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1
Chateigner, Coelsch Sophie Santoul Jérôme. „L'enfant en altitude“. [S.l.] : [s.n.], 2004. http://theses.univ-nantes.fr/thesemed/chateignerMED04.pdf.
2
Campos, Prímula Viana. „Interação solo-altitude-vegetação em campos de altitude no sudeste do Brasil“. Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/10129.
Annotation:
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Conselho Nacional de Desenvolvimento Científico e Tecnológico
O estudo avaliou padrões de diversidade, estrutura e formas de vida em três comunidades vegetais associadas a afloramentos rochosos nos campos de altitude do Parque Nacional (PARNA) do Caparaó, MG/ES, Brasil, bem como a influência da altitude e solo nos mesmos parâmetros vegetacionais em três comunidades no Parque Estadual Serra do Brigadeiro (PESB), MG, Brasil. Foram alocadas 100 parcelas de 1x1 m distribuídas ao acaso em cada um dos três ambientes (300 em cada parque). Foram calculados os parâmetros quantitativos clássicos, os índices de diversidade e equabilidade, similaridade florística, curvas de rarefação e dominância-diversidade, bem como análise dos espectros biológicos e vegetacionais, usando as formas de vida de Raunkiaer. Para análise químicas e físicas coletou-se uma amostra simples de solo (0-10 cm). No PARNA Caparaó, foram amostradas 58 espécies, pertencentes a 49 gêneros e 32 famílias. As curvas de rarefação apresentaram tendência à estabilização da assíntota aproximadamente a partir das 75 unidades amostrais em todas as áreas. Entre as áreas existem diferenças significativas entre a riqueza, abundância e cobertura. O índice de diversidade de Shannon-Wiener permaneceu entre 3,00-2,76 e equabilidade de Pielou com dois valores 0,77 e 0,75. As curvas de dominância-diversidade apresentaram distribuição log-normal e geométrica. A proporção do número de espécies por forma de vida foi similar entre as áreas, ao contrário do espectro vegetacional, com destaque para as espécies hemicriptófitas. No PESB, foram amostrados 9.276 indivíduos, pertencentes a 39 famílias e 102 espécies. Entre as áreas existem diferenças significativas entre a riqueza, abundância, cobertura, bem como nos parâmetros edáficos. O índice de diversidade de Shannon-Wiener permaneceu entre 3,07-3,20 e equabilidade de Pielou (0,74-0,79). A CCA indicou dois grupos distintos formados para abundância e cobertura, indicando a concentração das espécies em habitats preferenciais, em função da altitude, bem como da fertilidade e textura do solo. A partir do GLM, a riqueza de espécies foi correlacionada com atributos químicos do solo, assim como ambos os parâmetros estruturais da vegetação, que além de apresentar relação com variáveis químicas do solo, foram influenciados pela altitude. Os resultados apontam a falta de informações em relação aos fatores abióticos que possam reger nesses ambientes.
This study assessedthe diversity, structure and life-form patterns in three plant communities associated with rocky outcrops in the campos de altitude of the Caparaó National Park, MG/ES states, Brazil, as well as the influence of altitude and soil on these vegetation parameters in three communities from the Serra do Brigadeiro State Park, MG state, Brazil. For that, 100 plots (1x1 m) were randomly distributedacross each of the three environments (300 in each park).Classical quantitative parameters were calculated: diversity and evenness indexes, floristic similarity, and rarefaction and dominance-diversity curves. Biological and vegetation spectra were also analyzed, by using Raunkiaer‟s life-form classification. For soil chemical and physical analyses, a simple sample (0-10 cm depth) was collected. In the PARNA Caparaó, were sampled a total of 58 species belonging to 49 genera and 32 families were sampled. The rarefaction curves showed a tendency to stabilization of the asymptote at approximately 75 of the sampled units in all areas. There are significant differences between the areas regarding species richness, abundance and coverage. Shannon-Wiener‟s diversity index ranged between 3.00 and 2.76, while Pielou‟s evenness index showed the values of 0.77 and 0.75. The dominance-diversity curves showed log-normal and geometric distributions. The proportion of the number of species per life-form was similar between the areas, with the hemicryptophytes showing the highest values. The vegetation spectrum, however, differed. In the PESB, were sampled A total of 9276 individuals belonging to 39 families and 102 species were analyzed. There are significant differences between the areas regarding richness, abundance, coverage and edaphic parameters. The areas, however, are relatively similar. Shannon-Wiener‟s diversity index ranged between 3.07 and 3.20, while Simpson‟s index ranged from 0.6 to 0.8 and Pielou‟s evenness from 0.74 to 0.79. The CCA revealed the existence of two distinct gradients formed by abundance and coverage, thus indicating the concentration of species in preferential habitats according to the altitude, as well asto soil fertility and texture. Through the GLM, the species richness was shown to be correlated with soil chemical attributes, as were both vegetation structural parameters, which besides showing a relationship with soil chemical variables were also influenced by the altitude.The results indicate the lack of a relationship with abiotic factors on these environments.
3
Suissa, Nathalie. „Bioimpedance transthoracique en altitude“. Toulouse 3, 1994. http://www.theses.fr/1994TOU31068.
4
Bennett, April M. „Active Regulation of Speed During a Simulated Low-altitude Flight Task: Altitude Matters!“ Wright State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=wright1167238078.
5
Mason, Nicholas. „Mechanisms of altitude-related cough“. Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209711.
Annotation:
The original work presented in this thesis investigates some of the mechanisms that may be responsible for the aetiology of altitude-related cough. Particular attention is paid to its relationship to the long recognised, but poorly understood, changes in lung volumes that occur on ascent to altitude. The literature relevant to this thesis is reviewed in Chapter 1.Widespread reports have long existed of a debilitating cough affecting visitors to high altitude that can incapacitate the sufferer and, on occasions, be severe enough to cause rib fractures (22, 34, 35). The prevalence of cough at altitude has been estimated to be between 22 and 42% at between 4200 and 4900 m in the Everest region of Nepal (10, 29). Traditionally the cough was attributed to the inspiration of the cold, dry air characteristic of the high altitude environment (37) but no attempts were made to confirm this aetiology. In the first formal study of cough at high altitude, nocturnal cough frequency was found to increase with increasing altitude during a trek to Everest Base Camp (5300 m) and massively so in 3 climbers on whom recordings were made up to 7000 m on Everest (8). After 9 days at 5300 m the citric acid cough threshold, a measure of the sensitivity of the cough reflex arc, was significantly reduced compared with both sea level and arrival at 5300 m.
During Operation Everest II, a simulated climb of Mount Everest in a hypobaric chamber, the majority of the subjects were troubled above 7000 m by pain and dryness in the throat and an irritating cough despite the chamber being maintained at a relative humidity of between 72 and 82% and a temperature of 23ºC (18). This argued against the widely held view that altitude-related cough was due to the inspiration of cold, dry air.
In the next major hypobaric chamber study, Operation Everest III, nocturnal cough frequency and citric acid cough threshold were measured on the 8 subjects in the study. The chamber temperature was maintained between 18 and 24ºC and relative humidity between 30 and 60% (24). This work is presented in Chapter 2 and, demonstrated an increase in nocturnal cough frequency with increasing altitude which immediately returned to control values on descent to sea level. Citric acid cough threshold was reduced at 8000 m compared to both sea level and 5000 m values. Changes in citric acid cough threshold at lower altitudes may not have been detected because of the constraints on subject numbers in the chamber. The study still however demonstrated an increase in clinical cough and a reduction in the citric acid cough threshold at extreme altitude, despite controlled environmental conditions, and thus refuted the long held belief that altitude-related cough is solely due to the inspiration of cold, dry air.
If altitude-related cough is not simply due to the inspiration of cold, dry air, other possible aetiologies are:
•\
Doctorat en Sciences médicales
info:eu-repo/semantics/nonPublished
6
Brown, K. D., und Trevor Sorensen. „HIGH ALTITUDE TRANSMITTER FLIGHT TESTING“. International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605062.
Annotation:
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaThis paper describes a high altitude experimental flight test platform developed by the University of Kansas (KU) and the National Nuclear Security Administration’s Kansas City Plant (NNSA’s Kansas City Plant) for high altitude payload flight testing. This platform is called the Kansas University Balloon Experiment Satellite (KUBESat). The paper describes the flight test platform and experimental flight test results captured at Fort Riley, KS from characterization of the KCP developed Distributed Transmitter (DTX).
7
Cohen, Hagit. „Hovering at a low altitude /“. Online version of thesis, 1990. http://hdl.handle.net/1850/10903.
8
Sengul, Orhan. „Low Altitude Radar Wave Propagation Modelling“. Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608467/index.pdf.
Annotation:
LOW ALTITUDE RADAR WAVE PROPAGATION MODELLING
In this PhD thesis, propagation aspects of low altitude radar performance have been modeled using geometrical optics. Both the path propagation factor and the radar clutter have been modeled. Such models already exist at various complexity levels, such as round earth specular reflection combined with knife edge hill diffraction [SEKE:IEEE,Ap-
34,No:8,1980] and round earth and slant plateau reflection combined with hill diffraction [RADCAL: 1988-2000,EE,METU]. In the proposed model we have considered an extension
to RADCAL&rsquos model to include convex and concave slant plateaus between hills and depressions (troughs). This propagation model uses a reflection model based on the Geometrical Theory of Reflection for the convex and concave surfaces. Also, back scattering from surface (clutter) is formulated for the new model of the terrain profile. The effects of the features of the terrain profile on the path propagation factor have been investigated. A real terrain data have been smoothed on the basis of the above study. In order to verify the formulation, the Divergence and Convergence Factors associated with the convex and concave plateaus, respectively are inserted into the RADCAL program. The chosen terrains have convex or concave plateaus in the model. The output of the RADCAL is compared with measured values and other propagation algorithms such as Forward-Backward Spectrally Accelerated (FBSA) [FBSA:IEEE Vol.53, No:9,2005] and Parabolic Equation Method [TPEM:IEEE Vol.42,No:1,1994]. Moreover, as the RADCAL Propagation model is based on the ray optics, the results are also compared with another ray optics based propagation model. For this purpose the results of SEKE [Lincoln Lab.] propagation model are used. SEKE model has been used to compute path loss for different types of terrain as a function of receiving antenna height at a fixed distance between transmit and receive antennas. For Beiseker W35 Terrain profile, the results of RADCAL, SEKE and measurements are compared. All results are in good agreement with those of RADCAL.
9
York, Julia McRae. „Respiratory mechanics of high altitude waterfowl“. Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58744.
