Tesi sul tema "High altitude"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "High altitude".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
Brown, K. D., e Trevor Sorensen. "HIGH ALTITUDE TRANSMITTER FLIGHT TESTING". International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605062.
Testo completoThis 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).
Hansen, Christel Dorothee. "On high-altitude and high- latitude frost environments". Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/62383.
Testo completoWilliams, David Reid. "The pulmonary circulation at high altitude". Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316610.
Testo completoJohnson, Pamela Lesley. "Sleep and Breathing at High Altitude". University of Sydney, 2008. http://hdl.handle.net/2123/3531.
Testo completoThis 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.
White, Ryan D. "A high-altitude nuclear environment simulation". Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2315.
Testo completoCroft, Quentin. "Human responses to simulated high altitude". Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711614.
Testo completoYork, Julia McRae. "Respiratory mechanics of high altitude waterfowl". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58744.
Testo completoScience, Faculty of
Zoology, Department of
Graduate
De, Frey Willem Hendrik. "Phytosociology of the Mpumalanga high altitude grasslands". Diss., University of Pretoria, 1999. http://hdl.handle.net/2263/23808.
Testo completoDissertation (MSc)--University of Pretoria, 1999.
Plant Science
unrestricted
Wood, Curtis Ron. "The biometeorology of high-altitude insect layers". Thesis, University of Reading, 2007. http://centaur.reading.ac.uk/852/.
Testo completoZapfe, 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.
Testo completoLim, 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.
Testo completoKatzis, Konstantinos. "Resource allocation techniques for high altitude platforms". Thesis, University of York, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424529.
Testo completoChen, Guanhua. "Capacity enhancement using multiple high altitude platforms". Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434000.
Testo completoDeng, Yu. "Coded polarization multiplexing for high-altitude platforms". Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444290.
Testo completoWindsor, Jeremy S. "Electrocardiographic changes in the high altitude environment". Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/19877/.
Testo completoEastham, Sebastian D. (Sebastian David). "Human health impacts of high altitude emissions". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98585.
Testo completoThis 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.
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.
Testo completoMartin, D. S. "Human adaptation to hypobaric hypoxia at high altitude". Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1383226/.
Testo completoFrisk, 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.
Testo completoCook, Eric C. "Broad area wireless networking via high altitude platforms". Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/34648.
Testo completoThis 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.
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/.
Testo completoMei, Qiang. "A Solar Power System for High Altitude Airships". University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1306077427.
Testo completoMastretta-Yanes, Alicia. "Landscape genomics of tropical high altitude plant species". Thesis, University of East Anglia, 2014. https://ueaeprints.uea.ac.uk/52157/.
Testo completoWaara, Martin. "High altitude ion heating observed by the Cluster spacecraft". Doctoral thesis, Umeå universitet, Institutionen för fysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-43611.
Testo completoFitzsimmons, Joeleff T. "Development of a tethered, high-altitude, rigid-wing platform". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29366.pdf.
Testo completoWahlers, Kristen Erin. "A Design for a High Altitude Flight Test System". MSSTATE, 2006. http://sun.library.msstate.edu/ETD-db/theses/available/etd-04162006-163320/.
Testo completoFoo, Yu Chiann. "Call admission control for high altitude platform station UMTS". Thesis, University of Surrey, 2002. http://epubs.surrey.ac.uk/689/.
Testo completoAcosta, Marcus P. "High altitude warfare : the Kargil Conflict and the future /". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FAcosta.pdf.
Testo completoThesis advisor(s): Peter Lavoy, Douglas Porch. Includes bibliographical references (p. 79-83). Also available online.
Aziz, Imran. "Design of a High Altitude Wind Power Generation System". Thesis, Linköpings universitet, Maskinkonstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-104569.
Testo completoLevett, D. Z. H. "Adaptions of exercise energetics and performance to high altitude". Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1450243/.
Testo completoPaxton, 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.
Testo completoSimmons, Grant H. 1981. "Cutaneous vasodilation at simulated high altitude: Impacts on human thermoregulation and vasoconstrictor function". Thesis, University of Oregon, 2008. http://hdl.handle.net/1794/9495.
