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Livingstone, I. "The dynamics of sand transport on a Namib linear dune." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375978.
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Kirkwood, Donovan. "Establishment patterns of thicket and forest species in coastal dune landscapes of the southern Cape." Thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/26396.
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Joubert, Eugene Christiaan. "A computational fluid dynamics study of the near surface wind patterns over a desert dune and the effect on seed dispersion." Thesis, Stellenbosch : Stellenbosch University, 2010. http://hdl.handle.net/10019.1/4357.
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Thesis (MScEng)--Stellenbosch University, 2010.<br>ENGLISH ABSTRACT: This project originated when a team of scientists at the Gobabeb training and research and centre
observed seed accumulation sites on the slope of sand dunes in the Namib Desert. Seeds that
accumulate on the slip face of a sand dune provide food for small desert creatures that in turn
attract larger animals, resulting in a small ecosystem on the side of the dune. Since wind is the
primary transport of seeds throughout the Namib Desert it is of interest to investigate wind
patterns over the dune. In this project it is therefore desired to look at seed dynamics and
deposition as a result of near surface wind patterns around a three-dimensional dune geometry
using computational fluid dynamics. The project is a joint venture between the University of
Stellenbosch and the University of Namibia. This document presents the South African MScEng
thesis part.
The literature review shows the dominant winds in the Namib Desert to be from the south to
westerly direction. Previous studies on air flow over dunes focussed on sand movement and were
often limited to simplified two-dimensional geometries and steady state simulations. From these
studies the basic flow features associated with dunes can be identified. Lastly, factors that
influence particle dynamics around dune geometries are looked at. These particle studies mostly
involve the movement of sand rather than seeds but still provide valuable insight.
The project methodology is explained and includes the equipment used, the considerations taken
into account, the simplifications made as well as the procedure followed when conducting field
work and simulations. A section of an actual Namibian linear dune is mapped in order to obtain
a geometry for the simulations. Flow measurements are carried out with a wind mast to obtain
velocity profile inlet conditions for the simulations. Furthermore, seed sampling is done by the
collaborating Namibian team of which the data is used to obtain an effective seed particle model.
Lastly, simulations are carried out using primarily OpenFOAM-1.5. The simulations look at
general near surface wind patterns, time dependant flow features and particle movement and seed
deposition around and on the linear dune.
The results show different wind profiles for different wind direction. It is also possible to see
how the profile changes as the flow accelerates up the dune slope. Two-dimensional results
provide the opportunity to compare results with previous studies as well as to provide the basis
for looking at aspects such as differencing schemes, turbulence models and parallel computing
before three-dimensional simulations are carried out. The importance of higher order
differencing schemes are confirmed in the two-dimensional results. The turbulence models,
however, produce very similar results. The results from the two- and three-dimensional results
show typical flow features associated with dunes. Transient flow features and separation vortex
structures can be identified from time dependant simulations. Furthermore, particle simulations
reveal how particles tend to be trapped in the recirculation regions.
The conclusions explain how the project objectives were achieved and provide recommendations
for future studies related to this project.<br>AFRIKAANSE OPSOMMING: Die projek het ontstaan toe naforsers areas van saad akumulasie op die hellings van duine in
Namibë opgelet het. Hierdie akumulasie van plant materiaal verskaf die voedsel vir klein diere
op die duin wat ‘n klein ekosisteem tot gevolg het. Aaangesien die primêre vervoermiddel vir
sade in die woestyn wind is beoog die projek om deur die wind patrone oor die duin beter te
verstaan die saad verspreiding te beskryf. Die doel is dus om saad verspreiding en akumulasie te
beskryf deur die wind patrone te bekyk wat die verspreiding tot gevolg het deur gebruik te maak
van numeriese vloei dinamika. Die projek is ‘n saamgestelde projek tussen die Universiteit van
Stellenbosch en die Universiteit van Namibië. Hierdie dokument behels die Suid Afrikaanse
MScIng gedeelte van die projek.
Deur die hersiening van literatuur word daar gesien dat die domineerende wind rigtings as suid
tot wes beskryf kan word. Vorige studies wat verband hou met wind vloei oor duine wys dat die
meeste op twee-dimensionele eenvoudige geometrië gefokus het met tyd onafhankike simulasies.
Dit is egter moontlik om die resultate te gebruik om karakteristieke vloei patrone te identifiseer
wat met duin wind patrone geassosieer kan word. Laastens word daar gekyk na die faktore wat
partikel beweeging beïnvloed, maar hierdie studies sluit hoofsaaklik sand partikels in eerder as
sade.
Die motodologie beskryf die toerusting, oorwegings en prosedures wat gevolg is tydens veld
werk asook simulasies. Tydens die veld werk is ‘n gedeelte van ‘n Namib lineêre duin gemeet en
so gebruik om ‘n geometrie te maak wat vir simulasie doeleindes gebruik kan word. Daar is ook
wind meetings gedoen met ‘n wind mas om wind profiele vir inlaat kondisies vir die simulasies te
kry. Verder het saad bestudeering die nodige data verskaf om ‘n voledige saad partikel model op
te stel wat in die simulasies gebruik kan word. Laastens kyk die simulasies veral na algemene
vloei patrone, tyd afhanklike vloei effekte en ook partikel beweging in die vloei veld.
Die resultate wys hoe wind profiele verskil wat van verskillende rigtings af waai. Dit is ook
moontlik on te wys hoe die wind profiele verander soos die wind versnel teen die duin op. Tweedimensionele
simulasies verskaf die geleentheid om te kyk na die effek van verkillende
numeriese modelle, turbulensie modelle en ook multi-prosesseerder verwerking. Tydens die
twee-dimensionele simulasies is die belangrikheid van hoër orde numeriese metodes besef. Die
verkillende turbulensie modelle het egter klein verkille gewys. Alby die twee- en driedimensionele
resultate wys karakteristieke vloei patrone wat met duine geasosieer kan word.
Verder het tyd afhanklike simulasies gewys hoe wind patrone verander met tyd. Die partikel
simulasies wys ook die beweging van partikels deur die wind en hoe dit neig om te akumuleer in
die hersirkulasie gebied agter die duin.
Die gevolgtrekkings wys dat al die doelstellings bereik is en maak voorstelle vir toekomstige
studies wat met hierdie studie verband hou.
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McConnachie, Lauren Bernyse. "Morphology, patterns and processes in the Oyster Bay headland bypass dunefield, South Africa." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1001904.
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Studies of the dunefield systems crossing the Cape St. Francis headland in the Eastern Cape have focused on the role that wind plays in sediment transfer in coastal dunefield systems, with limited consideration of the role of water. The aim of this study was to improve understanding of the morphology, processes and patterns within the Oyster Bay HBD system, focussing particularly on surface water and groundwater interactions and the role of surface water in sediment transfer across the dunefield system. An extensive field survey was conducted, to collect related data, complimented by spatial and temporal analysis of the study area using GIS. The key findings from this research were the apparent differences between the western and eastern regions of the dunefield with regard to specific drivers and the respective processes and responses. Wind is the major driver of change up to and across the crest of the dunefield. In the eastern region water (ground water, surface water and the Sand River System) is the primary agent of sediment flux through processes of aggregation and slumping as well as episodic events including debris flows. This study has highlighted a need for further quantitative studies that investigate the movement of sediment through dunefield systems such as this (where water is at or near the land surface). The paradigm that sediment flux is entirely due to wind is almost certainly simplistic, and deeper understanding of these systems is needed<br>Maiden name: Elkington, Lauren
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Hays, Allison Whitney. "Determining the impacts of beach restoration on loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting patterns and reproductive success along Florida's Atlantic coast." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5295.