Annotation:
Birds living at high altitude (>3,000 meters) are not only able to cope with reduced oxygen availability due to hypobaria, but they are also able to achieve one of the most metabolically costly form of locomotion at these altitudes: flight. To perform such a metabolically demanding activity, in addition to energetically expensive daily tasks such as foraging, predator escape, and reproduction, all in oxygen limited (hypoxic) conditions, means that high altitude birds must enhance oxygen supply to maintain oxygen homeostasis. The primary means of increasing oxygen supply is increasing ventilation of the respiratory gas exchange surface. However, the metabolic cost of ventilation is unknown for birds at rest, as is whether this cost varies among bird species. In this thesis, the cost and work of breathing are compared in fourteen avian species to determine whether variation in the work of breathing is due to mechanical or morphological changes in the respiratory system, and if any observed changes are associated with living at high altitude. High altitude birds tended to have large and compliant respiratory systems compared with low altitude taxa, which reduces the work of breathing. However, the evidence also suggests that respiratory morphology and mechanics in birds may be more constrained by life history strategy than by evolutionary time at altitude, although species in this study that have no high altitude sister taxa (their lineages have never radiated to high altitude) struggled the most with increasing oxygen supply. Finally, birds at rest were estimated to have a lower cost of breathing than mammals, contrary to the hypothesis that cost of breathing would be high in birds due to the heavy flight muscles weighing down the sternum.Science, Faculty of
Zoology, Department of
Graduate
10
Johnson, Pamela Lesley. „Sleep and Breathing at High Altitude“. University of Sydney, 2008. http://hdl.handle.net/2123/3531.
Annotation:
Doctor of Philosphy (PhD)This thesis describes the work carried out during four treks, each over 10-11 days, from 1400m to 5000m in the Nepal Himalaya and further work performed during several two-night sojourns at the Barcroft Laboratory at 3800m on White Mountain in California, USA. Nineteen volunteers were studied during the treks in Nepal and seven volunteers were studied at White Mountain. All subjects were normal, healthy individuals who had not travelled to altitudes higher than 1000m in the previous twelve months. The aims of this research were to examine the effects on sleep, and the ventilatory patterns during sleep, of incremental increases in altitude by employing portable polysomnography to measure and record physiological signals. A further aim of this research was to examine the relationship between the ventilatory responses to hypoxia and hypercapnia, measured at sea level, and the development of periodic breathing during sleep at high altitude. In the final part of this thesis the possibility of preventing and treating Acute Mountain Sickness with non-invasive positive pressure ventilation while sleeping at high altitude was tested. Chapter 1 describes the background information on sleep, and breathing during sleep, at high altitudes. Most of these studies were performed in hypobaric chambers to simulate various high altitudes. One study measured sleep at high altitude after trekking, but there are no studies which systematically measure sleep and breathing throughout the whole trek. Breathing during sleep at high altitude and the physiological elements of the control of breathing (under normal/sea level conditions and under the hypobaric, hypoxic conditions present at high altitude) are described in this Chapter. The occurrence of Acute Mountain Sickness (AMS) in subjects who travel form near sea level to altitudes above 3000m is common but its pathophysiology not well understood. The background research into AMS and its treatment and prevention are also covered in Chapter 1. Chapter 2 describes the equipment and methods used in this research, including the polysomnographic equipment used to record sleep and breathing at sea level and the high altitude locations, the portable blood gas analyser used in Nepal and the equipment and methodology used to measure each individual’s ventilatory response to hypoxia and hypercapnia at sea level before ascent to the high altitude locations. Chapter 3 reports the findings on the changes to sleep at high altitude, with particular focus on changes in the amounts of total sleep, the duration of each sleep stage and its percentage of total sleep, and the number and causes of arousals from sleep that occurred during sleep at increasing altitudes. The lightest stage of sleep, Stage 1 non-rapid eye movement (NREM) sleep, was increased, as expected with increases in altitude, while the deeper stages of sleep (Stages 3 and 4 NREM sleep, also called slow wave sleep), were decreased. The increase in Stage 1 NREM in this research is in agreement with all previous findings. However, slow wave sleep, although decreased, was present in most of our subjects at all altitudes in Nepal; this finding is in contrast to most previous work, which has found a very marked reduction, even absence, of slow wave sleep at high altitude. Surprisingly, unlike experimental animal studies of chronic hypoxia, REM sleep was well maintained at all altitudes. Stage 2 NREM and REM sleep, total sleep time, sleep efficiency and spontaneous arousals were maintained at near sea level values. The total arousal index was increased with increasing altitude and this was due to the increasing severity of periodic breathing as altitude increased. An interesting finding of this research was that fewer than half the periodic breathing apneas and hypopneas resulted in arousal from sleep. There was a minor degree of upper airway obstruction in some subjects at sea level but this was almost resolved by 3500m. Chapter 4 reports the findings on the effects on breathing during sleep of the progressive increase of altitude, in particular the occurrence of periodic breathing. This Chapter also reports the results of changes to arterial blood gases as subjects ascended to higher altitudes. As expected, arterial blood gases were markedly altered at even the lowest altitude in Nepal (1400m) and this change became more pronounced at each new, higher altitude. Most subjects developed periodic breathing at high altitude but there was a wide variability between subjects as well as variability in the degree of periodic breathing that individual subjects developed at different altitudes. Some subjects developed periodic breathing at even the lowest altitude and this increased with increasing altitude; other subjects developed periodic breathing at one or two altitudes, while four subjects did not develop periodic breathing at any altitude. Ventilatory responses to hypoxia and hypercapnia, measured at sea level before departure to high altitude, was not significantly related to the development of periodic breathing when the group was analysed as a whole. However, when the subjects were grouped according to the steepness of their ventilatory response slopes, there was a pattern of higher amounts of periodic breathing in subjects with steeper ventilatory responses. Chapter 5 reports the findings of an experimental study carried out in the University of California, San Diego, Barcroft Laboratory on White Mountain in California. Seven subjects drove from sea level to 3800m in one day and stayed at this altitude for two nights. On one of the nights the subjects slept using a non-invasive positive pressure device via a face mask and this was found to significantly improve the sleeping oxyhemoglobin saturation. The use of the device was also found to eliminate the symptoms of Acute Mountain Sickness, as measured by the Lake Louise scoring system. This finding appears to confirm the hypothesis that lower oxygen saturation, particularly during sleep, is strongly correlated to the development of Acute Mountain Sickness and may represent a new treatment and prevention strategy for this very common high altitude disorder.
11
Scherer, Sebastian. „Low-Altitude Operation of Unmanned Rotorcraft“. Research Showcase @ CMU, 2011. http://repository.cmu.edu/dissertations/62.
Annotation:
Currently deployed unmanned rotorcraft rely on preplanned missions or teleoperation and do not actively incorporate information about obstacles, landing sites, wind, position uncertainty, and other aerial vehicles during online motion planning. Prior work has successfully addressed some tasks such as obstacle avoidance at slow speeds, or landing at known to be good locations. However, to enable autonomous missions in cluttered environments, the vehicle has to react quickly to previously unknown obstacles, respond to changing environmental conditions, and find unknown landing sites.
We consider the problem of enabling autonomous operation at low-altitude with contributions to four problems. First we address the problem of fast obstacle avoidance for a small aerial vehicle and present results from over a 1000 runs at speeds up to 10 m/s. Fast response is achieved through a reactive algorithm whose response is learned based on observing a pilot. Second, we show an algorithm to update the obstacle cost expansion for path planning quickly and demonstrate it on a micro aerial vehicle, and an autonomous helicopter avoiding obstacles.
Next, we examine the mission of finding a place to land near a ground goal. Good landing sites need to be detected and found and the final touch down goal is unknown. To detect the landing sites we convey a model based algorithm for landing sites that incorporates many helicopter relevant constraints such as landing sites, approach, abort, and ground paths in 3D range data. The landing site evaluation algorithm uses a patch-based coarse evaluation for slope and roughness, and a fine evaluation that fits a 3D model of the helicopter and landing gear to calculate a goodness measure. The data are evaluated in real-time to enable the helicopter to decide on a place to land.
We show results from urban, vegetated, and desert environments, and demonstrate the first autonomous helicopter that selects its own landing sites. We present a generalized planning framework that enables reaching a goal point, searching for unknown landing sites, and approaching a landing zone. In the framework, sub-objective functions, constraints, and a state machine define the mission and behavior of an UAV. As the vehicle gathers information by moving through the environment, the objective functions account for this new information. The operator in this framework can directly specify his intent as an objective function that defines the mission rather than giving a sequence of pre-specified goal points. This allows the robot to react to new information received and adjust its path accordingly. The objective is used in a combined coarse planning and trajectory optimization algorithm to determine the best path the robot should take. We show simulated results for several different missions and in particular focus on active landing zone search.
We presented several effective approaches for perception and action for low-altitude flight and demonstrated their effectiveness in field experiments on three autonomous aerial vehicles: a 1m quadrocopter, a 3.6m helicopter, and a full-size helicopter. These techniques permit rotorcraft to operate where they have their greatest advantage: In unstructured, unknown environments at low-altitude.
12
Williams, David Reid. „The pulmonary circulation at high altitude“. Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316610.
13
AGOPIAN, VALERIE. „Oxygene, respiration et altitude : revue generale“. Aix-Marseille 2, 1993. http://www.theses.fr/1993AIX20133.
14
Croft, Quentin. „Human responses to simulated high altitude“. Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711614.
15
White, Ryan D. „A high-altitude nuclear environment simulation“. Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2315.
16
Ching, Hung. „Association Between Altitude and Bronchopulmonary Cancer“. ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/5614.
Annotation:
As a validation study, this study addressed an under-researched area of bronchopulmonary cancer mortality and incidence. The association between altitude and bronchopulmonary cancer mortality and incidence was investigated using data from the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research. The theoretical framework for my study was Bronfenbrenner's ecological model. This model emphasizes the relevance of social and physical environments that influence patterns of disease and injury and shape responses to these patterns of disease and injury. The age-adjusted bronchopulmonary cancer mortality and incidence rates per 100,000 people in the highest elevation and lowest elevation states were investigated. The data used in this study spans from 2006 to 2014. In this study, bivariate statistics were used to analyze the data. The relevant technique of performing an unpaired t-test was used. After performing age, gender, and race-stratified analysis, no significant difference in cancer mortality and incidence was found within the following three groups: Black or African American, Asian or Pacific Islander, and American Indian or Alaska Native. This was a new finding, as previous studies did not stratify for race. Cancer mortality and incidence were found to be lower in both the male and female groups for the highest elevation states. Cancer mortality and incidence were also found to be lower in all age categories for the highest elevation states. A positive social change impact of this study is that this research provides the groundwork for future studies to probe what in the environment is lowering the bronchopulmonary cancer mortality and incidence for the White population.
17
Chambre, Muriel. „Altitude et coronaropathie : à propos de patients réadaptés en haute et moyenne altitude : étude ergonométrique et ventilatoire“. Bordeaux 2, 1993. http://www.theses.fr/1993BOR2M138.
18
Cordeiro, Anaïs de Almeida Campos. „Influência da altitude na florística e na diversidade de plantas em campo de altitude, Parque Nacional do Caparaó“. Universidade Federal de Viçosa, 2017. http://www.locus.ufv.br/handle/123456789/10618.
