong Kong." Click to view the E-thesis via HKUTO, 2003. http://sunzi.lib.hku.hk/hkuto/record/B43895219.
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Yip, Tat-wing Francis, and 葉永達. "The effect of water to the stability of man-made slope in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B43895219.
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Marshall, Hans-Peter. "Snowpack spatial variability: Towards understanding its effect on remote sensing measurements and snow slope stability." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p3190378.
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Fritzson, Hanna. "Effect of Environmental Factors on Pore Water Pressure in River Bank Sediments, Sollefteå, Sweden." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-333788.
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Pore water pressure in a silt slope in Sollefteå, Sweden, was measured from 2009-2016. The results from2009-2012 were presented and evaluated in a publication by Westerberg et al. (2014) and this report is an extension of that project.In a silt slope the pore water pressures are generally negative, contributing to the stability of theslope. In this report the pore water pressure variations are analyzed using basic statistics and a connection between the pore water pressure variations, the geology and parameters such as temperature, precipitation and soil moisture are discussed.The soils in the slope at Nipuddsvägen consists of sandy silt, silt, clayey silt and silty clay. The main findings were that at 2, 4 and 6 m depth there are significant increases and decreases in the pore water pressure that can be linked with the changing of the seasons, for example there is a significant increase in the spring when the ground frost melts. As the seasons change, so do the temperature and amount and type of precipitation. Other factors that vary with the season are the amount of net radiation, wind speed and relative humidity, all of which affect the amount of evapotranspiration. At greater depths the pore water pressue is most likely affected by a factor/factors that varies from year to year, possibly the total amount of rainfall. Therefore, the anticipated increase in precipitation in Scandinavia due to climate change could be an important factor influencing slope stability.What precipitation, temperature and evapotranspiration have in common is that they affect the amount of water infiltrating the soil, and thereby the soil moisture content. How the soil moisture is distributed and flows through the soil (sub-surface flow) is governed by the different soil types and their mutual order in the slope, as well as by factors affecting the structure of the soil, e.g. animal burrows and aggregation. The formation of ground frost also affects the way in which the water present in the soil is redistributed.At c. 14 m depth in the slope, there is a saturated layer with positive pore water pressures, which could be one of several such layers. The overall groundwater situation in a silt slope is complex; several different bodies of water can develop, and to get a complete picture of the ground water situation (andthereby also the pore water pressure variations) thorough hydrological surveys are needed.Under 2009-2016 mättes porvattentrycket i en siltslänt i Sollefteå. Resultaten från 2009-2012presenterades och utvärderades i en publikation av Westerberg et al. (2014) och detta examensarbete är en förlängning av det projektet.I en siltslänt är porvattentrycket vanligtvis negativt vilket bidrar till stabiliteten i slänten. I den härrapporten är variationerna av porvattentrycket analyserade med hjälp av enkel statistik och en koppling mellan variationerna och geologin samt parametrar så som temperatur, nederbörd och fukthalt i marken diskuteras.Jordarterna i slänten vid Nipuddsvägen består av sandig silt, silt, lerig silt och siltig lera. Slutsatsen var att på 2, 4 och 6 m djup ökade och minskade porvattentrycket med årstiderna, till exempel ökade porvattentrycket signifikant vid tjällossningen. När årstiderna skiftar ändras även temperaturen och mängden, och typen, av nederbörd. Andra faktorer som varierar över året är netto-instrålningen, vindhastigheten och den relativa fuktigheten och dessa faktorer påverkar i sin tur evapotranspirationen. På större djup beror antagligen portrycksvariationerna på någon eller några faktorer som skiljer sig åt från år till år, möjligtvis den totala mängden nederbörd. Därmed skulle den ökade nederbörd som förväntas i Skandinavien på grund av klimatförändringarna kunna påverka släntstabiliteten.Vad nederbörd, temeperatur och evapotranspiration har gemensamt är att de påverkar mängden vatten som infiltrerar marken, det vill säga de påverkar markens fukthalt. Hur vattnet är födelat i marken beror på de olika jordarterna och deras inbördes ordning i slänten, men också av faktorer som påverkar markens struktur så som aggregation och uppluckring av jorden på grund av marklevande djurs aktivitet. Även formationen av tjäle på vintern har troligtvis en viss inverkan på hur vattnet i marken omfördelas.På 14 m djup finns ett vattenmättat lager med positiva porvattentryck vilket skulle kunna vara ett av flera sådana lager. I en siltslänt är grundvattensituationen mycket komplex, flera magasin av vatten kan bildas. För att få en bra bild av grundvattensituationen (och där med också porvattentrycksvariationerna)behöver noggranna hydrologiska undersökningar genomföras.
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Berti, Debora. "Clay mineralogy and its effect on physical properties in the Gulf of Mexico northwestern continental slope." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/1624.
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The clay mineral composition of sediments deposited in the last six oxygen isotope stages in the Gulf of Mexico continental slope was characterized. Smectite and illite were found to be the two major clay minerals of the clay fraction while kaolinite, chlorite and quartz were present in the clay fraction but in less proportions. Variations in clay mineral abundances, especially in the relative abundances of smectite and illite, were identified in relation to climate changes. Smectite was the most abundant mineral in sediments of the current (stage 1) and last interglacial maxima (stage 5) while illite dominates the clay min-eralogy of sediments from the last glacial maximum (stage 2). Relationships between clay mineralogy and physical properties were investigated as well. Significant positive correla-tions were found between Atterberg limits with the smectite content of the bulk sediment and with clay content. However, the relationship with smectite yielded a significantly higher correlation coefficient. Smectite and clay content also affect the natural water con-tent of sediments and its changes with depth.
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Thomas, Ian Martin. "Numerical studies of the effect of shelf-edge topography on the stability of along-slope currents." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246230.
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Moura, Nícolas Rodrigues. "Contribution to the study of the effect of three-dimensional stress states to slope stability analysis." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8904.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Análises de estabilidade de taludes são predominantemente realizadas em duas-dimensões (2D) por métodos de equilíbrio limite. Os métodos convencionais de equilíbrio limite são alvos de muitas críticas pelo o uso do equilíbrio estático, pressuposições de forças na análise e por possuir o mesmo fator de segurança ao longo de toda a superfície de deslizamento. Para superar essas deficiências, o método proposto por Kulhawy (1969) incorpora o comportamento tensão-deformação do solo com tensões oriundas do Método de Elementos Finitos (FEM) e tem a mesma estrutura dos métodos de equilíbrio dos métodos de equilíbrio de equilíbrio limite clássicos. É também chamado de método aperfeiçoado. Devido à existência de taludes com geometrias complexas, a abordagem tridimensional (3D) é a única capaz de incorporar todos os aspectos geométricos do problema. Esta dissertação é dividida em dois artigos com o tema de estabilidade de taludes pelo o método de Kulhawy em abordagens 2D e 3D. O objetivo primário dessa dissertação é avaliar os principais fatores que influenciam a estabilidade de taludes. O primeiro artigo propôs geometrias variando de convexo a côncavo em um conjunto de propriedades típicas de solos. Duas trajetórias de geração de tensões in- situ foram utilizadas, i.e., construção e escavação. O método GLE foi calculado para fins de comparação. A superfície de deslizamento é muito dependente do histórico de tensão e da forma da face do talude. A diferença relativa no estado de tensões inicial típico alcançou 15% nas análises 2D e 34% nas análises 3D. A análise de sensibilidade do efeito do Poisson no fator de segurança mostrou-se muito relevante. A relação entre os fatores de segurança 2D e 3D são quase lineares independente do estado de tensões, das propriedades de resistência, formato da face do talude, na ordem de 30 a 40%. O segundo artigo propõe análises em barragens construídas em vales estreitos. Três abordagens de análises foram utilizadas: redução de resistência ao cisalhamento (SSR), métodos de Kulhawy e GLE. Condições típicas de fundações são muito variáveis como topografia e deformabilidade. A análise de sensibilidade do módulo de fundação de Young no fator de segurança foi insignificante em 2D e relevantes em 3D. A relação entre o comprimento do aterro (W) e a altura () é uma variável representativa do grau de estreitamento da barragem e na estabilidade de taludes. A análise de deformações planas tende a altas relações W/H e o oposto mostra elevados efeitos 3D. A inclinação da ombreira mostrou-se relevante no fator de segurança apenas em aterros em vales estreitos. Fundações mais rígidas são mais beneficias para o fator de segurança devido à produção de altos efeitos de arqueamento neste cenário. O método de Kulhawy provou-se ser vantajoso pela a incorporação do comportamento mecânico do solo, o uso de tensões mais realísticas nas análises e avaliação da estabilidade local na superfície de deslizamento. Isso aumenta a quantidade de informações úteis e confiáveis para o profissional de engenharia no projeto de taludes. Todas as análises foram realizadas usando o software SoilVision Systems, Saskatchewan, Canadá. Os módulos utilizados foram o SVLOPE, SVSOLID e o SVFLUX (SoilVision Systems Ltd., 2018). A análise de tensão para a simulação de trajetórias de escavação e construção utilizou do solucionador de Equações Diferenciais Parcias (PDE) o FlexPDE 6 (PDE Solutions Inc., 2014).