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Artificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, the ratio of nests to the total number of nests and non-nesting emergences, and reproductive success, the ratio of hatched and emerged hatchlings to the total number of eggs deposited. Two types of restoration designs exist along the southern Brevard County, FL coastline, which supports some of the highest density loggerhead and green turtle nesting worldwide. Since 2005, approximately 35 kilometers of beach have undergone 1) full-scale restoration (typically called nourishment), where sand was added above and below the mean high tide line (2005, 2010) or 2) dune restoration, where sand was placed on the dune (2005, 2006, 2008, 2009). To quantify the effects of these restoration types, we used a Before-After-Control-Impact-Paired Series (BACIPS) model, which tests for significance between the difference in nesting success rates at the impact (engineered) and control sites (natural beach) before and after restoration ([delta]). For loggerheads, there was a significant difference in [delta] after dune restoration during the years of construction (2005, 2006, 2008, and 2009; p<0.001) and one year post-construction (2007; p<0.05 and 2010; p<0.001). After full-scale restoration, there was a significant difference in [delta] during the years of construction (2005 and 2010; p <0.001) and one year post-construction (2006; p<0.001). For green turtles, there was a significant difference in [delta] after dune restoration during two of the four years of construction (2006; p<0.05 and 2008; p<0.01) and one of the two one-year post-construction years (2010; p<0.05). After full-scale restoration, the significant difference in [delta] lasted every season (2005-2010; p<0.001). There were no significant differences in [delta] for loggerhead or green turtle reproductive success rates after either type of restoration. The second objective was to use the different restoration designs to study what beach characteristics function as loggerhead nesting cues to explain why altering the beach decreases nesting success rates. We examined beach elevation and slope, sand moisture content, sand grain size, beach width, and distance traveled. Logistic regression model selection found all variables were important (R2=0.75). Further examination of trends, with each crawl divided into quarters, found beach slope served as a nesting cue. In all study sites except one, when turtles false crawled, the beach flattened out in the final quarter of the crawl. Conversely, in nesting emergences, the final quarter rose at a steeper slope than the previous quarter. Additionally, model selection found variables important in nest site selection were also important in hatching (R2=0.44) and emergence (R2=0.45) success. These results offer new insight into how and why marine turtle nesting patterns change after artificial nourishment, providing information necessary to nourish beaches in a more “turtle-friendly” manner.<br>ID: 031001543; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: John Weishampel.; Co-adviser: Llewellyn Ehrhart.; Title from PDF title page (viewed August 22, 2013).; Thesis (M.S.)--University of Central Florida, 2012.; Includes bibliographical references (p. 84-90).<br>M.S.<br>Masters<br>Biology<br>Sciences<br>Biology
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Diniega, Serina. "Modeling Aeolian Dune and Dune Field Evolution." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/195665.
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sand hops and bounces -see the dunes grow, run, collide -form the field's pattern.Aeolian sand dune morphologies and sizes are strongly connected to the environmental context and physical processes active since dune formation. As such, the patterns and measurable features found within dunes and dune fields can be interpreted as records of environmental conditions. Using mathematical models of dune and dune field evolution, it should be possible to quantitatively predict dune field dynamics from current conditions or to determine past field conditions based on present-day observations.In this dissertation, we focus on the construction and quantitative analysis of a continuum dune evolution model. We then apply this model towards interpretation of the formative history of terrestrial and martian dunes and dune fields. Our first aim is to identify the controls for the characteristic lengthscales seen in patterned dune fields. Variations in sand flux, binary dune interactions, and topography are evaluated with respect to evolution of individual dunes. Through the use of both quantitative and qualitative multiscale models, these results are then extended to determine the role such processes may play in (de)stabilization of the dune field. We find that sand flux variations and topography generally destabilize dune fields, while dune collisions can yield more similarly-sized dunes. We construct and apply a phenomenological macroscale dune evolution model to then quantitatively demonstrate how dune collisions cause a dune field to evolve into a set of uniformly-sized dunes. Our second goal is to investigate the influence of reversing winds and polar processes in relation to dune slope and morphology. Using numerical experiments, we investigate possible causes of distinctive morphologies seen in Antarctic and martian polar dunes. Finally, we discuss possible model extensions and needed observations that will enable the inclusion of more realistic physical environments in the dune and dune field evolution models.By elucidating the qualitative and quantitative connections between environmental conditions, physical processes, and resultant dune and dune field morphologies, this research furthers our ability to interpret spacecraft images of dune fields, and to use present-day observations to improve our understanding of past terrestrial and martian environments.
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Savage, Christopher Jon. "Implications of Dune Pattern Analysis for Titan's Surface History." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/3077.
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Analyzing dune parameters such as dune width and spacing can be useful in determining the reaction of dunes to changes in atmospheric and sedimentary conditions currently and in the recent geologic past. Dune parameters, dune width and spacing, were measured for linear dunes in regions across Saturn's moon Titan from images T21, 23, 28, 44 and 48 collected by Synthetic Aperture RADAR aboard the Cassini spacecraft in order to reconstruct the surface history of Titan. Dunes in the five study swaths are all linear in form, but lack superimposed or flanking dunes. They have a mean width of 1.3 km and mean crest spacing of 2.7 km, wider and farther apart on average than similar terrestrial dunes in the Namib and Agneitir Sand Seas though larger linear dunes exist on Earth. Because of the lack of superimposed and flanking dunes and their size, Titan's dunes are classified as very large simple linear dunes. The large size, spacing and uniform morphology are all indicators that Titan's dunes are very mature and long-lived features. The ratio of dune width to spacing for Titan's dunes is similar to that found in terrestrial dunes in that dune spacing tends to be twice dune width. In addition to being similar in size, this is further evidence that terrestrial dunes can be used as analogues for Titan's dunes and vice versa and that the essential dune-forming processes are the same on both bodies. Dune width and spacing decrease northward, which is attributed to, but not limited to, increased maturity of dune fields to the south or increased sediment stabilization to the north. Sediment stabilization may be caused by Titan's asymmetric seasons and a net transport of moisture from south to north. The majority of dunes have spacings consistent with an upper limit of 2 to 4 km established by the atmospheric boundary layer, further evidence they are mature. Dunes are more widely spaced in the south are evidence they have been growing toward a steady state for a longer period of time than those in the north. Titan's large linear dunes have long reconstitution times. This is in part due to the fact that winds sufficient for saltation are reached only near the Titan equinox every 14 Earth years. Based on rates for similar terrestrial dunes the reconstitution time for Titan's dune is 600,000 Earth years or more, and therefore substantial changes in dune form should not be observable over Cassini's lifetime. Cumulative probability plots of dune parameters measured at different locations across Titan indicate there is a single population of dunes on Titan. This suggests that, unlike analogous dunes in the Namib and Agneitir Sand Seas, dune-forming conditions that currently exist on Titan are either the only dune-friendly conditions in the moon's history, or the current conditions have been stable and active long enough to erase any evidence of past conditions.
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Mello, Raquel Gewehr de. "Reconstrução dos paleoventos do Gonduana no Juro-cretáceo." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/173583.