Annotation:
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Os campos de altitude são ecossistemas frágeis, que abrigam muitas espécies vulneráveis e susceptíveis à extinção. Para evitar a perda de espécies e manter o funcionamento destes ecossistemas, é preciso conhecer seus aspectos florísticos e ecológicos, e estimar e mapear a diversidade biológica. No entanto, tais características ainda são pouco investigadas. Assim, os objetivos desta dissertação foram (i) caracterizar a comunidade de plantas (florística e formas-de-vida) em diferentes intervalos altitudinais de uma área de campo de altitude, (ii) detectar espécies associadas a altitudes específicas, (iii) avaliar como a riqueza de espécies se relaciona com a escala espacial considerada, (iv) estimar a contribuição relativa da substituição espacial e do aninhamento de espécies para gerar a diversidade de plantas na região e (v) avaliar a influência da altitude sobre os padrões espaciais de diversidade. As coletas foram realizadas no Parque Nacional do Caparaó, no entorno da trilha que leva até o Pico da Bandeira. Foram definidos quatro intervalos altitudinais para as coletas: de 2100 a 2150 m, de 2300 m a 2350 m, de 2500 m a 2550 m, e de 2700 a 2750 m. Em cada intervalo, foram estabelecidas cinco parcelas (5 x 3 m), nas quais foi realizado o levantamento florístico de todas as espécies presentes com as respectivas abundâncias. A ocorrência de apenas quatro espécies foi inversamente relacionada à altitude, enquanto a ocorrência de 13 espécies apresentou relação direta com a elevação. A maior parte das espécies com maior probabilidade de ocorrência em maiores elevações é restrita a áreas de elevada altitude no Brasil. Rubiaceae e Polygalaceae foram as únicas famílias com maior probabilidade de ocorrência em maiores altitudes, e todos os representantes destas famílias apresentaram traços típicos de adaptação às condições locais, como gemas próximas ou no nível do solo e folhas pequenas e coriáceas. A diversidade de plantas é gerada principalmente pela substituição espacial de espécies, e processos interativos que operam em grandes escalas espaciais parecem ser os mais determinantes para a grande riqueza de espécies amostrada. A comparação dos espectros vegetacionais de cada intervalo altitudinal revelou alterações significativas na estrutura da vegetação em todos os intervalos, porém sem padrão aparente. A extrapolação da riqueza observada pelo índice Bootstrap com 999 permutações apontou maior riqueza de espécies a 2500 m, altitude esta que correspondeu à zona de transição entre duas subcomunidades distribuídas ao longo do gradiente com dissimilaridade superior a 80%. O intervalo altitudinal mais elevado apresentou grande número de espécies indicadoras e menor diversidade do que os outros intervalos altitudinais, o que sugere forte influência das condições ambientais mais restritivas de maiores elevações sobre a composição de espécies e sobre os padrões espaciais de diversidade.
High altitude grasslands are fragile ecosystems that host many vulnerable and extinction-prone species. In order to prevent species loss and maintain these ecosystem’s functioning, one must know, for instance, its floristic and ecological features, and to estimate and map diversity. However, these characteristics are still poorly studied. Accordingly, the main objectives of this study were (i) to characterize the plant community (floristic and life forms) in several altitudinal belts of a high altitude grassland area, (ii) to detect species associated to particular altitudes, (iii) to assess the relationship between species richness and the spatial scale taken into account, (iv) to estimate the relative contribution of turnover and nestedness to generate diversity therein and (v) to evaluate the influence of the altitude upon diversity spatial patterns. Sampling was held on the surroundings of the track that leads to the Flag Peak, in National Park of Caparaó. Plots were established in four altitudinal belts: from 2100 m to 2150 m, from 2300 to 2350 m, from 2500 to 2550 m and from 2700 to 2750 m. In each altitudinal belt, five plots (5 x 3 m) were set to proceed with a floristic survey and abundance records on all species. Only four species’ occurrence was negatively related to the altitude, whilst 13 species had higher occurrence probability in higher elevations. Most of the species with occurrence directly related to the altitude were restricted to high altitude areas in Brazil. Rubiaceae and Polygalaceae were the only families more likely to occur in higher altitudes, and all species belonging to both families had typical adaptation traits to local environmental conditions, such as buds close to the soil or at ground level and small leaves somewhat coriaceous. Species turnover is the main process generating diversity therein and regional processes seem to be the most important to determine the observed species richness, which was higher than expected by chance. Vegetation spectra changed significantly among all altitudinal belts, indicating big variations in vegetation structure all along the studied gradient. Extrapolation of species richness through Bootstrap index with 999 permutations indicated higher expected species richness at 2500 m. This altitudinal belt corresponded to the transition zone between two subcomunities distributed along the gradient with dissimilarity in species composition higher than 80%. The highest altitudinal belt showed a big number of indicator species and smaller diversity then all other belts. These results highlight the influence of limiting environmental conditions predominant in higher altitudes upon species composition and diversity spatial patterns.
19
Moe, Anders. „Passive Aircraft Altitude Estimation using Computer Vision“. Licentiate thesis, Linköping University, Linköping University, Computer Vision, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-53415.
Annotation:
This thesis presents a number of methods to estimate 3D structures with a single translating camera. The camera is assumed to be calibrated and to have a known translation and rotation.
Applications for aircraft altitude estimation and ground structure estimation ahead of the aircraft are discussed. The idea is to mount a camera on the aircraft and use the motion estimates obtained in the inertia navigation system. One reason for this arrangement is to make the aircraft more passive, in comparison to conventional radar based altitude estimation.
Two groups of methods are considered, optical flow based and region tracking based. Both groups have advantages and drawbacks.
Two methods to estimate the optical flow are presented. The accuracy of the estimated ground structure is increased by varying the temporal distance between the frames used in the optical flow estimation algorithms.
Four region tracking algorithms are presented. Two of them use canonical correlation and the other two are based on sum of squared difference and complex correlation respectively.
The depth estimates are then temporally filtered using weighted least squares or a Kalman filter.
A simple estimation of the computational complexity and memory requirements for the algorithms is presented to aid estimation of the hardware requirements.
Tests on real flight sequences are performed, showing that the aircraft altitude can be estimated with a good accuracy.
20
Chauvigné, Aurélien. „Impact radiatif des aérosols de haute altitude“. Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22757/document.
Annotation:
La présence des particules d’aérosols dans l’atmosphère influencent le bilan radiatif de notre planète et ainsi son équilibre climatique. Selon les différents mécanismes d’émission et processus de transports atmosphériques, les aérosols peuvent être entrainés dans la troposphère libre et ainsi y résider pendant plusieurs semaines. Les contributions optiques et radiatives des aérosols de troposphère libre par rapport à celles de la colonne atmosphérique sont encore mal évaluées du fait de la difficulté d’accès et du manque de mesures sur de longues périodes. Ces travaux de thèse se sont donc appuyés sur deux sites d’altitude présentant des topographies adéquates pour l’analyse des aérosols de troposphère libre : le site ACTRIS/GAW du puy de Dôme (PUY, 1 465 m, France) et le site ACTRIS/GAW de Chacaltaya (CHC, 5 240 m, Bolivie). Ces deux sites disposent d’un large jeu de données in-situ et de télédétection. Les résultats montrent ainsi l’importance de la prise en compte de la structure verticale de l’atmosphère et de l’effet de l’humidité sur les propriétés des aérosols dans l’analyse des mesures. Pour la première fois à notre connaissance, l’utilisation de ces techniques instrumentales depuis la station de mesures météorologiques la plus haute du monde (Chacaltaya) a permis d’établir les propriétés optiques des aérosols dans cette région largement influencée par la ville de La Paz et par les émissions de la forêt amazonienne. Les résultats montrent que l’influence des feux de forêt amazoniens à la fin de la saison sèche peut accroitre les propriétés optiques de l’aérosol à cette altitude d’un facteur de 3,5 en moyenne et celles de la troposphère libre de 28 à 80%. La station est d’ailleurs régulièrement influencée par les conditions de la troposphère libre (30% du temps en journée et 60% la nuit). Ce manuscrit présente également des méthodes originales pour la détermination des contributions optiques et radiatives des aérosols de troposphère libre avec l’utilisation conjointe des mesures in-situ, photométriques et LIDAR. Les résultats établissent ainsi des contributions optiques de la troposphère libre au-dessus du puy de Dôme variant de 20%en hiver à 80% en été en moyenne. L’utilisation du modèle de transfert radiatif SBDART permet d’évaluer les contributions radiatives correspondantes qui oscillent entre 13 et 40% pour les courtes longueurs d’onde, soit des forçages radiatifs de -1 W.m-2 à -10 W.m-2. Les différentes sources d’aérosols en surface influencent donc fortement la composition de la troposphère libre, qu’il est alors nécessaire de prendre en compte dans le bilan radiatif global de notre planèteAtmospheric aerosols impact the earth radiative budget and its climate. Depending on their emission mechanisms and atmospheric transport processes, aerosols can be injected into the free tropophere where their lifetime is increased to up to several weeks. Optical and radiative properties of free tropospheric aerosols are still poorly known because of the difficulties to access high altitudes over long periods of time. The present work is based on two high altitude sites measurements: the ACTRIS/GAW station of puy de Dôme (PUY, 1 465 m, France) and the ACTRIS/GAW station of Chacaltaya (CHC, 5 240 m, Bolivia). These two sites are equipped with a unique set of both in-situ and remote sensing measurements. Results first show the importance of taking into account the vertical atmospheric structure and the hygroscopic properties of aerosols when combining in situ and remote sensing measurements. Measurements from the highest atmospheric station in the world (Chacaltaya), provide for the first time to our knowledge, the aerosol optical properties from this region of the world, segregated into mixing layer aerosols and free tropospheric aerosols.The site is both influenced by anthropogenic emissions from the nearby city, La Paz and pristine emissions from the Amazonian forest. From these measurements, we observe that biomass burning emissions can increase column aerosol optical properties by an average factor of 3,5 and the free tropospheric aerosol optical properties between 28 and 80%. The station is regularly influenced by free tropospheric conditions (30% of the time during daytime and 60% during nighttime). This manuscript is also presenting original methods for retrieving the optical and radiative aerosol contributions from the free tropospheric layer to the total atmospheric column using a combination of in-situ, photometric and LIDAR measurements. Results show that free tropospheric contributions above puy de Dôme station vary from 20% during winter to 80% during summer. The use of the radiative transfer model SBDART allows to evaluate the corresponding shortwave radiative contributions of free tropospheric aerosols between 13 and 40% (between -1 and -10 W.m-2). Thus, the different surface aerosol emissions influence significantly the free tropospheric composition which is essential for radiative budget determination
21
McClelland, Grant Bryce. „Fuel preference during exercise after altitude acclimation“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0018/NQ48672.pdf.