Slope stability analyses are predominantly performed using the two-dimensional (2D) conventional limit equilibrium methods. Conventional limit equilibrium methods are targets of many criticisms for using static equilibrium, assumptions of forces in the analysis and the same factor of safety along the slip surface. In order to overcome these shortcomings, the method proposed by Kulhawy (1969) incorporates the stress-strain behavior of the soil with stresses from the Finite Element Method (FEM) with the same structure as limit equilibrium methods. It is also called enhanced method. Due to the existence of slopes with complex geometries, the three-dimensional (3D) approach is only able to incorporate all the geometric aspects of the problem. This thesis is divided into two papers with the subject of slope stability analyses by the Kulhawy’s method in 2D and 3D approaches. The primary objective of this thesis is to evaluate major factors that influence slope stability. The first paper proposed geometries ranging from convex to concave in a set of soil properties. Two stress paths were considered, i.e., construction and excavation. The GLE method was computed for comparison purposes. The slip surface is very dependent on the stress history and the shape of slope face. The relative difference in typical initial stress state reached 15% in 2D analyses and 34% in 3D analyses. Sensitivity analysis of effect of Poisson’s ratio on factor of safety was very relevant. The relationship between 2D and 3D factors of safety are nearly linear independent of stress state on order of 30 to 40%. The second paper propose analyses on embankment dams built in narrow valleys. Three approaches of slope stability were used: shear strength reduction (SSR), Kulhawy’s and GLE methods. The typical conditions of foundation sites are very variable as topography and deformability. Sensitivity analysis of Young’s modulus of foundation on factor of safety was insignificant in 2D and relevant in 3D analyses. The ratio between embankment length (W) and height (H) was very important on slope stability. The plane strain analysis tends to high W/H ratio and the opposite shows high 3D effects. The inclination of abutment showed to be relevant on factor of safety only in embankments in narrow valleys. Stiffer foundations are beneficial to the factor of safety due producing high arching effects in this scenario. The Kulhawy’s method proved to be advantageous by the incorporation of mechanical behavior of soil, more realistic stress and local stability evaluation on slip surface. It increases the amount of useful and reliable information to the engineering professional in design of slopes. All analyses were performed using SoilVision Systems suite software, Saskatchewan, Canada. The modules used were SVSLOPE, SVSOLID and SVFLUX (SoilVision Systems Ltd., 2018). The stress analysis for the simulation of excavation and construction trajectories used partial differential equation (PDE) solver, FlexPDE 6 (PDE Solutions Inc., 2014).
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Baret, Christophe Marc Eric. "The effect of structure slope and packing arrangement on the hydraulic stability of geotextile sand container revetments." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79919.
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Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Innovative and versatile coastal protection structures made of Geotextile Sand Containers (GSCs) are increasingly being incorporated into coastal management solutions because of their cost effective and environmentally friendly characteristics. This is as opposed to conventional ‘hard’ coastal protection solutions that utilise rocks and or concrete units to protect the coastline. With GSC structures being a relatively new coastal protection solution, few design and construction guidelines are available. Research into the behaviour of GSC structures under wave attack is on-going with particular emphasis on the hydraulic processes that affect GSC structures and cause them to fail. The use of GSC revetments as coastal protection solutions has become more popular in South Africa during recent times, particularly along the coastline of KwaZulu-Natal. However, the chosen design of these GSC revetments falls outside the range of applicability of the available design charts and stability equations. Therefore the hydraulic stability of these structures is largely unknown. The primary objective of this study is to investigate the effect of structure slopes and packing arrangements on the hydraulic stability of GSC revetments. The application of available design charts and stability equations was also evaluated. Two-dimensional physical modelling was undertaken and a total of 12 GSC revetment permutations were tested during the physical modelling test series. The results of the physical modelling showed that the structure slope had the most significant effect on the hydraulic stability. Steeper structure slopes were more hydraulically stable than gentler structure slopes. The packing arrangements of the GSCs had less of an effect on the hydraulic stability of the GSC revetments. Single layer GSC armour revetments matched or out-performed the equivalent double layer GSC revetments; while GSC revetments with GSCs orientated with the long axis perpendicular to the wave attack performed marginally better than the equivalent GSC revetments with GSCs orientated with the long axis parallel to the wave attack. The available design charts and stability equations were assessed against the results of the physical modelling and showed varying degrees of correlation. The stability equation proposed by Recio (2007) proved to be particularly accurate.
AFRIKAANSE OPSOMMING: Innoverende en veelsydige kusbeskermingstrukture wat van geotekstielsandhouers (GSH’s) gemaak is, word al hoe meer by kusbestuursoplossings ingesluit weens die kostedoeltreffendheid en omgewingsvriendelike aard daarvan. Dít is in teenstelling met konvensionele ‘harde’ kusbeskermingsoplossings, wat van rotse en/of betoneenhede gebruik maak om die kuslyn te beskerm. Aangesien GSH-strukture ’n betreklik nuwe kusbeskermingsoplossing is, is weinig ontwerp- en konstruksieriglyne beskikbaar. Navorsing oor die werkverrigting van GSH-strukture onder golfaanslag duur voort, met bepaalde klem op die hidrouliese prosesse wat GSH-strukture beïnvloed en die werking daarvan benadeel. Die gebruik van GSH-bedekte hellings as kusbeskermingsoplossings het in die laaste tyd al hoe gewilder geword in Suid-Afrika, veral langs die kus van KwaZulu-Natal. Tog val die gekose ontwerp van hierdie GSH-bedekte hellings buite die toepaslikheidsbestek van die beskikbare ontwerpriglyne en stabiliteitsvergelykings. Die hidrouliese stabiliteit van hierdie strukture is dus grotendeels onbekend. Die hoofoogmerk van hierdie studie was om ondersoek in te stel na die effek van struktuurhellings en pakformasies op die hidrouliese stabiliteit van GSH-bedekte hellings. Die toepaslikheid van beskikbare ontwerpriglyne en stabiliteitsvergelykings is ook geëvalueer. Tweedimensionele fisiese modellering is onderneem en altesaam 12 GSH-bedekte hellings is gedurende die fisiese-modelleringstoetsreeks getoets. Die resultate van die fisiese modellering toon dat die struktuurhelling die beduidendste effek op hidrouliese stabiliteit het. Steiler struktuurhellings was hidroulies meer stabiel as platter hellings. Die pakformasies van die GSH’s blyk ’n kleiner effek op die hidrouliese stabiliteit van die GSH-bedekte hellings te hê. GSH-bedekte hellings wat met ’n enkele laag GSH’s versterk is, het ewe goed of beter presteer as die keermure met ’n dubbele laag GSH’s, terwyl GSH-bedekte hellings met die lang-as van die GSH’s loodreg op die rigting van die golfaanslag effens beter presteer het as dié met die lang-as parallel met die golfaanslag. Die beskikbare ontwerpriglyne en stabiliteitsvergelykings is geëvalueer aan die hand van die resultate van die fisiese modellering, en het ’n wisselende mate van korrelasie getoon. Veral die stabiliteitsvergelyking van Recio (2007) blyk besonder akkuraat te wees.
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Mirzoyan, Artak Davit. "Lateral Resistance of Piles at the Crest of Slopes in Sand." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2088.pdf.
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Gallacher, Jonathan R. "The Influence of Season, Heating Mode and Slope Angle on Wildland Fire Behavior." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/5691.