Testo completoDuring acute altitude exposure, humans maintain higher skin temperature and lower core body temperature. However, the role of cutaneous vascular regulation in these thermoregulatory differences is unclear. Therefore, the purpose of these studies was to investigate the impact of altitude exposure on reflex control of skin blood flow and core temperature during cold exposure. In Chapter IV, the effects of hypoxia and hypocapnia on cutaneous vasoconstriction during mild cold exposure were investigated. We found that hypoxia stimulates cutaneous vasodilation in men whereas skin blood flow is unaltered in women. However, during whole body cooling skin blood flow is upward shifted in both sexes. The development of hypocapnia does not affect the vascular response to hypoxia in either sex, but reduces the magnitude of cutaneous vasoconstriction during cold exposure by 50% in women. In Chapter V, we studied the timecourse of α-adrenergic blockade by yohimbine in the cutaneous circulation and how the duration of cold exposure modulates cotransmitter-mediated vasoconstriction during cold stress. We found that yohimbine produces functional α-adrenergic blockade within 30 minutes of initial delivery and completely abolishes reflex cutaneous vasoconstriction during mild cold stress. This latter finding was surprising, and an additional protocol demonstrated that cotransmitter-mediated vasoconstriction only participates in the vascular response to cold stress when the exposure is more prolonged. In Chapter VI, the effects of hypoxia on cutaneous vasoconstrictor mechanisms and core cooling rate were tested during more prolonged and severe cold stress. In contrast to our findings during brief cold exposure, we showed that cutaneous vasoconstriction during prolonged cold stress is potentiated by hypoxia and abolishes hypoxic vasodilation. Moreover, increased cotransmitter-mediated vasoconstriction appears to account for this response. Hypoxia had no effect on core cooling rate during severe cold exposure. The selective potentiation of cotransmitter-mediated vasoconstriction observed during hypoxia in Chapter VI provided the basis for Chapter VII. This study was designed to test the effect of hypoxia on cutaneous vascular responsiveness to peripherally stimulated sympathetic vasoconstriction. The results demonstrated that α-adrenergic vasoconstrictor transduction is not affected by hypoxia, and that stimulation of adrenergic nerves with tyramine does not elicit cotransmitter-mediated vasoconstriction in skin.
Adviser: John R. Halliwill
Thompson, C. J. "ACE insertion/deletion polymorphism and human performance at high altitude". Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1417080/.
Testo completoBrizon, Mathilde. "Solar Energy Generation Model for High Altitude Long Endurance Platforms". Thesis, KTH, Flygdynamik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180278.
Testo completoLiu, Yiming. "Radio resource management for a multiple high altitude platform system". Thesis, University of York, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440732.
Testo completoParo, Autumn D. "Modeling High Altitude Electron Density Plumes Using Direct Numerical Simulation". Digital WPI, 2014. https://digitalcommons.wpi.edu/etd-theses/210.
Testo completoGomes, Themis de Brito Abagge e. Varella. "High-altitude operations for a typical 70 - seat-regional jet". Instituto Tecnológico de Aeronáutica, 2005. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=687.
Testo completoRead, Robert William. "Experimental investigations into high-altitude relight of a gas turbine". Thesis, University of Cambridge, 2008. https://www.repository.cam.ac.uk/handle/1810/224982.
Testo completoKacala, Jeffrey C., e Corey M. Collier. "A cost-effectiveness analysis of tactical satellites, high-altitude long-endurance airships, and high and medium altitude unmanned aerial systems for ISR and communication missions". Thesis, Monterey, California. Naval Postgraduate School, 2008. http://hdl.handle.net/10945/3934.
Testo completoCollier, Corey M. Kacala Jeffrey C. "A cost-effectiveness analysis of tactical satellites, high-altitude long-endurance airships, and high and medium altitude unmanned aerial systems for ISR and communication missions". Monterey, Calif. : Naval Postgraduate School, 2008. http://edocs.nps.edu/npspubs/scholarly/theses/2008/Sept/08Sep%5FCollier.pdf.
Testo completoThesis Advisor(s): Welch, William J. "September 2008." Description based on title screen as viewed on November 5, 2008. Includes bibliographical references (p. ). Also available in print.
Blass, Alexander J. H. "Sediments of two high-altitude Swiss lakes as high-resolution late Holocene paleoclimatic archives /". [S.l.] : [s.n.], 2006. http://www.zb.unibe.ch/download/eldiss/06blass_a.pdf.
Testo completoLeitner, Andreas Rodolfo. "Improvement of Mexican high altitude waste stabilisation pond effluents for reuse". Thesis, University of Surrey, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417536.