22
Wood, Curtis Ron. „The biometeorology of high-altitude insect layers“. Thesis, University of Reading, 2007. http://centaur.reading.ac.uk/852/.
Annotation:
Flight at high altitude is part of a migration strategy that maximises insect population displacement. This thesis represents the first substantial analysis of insect migration and layering in Europe. Vertical-looking entomological radar has revealed specific characteristics of high-altitude flight: in particular layering (where a large proportion of the migrating insects are concentrated in a narrow altitude band). The meteorological mechanisms underpinning the formation of these layers are the focus of this thesis. Aerial netting samples and radar data revealed four distinct periods of high-altitude insect migration: dawn, daytime, dusk, and night-time. The most frequently observed nocturnal profiles during the summertime were layers. It is hypothesised that nocturnal layers initiate at a critical altitude (200–500 m above ground level) and time (20:00–22:00 hours UTC). Case study analysis, statistical analysis, and a Lagrangian trajectory model showed that nocturnal insect layers probably result from the insects’ response to meteorological conditions. Temperature was the variable most correlated with nocturnal insect layer presence and intensity because insects are poikilothermic, and temperatures experienced during high-altitude migration in temperate climates are expected to be marginal for many insects’ flight. Hierarchical effects were detected such that other variables—specifically wind speed—were only correlated with insect layer presence and intensity once temperatures were warm. The trajectory model developed comprised: (i) insect flight characteristics; (ii) turbulent winds (which cause vertical spread of the layer); and (iii) mean wind speed, which normally leads to horizontal displacements of hundreds of kilometres in a single migratory flight. This thesis has revealed that there is considerable migratory activity over the UK in the summer months, and a range of fascinating phenomena can be observed (including layers). The UK has moved from one of the least studied to perhaps the best studied environments of aerial insect migration and layering in the world.
23
Zapfe, Bettina Dorothee. „Millimetre wave propagation from high-altitude platforms“. Thesis, University of Bath, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275452.
24
Lim, Woo Lip. „Handover for high altitude platform station UMTS“. Thesis, University of Surrey, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250939.
25
Katzis, Konstantinos. „Resource allocation techniques for high altitude platforms“. Thesis, University of York, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424529.
26
Chen, Guanhua. „Capacity enhancement using multiple high altitude platforms“. Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434000.
27
Deng, Yu. „Coded polarization multiplexing for high-altitude platforms“. Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444290.
28
Windsor, Jeremy S. „Electrocardiographic changes in the high altitude environment“. Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/19877/.
Annotation:
Objective: This thesis sets out to identify the rate, rhythm and morphological changes that occur in the ECG’s of healthy lowland residents who are exposed to hypoxic conditions at sea level and high altitude. Methods: Three separate ECG studies were performed on healthy lowland residents. The first was conducted on 16 members of the Caudwell Xtreme Everest Expedition (CXE) during a stay at Mt Everest Base Camp (EBC) (5300m). The second was conducted on 37 members of the Team Everest Expedition (TE) during an ascent to EBC. Finally, a group of 10 participants were studied whilst breathing a range of hypoxic gas mixtures (12-18% oxygen) at sea level (AHS). Results: Rate - CXE - The median resting heart rate increased following ascent to Mt Everest Base Camp (EBC) (5300m) (P < 0.05). TE - The mean resting heart rate of male and female participants increased following ascent to Namche Bazaar (3500m) (P < 0.05). Rhythm – CXE, TE and AHS: No significant difference was observed in the incidence of atrial or ventricular ectopics following ascent to Mt Everest Base Camp (5300m). Morphology – CXE: The sum of P wave amplitudes in II, III and aVF increased at EBC (P < 0.05). The T wave amplitude in V1 decreased at EBC (P < 0.05). QTc (Bazett’s and Fridericia’s) increased on arrival at EBC (P < 0.05). TE: QTc (Bazett’s and Fridericia’s) increased on ascent to high altitude. QTc (Bazett’s) increased following ascent from Namche Bazaar (3500m) to Gorak Shep (5200m) (P < 0.05). AHS: QTc (Bazett’s and Fridericia’s) increased in hypoxia (P < 0.05). Conclusion: Significant changes in rate, rhythm and morphology occur in healthy lowland residents who are exposed to hypoxic conditions.
29
Eastham, Sebastian D. (Sebastian David). „Human health impacts of high altitude emissions“. Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98585.
Annotation:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 132-159).
Millions of deaths worldwide are attributed annually to exposure degraded surface air quality and UV-induced skin cancer. However, the focus has been on surface emissions, and the contribution of high altitude emissions to these issues is rarely examined. In this thesis, potential links are investigated between high altitude emissions and damages or benefits to human health via photochemical effects. Changes in population exposure to fine particulate matter, ozone and UV-B radiation resulting from current and future high altitude emissions are calculated, applying epidemiologically-derived impact functions to estimate resultant mortality and morbidity. A stratospheric extension is developed for the widely-used tropospheric model GEOS-Chem, which has been shown to accurately model tropospheric conditions and used in simulations of remote and urban pollution. This extended model, the GEOS-Chem UCX, can propagate a stratospheric perturbation through to a tropospheric impact, including shortwave UV fluxes, long-lived species, stratospheric water chemistry and high altitude aerosols. This model is employed to estimate the impacts of reversing 1 K of global warming using stratospheric sulfate aerosol injection. In total, it is projected that 85,000 additional premature mortalities would occur in 2040 due to particulate matter exposure, but that reduced ozone loading would prevent 64,000 mortalities worldwide. Aerosol injection also results in a 5.7% reduction in the global ozone column and a 3.0% increase in surface UV-B, which could cause 3,700 additional melanoma mortalities per year. By comparison, surface air quality and UV-B impacts due to aviation emissions are found to have resulted in 16,000 premature mortalities globally in 2006, of which 450 occurred in North America. Ozone exposure contributes 43% of this total. The increase in tropospheric ozone due to aviation emissions is found to have prevented 390 skin cancer mortalities in 2006. This thesis quantifies the photochemical mechanisms connecting future and proposed high altitude emissions schemes to human health impacts and provides an estimate of mortality and morbidity attributable to aviation and sulfate aerosol injection.
by Sebastian D. Eastham.
Ph. D.
30
Riley, Heather L. „Hypoxia adaptation and exercise performance at altitude“. Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/57196/.
Annotation:
Hypoxia is defined as a deficiency in the amount of oxygen reaching the tissues, and is a common problem in critically ill patients. It is not currently possible to predict how well an individual will adapt to hypoxic conditions, and patients presenting with hypoxia are often treated with supplemental oxygen. However, this blanket-treatment approach is not suitable in all cases and a more personalised approach is required. My thesis project builds on information acquired during the Caudwell Xtreme Everest (CXE 2007) expedition, where over 200 volunteers trekked to Everest Base Camp. CXE uses studies on healthy volunteers exposed to extreme environments to aid in the understanding of the complicated issues concerned with critical illness, and aims to use these findings to improve the treatment of critically ill patients, without putting them directly at risk. My thesis project has combined physiological information acquired during CXE with biochemical information measured in plasma samples taken during CXE. Performance at altitude has been used as a proxy for hypoxia adaptation, with individuals who show a small loss of performance at altitude compared to London assumed to be adapting better compared to individuals who show a larger loss. Analysis of the physiological and biochemical data for a core group of 24 individuals has culminated in the application of multiple linear regression to produce a number of models capable of predicting the key changes in physiological response as a function of a number of biochemical metabolites. These models have been used to identify a set of biochemical metabolites to measure in a further 190 individuals, to allow validation and training of the models on a larger sample size. These models can then be adapted for use in a critical illness environment, to allow the prediction of how well an individual will adapt to hypoxic conditions.
31
De, Frey Willem Hendrik. „Phytosociology of the Mpumalanga high altitude grasslands“. Diss., University of Pretoria, 1999. http://hdl.handle.net/2263/23808.