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A passagem de um padrão monsoonal para um padrão de circulação atmosférica zonal ocorreu durante o Cretáceo devido à fragmentação do Supercontinente Gonduana. Essa mudança na direção dos paleoventos é registrada no mergulho de estratos cruzados de dunas eólicas acumuladas em várias bacias de Gonduana. Três mapas de reconstrução de paleoventos foram construídos com a integração de dados paleocorrentes compilados de bacias Fanerozoicas brasileiras, Bacia de Neuquén na Argentina e bacias do Congo e Huab na África. O Gonduana foi dominado por ventos do nordeste ao norte e ventos do sudoeste ao sul, deslocando, assim, a Zona de Convergência Intertropical para 15º a 20 sul do equador durante o Jurássico Tardio até o início do Cretáceo. Por sua vez, os ventos apresentaram uma tendência geral para o oeste-noroeste em latitudes baixas e médias no Gonduana no final do Cretáceo Inical. Esses resultados apontam para a existência de um padrão monsoonal durante o Jurássico Tardio até o início do Cretáceo Inicial e a entrada do padrão zonal no final do Cretáceo Inicial, associado à fragmentação de Gonduana.<br>The passage of a monsoonal pattern to a zonal atmospheric circulation pattern occurred during the Cretaceous due to fragmentation of Gondwana Supercontinent. This change in the paleowind direction is recorded in crossstrata dip directions of eolian dunes accumulated in various basins of Gondwana. Three maps of paleowind reconstruction were built with integration of compiled paleocurrent data from Phanerozoic basins in Brazil, Neuquén Basin in Argentina and Congo Basin and Huab Basin in Africa. Gondwana was dominated by northeast winds to the north and southwest winds to the south, thus shifting the Intertropical Convergence Zone to 15º to 20⁰ south of the equator during Late Jurassic to the beginning of the Cretaceous. In turn, winds had a general tendency towards west-northwest at low and mid-latitudes in Gondwana at the end of Early Cretaceous. These results point to the existence of a monsoonal pattern during the Late Jurassic to the beginning of Early Cretaceous and the entry of zonal pattern at the end of Early Cretaceous, associated with fragmentation of Gondwana.
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Pierce, Shirley M. "Pattern and process in South Coast dune fynbos : population, community and landscape level studies." Doctoral thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/8422.
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Includes bibliographies.<br>The study aimed to explain vegetation dynamics in response to disturbance in a dune landscape comprising a mosaic and admixture of grassland, fynbos and thicket. A hierarchical approach directed investigations at the landscape, community and population levels, with emphasis on seed banks. The study concentrated on fynbos, the predominant vegetation type. At the landscape-level, pattern was attributed to successional processes rather than abiotic factors. Each vegetation was maintained under defined disturbance regimes of fire, grazing and bushcutting. In the absence of disturbance, succession proceeded from grassland, through fynbos, to thicket. The study contributed to existing theory on the effects of disturbance on seed bank size, and the relationship between seed bank composition and its above-ground vegetation. No single model for successional pathways and mechanisms was supported: these differed amongst vegetation types and within fynbos communities.
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Wiebe, Joshua Daniel. "Time and patterns of development of dunes subjected to sudden changes in flow depth." Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/706.
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Van, Zyl Verena Helen. "Searching for histogram patterns due to macroscopic fluctuations in financial time series." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/3078.
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Thesis (MComm (Business Management))--University of Stellenbosch, 2007.<br>ENGLISH ABSTRACT: his study aims to investigate whether the phenomena found by Shnoll et al. when applying histogram
pattern analysis techniques to stochastic processes from chemistry and physics are also present in
financial time series, particularly exchange rate and index data. The phenomena are related to fine
structure of non-smoothed frequency distributions drawn from statistically insufficient samples of
changes and their patterns in time. Shnoll et al. use the notion of macroscopic fluctuations to explain
the behaviour of sequences of histograms. Histogram patterns in time adhere to several laws that could
not be detected when using time series analysis methods.
In this study general approaches are reviewed that may be used to model financial markets and
the volatility of price processes in particular. Special emphasis is placed on the modelling of highfrequency
data sets and exchange rate data. Following previous studies of the Shnoll phenomena from
other fields, different steps of the histogram sequence analysis are carried out to determine whether
the findings of Shnoll et al. could also be applied to financial market data.
The findings of this thesis widen the understanding of time varying volatility and can aid in financial
risk measurement and management. Outcomes of the study include an investigation of time series
characteristics in terms of the formation of discrete states, the detection of the near zone effect as
proclaimed by Shnoll et al., the periodic recurrence of histogram shapes as well as the synchronous
variation in data sets measured in the same time intervals.
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Harkema, Stephan. "Capillary instabilities in thin polymer films mechanism of structure formation and pattern replication /." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2006. http://irs.ub.rug.nl/ppn/291147801.
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Asada, Niclas. "A study of the effect onRadar Cross Section (RCS) due to”Starved horse patterns”." Thesis, KTH, Aeronautical and Vehicle Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11102.
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<p>This thesis is made in cooperation with the Swedish Defense ResearchAgency (FOI) and the Swedish Defense Material Administration (FMV). Partof the report is classified and is only published in a classified appendix.</p><p>The purpose of the thesis was to study the influence on RCS (Radar-Cross-Section) due to permanent deformation on ships hulls made of metal. Thedeformation studied is occurring on the plating between the web and thelongitudinals, commonly called “starved horse pattern” (see cover picture!).A comparison was made between a metal and an ideal flat compositestructure.</p><p>The main tool used for the study is the RCS program, OPTISCAT, developed by Kockums. Data has been gatered from several different ships meeting the operating profile for YS-NY. The data has then been processed by using Cubic splines and has then been interpolated to describe the deformation. The deformed panels has then been benchmarked against ideally flat panels, the latter simulating the composite case.</p><p>The results are quite astonishing, but in some way they are ecpected. The RCS is greatly effected by the deformations.At the Swedish Defence Material Administration, FMV, the work to produce the next generation of surface ships (YS-NY), for the Royal Swedish Navy, has begun. The question has been asked just how good, or bad, a metal hull supported by framing versus a composite hull is in a RCS sense. A ship built by steel (or metal in general), will develop deformations called "Starved Horse Patterns". These patterns may occur during the building process, but are most certainly also generated by the heavy dynamic preassures generated by waves. These patterns affect on the RCS are studied in this thesis.</p>
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Klopp, Karl A. "Antenna gain loss and pattern degradation due to transmission through dielectric radomes." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from the National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA267242.
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Shrestha, Samata. "IMPACT OF NEIGHBORHOOD MORPHOLOGY ON AIR POLLUTION DISPERSION PATTERNS DUE TO UNPLANNED BUILDING DEMOLITION: A PARAMETRIC STUDY." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent155654365109521.
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Ideta, Makoto. "NUMERICAL SIMULATIONS OF DISK GALAXIES DAMPING TIME OF A LOPSIDED PATTERN DUE TO DYNAMICAL FRICTION." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149977.
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Mak, Hong-man Herman, and 麥匡文. "Effective slip due to Stokes flow through channels with patterned stick-slip walls." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47153970.