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Wildland fire behavior research in the last 100 years has largely focused on understanding the physical phenomena behind fire spread and on developing models that can predict fire behavior. Research advances in the areas of live-fuel combustion and combustion modeling have highlighted several weaknesses in the current approach to fire research. Some of those areas include poor characterization of solid fuels in combustion modeling, a lack of understanding of the dominant heat transfer mechanisms in fire spread, a lack of understanding regarding the theory of live-fuel combustion, and a lack of understanding regarding the behavior of flames near slopes. In this work, the physical properties, chemical properties and burning behavior of the foliage from ten live shrub and conifer fuels were measured throughout a one-year period. Burn experiments were performed using different heating modes, namely convection-only, radiation-only and combined convection and radiation. Models to predict the physical properties and burning behavior were developed and reported. The flame behavior and associated heat flux from fires near slopes were also measured. Several important conclusions are evident from analysis of the data, namely (1) seasonal variability of the measured physical properties was found to be adequately explained without the use of a seasonal parameter. (2) ignition and burning behavior cannot be described using single-parameter correlations similar to those used for dead fuels, (3) moisture content, sample mass, apparent density (broad-leaf species), surface area (broad-leaf), sample width (needle species) and stem diameter (needle) were identified as the most important predictors of fire behavior in live fuels, (4) volatiles content, ether extractives, and ash content were not significant predictors of fire behavior under the conditions studied, (5) broadleaf species experienced a significant increase in burning rate when convection and radiation were used together compared to convection alone while needle species showed no significant difference between convection-only and convection combined with radiation, (6) there is no practical difference between heating modes from the perspective of the solid—it is only the amount of energy absorbed and the resulting solid temperature that matter, and (7) a radiant flux of 50 kW m-2 alone was not sufficient to ignite the fuel sample under experimental conditions used in this research, (8) the average flame tilt angle at which the behavior of a flame near a slope deviated from the behavior of a flame on flat ground was between 20° and 40°, depending on the criteria used, and (9) the traditional view of safe separation distance for a safety zone as the distance from the flame base is inadequate for fires near slopes.
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Wright, Nathan W. "Air Vent Sizing in Low-Level Outlet Works for Small- to Medium-Sized Dams." DigitalCommons@USU, 2013. http://digitalcommons.usu.edu/etd/1531.
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The majority of dams contain low-level outlet works, which typically consist of closed conduits that run through the dam, and are used to release water from the reservoir when the water level is below the level of the surface spillways. It is also used to flush the reservoir of sediments and to control the elevation of the reservoir. Low-level outlet works typically consist of a gate that controls the flow within a closed conduit that runs through the dam and an air vent that supplies air behind the gate. In the absence of properly designed air vents, negative pressures may develop downstream of the gate. These negative pressures could potentially lead to cavitation and vibration damage. Properly sized air vents help maintain the downstream air pressure at or near atmospheric pressure and/or provide air to absorb the energy generated by cavitation, reducing the potential for damage. The majority of research done on air vent sizing is for dams having large dam geometry, which consist of a pressurized conduit leading to a vertical slide gate that is followed by a discharge tunnel. The typical air vent design for these large dams uses the water flow rate and the Froude number measured at the vena contracta downstream of the gate. The low-level outlet works for small-to-medium-sized embankment dam geometries typically have an inclined slide gate, installed at the inlet on the upstream face of the dam slope, followed by an elbow that connects to a conduit that passes through the dam and discharges downstream. This type of outlet geometry does not produce the typical vena contracta. Consequently, the use of the Froude number, at the vena contracta , as a characteristic parameter for characterizing airflow demand is not practical. Recently a laboratory study was performed calculating the head-discharge characteristics of low-level outlets for small-to-medium sized dam geometries. In addition to validating some of the previous laboratory-scale air venting research, the objective of this study was field verification of air-demand/air vent sizing predicted by the laboratory-based method. The influence of conduit slope, air port location, and hydraulic jumps on air demand was also evaluated in the laboratory. The findings of this study can be found within this thesis.
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Stephen-Brownie, Charlotte Jane. "Earthquake-Induced Ground Fissuring in Foot-Slope Positions of the Port Hills, Christchurch." Thesis, University of Canterbury. Geological Sciences, 2012. http://hdl.handle.net/10092/9285.
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Following the 22 February 2011, MW 6.2 earthquake located on a fault beneath the Port Hills of Christchurch, fissuring of up to several hundred metres in length was observed in the loess and loess-colluvium of foot-slope positions in north-facing valleys of the Port Hills. The fissuring was observed in all major valleys, occurred at similar low altitudes, showing a contour-parallel orientation and often accompanied by both lateral compression/extension features and spring formation in the valley floor below. Fissuring locations studied in depth included Bowenvale Valley, Hillsborough Valley, Huntlywood Terrace–Lucas Lane, Bridle Path Road, and Maffeys Road–La Costa Lane.
Investigations into loess soil, its properties and mannerisms, as well as international examples of its failure were undertaken, including study of the Loess Plateau of China, the Teton Dam, and palaeo-fissuring on Banks Peninsula. These investigations lead to the conclusion that loess has the propensity to fail, often due to the infiltration of water, the presence of which can lead to its instantaneous disaggregation. Literature study and laboratory analysis of Port Hills loess concluded that is has the ability to be stable in steep, sub-vertical escarpments, and often has a sub-vertically jointed internal structure and has a peak shear strength when dry.
Values for cohesion, c (kPa) and the internal friction angle, ϕ (degrees) of Port Hills loess were established. The c values for the 40 Rapaki Road, 3 Glenview Terrace loess samples were 13.4 kPa and 19.7 kPa, respectively. The corresponding ϕ values were thought unusually high, at 42.0° and 43.4°.The analysed loess behaved very plastically, with little or no peak strength visible in the plots as the test went almost directly to residual strength.
A geophysics resistivity survey showed an area of low resistivity which likely corresponds to a zone of saturated clayey loess/loess colluvium, indicating a high water table in the area. This is consistent with the appearances of local springs which are located towards the northern end of each distinct section of fissure trace and chemical analysis shows that they are sourced from the Port Hills volcanics.
Port Hills fissuring may be sub-divided into three categories, Category A, Category B, and Category C, each characterised by distinctive features of the fissures. Category A includes fissures which display evidence of, spring formation, tunnel-gullying, and lateral spreading-like behaviour or quasi-toppling. These fissures are several metres down-slope of the loess-bedrock interface, and are in valleys containing a loess-colluvium fill. Category B fissures are in wider valleys than those in Category A, and the valleys contain estuarine silty sediments which liquefied during the earthquake. Category C fissures occurred at higher elevations than the fissures in the preceding categories, being almost coincident with bedrock outcropping.
It is believed that the mechanism responsible for causing the fissuring is a complex combination of three mechanisms: the trampoline effect, bedrock fracturing, and lateral spreading. These three mechanisms can be applied in varying degrees to each of the fissuring sites in categories A, B, and C, in order to provide explanation for the observations made at each. Toppling failure can describe the soil movement as a consequence of the a three causative mechanisms, and provides insight into the movement of the loess. Intra-loess water coursing and tunnel gullying is thought to have encouraged and exacerbated the fissuring, while not being the driving force per se. Incipient landsliding is considered to be the least likely of the possible fissuring interpretations.
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Rizo, Steven R. "Quantifying the Effect of Topographic Slope on Lava Flow Thickness: A First Step to Improve Lava Flow Volume Estimation Methods." Scholar Commons, 2018. http://scholarcommons.usf.edu/etd/7222.
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The volume of lava flows provide important information on the magnitude of volcanic eruptions, and accurate volumes are necessary to produce reliable models of lava flow emplacement or constrain the internal structure of volcanoes. The most accurate lava flow volumes are obtainable when the topography before and after an eruption are both known, but information for the topography before lava flow emplacement is absent in non-historic lava flows. To calculate the volume of non-historic lava flows, this pre-emplacement topography needs to be reconstructed. Common methods for this include using inverse distance-weighted averages or global polynomial interpolation methods, but these can still underestimate the volume of the flow, and the surface of the flow itself is not considered in these interpolations. A new calculation method seems necessary to better constrain the volume of lava flows, and including the lava flow surface in the volume calculation, given that it is generally excluded during interpolation of pre-emplacement topography, may be the solution to improving lava flow volume calculation for flows where the base surface is unknown. The 2012-2013 Tolbachik lava flow is used to look at potential relationships due to the availability of elevation data before and after the eruption. A quantitative analysis on the relationships between the slope of topography before and after lava flow emplacement and on the relationship between the slope and thickness of lava flows is performed. In addition to this, the slope of the topography calculated over local and regional scales is used as a new interpolation method, and the calculated thickness from the interpolated surface is compared to the known thickness for the lava flow.
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Reese, Jessica Lee. "The Effect of the Slope of the Psychometric Function on the Measurement of Speech Recognition Threshold Using a Female Talker." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6868.