Annotation:
A phytosociological study covering approximately 12 000 km2 was completed within Southeastern Mpumalanga high altitude grasslands. The towns of Belfast, Barberton, Piet Retief and Wakkerstroom represented the four corners of the area. The study formed part of the Grassland Biome Project sponsored by the Department of Environmental Affairs and Tourism. The Braun-Blanquet approach was applied. Grassland research results from the western side of the country, determined that soil patterns and vegetation distribution are significantly correlated. Based on these results, it was hypothesised that the same correlation would exist in the east. The eight soil patterns used during the survey as homogenous units, were Ab, Ac, Ad, Ae, Ea, Fa, Fb and lb. A pro rata, randomly stratified sample size of 405 plots were used. An in-depth literature study of the environmental and other factors related to vegetation distribution, indicated on local scale that a significant correlation exists between landform and plant distribution. Two geographic information systems, Idrisi and Arc-Info/Niew, aided in the modelling and extraction of environmental attributes from existing databases. A TWINSPAN classification of the complete floristic data set falsified the null hypothesis based on the soil patterns but verified the null hypothesis based on landforms. The TWINSPAN dendrogram revealed clusters associated with three landforms (mountains, hills and lowlands, and plains) in two ecosystems, the terrestrial and the wetlands or aquatic. The three landforms represented three mapping units: Southeastern Mpumalanga Mountain Vegetation Type, Southeastern Mpumalanga Hills and Lowland Vegetation Type and Southeastern Mpumalanga Plain Vegetation Type. A second TWINSPAN classification was executed on each of the vegetation types. The resulting clusters were tested for uniqueness and informational value using a set of criteria. Those clusters which qualified were arranged in a Braun-Blanquet table to determine communities, sub-communities and variations using constancy and fidelity values. The plant communities within the vegetation types were described in terms of floristic composition and environmental attributes. The indirect gradient analysis ordination program DECORANA was used to determine environmental trends and was confirmed by using multiple regression. Soil water availability was the most significant environmental trend between the two ecosystems and within the communities of the ecosystems in each vegetation type. Soil water availability is influenced by numerous factors, whose significance differs from one vegetation type to another. lt was concluded from this study that, in high rainfall areas, soil patterns and vegetation distribution are not significantly correlated but that landforms and vegetation distribution are significantly correlated. Landscape slope configuration or landform influences soil water availability through soil characteristics (rockiness, texture and depth) and local climatic conditions (aspect, perpendicular insolation and precipitation). lt is suggested that the current Grassland - Savanna Biome boundary be changed towards the west using the boundary between the covered and exposed shields. This suggestion is supported by the presence of Hyparrhenia hirta/Hyperthelia dissoluta - Acacia sieberiana communities to the east of the study area in the different vegetation types which correlate significantly with the thorntree-tall grass savanna formation on a global scale. AFRIKAANS : 'n Fitososiologiese studie is gedoen van die Suid-oostelike Mpumalanga hoe liggende grasveld tussen die dorpe Belfast, Barberton, Piet Retief en Wakkerstroom. 'n Area van ongeveer 12 000 km2 is bestudeer. Die studie is deel van die Grasveld Bioom Projek gefinansier deur die Departement van Omgewingsake en Toerisme. Die Braun-Blanquet benadering is gebruik. Resultate van grasveldnavorsing in die westelike deel van die grasveld bioom, het aangedui dat 'n betekenisvolle verband tussen grondpatrone en plantegroei verspreiding bestaan. Na aanleiding van hierdie resultate, is die hipotese gemaak dat dieselfde verband in die ooste sal voorkom. Agt grondpatrone, Ab, Ac, Ad, Ae, Fa, Fb, en lb is as homogene eenhede beskou. 'n Eweredige ewekansige steekproefneming van 405 punte is gebruik. 'n Deeglike literatuurstudie van die omgewing en faktore wat verband hou met plantegroei verspreiding, het aangedui op lokale skale, dat 'n verband tussen landvorm en plantegroei verspreiding bestaan. Twee geografiese inligtingstelsels, ldrisi en Arc-lnfo/View, is gebruik in die modelering en verkryging van omgewings data vanuit bestaande databasisse. 'n TWINSPAN klassifikasie gebaseer op die volledige spesiesamestelling, het die nul hipotese oor die grondpatrone ongeldig verklaar maar die nul hipotese oor die landvorme bevestig. Die TWINSPAN dendrogram het groeperings bevat wat verband hou met drie landvorme (berge, heuwels en laaglande en vlaktes) in twee ekosisteme, terrestrieel en vleiland van akwatiese omgewings. Die drie landvorme is beskou as drie karteerbare eenhede: Suid-oostelike Mpumalanga Berg Plantegroeitipe, Suidoostelike Mpumalanga Heuwels en Laagland Plantegroeitipe en Suid-oostelike Mpumalanga Vlakte Plantegroeitipe. 'n Tweede TWINSPAN klassifikasie is op elk van die plantegroeitipes toegepas. Elke plantegroeitipe se groeperings is met behulp van bepaalde voorwaardes vir uniekheid en inligtingswaarde getoets. Die groeperings wat gekwalifiseer het, is met behulp van konstantheids en getrouheids waardes in 'n Braun-Blanquet tabel gerangskik in gemeenskappe, sub-gemeenskappe en variasies. Elke plantegroei tipe se gemeenskappe is beskryf in terme van floristies spesiesamestelling en omgewingsfaktore. 'n indirekte gradientanalise ordeningsprogram DECORANA is gebruik vir die bepaling van omgewings tendense en is bevestig met behulp van veelvuldige regressies. Grondwaterbeskikbaarheid was die mees betekenisvolle omgewingstendens tussen die ekosisteme en die gemeenskappe van die plantegroei tipes. Grondwaterbeskikbaarheid word deur 'n aantal faktore beïnvloed, waarvan die belangrikheid van plantegroei tipe tot plantegroeitipe wissel. 'n Gevolgtrekking van die studie is, dat in hoë reënvalomgewings daar nie 'n betekenisvolle verband is tussen grondpatrone en plantegroei verspreiding nie maar wel tussen landvorme en plantegroeiverspreiding. Landskap hellingsamestelling of landvorme beïnvloed grondwaterbeskikbaarheid deur middel van grondeienskappe (klipperigheid, tekstuur en diepte) en lokale klimaatstoestande (aspek, loodregte bestraling en presipitasie). Daar word voorgestel dat die huidige Grasveld- Savanna Bioom grens weswaarts geskuif word om ooreen te stem met die grens tussen die bedekte en blootgestelde plate. Die voorstel word ondersteun deur die teenwoordigheid van Hyparrhenia hirta/Hyperthelia dissoluta - Acacia sieberana plantgemeenskappe in die ooste van die plantegroeitipes wat betekenisvol ooreenstem met die langgras-doring boom savanna formasie op globale skaal.Dissertation (MSc)--University of Pretoria, 1999.
Plant Science
unrestricted
32
Ashton, Louise. „Moths and Mountains: Diversity, Altitude and Latitude“. Thesis, Griffith University, 2013. http://hdl.handle.net/10072/365540.
Annotation:
Moth assemblages have been widely used to examine patterns of beta-diversity in forest ecosystems. This thesis aims to expand and test the generality of results obtained as part of the IBISCA-Queensland Project (Investigating Biodiversity of Soil and Canopy Arthropods-Qld) which examined patterns of diversity in a large sub-set of night-flying moths along an altitudinal gradient in subtropical rainforest. The permanent IBISCA-Qld transect, located in Lamington National Park (NP), in south-east Queensland, Australia, spans altitudes from 300 to 1100 meters above sea level (m a.s.l.) within continuous rainforest. Along this transect, moth assemblages showed strong altitudinal stratification. A number of species were restricted to the Nothofagus moorei dominated cloud forest around 1100m a.s.l., and may be the most threatened by climatic change. The IBISCA-Qld Project produced a set of moth species that could be included within a predictor set of taxa that may be useful for future monitoring of the impact of global warming on forest biodiversity. The IBISCA-Qld study was predicated on the idea that a range of adjacent climates along a single altitudinal gradient can be taken as a surrogate for larger scale climatic changes which occur along latitudinal gradients. This thesis expands on the IBISCA-Qld Project by establishing a latitudinal network of analogous altitudinal transects, in Australia and south-west China (tropical, subtropical and sub-alpine temperate forests), allowing inter-continental comparisons on the generality of altitudinal patterns of diversity.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text
33
Losso, Flavia Baratieri. „A vitivinicultura de altitude em Santa Catarina“. reponame:Repositório Institucional da UFSC, 2016. https://repositorio.ufsc.br/xmlui/handle/123456789/173660.
Annotation:
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Geografia, Florianópolis, 2016.Made available in DSpace on 2017-02-21T04:37:09Z (GMT). No. of bitstreams: 1 343749.pdf: 10681653 bytes, checksum: c3984f3ccfc0f6cc31c2111a8489ac27 (MD5) Previous issue date: 2016
O presente estudo analisou as relações entre a formação sócio-espacial, a produção e o consumo de vinhos finos de altitude em Santa Catarina como indutores do desenvolvimento do Enoturismo no Estado mediante o entendimento de que este tipo de turismo poderá intervir na economia do vinho, agregando valor e influenciando o consumo dessa bebida. O Planalto Catarinense detém uma expectativa altamente positiva no que se refere à vitivinicultura no Estado, onde empresas vitivinícolas produtoras de vinhos finos de altitude se instalaram a partir do final da década de 1990, a exemplo da Villa Francioni, Quinta da Neve, Villaggio Grando e Panceri. A área objeto deste estudo corresponde às regiões catarinenses produtoras de vinhos finos de altitude (Região de São Joaquim, Campos Novos e Caçador), tomando-se como ponto de partida retratar sua recente instalação, assim como a forma como vem evoluindo e o panorama atual do setor, considerando-se sua perspectiva de expansão a ponto de se tornar um novo produto e atrativo para o enoturismo. Ao abordar o desenvolvimento da atividade de vitivinicultura no Brasil, considerou-se a expansão do povoamento do território do país através dos fluxos de imigrantes europeus, visto que a origem e o desenvolvimento desta atividade estão intimamente relacionados à sua cultura. No caso das regiões estudadas, o Meio-Oeste se destaca como uma das tradicionais regiões produtoras de vinhos catarinenses, estando a gênese de sua vitivinicultura relacionada à imigração italiana. Entretanto, atualmente, os investidores envolvidos com a produção de vinhos finos de altitude são, em sua maioria, empresários e profissionais liberais atuantes em outras atividades, com pouca ou nenhuma tradição na vitivinicultura. A matriz teórica utilizada para o entendimento desse processo tem como ponto de partida a análise da realidade sócio-espacial e tem por base a categoria de formação sócio-espacial proposta por Milton Santos (1977), aliada à ideia de complexo de combinações de André Cholley (1964). Aos referenciais da pesquisa, soma-se ainda a formulação teórica de Armen Mamigonian (1986) acerca da força e do dinamismo da pequena produção mercantil nas áreas de colonização europeia no Brasil Meridional. A investigação se sustenta também na teoria da dualidade de Ignácio Rangel que abarca esferas distintas da realidade social entendida como uma totalidade histórico-estrutural, permitindo a apreensão do desenvolvimento da economia e da sociedade estudadas. O estudo caracteriza-se por uma abordagem qualitativa de cunho histórico exploratório. A coleta de dados exigiu pesquisa bibliográfica e documental, aplicação de entrevistas semiestruturadas e questionários e a realização de saídas de campo. As vinícolas visitadas expressaram seu interesse na busca pela qualidade e em estratégias de diferenciação da produção para salvaguardar a competitividade, estimulando o desejo de consumo por sua singularidade, em razão das características especiais das áreas de altitude de Santa Catarina. A vitivinicultura de altitude existente nessa região permite vislumbrar o desenvolvimento de uma rota enoturística integrada que já começa a se difundir entre os visitantes com reflexos positivos para o setor.
Abstract : This study examined the relationship between socio-spatial formation, production and consumption of high altitude fine wines in Santa Catarina as inducers of wine tourism development in the State. This study is based on the assumption that this type of tourism may impact wine economy, adding value and influencing the consumption of high altitude fine wine. Santa Catarina Plateau is a region with high potential to develop viniculture in the state. Companies producing high altitude fine wines, such as the Villa Francioni, Quinta da Neve, Villaggio Grando and Panceri were established in the region at the end of the 1990s. The territory covered in this study is the region of Santa Catarina where high altitude fine wines are produced (around the cities of São Joaquim, Campos Novos and Caçador). This study describes the recent start of the production of high altitude fine wines, the evolution of this specific industry and its current context, considering the perspective of expansion to the point of becoming a new product that is attractive to wine tourism. In addressing the development of wine production activity in Brazil, the extensive flow of European immigrants throughout the country's territory has to be considered, given the culture of wine production among the immigrants. Of the regions hereby studied, the Midwest stands out as one of the traditional wine producing regions of Santa Catarina, with the genesis of its viniculture related to Italian immigration. However, investors currently involved in the production of high altitude fine wines are mostly businessmen and professionals with background in other activities, and with little or no tradition in viniculture. The theoretical framework used to understand this process takes as its starting point the analysis of socio-spatial reality and is based on the category of socio-spatial formation proposed by Milton Santos (1977), together with the idea of André Cholley?s complex combinations (1964). The theoretical formulation of Armen Mamigonian (1986) about the market strength and dynamism of small production in the areas of European colonization in southern Brazil was added to the theoretical framework. The research is also based on Ignacio Rangel duality theory that embraces different dimensions of social reality ? social reality is understood as complete historical-structural ? allowing the comprehension of the development of economy and society studied. The study is characterized by a qualitative approach of exploratory historical nature. Data collection required bibliographical and documentary research, application of semi-structured interviews and questionnaires and conducting field trips. The visited wineries expressed their interest in the search for quality and production differentiation strategies to safeguard competitiveness, stimulating consumer desire for uniqueness, due to the special features of high altitude areas of Santa Catarina. The existing high altitude viniculture in this region provides a glimpse of the development of an integrated enoturistic route that starts to spread among visitors with positive effects for the sector.