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This thesis comprises studies of two problems on Stokes flows through (i) a plane microchannel, and (ii) a microscale circular capillary tube, of which the walls are superhydrophobic surfaces featuring micro- or nano-patterns. In the first problem, an analytical study on longitudinal and transverse flows through a plane microchannel, which is made up of a periodic array of ribs and grooves on the upper and lower walls, is performed. This study focuses not only on the Cassie state, but also on the state whereby the liquid is allowed to penetrate the grooves between the ribs. These grooves are filled with inviscid gas and this periodic array gives rise to heterogeneous boundary conditions for the flow. Partial-slip and shear-free conditions are applied on the solid–liquid interface and the liquid–gas interface, respectively. Using the methods of eigenfunction expansions and domain decomposition, semi-analytical models are developed for four different settings. Two of them correspond to longitudinal flow with in-phase and 180-out-of-phase alignments of ribs between the upper and lower walls. The other two are for transverse flow with the in-phase and out-of-phase wall alignments. These models enable the effective slip lengths, normalized by half the pitch of the pattern, to be deduced as functions of the channel height, the microscopic or intrinsic partial slip length, the depth of liquid penetration, and the width of the grooves or the shear-free area fraction of the liquid-gas interface. Numerical calculations are performed to examine effects of these parameters on the effective slip length. The effect of the phase of alignment of ribs is appreciable when the surface is in the Cassie state and the channel height is sufficiently small. In-phase alignment yields a larger effective slip length in longitudinal flow. In sharp contrast, out-of-phase alignment is preferable in transverse flow. In the case involving penetration, a larger liquid penetration can give rise to a larger slip length in a thin channel.
In the second problem, an analytical study on flow through a microscale circular tube, of which the wall is patterned with a periodic array of spots or holes, is performed. Void region is filled with inviscid gas and patterns of circular and square shapes are considered. For simplicity, liquid penetration into the cavities is not considered, and hence the focus is on the Cassie state. No-slip and shear-free conditions are applied on the solid–liquid interface and the liquid–gas interface, respectively. By the methods of eigenfunction expansions and point collocation, a semi-analytical model is established. The effective slip length, normalized by the tube radius, is found as a function of the pitch of the pattern in the streamwise direction, the number of periodic units in the circumferential direction, and the solid fraction. Comparisons with some proposed scaling laws, varying pitch, solid fraction and tube size are performed. Large slip length is produced by arranging small circular no-slip spots with large separation in the streamwise direction. In some situations, spots and holes can be replaced by parallel stripes to increase the slip length.<br>published_or_final_version<br>Mechanical Engineering<br>Master<br>Master of Philosophy
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Cullins, Miranda J. "Parsing Variability: Variability in Aplysia Feeding Motor Programs and Behavior Performance due to Behavioral Differences, Individuality, and Sensory Feedback." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1400677648.
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Perkins, Joel K. "Exploring Patterns in Due Process Hearing Decisions Regarding the Usage of One-on-One Inclusion Aides for Students with Disabilities." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6825.
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This study reviews due process hearing decisions from the years 2014 and 2015. This is primarily a legal analysis, specifically looking at legal and regulatory patterns regarding the provision of one-on-one special education aides for students with disabilities in general education settings. Our findings from the due process hearing decisions reveal that one-on-one aides for students with a wide variety of disabilities are being provided with greater frequency than we anticipated and that, specifically, behavioral aides are being provided for students with autism. Decisions of disabilities such as hearing impairment have higher provision rates, while other disabilities like autism and emotional disturbance do not see the same rate of provision. There are clear patterns of differences between the states in the number of cases that reach due process hearings and in the number of one-on-one aides provided.
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Clark, Courtnee. "Patterns of death due to blunt force trauma in the West Metropole of the City of Cape Town, South Africa." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/16521.
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Includes bibliographical references<br>There is currently a paucity of information regarding the prevalence and characteristics associated with blunt force trauma related homicides in South Africa. Information relating to the patterns of blunt force trauma could assist in the implementation of appropriate interventions targeted at specific areas or individuals. Furthermore, it can direct research toward topics in blunt force trauma which are in need of investigation. As such the primary objective of this study was to determine the prevalence of blunt force trauma related homicides in the West Metropole of the City of Cape Town, South Africa. The secondary objective was to describe the characteristics associated with blunt force trauma related homicides in the West Metropole of the City of Cape Town, South Africa. This thesis begins by defining blunt force wounds and comparing and contrasting the prevalence and documented characteristics associated with blunt force trauma nationally as well as internationally. Blunt force wounds occur when the body comes into contact with a blunt object at great force. Homicides by blunt force trauma are usually the result of assaults with fists, feet, bats or clubs, etc. Common wounds associated with blunt force assaults are contusions, lacerations and in some cases, bone fractures. In fatal blunt force assaults, these wounds tend to be located primarily on the head region. Salt River Mortuary receives cases from the West Metropole of the City of Cape Town, hence the results of this thesis are considered in the context of this area. This region is comprised of areas with diverse socio-economic status' and heterogeneous crime rates. The study was a retrospective review of autopsy reports obtained from Salt River mortuary from 1 January 2013 to 31 December 2014. The prevalence of blunt force trauma was considered for unnatural deaths with a focus on homicide. The inclusion criteria were cases where the cause of death was blunt force trauma as determined by the pathologist. Cases in which the death was not caused solely by blunt force trauma were classified as combination deaths, and cases involving deaths due to blunt force trauma as a result of falling from a height, train-related, pedestrian or motor vehicle accidents were excluded. A total of 3346 and 3461 cases of unnatural deaths occurred in the West Metropole of the City of Cape Town in 2013 and 2014 respectively. 247 (7.4%) cases in 2013 and 277 (8%) cases in 2014 involved blunt force injuries, and of these cases 183 (5.5%) in 201 3 and 201 (5.8%) in 2014 were classified as homicides. The results of the characteristics of blunt force homicide analysed in this study broadly concur with previous studies undertaken in South Africa, with some areas of divergence. Additional features that have not been extensively covered in previous studies also emerged, which could possibly form the basis for future investigations.
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Farooqi, Owais Ehtisham. "An Assessment and Modeling of Copper Plumbing pipe Failures due to Pinhole Leaks." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/33918.
Full textAbstract:
Pinhole leaks in copper plumbing pipes are a big concern for the homeowners. The problem is spread across the nation and remains a threat to plumbing systems of all ages. Due to the absence of a single acceptable mechanistic theory no preventive measure is available to date. Most of the present mechanistic theories are based on analysis of failed pipe samples however an objective comparison with other pipes that did not fail is seldom made. The variability in hydraulic and water quality parameters has made the problem complex and unquantifiable in terms of plumbing susceptibility to pinhole leaks.
The present work determines the spatial and temporal spread of pinhole leaks across United States. The hotspot communities are identified based on repair histories and surveys. An assessment of variability in water quality is presented based on nationwide water quality data. A synthesis of causal factors is presented and a scoring system for copper pitting is developed using goal programming. A probabilistic model is presented to evaluate optimal replacement time for plumbing systems. Methodologies for mechanistic modeling based on corrosion thermodynamics and kinetics are presented.<br>Master of Science
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Nguyen, Quoc-Dung [Verfasser], Coninx [Gutachter] Frans, and Greisbach [Gutachter] Reinhold. "Designs of Speech Audiometric Tests in Vietnamese – The Issues of Normative Values, Dialectal Effects, and Tonal Patterns / Quoc-Dung Nguyen ; Gutachter: Coninx Frans, Greisbach Reinhold." Köln : Universitäts- und Stadtbibliothek Köln, 2017. http://d-nb.info/1139117084/34.