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Speech audiometry has long been a component of a thorough audiological examination. The speech recognition threshold (SRT) measurement is perhaps the most widely used measurement in speech audiometry. For decades, researchers and clinicians have worked to create and fine-tune word lists that for use in SRT testing; their aim being to improve the accuracy for classifying a client's ability to hear and comprehend speech. Experts in the field have agreed to follow four tenets of speech audiometry when selecting word sets. This study examined whether improvement to stimulus lists for SRT measurement could be made in regards to the tenet of homogeneity with respect to audibility if the slope of the psychometric function were a selection consideration. The study was performed with the hypothesis that steeply sloping words would significantly reduce the number of words needed to obtain the SRT. Three word lists, all recorded by a female talker, comprising of steeply sloping words, medium sloping words, and shallow sloping words, were used in the study. Participants with normal hearing between the ages of 18 and 30 years provided data that was used to calculate SRT measurements for all three lists from each ear. The results showed a significant difference in the number of words needed to obtain the SRT when comparing the steep and shallow word sets and the shallow and medium word sets. Steeply sloping words required fewer words to obtain the SRT, M = 17.02. Shallow sloping words required the most words, M = 18.88, amounting to a difference of 1.86 words. While statistically different, a reduction by fewer than 2 words during the course of SRT testing will not equate to a substantial saving of time for the clinician. For clinical application, the slope of the psychometric function of the words used in SRT measurement need not be a primary consideration when developing stimulus lists.
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Bakhsh, Nujod Ali. "The Effect of the Slope of the Psychometric Function on the Measurement of Speech Recognition Threshold Using a Male Talker." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6841.
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Speech audiometry is the aspect of audiology that provides critical information on how individuals hear one of the most important sounds of daily life: speech. The speech recognition threshold (SRT) is a measure of speech audiometry that is widely used to provide information on an individual's capacity to hear speech. Over time, researchers and clinicians have worked to improve the SRT by developing and modifying a variety of word lists to be used during testing. Eventually, spondaic words were selected as the best stimuli for the SRT. The spondaic words had to meet four criteria: familiarity, phonetic dissimilarity, normal sampling of English sounds, and homogeneity with respect to audibility. This study examined the aspect of homogeneity with regard to slope of the psychometric function. Specifically, whether slope of the psychometric function had an effect on the number of words used to obtain the SRT, and thus reduce test time, as well as whether slope had an effect on the relationship between the SRT and the pure-tone average (PTA). It was hypothesized that words with a steep slope would significantly reduce test time and yield a close SRT-PTA agreement. Three word lists (steep, medium, and shallow sloping words), all recorded by a male talker, were used to obtain the SRT on 40 participants (ages 18-30 years). Statistical analysis showed significant differences in the number of words to obtain the SRT and the SRT-PTA agreement. However, when the differences were examined from a clinical perspective, the results were negligible. When compared with words with medium and steep slopes, words with shallow slope required an average of four extra words to obtain the SRT, which does not result in a meaningful reduction in test time. For clinical purposes, it appears that the slope of the psychometric function does not need to be taken into consideration for the SRT. Clinicians may use a variety of words as long as they meet the original four criteria for selection of spondees.
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Black, Marianne Susan. "The effect of wedge and slope angles on knee contact pressure and kinematics in medial opening wedge high tibial osteotomy." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/50103.
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BARTON, JOHN M. H. "EFFECT OF MEDIA GRAIN SHAPE ON PHYSICAL CAPTURE OF PARTICLES IN A FILTER BED." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1092931427.
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Pettersson, Ellinor. "Eutanasi : Huruvida eutanasi är moraliskt tillåtligt inom samtida moralfilosofi." Thesis, Linköpings universitet, Institutionen för kultur och kommunikation, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157298.
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Euthanasia has been subject of controversy since antiquity, but 3000 years later it still seems to be highly debated among contemporary ethicists and philosophers. The main purpose of this essay is to investigate under which circumstances euthanasia could be morally permissible, by highlighting and discussing the most debated objections against it. The first objection brings up the problem of how we can be sure that a wish to die is confident and final. This objection is followed by a discussion about the risks of administering euthanasia incorrectly. The second objection concerns whether voluntary euthanasia and physician-assisted suicide really is necessary. Here, the main question is whether people about to die would be harmed rather than helped if they had euthanasia and physician-assisted suicide available as an alternative. The third section discusses the doctrine of double effect. Here, the main purpose is to investigate where DDE stands in relation to cases of euthanasia and physician-assisted suicide. Furthermore, the final two objections concern the parallel between killing and letting die, and second of all the slippery-slope argument in connection with euthanasia. The essay concludes with a discussion about the ways in which practicing euthanasia can be harmful, as well as a more detailed debate about the sustainability of the objections mentioned above.
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Ali, Heba. "THE EFFECT OF DEPTH ON DEVELOPMENT AND SEXUAL DIMORPHISM OF THE SONIC SYSTEM IN DEEP SEA NEOBYTHITINE FISHES: THE UPPER CONTINENTAL SLOPE." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4095.
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Abstract
Background: Cusk-eels from the subfamily Neobythiitinae are one of the major groups of sound-producing fishes on the continental slope. Sounds have never been recorded from a member of this subfamily, and sonic anatomy is considered a proxy for sound production. As the first part of a study on the effects of depth on sonic anatomy, we examined three relatively shallow species from the upper continental slope.
Methods: Three species (Hoplobrotula armata, Neobythites longipes and Neobythites unimaculatus) were examined for sonic anatomy (skeleton, swimbladder and sonic muscles), and sonic and epaxial muscle fibers were measured for diameter. Regressions of dimensions and weights of sonic muscles and swimbladders against fish total length and weight were compared to determine sexual dimorphism and relative development between species.
Results: Four pairs of sonic muscles (two medial and two lateral) originate on the skull and insert on the medial swimbladder or on modified epineural ribs that attach to the lateral swimbladder. The medial and medial intermediate muscles are generally larger in males than females and are made of relatively small fibers (ca 10 um in diameter), and lateral muscles are generally larger in females and consist of larger fibers as in epaxial muscles. Medial muscles are considerably larger in Hoplobrotula armata than in the Neobythites species.
Conclusion: Neobythitines from the upper slope have relatively well-developed sexually-dimorphic sonic systems, suggesting that males produce advertisement calls for courtship. There are major quantitative differences between species. We suggest that sound production involves tonic contraction of the large-fibered lateral muscle pair and oscillatory contractions of the smaller medial fibers setting the swimbladder into vibration. Hoplobrotula armata is probably capable of making more intense sounds than the Neobythies spp.
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Revilla, Iñigo, and Laia Pons. "Study of a vertical slot fish ladder : Evaluation of flow dynamics through a standardized bypass and the effect of predesigned roughness elements." Thesis, Högskolan i Gävle, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-32576.
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Migrating freshwater fish population has been significantly declined, mostly by the obstruction of their migratory routes by hydropower dams. To diminish such impacts, fish ladders have been developed to facilitate the passage of migrating fish. However, fish ladders are associated with mortality and migratory failure, resulting in an ecological problem which has been a concern for years. The paper contained in the following pages focuses on studying the viability of an innovative modular design for a fish ladder developed by Fiskvägsteknik AB. The design is based in a vertical slot fishway (VSF) to which some roughness elements are attached to modify the flow. The aim of this bypass system is to restore the original biological continuity and diversity in the Swedish rivers, therefore solving a long-lasting ecological problem that hydroelectric production has caused over the years. Through a computational analysis, the flow has been evaluated as a function of the parameters that present an influence over its behaviour. First, a study of the changes in flow velocity influenced by four different slopes: 5 %, 10 %, 15 % and 20 %, has been performed with the objective to find an appropriate inclination according to the capabilities of the fish species considered. The lowest slopes have resulted to be the most appropriate ones, coinciding with low values of turbulent kinetic energy and lower flow velocities. The second step has been checking the effect of roughness elements on the bottom part of the structure tilted a 5%. The flow velocity has shown a considerable decrease, falling in the range of the fish swimming capabilities established. As for the streamlines of the flow, they were altered compared to the cases without the roughness elements.
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Ji, Jinnan. "Finite elements modelling and analysis of the effect of vegetation on forested slopes stability." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20213.