34
Govus, Andrew. „The regulation of human iron metabolism in hypoxia“. Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2015. https://ro.ecu.edu.au/theses/1719.
Annotation:
Athletes commonly use altitude exposure in an attempt to improve their aerobic performance at sea level. Altitude exposure enhances erythropoiesis and iron-dependent oxidative and glycolytic enzyme production, for this reason, athletes must maintain a healthy iron balance at altitude. A negative iron balance at altitude may limit such physiological adaptations, potentially reducing the performance benefits of altitude exposure.
This thesis examined the regulation of iron metabolism during acute (~31 min, Study One) and prolonged altitude exposure (14 days, Study Two). Finally, Study Three examined how daily oral iron supplementation influenced haemoglobin mass (Hbmass) and iron parameter responses to prolonged, moderate altitude exposure in a large cohort of elite athletes. Specifically, Study One found acute (~31 min) interval exercise [5 × 4 min at 90% of the maximal aerobic running velocity (vVO2max)] increased post-exercise interleukin-6 (IL-6) production and elevated hepcidin production 3 h thereafter in both normoxia (fraction of inspired oxygen (FIO2) = 0.2093) and normobaric hypoxia (i.e. 3,000 m simulated altitude; FIO2 = 0.1450). These results suggest exercise performed in acute hypoxia does not alter the post-exercise hepcidin response, relative to exercise in normoxia, possibly owing to the short duration of the hypoxic stimulus.
Prolonged altitude exposure suppresses resting hepcidin levels in sojourning mountaineers, but its influence on the post-exercise hepcidin response exercise has not yet been investigated. Therefore, Study Two investigated how 14 days of live high: train low (LHTL) (exposure to 3,000 m simulated altitude for 14 h.d-1) influenced resting levels of hepcidin, erythropoietin (EPO) and blood iron parameters. Study Two also examined the post-exercise hepcidin and iron parameter responses to interval exercise (5 × 1,000 m at 90% of the maximal aerobic running velocity) performed in normoxia (600 m natural altitude) and normobaric hypoxia (i.e. ~3,000 m simulated altitude), following 11 and 14 days of LHTL. The post-exercise hepcidin response was compared with interval exercise performed at a matched exercise intensity in normoxia or hypoxia before LHTL. Here, LHTL suppressed resting hepcidin levels after two days of exposure, but the post-exercise hepcidin response to interval exercise was similar in normoxia and hypoxia, both before and after LHTL. Additionally, Hbmass increased by 2.2% and plasma ferritin levels decreased following LHTL. In conclusion, prolonged, moderate altitude exposure suppresses resting hepcidin levels, which likely ensures more iron can be transported to the erythron to support accelerated erythropoiesis.
Prolonged altitude exposure places a large burden on body iron stores because additional iron is required to support accelerated erythropoiesis. Accordingly, athletes often ingest oral iron supplements during altitude exposure to ensure they maintain a healthy iron balance. By analysing ten years of haematological data collected from welltrained athletes who undertook two-to-four weeks of LHTL at simulated (3,000 m) or natural (1,350-2,700 m) altitudes, Study Three established how oral iron supplement dose moderates the Hbmass, serum ferritin and transferrin saturation response to prolonged moderate altitude exposure. In general, athletes supplemented with 105 mg.d- 1 or 210 mg.d-1 of oral iron supplement increased their Hbmass from pre-altitude levels by 3.3% and 4.0% respectively. Serum ferritin levels decreased by 33.2% in non-iron supplemented athletes and by 13.8% in athletes supplemented with 105 mg.d-1 of oral iron, however, those athletes who ingested 210 mg.d-1 markedly increased their iron storage compartment by 36.8% after moderate altitude exposure. Thus, daily oral iron supplementation at altitude assists athletes to maintain a healthy iron balance, providing them with sufficient iron to sustain accelerated erythropoiesis.
In conclusion, this thesis suggests exercise in acute hypoxia does not seem to alter the post-exercise hepcidin response relative to exercise in normoxia, but prolonged altitude exposure suppresses resting hepcidin levels and may attenuate the magnitude of postexercise hepcidin response after 14 days of LHTL. Finally, daily oral iron supplementation may support iron balance and Hbmass production in athletes undertaking prolonged moderate altitude exposure.
35
Gómez, Gil Javier. „Development of an altitude simulator and analysis of the performance and emissions of turbocharged Diesel engines at different altitudes“. Doctoral thesis, Universitat Politècnica de València, 2018. http://hdl.handle.net/10251/101284.
Annotation:
En el pasado, la investigación de los motores de combustión interna se ha centrado en la reducción del combustible y las emisiones, manteniendo constante el rendimiento. Además, en los últimos años la presión está aumentando aún más para los fabricantes de motores. La nueva homologación es un gran desafío, principalmente debido a la introducción de los ciclos de emisiones de conducción reales (RDE), lo que obligará a homologar los coches en condiciones reales de conducción, más dinámicas y con un amplio rango de condiciones ambientales, donde la altitud ambiente puede llevar a los 1300 metros sobre el nivel del mar.
Hoy en día, los fabricantes tienen diferentes formas de ensayar los motores y los automóviles en condiciones de altitud. Pruebas en altitud real, donde el automóvil, los ingenieros y los sistemas de medida y ensayo deben desplazarse a un lugar en altitud durante largos períodos de tiempo. La otra solución es ensayar el automóvil en una cámara hipobárica, donde se puede controlar la presión. Sin embargo, estas cámaras son costosas, difíciles de operar e intensivas en espacio y recursos.
En la presente tesis, se desarrolla un simulador de altitud, que presentará otra alternativa para el ensayo de motores en altitud. En este simulador de altitud, el motor está a presión ambiente y solo sus conductos de admisión y escape están a la altitud del ensayo. En la tesis, se describe el principio de operación del simulador de altitud, sus diferentes elementos y su efecto sobre el rendimiento del simulador de altitud, así como las estrategias de control aplicadas para controlar las diferentes variables y elementos.
Para estudiar el potencial del simulador de altitud, un motor diésel turboalimentado se ha ensayado a diferentes altitudes y su rendimiento y emisiones se han comparado con los obtenidos en una cámara hipobárica. Además, el motor se ha ensayado a diferentes altitudes en ciclos dinámicos y se ha analizado su rendimiento y emisiones, cuyos resultados muestran que la estrategia de control del motor cuando está operando en altitud se centra en la protección de los diferentes elementos sin tener en cuenta las emisiones. Por estas razones, es importante estudiar diferentes estrategias para reducir las emisiones de los motores en altitud.
Finalmente, se han realizado diferentes estudios paramétricos cambiando la geometría de las válvulas del motor y colector de escape para analizar su efecto sobre la temperatura de entrada de los sistemas de postratamiendo y el consumo especifico de combustible, como una forma de reducir el tiempo que tardan dichos sistemas en alcanzar la temperatura objetivo con mayor eficiencia de trabajo.In the last decades, the internal combustion engines research has been focused in the reduction of the fuel consumption and emissions while keeping constant the performance. Besides, in the last years the pressure is increasing even more to the engine manufacturers. The new homologation is a big challenge, mainly because of the introduction of the real driving emissions cycles, which will force to homologate the cars under real driving conditions, more dynamic and with an extended range of ambient conditions. The ambient altitude can reach up to 1300 meters above sea level. Nowadays, the manufacturers have different ways to test the engines and cars in altitude conditions. Real altitude tests, where the car, engineers and testing systems have to be displaced to an altitude place during long periods of time. The other solution is to test the car in a hypobaric chamber, where the pressure can be controlled. However, these chambers are expensive, difficult to operate and intensive in space and resources. In the present thesis, an altitude simulator is developed, which will introduce another alternative to test engines in altitude. In this altitude simulator, the engine or car is at room pressure and only its intake and exhaust pipes are at the tested altitude. In the thesis, it is described the altitude simulator operation principle, its different elements and their effect on the altitude simulator performance, as well as the control strategies applied to control the different variables and elements. In order to proof the potential of the altitude simulator, a turbocharged diesel engine is tested at different altitudes and its performance and emissions results are compared with those obtained in a hypobaric chamber. Also the engine is tested at the different altitudes in dynamic cycles and its performance and emissions are analyzed, showing that the engine control strategy when it is operating in altitude is focused in the protection of the different elements without taking into account the emissions. For these reason, it is important to study different strategies to reduce engine emissions in altitude. Finally, different parametric studies changing different geometries of the engine valves and exhaust manifold in order to analyze its effect on the aftertreatment inlet temperature and the specific fuel consumption, as a way to reduce the time that it takes to the aftertreatment to reach the target conversion efficiency temperature.
En el passat, la investigació dels motors de combustió interna s'ha centrat en la reducció del combustible i les emissions, mantenint constant el rendiment. A més, en els últims anys la pressió està augmentant encara més per als fabricants de motors. La nova homologació és un gran desafiament, principalment a causa de la introducció dels cicles d'emissions de conducció reals (RDE), el que obligarà a homologar els cotxes en condicions reals de conducció, més dinàmiques i amb un ampli rang de condicions ambientals, on l'altitud ambient pot portar els 1300 metres sobre el nivell del mar. Avui dia, els fabricants tenen diferents formes d'assajar els motors i els automòbils en condicions d'altitud. Proves en altitud real, on l'automòbil, els enginyers i els sistemes de mesura i assaig han de desplaçar-se a un lloc en altitud durant llargs períodes de temps. L'altra solució és assajar l'automòbil en una cambra hipobàrica, on es pot controlar la pressió. No obstant això, aquestes càmeres són costoses, difícils d'operar i intensives en espai i recursos. En la present tesi, es desenvolupa un simulador d'altitud, que presentarà una altra alternativa per a l'assaig de motors en altitud. En aquest simulador d'altitud, el motor està a pressió ambient i només els seus conductes d'admissió i escapament estan a l'altitud de l'assaig. A la tesi, es descriu el principi d'operació del simulador d'altitud, els seus diferents elements i el seu efecte sobre el rendiment del simulador d'altitud, així com les estratègies de control aplicades per controlar les diferents variables i elements. Per estudiar el potencial del simulador d'altitud, un motor dièsel turboalimentat s'ha assajat a diferents altituds i el seu rendiment i emissions s'han comparat amb els obtinguts en una cambra hipobàrica. A més, el motor s'ha assajat a diferents altituds en cicles dinàmics i s'ha analitzat el seu rendiment i emissions, els resultats mostren que l'estratègia de control del motor quan està operant en altitud se centra en la protecció dels diferents elements sense tenir en compte les emissions. Per aquestes raons, és important estudiar diferents estratègies per reduir les emissions dels motors en altitud. Finalment, s'han realitzat diferents estudis paramètrics canviant la geometria de les vàlvules del motor i col·lector d'escapament per analitzar el seu efecte sobre la temperatura d'entrada dels sistemes de postratamiendo i el consum especäifico de combustible, com una forma de reduir el temps que triguen aquests sistemes en arribar a la temperatura objectiu amb major eficiència de treball.