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Dworak, Jennifer Lynn. "Modeling defective part level due to static and dynamic defects based upon site observation and excitation balance." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/323.
Full textAbstract:
Manufacture testing of digital integrated circuits is essential for high quality. However, exhaustive testing is impractical, and only a small subset of all possible test patterns (or test pattern pairs) may be applied. Thus, it is crucial to choose a subset that detects a high percentage of the defective parts and produces a low defective part level. Historically, test pattern generation has often been seen as a deterministic endeavor. Test sets are generated to deterministically ensure that a large percentage of the targeted faults are detected. However, many real defects do not behave like these faults, and a test set that detects them all may still miss many defects. Unfortunately, modeling all possible defects as faults is impractical. Thus, it is important to fortuitously detect unmodeled defects using high quality test sets. To maximize fortuitous detection, we do not assume a high correlation between faults and actual defects. Instead, we look at the common requirements for all defect detection. We deterministically maximize the observations of the leastobserved sites while randomly exciting the defects that may be present. The resulting decrease in defective part level is estimated using the MPGD model. This dissertation describes the MPGD defective part level model and shows how it can be used to predict defective part levels resulting from static defect detection. Unlike many other predictors, its predictions are a function of site observations, not fault coverage, and thus it is generally more accurate at high fault coverages. Furthermore, its components model the physical realities of site observation and defect excitation, and thus it can be used to give insight into better test generation strategies. Next, we investigate the effect of additional constraints on the fortuitous detection of defects-specifically, as we focus on detecting dynamic defects instead of static ones. We show that the quality of the randomness of excitation becomes increasingly important as defect complexity increases. We introduce a new metric, called excitation balance, to estimate the quality of the excitation, and we show how excitation balance relates to the constant τ in the MPGD model.
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Baitis, Elke Elise. "Patterns and paleoshorelines of White Sands Dune Field, New Mexico." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-3354.
Full textAbstract:
The dune field at White Sands, New Mexico, shows a well-defined pattern of dunes and interdune areas, as well as spatial variations in this pattern. The purpose of this research is to determine which measured pattern parameters are most consistent across the dune field and to determine the cause of depositional spatial variability. This was accomplished using an airborne LiDAR generated digital-elevation model (DEM) collected in June 2007 and covering 39 km² of the dune field. Properties of the dune field are defined by measurements from three dune populations: 1) 110 randomly selected dunes, 2) 247 dunes along transects oriented in the net transport direction, and 3) 171 dunes from three zones within the field where differences in pattern are visible. Measurements of eight common dune parameters show that the lowest coefficients of variation occur with dune orientation and crestline sinuosity, which largely define the field pattern. Cross-plotting of parameters shows generally poor correlations, which is thought to reflect variation around field-scale means that are comparable to other dune fields globally. Removing the dunes from the LiDAR DEM reveals a depositional substrate with breaks in slope interpreted as three paleoshorelines associated with Pleistocene Lake Otero. The paleoshorelines are antecedent boundary conditions that exert the primary control on spatial variability within the dune pattern.<br>text
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Ewing, Ryan Cotter. "Aeolian dune-field boundary conditions and dune interactions related to dune-field pattern formation on Earth and Mars." 2009. http://hdl.handle.net/2152/7561.
Full textAbstract:
Aeolian dune fields form some of the most striking patterns on Earth and Mars. These patterns reflect the internal dune dynamics of self-organization within boundary conditions, which are the unique set of environmental variables within which each dune field evolves. Dune-field pattern self-organization occurs because of interactions between the dunes themselves and the rich diversity of dune-field patterns arises because boundary conditions alter the type and frequency of dune interactions. These hypotheses are explored in three parts. First, source-area geometry and areal limits are two newly recognized boundary conditions. Measurements of crest length and spacing from satellite images of dune patterns with point and line source-area geometries show an increase in crest length and spacing over distance, whereas crest length and spacing in plane-sourced patterns emerge equally across the dune field. The areal limit boundary condition is the size and shape of the dune field itself. Empirical measurements from ten dune fields ranging over four orders of magnitude in area show that spacing increases and defect density decreases as the area of the dune field increases. A simple analytical model indicates that dune fields that are five times longer in the dune migration direction can achieve the greatest spacing for a given area. Second, time-series aerial photographs and airborne LiDAR show that fully developed, crescentic aeolian dunes at White Sands, New Mexico, interact and the dune pattern organizes in systematically similar ways as wind ripples and subaqueous dunes and ripples. Interaction type, classified as constructive, regenerative or neutral in terms of pattern development, changes spatially with the pattern because of the imposition of the line-source area and sediment availability boundary conditions. Upwind dominance by constructive interactions at the field line-source yields to neutral and regenerative interactions in the sediment availability-limited field center. Third, the dune-field pattern in the Olympia Undae Dune Field on Mars is comprised of two generations of dunes. This scenario of pattern reformation with a new wind regime shows that the emergence of the younger pattern is controlled by the boundary condition of the antecedent dune topography imposed upon the interaction between the younger and older patterns.<br>text
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Eastwood, Erin Nancy. "Reconstructing environmental forcings on aeolian dune fields : results from modern, ancient, and numerically-simulated dunes." Thesis, 2011. http://hdl.handle.net/2152/25791.
Full textAbstract:
This dissertation combines studies of aeolian bedforms and aeolian dune-field patterns to create a comprehensive set of tools that can be used in tandem (or separately) to extract information about climate change and landscape evolution, and to identify the controls on formation for specific modern dune fields or ancient aeolian sequences. The spatial distribution of surface processes, erosion/deposition rates, and lee face sorting on aeolian dunes are each a function of the incident angle. This correlation between stratification style and incidence angle can be used to develop a “toolbox” of methods based on measurements of key suites of parameters found in ancient aeolian deposits. Information obtained from the rock record can be used as input data for different kinds of numerical models. Regional-scale paleowind conditions can be used to validate paleoclimate and global circulation models. Understanding the natural variability in the Earth’s climate throughout its history can help predict future climate change. Reconstructed wind regimes and bedform morphologies can be used in numerical models of aeolian dune-field pattern evolution to simulate patterns analogous to those reconstructed from ancient aeolian systems. Much of the diversity of aeolian dune-field patterns seen in the real world is a function of the sediment supply and transport capacity, which in turn determine the sediment availability of the system. Knowledge of the sediment supply, availability, and transport capacity of aeolian systems can be used to predict the amount of sand in the system and where it might have migrated. This information can be extremely useful for development and production of oil and gas accumulations, where a discovery has been made but the spatial extent of the aeolian reservoir is unknown.<br>text
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Stallins, Jon Anthony. "Barrier island morphology and dune vegetation pattern and process in the Georgia Bight." 2000. http://purl.galileo.usg.edu/uga%5Fetd/stallins%5Fjon%5Fa%5F200008%5Fphd.
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Alaouna, Mohamed. "Expression patterns of immune associated genes in Euoniticellus intermedius and characterization of the embryonic cell line." Thesis, 2013. http://hdl.handle.net/10539/12370.
Full textAbstract:
As bacteria are becoming resistant to conventional antibiotics, researchers are looking for
new ways to combat microbial infection. We have begun to adopt genetic and functional genomic
approaches to define the molecular determinants of pathogen resistance in the dung beetle,
Euoniticellus intermedius. This dung beetle survives microbe-rich environments such as dung. This
ability makes it a potential model for the study of infectious agents and ecological damage. To date,
E. intermedius has not been studied at the molecular level. In this study, a range of complimentary
analytical techniques were used to characterize the E. intermedius embryonic cell line established in
our laboratory. These techniques characterize morphology, growth characteristics, karyotype,
isoenzyme patterns and embryonic development. Complete characterization of the E. intermedius
cell line is essential for the cell banks and for the regulatory requirements in biopharmaceutical
production.