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L'ingénierie écologique, qui est décrite comme «la gestion de la nature», a d'abord été proposée par Odum en 1971. Dans les dernières décennies, l'ingénierie écologique a été largement consacrée à lutter contre l'érosion des sols et les mouvements de masse, tout en permettant d'assurer la durabilité des écosystèmes. L'objectif de cette thèse est d'évaluer l'impact de peuplements forestiers sur la stabilité de pentes de dimension finie, en considérant à la fois les effets mécaniques et hydrologiques des racines peu profondes contre les glissements de terrain. Deux sites forestiers monospécifiques et équiennes, plantés respectivement de Robinia pseudoacacia et Platycladus orientalis, ont été sélectionnés sur le Plateau du Loess en Chine et utilisés comme sites d'étude. Le Facteur de Sécurité (FoS) de ces pentes ont été calculées en utilisant un modèle éléments finis 2D qui prend en compte la distribution des racines dans les couches superficielles du sol.Des mesures de terrain et des tests de laboratoire ont été effectués afin d'estimer les principaux paramètres du modèle, à savoir la distribution des surfaces relatives de racines dans le sol (Root Area Ratio), la résistance à la traction des racines, ainsi que les propriétés mécaniques et hydrologiques du sol nu. La contribution des racines à la résistance au cisaillement du sol a été considérée par l'intermédiaire d'une « cohésion additionnelle » calculée à l'aide de modèles fournis par la littérature. Six modèles existants ont été testés. Cette thèse est composée de deux chapitres principaux portant sur: (1) l'effet mécanique de l'hétérogénéité spatiale de la distribution des racines à l'échelle de pente; (2) l'influence de la distribution des racines sur le couplage entre la diffusion de l'eau interstitiel et les contraintes mécaniques dans le sol et son impact sur la stabilité des pentes.Les simulations amènent aux conclusions principales suivantes: (1) les pentes en terrasse sont en théorie 20% plus stables que les pentes rectilignes, sans tenir compte des effets hydrologiques; (2) le FoS atteint une valeur asymptotique lorsque l'on augmente la cohésion des racines; (3) les variations de la cohésion des racines observées sur le terrain ont peu d'effet sur la stabilité des pentes. Toutefois le renforcement de la partie basse des pentes, où les racines ont un plus grand impact positif sur le FOS, peut permettre de diminuer le risque de glissement; (4) l'effet des fortes précipitations sur la stabilité de la pente pourrait probablement être atténué par la présence de racines, mais cet effet dépend des caractéristiques des racines et de leur influence sur le débit d'eau dans le solEcological engineering, which is described as ‘the management of nature', was first proposed by Odum in 1971. In the past few decades, ecological engineering has been largely devoted to combat soil erosion and mass movement all over the world, because of its benefit on sustainable ecosystems. The objective of this thesis is to evaluate the impact of forest stands on the stability of finite slopes, considering both the mechanical and hydrological effects of roots against shallow landslides. Two monospecific and even-aged forest sites planted with Robinia pseudoacacia and Platycladus orientalis respectively were selected on the Loess Plateau of China and used as study sites. Slope Factors of Safety were calculated using a 2D finite element model that takes into account the distribution of roots in the shallow layers of soil.Field site experiments and laboratory tests were performed in order to estimate the main parameters of the model, i.e. distribution of root area ratio within the soil, root tensile strength, as well as bare soil mechanical and hydrological properties. The contribution of roots to soil shear strength was considered through an additional cohesion calculated with models provided by the literature. Six existing models were tested. This thesis is composed of two main chapters that make the focus on : (1) the mechanical effect of the spatial heterogeneity of root distribution at the slope scale; (2) the influence of root distribution on the coupling between pore fluid diffusion and mechanical stress and its impact on slope stability. This study brings to the following main conclusions: (1) terraced slopes were 20% more stable than rectilinear slopes, disregarding the differences in hydrological regimes between the two sites; (2) FoS could reach an asymptotic value when increasing root additional cohesion; (3) variations of the actual root cohesion do not affect much slope stability. However more attention should be given to the reinforcement of the bottom part of the actual slopes, where roots have a larger positive impact on the FoS; (4) the effect of heavy precipitations on slope stability could probably be overcome or at least mitigated by root system network, but this depends on root characteristics and their resulting effect on soil water flow
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Redwood, Mame S. "The Effect of Silviculture Management on the Spread of Three Invasive Species." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1337273012.
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Zhu, Pengtao [Verfasser], Karl Josef [Akademischer Betreuer] Witt, Tom [Gutachter] Lahmer, and Ivo [Gutachter] Herle. "The Variability of the Void Ratio of Sand and its Effect on Settlement and Infinite Slope Stability / Pengtao Zhu ; Gutachter: Tom Lahmer, Ivo Herle ; Betreuer: Karl Josef Witt." Weimar : Fakultät Bauingenieurwesen / Professur Grundbau, 2018. http://d-nb.info/1155730267/34.
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Zhu, Pengtao Verfasser], Karl Josef [Akademischer Betreuer] [Witt, Tom [Gutachter] Lahmer, and Ivo [Gutachter] Herle. "The Variability of the Void Ratio of Sand and its Effect on Settlement and Infinite Slope Stability / Pengtao Zhu ; Gutachter: Tom Lahmer, Ivo Herle ; Betreuer: Karl Josef Witt." Weimar : Fakultät Bauingenieurwesen / Professur Grundbau, 2018. http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180403-37411.
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Chiou, Li-Kuei. "The effect that design of the Nucleus Intracochlear Electrode Array and age of onset of hearing loss have on electrically evoked compound action potential growth and spread of excitation functions." Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/3060.
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The purpose of this study was to investigate how design changes in Cochlear Nucleus cochlear implants (CIs) (CI24M, CI24R, CI24RE and CI422) affected electrode impedance and ECAP measures, and to determine if these design changes affected post-lingually deafened adults and children with congenital hearing loss in a similar way.
Results of this study showed that electrode impedance was inversely related to the area of the electrode contacts in the array: lowest for the full-banded CI24M CI and highest for adults who used the CI422 device which has the smallest electrode contacts of all four devices. The noise floor of the NRT system likely plays a significant role in the finding that CI users with older devices (the CI24M, and CI24R CIs) had higher ECAP thresholds than individuals with the CI24RE electrode array. The position of the electrode array in the cochlea was also found to have a significant effect on ECAP measures. CI users with modiolar hugging (the CI24R and CI24RE CIs) electrode arrays were found to have lower ECAP thresholds than CI users whose electrode arrays were seated more laterally in the cochlear duct (e.g. the CI24M and CI422 implants). The position of the electrode contacts relative to the modiolus of the cochlea was found to be related to slope of the ECAP growth functions. The lowest slopes were found in CI24RE users. It also had a significant impact on the width of the channel interaction function. Electrode arrays seated further from the modiolus have significantly more channel interaction than electrode arrays that hug the modiolus of the cochlea.
Differences between results recorded from post-lingually deafened adults and children with congenital hearing loss were minimal. The difference only reflected on the ECAP slopes. Slopes in children with congenital hearing loss were significantly steeper than those recorded from adults. This may indicate that children with congenital hearing loss may have better neural survival than adults with acquired hearing loss.
In conclusion, the results of the current study show evidence of the effects of variations in design and function of the implanted components of the Nucleus CI. Perhaps the most significant finding from the current data set is that electrode arrays located closer to the modiolus of the cochlea have lower thresholds and exhibit less channel interaction than electrode arrays that are positioned more laterally. An argument could be made that lower stimulation levels and less channel interaction may result in better outcomes and/or longer battery life. For CI candidates who do not have significant residual acoustic hearing, the CI24RE implant might be a better choice than the more recently introduced CI422 electrode array.
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Milanesi, Marcos Alexandre. "Avaliação do efeito orográfico na pluviometria de vertentes opostas da Ilha de São Sebastião (Ilhabela-SP)." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/8/8135/tde-04012008-114406/.
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Com o intuito de se avaliar as diferenças pluviométricas nas vertentes continental e oceânica da Ilha de São Sebastião (Ilhabela - SP) para validação da ocorrência do efeito orográfico, foram instalados ao longo da Estrada de Castelhanos um conjunto de treze pluviômetros experimentais. Os totais mensais, obtidos no ano hidrológico 2004/2005, foram correlacionados, de forma geral, a outros postos pluviométricos da região, às altitudes diversas e à atuação das correntes de sudeste (predominantes). Os resultados apontam para o relevo como responsável por interferir no ritmo pluvial da região, claramente diferenciado na ilha e na distribuição espacial da chuva local. A vertente continental apresenta, em média, 20% menos chuva que a vertente oceânica a barlavento, o que caracteriza a sombra de chuva. Na vertente oceânica, verificou-se intensificação e aumento das quantidades de chuva a partir dos 300m de altitude. O total mensal máximo foi observado a 600m de altitude (708,5mm, em março/2005). Também foi calculado o gradiente pluviométrico em função do relevo que apresenta, em média, o acréscimo de 2,5mm de chuva a cada metro de altitude.In order to provide data for the evaluation of rainfall differences on the continental and sea slopes of São Sebastião Island (Ilhabela - SP) and to validate the occurrence of orographic effect, a set of 13 experimental rain gauges were installed throughout the Estrada de Castelhanos. The monthly totals from the 2004/2005 hydrological year were compared to other rainfall data recording posts, to different altitudes and to (predominant) southeastern currents. The results show topography as an agent interfering with the regional precipitation rhythm, clearly distinct in the island and in the spatial distribution of the local rain. The continental slope presents, in average, 20% less rain than the windward sea slope, which characterizes the rain shadow. In the sea slope, intensification and increase of the rainfall begins at 300m. The maximum monthly totals were observed at 600 m altitude (708.5mm, in march/2005).