Gómez Gil, J. (2018). Development of an altitude simulator and analysis of the performance and emissions of turbocharged Diesel engines at different altitudes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/101284
TESIS
36
Bailey, Christopher Mark. „Cycling Performance Following Intermittent Hypoxic Training using an Hypoxicator“. Thesis, University of Canterbury. Biological Sciences, 2004. http://hdl.handle.net/10092/1320.
Annotation:
Live high - train low altitude camps can enhance endurance power at sea level by 1-2% (Levine & Stray-Gunderson, 1997). More convenient methods to simulate altitude exposure are now available, but their effects on performance are less well characterized. In this study, we investigated intermittent hypoxic training (IHT) using an Hypoxicator, a device that produces oxygen-depleted air that athletes breathe intermittently through masks in a small group at a central venue. Twelve highly-competitive, male cyclists and multi-sport athletes (IHT group) underwent IHT in two, four-week bouts separated by eight weeks. Bout one consisted of 20 one-hour exposures and bout two 18 exposures where normal and low-oxygenated air was breathed in alternating five-minute intervals. The percentage of oxygen inhaled by the subjects was adjusted to produce an oxygen saturation of the blood of 88-92% in the first week of the study, decreasing to 76-80% (equivalent to an altitude of approximately 6000m) in the final week. A control group of 13 similar athletes did not use the Hypoxicator. Performance trials and blood tests were at four-week intervals; there were 3 trials (familiarization and reliability) before use of the Hypoxicator, 3 trials after to determine the effect of simulated altitude, then a second four-week exposure and one more trial. The measures of performance were mean power in a 16-km time trial on a Kingcycle ergometer (IHT group only) and power in a lactate-threshold test at 3 mmol/L above baseline (both groups). The measures from the blood tests were haemoglobin and haematocrit. There was a gradual but erratic improvement in performance in the time trial and lactate threshold tests over the course of the study in both groups, indicating an improvement through training. Relative to the last baseline test (Trial 3), the IHT group showed a 0.6% decrease in mean power over and above the effect of training in the 16-km time trial in Trial 4, nine days after last use of IHT. There was a 0.3% increase in mean power independent of the training effect in Trial 7, after the second round of altitude exposure. Uncertainty in these changes in performance was ±3.5% (95% confidence interval). The changes in lactate threshold in trials 4 and 7 indicate a possible improvement as a result of IHT exposure. Uncertainty in these changes was ±4.0%. There were negligible changes in the haemoglobin and hematocrit of either group at any time. There was small evidence of high responders, who were probably subjects with the DD genotype for the angiotensin converting enzyme gene. The time exposed to IHT had no bearing on performance and there was no evidence "peak" in results at either four or eight weeks after exposure to IHT. In summary, four weeks of IHT exposure probably resulted in a trivial effect on 16-km time-trial performance and the effort-independent measures provided no further clear-cut evidence of a performance improvement.
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Silva, CLAUDIA Vergetti de Albuquerque. „ESTUDOS DAS DISCREPÂNCIAS RELATIVAS ENTRE AS ALTITUDES ORTOMÉTRICAS E GEOMÉTRICAS E SUAS IMPLICAÇÕES EM TRABALHOS DE ENGENHARIA“. Universidade Federal de Pernambuco, 2012. https://repositorio.ufpe.br/handle/123456789/10250.
Annotation:
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Dissertaçao Claudia Vergetti Silva .pdf: 4653527 bytes, checksum: 88891d165baab9ccd0a8cbc47d7167f2 (MD5)Made available in DSpace on 2015-03-03T20:05:09Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Claudia Vergetti Silva .pdf: 4653527 bytes, checksum: 88891d165baab9ccd0a8cbc47d7167f2 (MD5) Previous issue date: 2012-10-09
Todas as obras de engenharia civil usam medidas de distâncias horizontais e verticais. No caso das verticais as diferenças de altura na maioria das obras podem ser apenas relativas, tem exigências de precisão variáveis que são mais rigorosas quando envolvem escoamento de líquidos, e são determinadas normalmente pelo método de nivelamento geométrico que fornece as altitudes ortométricas. Atualmente também estão se utilizando altitudes obtidas do GNSS (Global Navigation Satellite System) por questões de economia e produtividade nas obras, mas elas são medidas geométricas em relação à superfície de um elipsóide, sendo que para obras de drenagem e hidráulicas a referência adequada é uma superfície equipotencial da gravidade ou o geóide. A altitude ortométrica de um ponto também pode ser obtida através da altitude geométrica desde que se conheça a ondulação geoidal do mesmo. Como essa transformação contém os erros inerentes da determinação da ondulação geoidal essa metodologia tem sido questionada como não sendo confiável para uso em obras de engenharia civil. Este trabalho tem por finalidade analisar e propor o uso da altitude geométrica para obras de engenharia de modo direto, sem necessidade de ser feita a sua transformação para a altitude ortométrica. Para essas análises foram usados dois conjuntos de dados. Um foi de uma área levantada dentro e no entorno do perímetro da UFPE (Universidade Federal de Pernambuco). O outro foi de dados obtidos no levantamento do trecho Norte do canal de Transposição do Rio São Francisco. Todos os dados foram analisados quanto ao processamento, precisões obtidas e procedimentos de campo para identificar os erros inerentes na obtenção da altitude geométrica. Finalmente são sugeridos alguns cuidados básicos, restrições e procedimentos no uso das altitudes geométricas em determinadas obras de engenharia civil.
38
Laborde, Pierre. „Pathologie medicale a 2870 metres“. Toulouse 3, 1988. http://www.theses.fr/1988TOU31033.
39
Hansen, Christel Dorothee. „On high-altitude and high- latitude frost environments“. Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/62383.
Annotation:
Frost environments occur throughout the world, with associated processes occurring across climatic zones. Climatic geomorphology proposes that climatic zones, largely derived from annual average air temperature and precipitation values, have specific landforms and processes active within that zone. This study offers unique insights into the frost environments of three locations in the Southern Hemisphere, namely the Eastern Cape Drakensberg of South Africa, sub-Antarctic Marion Island, and Dronning Maud Land of Antarctica. The Drakensberg ranges from temperate to alpine, Marion Island is hyper-maritime, and Dronning Maud Land a polar desert. Drivers and forcings on the ground frost regime are identified, as are future climatic scenarios. Altitude and latitude were identified as the most important locational drivers, while air temperature showed highest correlation with freezing events. The initiation of a freeze event correlated strongly with maximum ground temperatures. Vegetation cover was found to ameliorate frost cycles, thereby increasing ground temperatures. Dronning Maud Land of Antarctica is characterised by annual frost (permafrost), with limited seasonal thaw in summer. Thawing cycles reflected the depth of the active layer, which ranged from just under 60 cm for Robertskollen (at lowest altitude) to less than 15 cm on Slettfjell (at greatest altitude). Marion Island had the most active frost environment, exhibiting both seasonal frost, and ubiquitous shallow diurnal frost cycles. The Drakensberg were largely frost-free, with limited seasonal frost and few diurnal freeze- thaw events. Diurnal frost processes were found to be azonal, and present at all three study locations. Evidence of landforms derived from diurnal frost processes were evident in each zone. Equifinality/convergence of form was present to a degree. The presence of patterned ground, which was not wholly derived from frost processes, suggests a measure of equifinality. Furthermore, openwork block deposits, of which not all are either blockstreams nor blockfields, are not necessarily the result of frost processes. The periglacial environment is poorly defined and methods to delineate this environment, as well as other climatic zones, should include additional parameters. Delineating zones on annual (and limited) monthly averages based on predominantly temperature, is not sufficient. While concepts of climatic geomorphology may be applied in a general sense, this framework is not suited to working at smaller scales. Specifically, periglacial environments should be delineated using ground moisture, as well as air temperature. Furthermore, vegetation and snow cover are important, as are soil textural properties.
40
Tang, Yunmo. „The current situation of high-altitude wind power“. Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14734.
Annotation:
The importance of the use of renewable energy sources is obviously. But what the problem confused us, is that renewable energy unlike the fossil fuel have such high energy density which means the renewable generally was dispersed form. In other words, in order to obtain amount of the energy we need, require to exploitation a wider cover area. Therefore, scientists and companies are struggling to find high densely renewable energy as possible, which is high altitude wind energy, have very promising but not developed so much by humans. High altitude wind power is indicating the altitude between 3000 meters and 10000 meters. So far, high altitude wind power is a new renewable energy that basically not development or utilization yet, but which is an abundant reserves. High altitude wind power is a widely distributed renewable clean energy. The characterized of high-altitude wind energy is fast speed, wide distribution, high stability and perennial. Utilize high-altitude wind power can get high stability with low cost of wind power generation, which is one of the notable features for high-altitude wind power, but also is one of the most significant advantages for high-altitude wind energy compared to conventional wind energy. High altitude wind power generation equipment is more compact and flexible, far superior then the traditional fan, which equip with thick blades and the tower must be fixed in the depths of the ocean or in the ground.To development renewable power in a large scale, to face the global climate change, achieve the sustainable development become the inevitable for human development. How to solve the energy shortage problem has become an important question, harness high altitude wind power was becomes the focus of multinational technology.
41
Frisk, Ulrika. „Effects of high-altitude trekking on body composition“. Thesis, Mittuniversitetet, Avdelningen för hälsovetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-22219.
Annotation:
Sojourns at high altitude are often accompanied by weight loss and changes in body composition. The aim was to study body composition before and after 40 days high-altitude exposure. The subjects were four women and six men, non-smoking, healthy and active students and a scientist from Mid Sweden University in Östersund with a mean (SD) age of 26 (10) years. All subjects volunteered for a six-week trek to the Mount Everest Base Camp via Rolwaling in Nepal. Before the sojourn subject’s height was 177 (10) cm and weight was 71.9 (10) kg. Body composition was measured with Lunar iDXA at the Swedish Winter Sports Research Centre in Östersund before and after the trek. Total body mass (SD) decreased from 71.8 (10.0) kg before to 69.7 (9.4) kg after the trek (P=0.00). Total fat mass decreased from 14.7 (5.9) kg to 13.8 (4.6) kg (P=0.01). Fat percent decreased from 21.6 (7.9) % to 21.0 (7.2) % (P=0.03). Total lean mass decreased from 54.0 (10.0) kg to 52.9 (9.7) kg (P=0.01). Bone mineral content was unchanged, 3.04 (0.5) kg before and 3.03 (0.5) after (P=0.13). Thus both total body mass and total lean mass had decreased after a six week trekking in Nepal.