This study followed gene sequences and their comparisons for both adult and cell line to
confirm that the E. intermedius (EISA08) cell line is originated from the embryonic E. intermedius
dung beetle. cDNA was synthesized from mRNA isolated from E. intermedius adult beetles and cell
line (EISA08) was sequenced using GS (FLX) technology by a commercial facility, Inqaba
Biotechnical Industries (Pty) Ltd, South Africa. In addition to characterization of the cell line, two
genes, namely hopscotch and ribosomal protein S9 (RpS9), were selected from the Flylab genome
data base. The E. intermedius database is a web-based system for the genome and transcriptome of
the dung beetle to evaluate the immune system of the dung beetle (http://Flylab.wits.ac.za/).
hopscotch was selected because it is believed to be involved in the JAK-STAT signalling pathway
for anti-viral response, embryonic development and cell growth. Rsp9 was chosen as a loading
control because it is expected to be a housekeeping gene. The conserved molecular signalling pathway JAK-STAT is used by E. intermedius (as in other insects and humans) for immune defence
and early embryonic development. The project followed hopscotch and Rsp9 gene expression in all
the E. intermedius life cycle developing stages; adult, pupae, larvae, embryo, and cell line cell
growth, life cycle developing stages and embryonic development has was monitored.
E. intermedius embryonic development is described as short germ-band. E. intermedius
embryogenesis is regarded as basal and is observed in most arthropods. The study revealed that
E. intermedius hopscotch is over expressed in the early developing stages, embryo, larvae, and
pupae and in the newly established cell line EISA08. The results from this study lead to the
suggestion that E. intermedius JAK-STAT pathway is activated early and has an important role in
embryonic development, cell proliferation and immune defence. Studies of E. intermedius could
provide more insight into the properties and evolution of innate immunity and embryonic
development.
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Chan, Chiao-Lan, and 詹喬嵐. "The Impact of Overland Runoff due to Changes of Watershed Land Use Patterns." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/55910866257062241222.
Full textAbstract:
碩士<br>國立中興大學<br>土木工程學系<br>88<br>Land use patterns within the watershed would lead to the change of peak flowrates as well as the runoff hydrograph. This research uses remote sensing technology based on satellite image to obtain land use patterns within the Yen-Shui watershed. Also, it uses overlay procedures of geographic information systems to extract hydrologic parameters from watershed geographic database and perform the HEC-1 simulation.The proposed study uses GIS software ArcView to not only obtain the required watershed physical parameters, but also build up a complete set of interfaces based on AVENUE to perform automated simulation of HEC-1 modeling. The hydrologic simulation also covers different land use maps for different time to find the influences of land use patterns within the same watershed. The results show that for different land use patterns would lead to different curve number CN. Since CN values are quite sensitive in HEC-1 modeling and thus lead to the changes of output runoff hydrograph, this coincides with the field measurements. Finally, the proposed research also modified the standard CN values based on Soil Conservation Service, and thus made the HEC-1 modeling more suitable for Taiwan area.
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Pohl, M. B., and John G. Buckley. "Changes in foot and shank coupling due to alterations in foot strike pattern during running." 2007. http://hdl.handle.net/10454/15848.
Full textAbstract:
No<br>The purpose of this article is determining if and how the kinematic relationship between adjacent body segments changes when an individual’s gait
pattern is experimentally manipulated can yield insight into the robustness of the kinematic coupling across the associated joint(s). The
aim of this study was to assess the effects on the kinematic coupling between the forefoot, rearfoot and shank during ground contact of
running with alteration in foot strike pattern.
Twelve subjects ran over-ground using three different foot strike patterns (heel strike, forefoot strike, toe running). Kinematic
data were collected of the forefoot, rearfoot and shank, which were modelled as rigid segments. Coupling at the ankle-complex and
midfoot joints was assessed using cross-correlation and vector coding techniques.
In general good coupling was found between rearfoot frontal plane motion and transverse plane shank rotation regardless of
foot strike pattern. Forefoot motion was also strongly coupled with rearfoot frontal plane motion. Subtle differences were noted in the
amount of rearfoot eversion transferred into shank internal rotation in the first 10–15% of stance during heel strike running compared to
forefoot and toe running, and this was accompanied by small alterations in forefoot kinematics.
These findings indicate that during ground contact in running there is strong coupling between the rearfoot and shank
via the action of the joints in the ankle-complex. In addition, there was good coupling of both sagittal and transverse plane forefoot with
rearfoot frontal plane motion via the action of the midfoot joints.
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Wu, Bi-Jun, and 吳必鈞. "Metal Corrosion of Pattern Wafer Due to Chloride Airborne Molecular Contaminants in Cleanrooms." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/79401310172977671026.
Full textAbstract:
博士<br>國立交通大學<br>環境工程系所<br>100<br>Chloride ions (Cl-) induce metal corrosion of integrated circuits and cause wafer scrap events in the clean room environment. In this study, pattern wafers were designed to monitor critical Cl- concentration which leads to metal corrosion effects in a simulated airborne molecular contamination (AMC) mini-environment, meanwhile, the HCl concentrations in the mini-environment and the real fab were monitored by a real-time Ion Mobility Spectrometer (IMS) and impinge+IC. The results help to understand the sensitivity, corrosion occurrence, and recommended exposure limit and preventive action plan.
The results indicate that the IMS can be used for HCl AMC monitoring, and show very good agreement (R2=0.9933) with the impinger+IC method. It also proved that the innovative “clean wiper” mini-environment can serve as a stable Cl- simulated source, which can control the simulation within 12%~17% error in ppbv levels. The designed pattern wafer exposure tests can be an effective method to monitor metal corrosion, and the corrosion defects’ reproducibility is 100%. Furthermore the Al-0.5%Cu pattern wafer with “sandwich” structure provided better anti-corrosion capability than the Al-1%Si-0.5%Cu pattern wafer. The TiN barrier layer also provide better anti-corrosion capability than TiW barrier layer. Above all, this study concludes the suggested exposure concentration of Cl- at 2 ppbv in a real fab application.
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Chiu, Yi-Feng, and 邱奕峰. "Study of Failure Pattern for Three Building Structures due to 921 Chi-Chi Earthquake." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/88611972309322405255.
Full textAbstract:
碩士<br>國立交通大學<br>土木工程系<br>88<br>The main purpose of this thesis is to discuss two main failure patterns of three building structures in 921 Chi-Chi earthquake. The soft story effect and the short-column effect are the major reasons for the failure. These two effects are strongly related to the existence of walls. We perform static analysis and dynamic time history analysis for three real buildings （labeled A, B and C） collapsed in this earthquake in order to compare the result with wall effect and that without wall effect. The results show that the columns in the ground story will bear more moment under the condition that the ground story becomes soft story which means that the walls in ground floor failure first. And the columns in the corner will bear extremely large axis force. The building A and C are failed by this effect. For building B, some half-height walls are filled for some spans in ground floor to create short column effect. And we found that those short columns during earthquake will have to resist double, even triple of the shears which is the result without considering short column effect.