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Sharma, Subedi Abhijit. "Quantification of the Effect of Bridge Pier Encasement on Headwater Elevation Using HEC-RAS." Youngstown State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1502982013572665.
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Landera, Mario Alberto. "Effects of spectral slope on perceived breathiness in vowels." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0014823.
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Bennie, Jonathan James. "The ecological effects of slope and aspect in chalk grassland." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/4017/.
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The microclimate of plants growing close to the ground is strongly influenced by the orientation of a soil/vegetation surface with respect to the sun's rays (slope and aspect). In chalk grassland in the UK, slopes of contrasting aspect frequently have distinctive patterns of vegetation. A series of climatic and microclimatic measurements were made at field sites indifferent regions on the English chalk (North Dorset and the Yorkshire Wolds) during the period June 2000 to September 2002. Using digital terrain models (DTMs), process-based models of microclimatic variables at different points in the landscape were developed. The mechanisms through which topography may influence vegetation and species distribution were investigated with field experiments and measurements. Both existing vegetation data from Perring (1956) and new data collected from the field sites were analysed using detrended correspondence analysis (DCA) and generalised additive models (GAMs), to elucidate the relationships between vegetation and soil, topography and climate. A consistent gradient in chalk grassland vegetation was found across spatial scales, associated with the frequency of species with a "stress tolerant” strategy. This gradient in vegetation is apparently driven by species' responses to several separate, but often correlated, variables including soil moisture, maximum summer temperatures and soil fertility. Over the past 50 years, stress tolerant species have declined in frequency at the North Dorset field site, Ellenberg fertility indices have increased and light indices have decreased. The observed changes are consistent with fertilization from atmospheric N deposition and/or relaxation of rabbit grazing after the myxomatosis outbreak in the 1950s. Plots on sloping ground, and in particular, south-west facing slopes, were least affected by these changes, suggesting that high temperatures, phosphorus and water limitation have acted as a buffer against vegetation change, and that complex topography creates refuges for stress tolerant species in the landscape.
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Nam, Soonkie. "Effects of Reservoir Releases on Slope Stability and Bank Erosion." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/77114.
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Reservoir release patterns are determined by a number of purposes, the most fundamental of which is to manage water resources for human use. Managing our water resources means not only controlling the water in reservoirs but also determining the optimum release rate taking into account factors such as reservoir stability, power generation, water supply for domestic, industrial, and agricultural uses, and the river ecosystem. However, riverbank stability has generally not been considered as a factor, even though release rates may have a significant effect on downstream riverbank stability. Riverbank retreat not only impacts land properties but also damages structures along the river such as roads, bridges and even buildings. Thus, reservoir releases need to also take into account the downstream riverbank stability and erosion issues.
The study presented here investigates the riverbank stability and erosion at five study sites representing straight as well as inside and outside channel meander bends located on the lower Roanoke River near Scotland Neck, North Carolina. Extensive laboratory and field experiments were performed to define the hydraulic and geotechnical properties of the riverbank soils at each site. Specifically, soil water characteristic curves were determined using six different techniques and the results compared to existing mathematical models. Hydraulic conductivity was estimated using both laboratory and in situ tests. Due to the wide range of experimentally obtained values, the values determined by each of the methods was used for transient seepage modeling and the modeling results compared to the actual ground water table measured in the field. The results indicate that although the hydraulic conductivities determined by in situ tests were much larger than those typically reported for the soils by lab tests, numerical predictions of the ground water table using the in situ values provided a good fit for the measured ground water table elevation. Shear strengths of unsaturated soils were determined using multistage suction controlled direct shear tests. The test method was validated, and saturated and unsaturated shear strength parameters determined. These parameters, which were determined on the basis of results from both laboratory and field measurements, and the associated boundary conditions, which took into account representative flow rates and patterns including peaking, drawdown and step-down scenarios, were then utilized for transient seepage analyses and slope stability analyses performed using SLIDE, a software package developed by Rocscience. The analyses confirmed that the riverbanks are stable for all flow conditions, although the presence of lower permeability soils in some areas may create excess pore water pressures, especially during drawdown and step-down events, that result in the slope becoming unstable in those locations. These findings indicate that overall, the current reservoir release patterns do not cause adverse impacts on the downstream riverbanks, although a gradual drawdown after a prolonged high flow event during the wet season would reduce unfavorable conditions that threaten riverbank stability.Ph. D.
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Wang, Shu-Yu, and 王書瑜. "Effect of Groundwater Level on Slope Stability." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/4wz7dk.
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碩士國立臺灣海洋大學
河海工程學系
105
Taiwan's economic development is rapid, people's quality of life increased year by year, the demand of land use in mountain area is increasing that the slope stability in mountain area is an important issue.In general, the slope of the destruction mode is mostly down the slope along the slope for the majority of damage.The damage of the slope is usually caused by the rainfall process or after a certain period of rain. The main reason for this result is the rainwater infiltration caused by rainfall. The rainwater infiltration increases the groundwater level and increases the unsaturated soil unit weight, followed by the gradual increase in the water content of soil particles, but also the reduction of the shear strength of the soil. In this study, the Geo-Slope slope stability analysis program developed by Calgary University in Canada was used to analyze the slope stability of the newly developed slopes in the vicinity of Taipei City. The average rainfall value, single field maximum rainfall value and the maximum rainfall value are used to calculate the amount of groundwater, and the slope stability analysis is carried out by simulating the three sections of the slope at the study area by Geo-Slope program. Safety factor FS and the soil shear strength parameters of the base section obtained from Geo-Slope program are compared with the results obtained by using STABL program.The safety factor of the section of the study base is significantly affected by the increase of the groundwater level, and the reduction of the soil shear strength.From the results of Geo-Slope analysis,it shows that slope is an important factor in slope stability analysis and that Geo-Slope program is a useful tool in the future engineering design.
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Jia-shiuan, Yang, and 楊佳勳. "The earthquake effect on intrinsic slope failure controlling factors." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/44356173060186423711.
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碩士國立成功大學
地球科學系
89
This study intends to analyze the quantitative changes of the intrinsic factors for slope failure development, with an example before and after the 921 Earthquake. According to the results of rock mass classification, and patterns of fractures, this work concludes the effect of the relationship between earthquake and intrinsic factors for slope failure development. Comparing the variation of rock quality classification data before and after the earthquake, the RQD values are generally decreased after earthquake. It shows that the earthquake shock wave will change the quality of rock mass; especially, the fractures. After earthquake, the number of fractures have been increased, which will cause the failure of slope. The variation of rock mass quality, lithological characteristics, and distance to epicenter are shown to be significant factors for slope failure to occur after the earthquake. Along the geologically sensitive zone of the slope, earthquake has induced a great deal of slope failure. Among the slopes, the original rock fractures have been greatly affected by the shock wave of the earthquake. Trend and quantity of the intrinsic factors for slope failure have been increased.
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Lin, Yi-Ling, and 林怡綾. "Effect of Weak Plane Orientation on Rock Slope Stability." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/30847911448885953020.
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碩士國立中興大學
水土保持學系所
105
Except the shallow landsides that are associated with soils, other slope stability problems are associated with rock. The hill slopes of Taiwan are mainly composed of sedimentary rocks and metamorphic rocks. The bedding planes in the sedimentary rocks and the cleavage in the slate are weak planes with good consistency. Various orientations of these weak planes have different effects on the stability of rock slopes. We study the effects of orientations of planar and wedge weak planes on slope stability, using the software PLAXIS 3D.Simple slope model with various weak plane conditions are simulated. The jointed rock model with overall Mohr-Coulomb failure criterion (Iso-JRMC) is used to take the weak planes into account. The results show that for planar weak planes conditions, the most unfavorable conditions appear when the weak planes and the slope dip to the same direction, and the dip angle of the weak planes coincides with that of the slope or is equal to 90 °. For wedge weak planes conditions, the most unfavorable condition appear when the line of intersection of two sets of weak planes and the slope dip to the same direction, and the plunge of the line of intersection coincides with the dip of the slope or is equal to 90 ° . In particular, the higher the difference of the dip angles of the two sets of weak planes, the lower the safety factor of the slope obtained. For the studied cases, the rainfall induced rizes of groundwater tables from highest to lowest appear in the oblique slope, anaclinal slope, and dip slope.
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Su, Wei-Che, and 蘇煒哲. "Effect of Slope on Surface Runoff and Soil Erosion." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31329478113106869870.