42
Cook, Eric C. „Broad area wireless networking via high altitude platforms“. Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/34648.
Annotation:
Approved for public release; distribution is unlimitedThis thesis explores a novel network design concept to address the data and communications needs of the Department of Defense (DoD). Current and future military operations are increasingly reliant upon data connectivity to facilitate situational awareness and distribute vital information. Current infrastructures are insufficient to meet the growing demand, especially in the myriad austere environments where military forces operate. The DoD has become reliant upon increasingly vulnerable and expensive satellite communications to fill those gaps. The wireless data technologies utilized in the commercial sector to meet the data distribution requirements of business and commercial telecommunications providers can be leveraged and adapted to meet the connectivity requirements of the DoD. By pairing these technologies with developing HAPs and their capabilities the potential for a long-range wireless broadband solution emerges. This thesis evaluates broadband wireless data technologies in combination with High Altitude Platform (HAP) technologies. It proposes a network design concept to serve as a model for future research and the ultimate integration of HAPs into battlefield information architecturesbringing the concepts of network centric warfare ever closer to reality.
43
Furey, Allister David John. „Evolutionary robotics in high altitude wind energy applications“. Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/7667/.
Annotation:
Recent years have seen the development of wind energy conversion systems that can exploit the superior wind resource that exists at altitudes above current wind turbine technology. One class of these systems incorporates a flying wing tethered to the ground which drives a winch at ground level. The wings often resemble sports kites, being composed of a combination of fabric and stiffening elements. Such wings are subject to load dependent deformation which makes them particularly difficult to model and control. Here we apply the techniques of evolutionary robotics i.e. evolution of neural network controllers using genetic algorithms, to the task of controlling a steerable kite. We introduce a multibody kite simulation that is used in an evolutionary process in which the kite is subject to deformation. We demonstrate how discrete time recurrent neural networks that are evolved to maximise line tension fly the kite in repeated looping trajectories similar to those seen using other methods. We show that these controllers are robust to limited environmental variation but show poor generalisation and occasional failure even after extended evolution. We show that continuous time recurrent neural networks (CTRNNs) can be evolved that are capable of flying appropriate repeated trajectories even when the length of the flying lines are changing. We also show that CTRNNs can be evolved that stabilise kites with a wide range of physical attributes at a given position in the sky, and systematically add noise to the simulated task in order to maximise the transferability of the behaviour to a real world system. We demonstrate how the difficulty of the task must be increased during the evolutionary process to deal with this extreme variability in small increments. We describe the development of a real world testing platform on which the evolved neurocontrollers can be tested.
44
Gao, Hang S. M. Massachusetts Institute of Technology. „Aircraft cruise phase altitude optimization considering contrail avoidance“. Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85768.
Annotation:
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 76-77).
Contrails have been suggested as one of the main contributors to aviation-induced climate impact in recent years. To reduce the climate impact of contrails, mitigation policies such as taxation will be necessary in the future to incentivize jet aircraft operators to reduce contrail production. Contrails form in regions of the atmosphere with the right ambient conditions and they can be avoided by flying around these regions; this research investigates one such contrail avoidance strategy that uses flight level optimization to minimize contrail formation. A cruise phase flight profile system model was developed in this research that optimizes for environmental objectives such as contrails, CO₂, and NOx, alongside traditional objectives such as fuelburn and flight time. Using this system model and 11 different aircraft types on 12 weather days, a preliminary study was done to determine the price range of contrail taxation that would incentivize airlines to operationally avoid contrails. Result suggests a price range of 0.12$/NM to 1.13$/NM on contrail tax would effectively incentivize contrail avoidance. Furthermore, since operating costs differ depending on the type of aircraft, a single price on contrail tax may incentivize contrail avoidance on a small aircraft, but not larger ones. To account for this difference, a method of assigning contrail tax to different aircraft types is introduced using the aircraft maximum takeoff weight. Assuming airlines are incentivized to fly contrail avoidance strategies, the climate impact of the flight profiles was evaluated for 287 flights along 12 O-D pairs for the 24 hour day of April 12, 2010. Under various assumptions of contrail radiative forcing and time horizon of climate impact evaluation, the flight level optimization reduced the average climate impact per flight by as much as 39.1% from a baseline of wind-optimal flight at optimal cruise altitude. In comparison, a complementary lateral optimization method reduced 13.3% from the same baseline. Furthermore, flight level optimization shows to be more fuel efficient by reducing the climate impact of contrails by as much as 94% from the baseline, compared to 60% using the lateral approach. In terms of the CO₂ emission from the additional fuelburn, the climate impact of lateral method was 4 times higher than the flight level approach. Lastly, result shows that designing for long-term environmental objectives is more energy efficient (reduction in climate impact per additional kilogram of fuel used) than short-term, which suggest reducing CO₂ emission is favored over contrail avoidance in designing for climate impact optimal flight profiles.
by Hang Gao.
S.M.
45
Martin, D. S. „Human adaptation to hypobaric hypoxia at high altitude“. Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1383226/.
Annotation:
As humans ascend to high altitude, the resulting hypobaric hypoxia necessitates adaptation in order continue functioning. Whilst much is known about changes that facilitate a restoration of systemic oxygen delivery during ascent, less is know about alterations in the peripheral microcirculation and how these affect acclimatisation and performance at altitude. The limit of human adaptation to hypoxia is also undefined. Using data derived from a number of studies conducted on healthy volunteers at high altitude, this thesis explores changes in skeletal muscle oxygenation and sublingual microcirculatory blood flow, and how these may relate to the process of acclimatisation. In addition, exercise was used to perturbate the relationship between oxygen delivery and utilisation at altitude, and experiments at extreme altitude sought to define the limits of human tolerance to hypoxia. Data relating to four subjects resting just below the summit of Mount Everest (at 8400m), demonstrated a degree of systemic hypoxia never before reported in humans. Given sufficient time, arterial oxygen content remained steady during ascent to 7100m. Sublingual microcirculatory blood flow declined at altitude, whilst the density of blood vessels increased. At altitude, absolute skeletal muscle oxygenation declined; the response to a brief ischaemic episode was a reduction in rate of subsequent muscle reoxygenation; and the rate of muscle desaturation during exercise increased. Systemic oxygen extraction during exercise at altitude remained unchanged from that observed at sea level. These results support the hypothesis that a significant barrier to oxygen flux exists within tissues that is heightened at altitude. Restoration of convective oxygen delivery does little to improve tissue oxygenation, and adaptations within the microcirculation may differentiate phenotypic responses observed on prolonged exposure to hypoxia. Graded ascent to altitude by healthy volunteers provides valid data that may herald further research in the clinical arena, bringing about improved outcome in critically ill patients.
46
Mastretta-Yanes, Alicia. „Landscape genomics of tropical high altitude plant species“. Thesis, University of East Anglia, 2014. https://ueaeprints.uea.ac.uk/52157/.
Annotation:
Changes to species distributions involve demographic processes that occur over generations and affect allele frequencies within populations, leading to patterns of genetic restructuring. The specific genetic structuring patterns that will be observed as a consequence depend on explicit geographical features, such as topography and latitude. Over the first decades of phylogeography, the effect of climate history and geography on species genomes was examined at low resolution with DNA sequences and other traditional molecular markers. However, During the last five years it has become feasible to obtain genomic data for non-model organisms and large sample sizes. The present thesis spans the transition years between phylogeographic studies being restricted to low resolution molecular markers, and new methods facilitating the generation of genomic data for non-model species. As such, this thesis focuses on two main points. First, on the methodological aspects of utilising double digest RAD-seq (ddRAD) for individual-based population genetics and phylogeography of plant species. Second, on applying the obtained data to examine one of the classic. but as yet not fully explained, biodiversity patterns: the biodiversity excess within tropical mountains. The main contributions of this thesis at the methodological level are; (1) demonstrating the utility of DNA replicates for the estimation of genotyping error and optimisation of de novo assembly; (2) proposing a method for identifying paralogous loci resulting from recent gene duplications; and (3) showing that such logi provide a measure of population differentiation. Regarding the drivers of biodiversity excess within tropical mountains, I used landscape genomic analyses and ddRAD data to examine two plant species from the alpine grasslands of the Transmexican Volcanic Belt. As a main result, this thesis supports from a population-level perspective that tropical mountains; (1) allow for long-term in situ population persistence; and (2) promote population differentiation as a function of topographic isolation.
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Santos, André Henrique Lameira dos, und 92992384056. „Identificação e Controle de Altitude de um Quadrirrotor“. Universidade Federal do Amazonas, 2018. https://tede.ufam.edu.br/handle/tede/6639.
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In this work approaches the development altitude control for a low-cost quadrotor vehicle. The identification of the model of the altitude dynamics of the quadrotor using the relay method is presented. This method is also a tool in the tuning of a PID controller implemented for dynamics model. Comparisons of controller performances, designed for the identified and mathematically modeled plant, were analyzed, in addition to the performance of the controller tuned by the Relay direct method, without the need for the altitude model. In the experiments, transient response performance parameters were evaluated for a step-type reference input. In addition, the behavior of the compensated altitude for a trapezoidal reference trajectory was evaluated. The results showed that the technique employed is, besides simple, efficient for this type of system.
Neste trabalho é abordado o desenvolvimento de um controlador de altitude para um veículo quadrirrotor de baixo custo. A identificação do modelo da dinâmica de altitude do quadrirrotor é realizada utilizando o método do relé. Esse método também é uma ferramenta de auxílio na sintonia de um controlador PID implementado para modelo da dinâmica. Comparações dos desempenhos do controlador, realizados para a planta identificada e modelada matematicamente, foram analisadas, além do desempenho do controlador sintonizado pelo método direto do Relé, esse sem a necessidade do modelo de altitude. Nos experimentos foram avaliados parâmetros de desempenho da resposta em regime transitório para uma entrada de referência do tipo degrau. Além disso, foi avaliado o comportamento da altitude compensada para uma trajetória de referência trapezoidal. Os resultados mostraram que a técnica empregada é, além de simples, eficiente para este tipo de sistema.
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Veedhi, Carisma Catherin, und Vasantha Sai Darahas Yeedi. „Estimation of Altitude : using ultrasoinc and pressure sensors“. Thesis, Blekinge Tekniska Högskola, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19950.
Annotation:
This paper deals with the estimation of altitude of the drone for which the sensors like ultrasonic, barometric pressure sensors and their characteristics plays a major role. To estimate the altitude of the drone, we used the matlab software with Simulink. apart from the software and hardware description, we discuss several issues regarding the equipment,abilities and performance of the drone.
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Mei, Qiang. „A Solar Power System for High Altitude Airships“. University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1306077427.
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Paxton, Brendan. „Systems Design and Experimental Evaluation of a High-Altitude Relight Test Facility“. University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1448037233.