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Tshikae, Balatlhane Power. "Local and regional factors influencing dung beetle assemblage structure across an environmental gradient in Botswana." Thesis, 2011. http://hdl.handle.net/2263/28856.
Full textAbstract:
The taxonomic composition, structure, and diversity of current local species assemblages results from an interacting complex of historical, regional ecological and local ecological factors. Structural differences between such current species assemblages are primarily determined by changing ecological conditions across spatial gradients. These conditions may change abruptly or they may represent a gradual divergence. Across the Botswana Kalahari basin there is a gradual northeast-southwest aridity and dung type gradient, which was demonstrated to strongly influence dung beetle assemblage structure at six study sites from Chobe National Park to the Central Kalahari Reserve to the Kgalagadi Transfrontier Park using carrion and four dung types as bait (pig, elephant, cattle, sheep). Regional patterns were primarily influenced by climate (rainfall) while dung type mainly showed a local influence on patterns of variation. Four distinct biogeographical groups were defined for the study region comprising widespread, northeast/widespread, northeast, and arid southwest Kalahari-centred species. Biogeographical diversity was higher in the more mesic NE than the arid SW but varied somewhat between bait types. In the SW, Kalahari endemics dominated all bait types. In general, abundance and species richness declined along the aridity gradient although the pattern was uneven due to low numbers in the north of the Central Kalahari Game Reserve. Species showed high turnover (beta – diversity), particularly between the moister NE and the Kalahari/Savanna ecotone. Hierarchical Analysis of Oblique Factors showed statistically distinct separation between assemblage structure at the six study sites and that the proportion of mesic NE shared influence on assemblage composition declined towards the SW where there was an increase in Kalahari endemics. Similarly the proportion of arid SW shared influence declined towards the NE. Plotting these results onto a map showed that the point of intersection between shared NE or SW influence lay very close to the ecotone between SW (Kalahari Xeric Savanna) and NE-centred ecoregions (Acacia-Baikiaea Savanna) defined for the area by Olson et al. (2001). In terms of dung type diversity, increasing aridity across the Kalahari represents a gradient of diminishing resources with the loss of large dung types to the SW and increasing dominance of dung pellets. Several different patterns of response were shown using different methods. Four principal patterns of bait type association were indicated by one method. Another method showed that, rather than diminishing numbers of competing species leading to widening niche widths to the SW, niche widths were narrowest at the Kalahari / mesic Savanna ecotone. Using several other multivariate techniques, three different patterns of dung type resource partitioning were demonstrated that paralleled the aridity gradient, one common to the NE and two to the SW. The historical, regional and local ecological factors influencing these patterns of dung beetle assemblage structure are discussed as well as implications and recommendations for conservation.<br>Thesis (PhD)--University of Pretoria, 2011.<br>Zoology and Entomology<br>unrestricted
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Bassa, Zaakirah. "An assessment of land cover change patterns using remote sensing : a case study of Dube and Esikhawini, KwaZulu-Natal, South Africa." Thesis, 2012. http://hdl.handle.net/10413/9858.
Full textAbstract:
During the past two centuries, land cover has been changing at an alarming rate in space and time and it is humans who have emerged as the dominant driver of change in the environment, resulting in changes of extraordinary magnitudes. Most of these changes occur due to demands placed on the land by the ever-increasing human population and their need for more land for both settlement and food production. Many researchers underscore the importance of recognizing and studying past land-use and land cover changes as the legacies of these changes continue to play a major role in ecosystem structure and function. The objectives of this study were to determine the extent of land cover changes between 1992 and 2008 in the study areas, Esikhawini and Dube located in the uMhlathuze municipality, KwaZulu-Natal, and to both predict and address the implications of the extent of future changes likely to occur in the area by 2016. Three Landsat satellite images of the study area were acquired for the years, 1992, 2000 and 2008. These images were classified into nine classes representing the dominant land covers in the area. An image differencing change detection method was used to determine the extent of the changes which took place during the specified period. Thereafter, a Markov chain model was used to determine the likely distribution of the land cover classes by 2016. The results revealed that aside from Waterbodies and Settlements, the rest of the classes exhibited a great degree of change between 1992 and 2008, having class change values greater than 50%. With regards to the predicted change in the land cover classes, the future land cover change pattern appears to be similar to that observed between 1992 and 2008. The Settlements class will most likely emerge as the dominant land cover in the study area as many of the other classes are increasingly being replaced by this particular class. The overall accuracy of the classification method employed for this study was 79.58% and the results have provided a good overview of the location and extent of land cover changes in the area. It is therefore plausible to conclude that these techniques could be used at both local and regional scales to better inform land management practices and policies.<br>Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
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Liu, Kun-Chen, and 劉昆宸. "The impact on traffic-line patterns and air quality due to the construction of Formosan Highway in Nantou County." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/35426965859622251898.
Full textAbstract:
碩士<br>逢甲大學<br>環境工程與科學所<br>95<br>Nantou County is famous for her many wonderful scenery. In case the
transportation system is well connected, a lot of tourists will come in great
numbers. However, crowded visitor will also bring pollution to the environment.
That’s why decision-making of any public work should be very careful.
This study undergoes three times of simultaneous vehicle-counting at six
selected positions in the main traffic lines in Nantou County. The change of
traffic-line patterns before and after the construction of Formosan Freeway was
studied. Then a numerical model was utilized to simulate their effect on air
quality around the main traffic line regions. Finally, evaluations of deterioration
of air quality due to the construction of Formosan Freeway were proceeded.
The result show that, Total Travel Index （TTI）values in weekdays,
weekends, and multiple-day holidays of the traffic in and out of Nantou County
were 1.2, 1.4 and 1.8, respectively. It was realized that the Formosan Freeway
did attract a large number of vehicles on weekend, especial on multiple-day
holidays. On the other hand, TTI values of the NO.3 highway was only 0.3 in
each cases of weekdays, weekends and multiple-day holidays. It revealed that
the traffic on NO.3 highway was greatly reduced owing to the appearance of
Formosan Freeway. It also indicates that almost all of the long-distance traffic
has transferred to Formosan Freeway.
According to the numerical simulations the worst situation arose when
NNE wind direction predominant. The highest concentration was found near
regions of Tsautun, Nantou city and Suangdong. For air pollutant CO, the Air
Pollution Index（API）value was less than 1 at weekdays and was a little larger
than 1 at holidays. For NMHC, most of the API value was smaller than 1.
However, all of the API values for NOx and SO2 were decrease and NOx and
iv 逢甲大學e-Thesys(95 學年度)
SO2 increase due to the construction on Formosan Freeway and hence the
traffic-line pattern change.
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Jockel, Dylan. "Patterns of Morphological Plasticity in Metriaclima zebra and Danio rerio Suggest Differently Canalized Phenotypes Due to Form-Function Relationships." 2019. https://scholarworks.umass.edu/masters_theses_2/837.
Full textAbstract:
In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior kinethmoid rotation in D. rerio. as opposed to force imparted upon the rostral cartilage of the premaxilla’s articular process in M zebra. Each is markedly distinct in the pharyngeal jaw as well, as zebrafish (also toothless at the oral jaw) bear teeth only on the lower set at the posterior of the mouth, while cichlids bear teeth on all jaws and additionally possess a unique, fused lower pharyngeal jaw. However, accounting for this difference in experimental models does allow for direct comparison, both at the morphological/behavioral and potentially the genetic level, though additional research is necessary. The evidence provided here also provides encouragement that more nuanced approaches to laboratory trophic niche exposure experiments could elucidate further evidence on the nature of phenotypic plasticity.