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碩士國立中興大學
水土保持學系所
95
The soil loss of slope profile was measured by collecting runoff and sediment or using the erosion pins to calculate soil loss usually. However, these measurements can not give the spatial information of erosion on slope (point values of detachment/deposition). In recent year, Three-D laser scanner has been applied to measure the surface variation before and after soil erosion. In the study, the traditional method and Three-D laser scanner method were used to measure the soil loss by rainfall simulator in the laboratory. The soil losses of different slope measured by different method were compared. We hope to fine an ideal method to measure soil loss accurately and get the information of soil detachment and deposition on slopeland. The results showed that the soil loss was increase with slope, especially above slope 15%. The red soil structure is more stable than the yellow soil, so the soil loss is smaller than yellow soil. The soil loss in this experiment was also estimated by Universal Soil Loss Equation (USLE). The estimated soil loss amount is higher than the measured, which was due to our plot length is less than the USLE standard plot, and the slope is steeper than the standard plot. The erosion amount caused by splash can be detected by Three-D scanner method. To compare measure and estimate value, we find out the Three-D laser scanner method is suitable for measuring soil loss on slopeland.
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Yu-ChengChang and 張育誠. "Effect of groundwater pressure on slope stability in shale formation." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/88202709448182998263.
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碩士國立成功大學
土木工程學系碩博士班
100
Recently, due to the impact of extreme weather caused by the rainfall changes. According to the rainfall data of the Central Weather Bureau statistics show that rainfall in Taiwan showing the wet and dry extremes, this situation makes the rainfall situation was concentrated in the rainy season and summer. Morakot brought a historical record of rainfall in August 2009, resulting in the collapse of the south of the country many mountain slope, including the slope of the water reservoir catchment area. Nanhua Reservoir is a important reservoir in the south of country, to cope with extreme rainfall on the slope stability of the water catchment area, This study selected the Nanhua Reservoir catchment slope as the object of study. In this study, we execute site survey along the South 179 County Road and compare the collection of image maps of different years.And chose the research site as study slope that has sliding potential. The study includes the investigation of geological drilling, the use the Geoelectric resistance detection, tilting observation tube, groundwater monitoring, rainfall data records on-site monitoring in the study area. This study was completed geological drilling survey in 2010 through the 2010-2011, and find out the trial slope of the regional rainfall and slope changes direction, the possible depth of the sliding surface, in the meantime using the finite difference software to test slope stability analysis, the relationship between groundwater table and slope safety factor ,and then obtain a critical rainfall obtained by monitoring the groundwater level changes and rainfall relationship.
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LIN, YU-HUI, and 林侑輝. "EFFECT OF BED SLOPE TO HYDRAULIC CHARACTERISTIC OF DETENTION DAM." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/00233336275995212149.
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碩士國立臺灣大學
農業工程學系研究所
86
There are many factors in designing detention dam. This study is concerened with the effect of slope on design models. Based on jet-flow theory, the study presents a detention dam model where the diameters of the circular apertures and their arrangement are interchangeable. The tests were divided into three types according to circular orifice sizes and arrangements. Four slopes from 0 to 4% were used. Flow discharges ranged from 0.0004 to 0.023 cms. By varying the bed slopes, diameters, number of orifices and correcting of discharge coefficient, the effect of bed slope to hydraulic characteristic of detention dam were further explored. After 60 sets of tests and analyzing 480 experimental data items, the principle results were got as following : With bed slopes from 0 to 4%, the discharge coefficient increases with an increase in the number of relative heads (the ratio of water depth to orifice diameter) as well as an increase in the bed slope. From this, a series of regression curves were derived. When the orifices were arranged horizontally, or when placed in a triangular arrangement, the modified coefficient tended towards a constant value if the relative head was more than 3.6 and was not by the bed slope. Nevertheless, bed slope effects should be considered as well.
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Fernando, Leanne. "The effect of flow induced erosion on riverbank stability along the Red River in Winnipeg." 2007. http://hdl.handle.net/1993/2816.
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A research program was undertaken to quantify the effect of flow induced erosion on the stability of natural river banks along the Red River in Winnipeg, Manitoba. The study correlated the percent decrease in factor of safety to intensity of river flow and duration. Two methods to quantify flow induced erosion were assessed, the first method based on observed erosion and the second on theoretically calculated erosion.
The first method involved aligning annual historical river bank cross-sections and measuring the distance between cross-sections to represent the erosion induced from the flow year between successive cross-sections. Due to the fact there are no sites along the Red River regularly surveyed, the analysis did not provide for a correlation between erosion from a specific flow event to percent decrease in factor of safety. The second part involved the use of theoretical equations to quantify erosion given the river elevation of a specific flow year. The study showed a 1% to 8% decrease in factor of safety from low to high intensity flows and as high as 14.5% for high intensity flows of long duration. Additionally, the evolutionary stability of the riverbank was generated showing the percent decrease each year in factor of safety due to erosion and the years during which failure occurs. The results correlated well to the previous analysis showing a 1% to 5% decrease for low to high intensity flows respectively and as high as 10% for high intensities of long duration.October 2007
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Ramesha, A. "Sub-Threshold Slope Modeling & Gate Alignment Issues In Tunnel Field Effect Transistor." Thesis, 2008. http://hdl.handle.net/2005/792.
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The Tunnel Field Effect Transistor (TFET) with sub-60mV/decade Sub-threshold slope and extremely high ION/IOFF ratio has attracted enough attention for low standby power (LSTP) applications where the battery life is very important. So far research in this area has been limited to numerical simulation and experimental analysis. It is however extremely necessary to develop compact models for TFET in order to use them in nano-scale integrated circuit design and simulation. In this work, for the first time, we develop analytical Sub-threshold slope model for n-channel double gate TFET (nDGTFET). Unlike conventional FETs, current in TFET is mainly controlled by the band-to-band tunneling mechanism at source/channel interface. As the total drain current is proportional to band-to-band generation rate, the main challenge in the present work is to find an explicit relationship between average electric field over the tunneling path and the applied gate voltage under nonlocal tunneling condition. Two dimensional Poisson’s equation (with Laplace approximation)is first solved in a rectangular coordinate system in order to obtain analytical expression for electron energy distribution over the channel region.Kane’s Model[J. Phy. Chem.Solids 12(181)1959]for band-to-band tunneling along with some analytical approximation techniques are then used to derive the expression for the Sub-threshold slope under nonlocal tunneling conditions. This Sub-threshold slope model is verified against professional numerical device simulator (MEDICI) for different device geometries.
Being an asymmetric device, TFET fabrication suffers from source misalignment with gate. As the doping in source and drain-gate are different, conventional-FET-like self-aligned gate stack formation is not possible for TFET. Such misalignment, at source side, seriously degrades the performance of TFETs. To overcome this problem, in this work we explore the possibility of using “gate replacement” technique for TFET fabrication. We first develop process flow for single gate bulk nTFET, and then we extend it to n-channel double gate TFET (nDGTFET) using modified FinFET process. Good alignments between source and gate are observed with TCAD-simulations in both the cases.
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Yu, Hsing Chih, and 邢治宇. "A STUDY OF THE EFFECT ON SLOPE STABILITY WITH REINFORCING MATERIALS." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/67246989755278887887.
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Chang, Pai-Hsin, and 張百欣. "Effect on surface roughness to toe scouring of a slope seawall." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/53347211122694925894.
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碩士國立中興大學
土木工程學系
84
ABSTRACT The variation of the toe scours profile by the surface roughness of a slope seawall was investigated experimentally in this research. The effects of the roughness on the wave characteristics, including the wave run-up on the slope, the flow in the down-rushing wave and the wave reflection from the wall, are also explored. Two types of the toe scours, named the L-type and N-type, were performed in the experiments. It was found from the experiments that the surface roughness was potentially reducing the intensity of the down- rushing flow and the wave run-up height, even the reflection of wave. The maximum depth of the scours as well as the scouring distance was thus reduced in the light of the surface roughness. The scouring depth and the values of the wave characteristics on the slope were descended obviously due to the surface roughness, from comparing with the smooth surface. However,these descended values were limitedly increased as the surface roughness became larger.
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AGRINA, DWI, and 郝瑞麗. "Effect of C-RHA Columns on Slope Stability by Centrifuge Modeling." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/4546qp.