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Liu, Li-Chih, and 劉禮智. "The impact on traffic-line patterns and air quality due to the construction of the NO.6 freeway in Nantou County." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/42938102529973761756.
Full textAbstract:
碩士<br>逢甲大學<br>環境工程與科學所<br>97<br>This study is to evaluate the change of traffic-patterns and air quality due to the construction of the NO.6 freeway. A in-situ vehicle counting program were performed while the coincident counting data from the toll station were collected. Then CALINE 4 model was utilized to simulate the air pollution on both weekday and weekend in Nantou County. Finally, the effects of air quality of the main traffic line regions and population concentrated regions, such as Guoshing and Puli were evaluated.
The result show that, the Total Traffic Index (TTI) value of the traffic in and out of Nantou County for weekday and weekend were 1.075 and 1.571, respectively. It was indicated that the NO.6 freeway did attract a large number of vehicles, especially on weekend. Vacation Traffic Index (VTI) value before and after the construction of NO.6 freeway were 1.463 and after 2.136, respectively. As it was seen, all VTI values were larger than 1, showed that there were more vehicles on weekend than those on weekday. And the VTI value after construction of NO.6 freeway was much larger than those before construction.
On the other hand, the TTI value of the 14th provincial highway (parallel to the NO.6 freeway) on weekday and weekend were 0.730 and 0.773, respectively. It revealed that the TTI values were all smaller than 1, meant that the traffic of the 14th provincial highway was reduced owing to the construction of NO.6 freeway. VTI values of the 14th provincial highway before and after the construction of NO.6 freeway were 1.210 and 1.281, respectively, it revealed only a small increment in weekend after construction. But if the 14th provincial highway and NO.6 freeway were considered altogether, the VTI values before and after the construction of NO.6 freeway were 1.210 and 1.634, respectively. It revealed that a large amount of increment of weekend traffic were observed after the construction of NO.6 freeway.
According to the numerical simulation, the highest concentration was found near Formosan Freeway, Tsautun interchange, before the construction of NO.6 freeway. It was found changing to near Jhushan town and Nantou city. For air pollutant CO, the Air Pollution Assessment Index (APAI) value was less than 1 on both weekday and weekend, at all evaluating regions: the N-S traffic line region, Guoshing and Puli regions. It revealed that after construction of NO.6 freeway, the air quality CO was better at all these regions. For air pollutant SO2, the APAI value was larger than 1 on weekday at all regions. It revealed that air quality SO2 were worse at these regions. However, the APAI values were smaller than 1 on weekend. It revealed that after construction of NO.6 freeway, air quality SO2 was better due to part of the overcrowded traffic on the 14th provincial highway has been transferred to NO.6 freeway.
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Hung, Chen-Yuan, and 洪振原. "Due to the “Balanced Dividend Policy”, the patterns of dividend policy in the publicly traded companies characteristics had been changed in Taiwan." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/11016550974087031922.
Full textAbstract:
碩士<br>國立中正大學<br>企業管理所<br>93<br>Due to the “Balanced Dividend Policy” promoted by SFC. Based on the trend of dividend yield and dividend payout ratio from 1998 to 2004 in Taiwan, it seems that the publicly traded companies have shown an increasing trend of cash dividend in the recent years. We predict that the publicly traded companies may tend to pay more cash dividend which is a substitution for stock dividend before as their dividend policy in the future.
First, this research compares the patterns of dividend policy in the publicly traded companies in Taiwan, with those observed by Megginson from the publicly traded companies around the world. Next, we use event study and cross section regression analysis to discover the price change after dividend announcement made by the BOD of each company and the effect of practicing the Balanced Dividend Policy. Also we explore the determinants of the corporate dividend policy in Taiwan over this period. Our empirical findings are as follows: The dividend policies in Taiwan are not all accordant with the patterns observed by Megginson. Besides, when the BOD makes their announcement of dividend issuance, the price of stock does appear a positive abnormal return. This is consistent with the theories of agency cost and signaling. However, after performing more detailed analysis, we find the stock dividend still provides a significantly positive abnormal return. On contrary, the cash dividend provides a significantly negative abnormal return. For the companies paying cash and stock dividend at the same time, it appears no effect on their prices. It is not conclusive that promoting the balanced dividend policy is successful or not, but the number of companies paying more cash dividend is certainly increasing in the past few years. In addition, our finding does not support the Bird-in-the-Hand Theory here.
Due to the “Balanced Dividend Policy” promoted by SFC. Our regression results provide strong evidences that the company earning ability, business risk, insider ownership, growth opportunities, and the firm size provide positive or negative impact on the level of total, cash and stock dividend. These are consistent with our hypotheses and most of our literature findings.
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Bamigboye, Samuel Oloruntoba. "Assessing species richness patterns and conservation threats (due to overharvesting and climate change) in South African Cycads, with emphasis on a population of Encephalartos tranvenosus Stapf and Burt Davy from the Soutpansberg Mountain, Limpopo Province." Thesis, 2018. http://hdl.handle.net/11602/1088.
Full textAbstract:
PhD (Botany)<br>Department of Botany<br>Cycads are regarded as the oldest living seed plants on earth and they have existed for about 300 million years. Ever since the awareness of the existence of this plant group, they have been facing high extinction risk. Currently they are referred to as the most threatened plant group in the world. Many ecological and anthropological forces are promoting extinction crisis of this taxonomic group.
Africa is one of the centres of diversity of this plant group with 70% of the total number of the taxa in this group in Africa found in South Africa. Also South Africa is one of the global hotspots for cycads and it contains the third largest number of cycads after Australia and Mexico. Studies have revealed that there have been high threats and extinction risks among the cycad taxa in South Africa.
The Soutpansberg Mountain is a major biodiversity hotspot in Limpopo Province in South Africa with high level of flora and fauna taxa. About 3000 vascular plants species are represented on this mountain. Biodiversity on this mountain has been under threat in recent times and there is need to investigate how cycads are facing risk on this mountain.
The main focus of this study is to look at the extinction pattern in South African cycads and cycads endemic to Soupandberg Mountain in Limpopo Province in South Africa.
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The first objective evaluated all African cycads over a decade using IUCN red list. Data from IUCN 2014 version was used to calculate the percentages of African cycads in each IUCN categories. The results were compared with those presented by Donaldson 2003. They showed that there have been significant decline and increase in extinction of African cycads over this period. It was also discovered that majority of this extinction crisis were trending in South Africa.
The second objective used the IUCN red list to evaluate extinction pattern in South African cycads. The percentages of IUCN threat categories of South African cycads was calculated using IUCN red list. ArcGIS was used to construct distribution map for threatened and extinct South African cycads. The study revealed that the proportion of historically Extinct and Critically Endangered cycads is higher in Limpopo, KwaZulu-Natal and Mpumalanga than the rest of the provinces in South Africa.
The third objective of this research investigated extinction pattern of Encephalartos transvenosus Stapf & Burtt Davy (Modjadji cycad) on Soutpansberg Mountain. Indigenous knowledge and population ecology approaches were used to determine current threats Modjadji cycads are facing on Soutpansberg Mountain. The results showed that anthropogenic activities have caused a substantial decline of one important unprotected population of this species on Soutpansberg Mountain.<br>NRF