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碩士國立中央大學
土木工程學系
106
Abstract Landslide is a typical natural disaster around the world. Factors such as slope material, intensity and duration of rainfall, earthquakes and loadings, infiltration and seepage conditions strongly influence the stability of slope because of the decrease in resistance forces or the increase of driving force. A lot of methods for increasing slope stability are already developed nowadays. This research using C-RHA columns for slope strengthening. C-RHA mortar was made of cement, sand and microsilica from fine rice husk ash (RHA). Replacement 10 % of the weight of cement by RHA would increase the strength of the column. The effect of C-RHA columns on slope stability simulated by a series of centrifuge modeling tests which were conducted at the Experimental Center of Civil Engineering, Department of Civil Engineering, National Central University. The slope is prepared by moist tamping method at optimum water content about 12 % with a mixture material consist of 20 % of the fine content (kaolinite) and 80 % of quartz sand. The C-RHA columns were penetrated perpendicular to the slope surface. During the test, the acceleration was gradually increased until the slope failed. The process of the failure was recorded through cameras during centrifuge spinning. Cameras and laser displacement scanner record the failure process, slope deformation and ground surface change. The decreasing spacing of C-RHA column increases the safety factor of the slope. The test results show that when the spacing between the C-RHA columns is reduced, the timing of the cracks at the top of the slope can be delayed, and the location of the cracks will be far away from the top of the slope, which will delay the timing of the slope failure. In this case delay means reaching higher g level. The first crack of the slope without column occurs at 40 g, the crack depth is about 0.33h, the second crack occurs at 45 g, and the damage occurs at the 50 g. When the spacing of the slope is 6.7d, 5d and 4d, the first crack of the slope occurs at 40 g, 45 g and 55 g, respectively, and the crack depth is 0.30h, 0.33h times and 0.56h. The second crack occurred at 43 g, 49 g, and 65 g, and fail at 48 g, 55 g, and 65 g. From the side view of the slope, the decreasing number of C-RHA column spacing will decrease the depletion mass of slope, which is the volume of displaced soil that overlies the failure surface but underlies the original ground surface. The depletions mass normalized by the volume of theoretical planar failure wedge with failure angle of θ=(β+∅)/2 are 67.0 %, 64.5 %, 59.3 % and 48.6 %, respectively. Keywords: C-RHA, Centrifuge modeling, Slope Stability
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LIN, PEI-YU, and 林珮玗. "A Study on Mountain Roadside Slope Construction and Ecological Effect Assessment." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/38350255288680717935.
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碩士中華大學
土木工程學系碩士班
102
For conventional reinforced concrete walls, reinforcement steels and concrete are the main materials. The use of these elements, however, creates a monotonic appearance and the quality also cannot be well controlled. Moreover, because of these elements do not support vegetation, they can cause significant impacts to the local habitat of plants and animals. Environmental changes can bring substantial damage to the environment, and people have become more aware of the importance of ecological conservation and environmental protection. The term "ecological engineering" was first proposed by Odum in 1962, and the concept was soon introduced into Taiwan, prompting the government of Taiwan to actively promoting the ecological engineering methods. This ecological conservation and safety oriented new engineering approach not only reduces the occurrence of landslides along mountain roads but also creates a more appealing look as well as matches natural environmental changes. This study, focused on mountain roads, assessed mountain roadside slope construction and ecological effects. The effect of applying ecological engineering methods on roadside slope construction was explored, too. This research first discussed differences between the conventional slope protection and the reinforced slope protection, and then factors related to their failure were analyzed. The basic structural components of these two types were compared as well. Lastly, a questionnaire survey was conducted, and the obtained information was used as the benchmark in the discussion. The analytic hierarchy process (AHP) was adopted to obtain the weight of each assessment factor, and the result were analyzed. The findings suggest that biological characteristics and life cycles were much more weighted than all other aspects, whereas road design and economic cost were weighted much less. Therefore, scholars have recognized that biological characteristics and life cycles are the most important issues. Global warming has an effect on climate change, and countries worldwide have begun to pay attention to this issue by integrating ecological conservation into their public infrastructure. Both public infrastructure and ecological environment have to be taken care of as equally important. As a result, ecological system stability and environmental pluralism need to be incorporated into public infrastructure. For the construction of mountain roadside slope protection, it is critical to take care of every detail to prevent causing environmental impacts. Using resources effectively can also maximize the effects. While using roadside slope protection to secure the earth, it is also important to add planting to beautify the environment and minimize greenhouse gas impacts. Through summarizing relating factors and reviewing relevant studies, the author hopes to generate positive information on mountain roadside slope construction and ecological effects and furthermore, to disseminate the idea of sustainable development.
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Chen, Yao-tin, and 程耀霆. "Study on the effect of parameters of cooling slope technique and the semisolid properties of cooling slope casting A356 Al alloys." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/37032027960214494850.
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碩士國立成功大學
材料科學及工程學系碩博士班
97
The cooling slope technique is the oncoming semi-solid process. The feature of this process is that it can achieve non-dendritic structure without any external force. In this study, we established the equipment of cooling slope technique first and then the Taguchi method was applied to design and analyze the experiments to study the effects of the pouring temperature, inclined slope angle and melt cooling rate on the microstructures of A356 alloy and its yields. The optimum parameters would be decided for coarsening experiment later. In addition to cooling slope casting billet, spray-formed and as-cast billets were employed in the coarsening experiment. This experiment focused on the relation between microstructure and two parameters including various holding temperature and holding time. Subsequently, we used the relation between holding time and grain size to obtain the coarsening exponent and coarsening rate constant. The calculating value of coarsening rate constant would be compared with the experimental value as well. The EPMA was employed to analyze the microsegregation of the material producing by three processes with heat treatment. Finally, we use micro-Vickers hardness and Rockwell hardness tests to measure the hardness of the material producing by three processes.
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Rogowski, Michael P. "The influence of maturation on the oxygen uptake efficiency slope." 2011. http://liblink.bsu.edu/uhtbin/catkey/1642176.
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This study examined the influence of maturation on the oxygen uptake efficiency slope (OUES) in healthy male subjects. The variables comprising the OUES are known to be affected by metabolism which in turn is influenced by maturation. The subjects performed a graded exercise test on a cycle ergometer to determine the OUES and VO2max. Subjects were divided into groups based on maturation status: early-pubertal (EP, n = 15), mid-pubertal (MP, n = 20), late-pubertal (LP, n = 17), and young-adult (YA, n = 19) males. Cardiorespiratory fitness (measured as VO2max mL·min-1·kg-1) was not significantly different between groups. OUES values in absolute terms were higher in groups LP and YA versus MP and EP. Scaling OUES relative to body mass failed to eliminate between group differences whereby LP and YA had lower mass relative OUES values compared to LP and YA. Scaling OUES relative to fat free mass also failed to eliminate between group differences with EP group values being higher versus LP and YA, but only MP values being higher than YA. Differences in OUES values between male across maturation status remained after accounting for differences in body size, suggesting an affect of maturation on this measurement.School of Physical Education, Sport, and Exercise Science
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Lin, J. C., and 林哲群. "Steep Subthreshold Slope Tunnel Field-Effect Transistor：Hetero-Tunneling, Orientation Effect and Ferroelectric Negative Capacitance Gate Stack." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/dt3s2j.
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碩士國立臺灣師範大學
光電科技研究所
101
The happy scaling of classic FET has been finished, as strain engineering technology for 90 nm, and gate stack ( high-K + metal gate ) for 45 nm technology node. Intel claimed that the 3D structure of tri-gate is mainstream in 22nm technology node, this is an important revolution for planar transistor in past 40 years. The possible candidates of the trend to achieve the future technology are FinFET, Ge/III-V, nanowire, graphene…etc. In order to More Moore’s Law, we have to the capability of New concept => operation mechanism, New material => channel material, and New structure => 3D for next generation devices. Tunnel-FETs (tFETs) operates with band-to-band tunneling current that change with the channel potential more abruptly than thermionic emission current. In this paper, we will research the Steep Subthreshold Slope Tunnel Field-Effect Transistor：Hetero-Tunneling, Orientation Effect and Ferroelectric Negative Capacitance Gate Stack. we have successfully demonstrated the first epi-Ge/Si hetero-tunnel FET with high current and < 60 mV/dec swing on (100), (110), and (111) orientations. The drain current of epi-Ge (100) HTFET is as high as 20 A/m(VGS-VBTBT = VDS = -3V), as well as excellent subthreshold swing (S.S.min = 42 mV/dec) and DIBT (28 mV/V). The epi-Ge HTFET is superior to the Si in terms of IDS, subthreshold swing and DIBT. Because, it is beneficial tunneling probability with BTBT current increasing by using band engineering design with heterojunction to narrow effective bandgap. The epi-Ge/Si HTFETs are compatible with current CMOS processes and are therefore a candidate for next-generation applications.
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Ferreira, Nelson John. "Assessing the effect of near surface environmental conditions on unsaturated slope instability." 2002. http://hdl.handle.net/1993/18940.
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