Testo completoChang, J. M. "A flexible, subsonic high altitude long endurance UVA conceptual design methodology". Thesis, Cranfield University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245445.
Testo completoWinterhalder, Ralph Martinelli Michele. "Muscle degenerative and regenerative changes with high altitude exposure in humans /". Bern, 1989. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Testo completoBakari, Salim Rashid. "Solar panel development for high altitude and low earth orbit application". Thesis, Cape Peninsula University of Technology, 2010. http://hdl.handle.net/20.500.11838/2208.
Testo completoStable and reliable source of electrical energy is a requirement for efficient operation of satellites. Several sources of electrical power for satellites exist such as fuel cells, nuclear or battery stored Direct Current energy but of late concentration has been on solar cells as the advantages compared to the other sources are many. Solar cells are p-n semiconductor devices which convert light energy into electrical energy by photovoltaic effect. The biggest drawback of solar cell energy system is the low light to electricity conversion efficiency. Apart from powering satellites, solar cells and panels have found other numerous applications such as in water pumping systems, rural electrification, street lightning. Photovoltaic principle of solar cells started way back in 1839 when Alexandre Edmund Becquerel observed that electrical currents arose from certain light induced chemical reactions. A comprehensive understanding of this phenomenon became clear when the science of quantum theory was unveiled in the early parts of the 20th century. Most solar cells and panels available today in the market are silicon based made of single junction technology. The disadvantage with single junction technology is that the p-n junction is made of a single type of solar cell material which absorbs a fraction of light wavelengths from the spectrum of light. The disability of the single p-n junction to convert all the light energy to electricity accounts for the low efficiency for the solar cells. One way to go around the problem of efficiency is to use multi-junction solar cells. Multijunction solar cells are designed to absorb a large fraction of the light spectrum and convert them to electrical energy. They are made of multiple p-n junctions made of different solar cell materials which absorb different parts of light spectrum and convert them to electrical energy. In this thesis, a design of a multi-junction solar cell for developing space solar panel is presented. The multi-junction cell has been designed from simulation results of different solar cell materials simulated with space conditions. Ideas and recommendations for future work are also presented.
Nordqvist, Emil. "Preliminary design of a modular high altitude balloon power distribution system". Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79762.
Testo completoRacine, Evan Michael. "Experimental Study - High Altitude Forced Convective Cooling of Electromechanical Actuation Systems". University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1450286609.
Testo completoSanchez, Maria Elisa. "Carbon flux dynamics in high altitude peatlands in the Ecuadorian Andes". Thesis, Michigan Technological University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10241527.
Testo completoAlthough knowledge of peatland CH4 and CO2 exchange in temperate mountain ecosystems is available, information about carbon (C) exchange in peatlands of the Andean mountains is limited and these ecosystems may behave differently given the particular characteristics of the Andean tropics. These ecosystems are highly productive and under pressure by grazing. Our first objective was to measure baseline carbon dioxide (CO2) and methane (CH4) flux in an undisturbed peatland in Cayambe-Coca National Park. Our second objective was to quantify CO2 and CH 4 fluxes in an intensively cattle grazed peatland near Antisana Ecological Reserve. CO2 and CH4 effluxes were measured using a static chamber method. The mean NEE values for the undisturbed and disturbed site were -0.69 ± 0.08 and -1.25 ± 0.13 g CO2 m -2 hr-1 respectively. A significant correlation between microtopography and CO2 and CH4 flux was found in the undisturbed site, with higher NEE, GPP, ER and CH4 values in hummocks than in lawns. Microtopography doesn’t seem to be a controller of CO 2 efflux in the grazed site, although the NEE and GPP rates are higher than those found in the undisturbed site, and show a linear relationship with vegetation cover. CH4 emissions in the undisturbed site were low (8.1 ± 1.17 mg CH4 m-2 d -1). However, CH4 emissions at the grazed site were very high (132.25 ± 34.22 mg CH4 m-2 d -1), which might be attributed to the high physical impact and inputs from cattle. In summary, it appears that cattle grazing may be capable of large changes to C exchange and greenhouse gas fluxes in Andean peatlands.
Hasan, Md Al-Mahadi, e Mainul Islam. "Improving the System Performance of High Altitude Platforms Serving Suburban Areas". Thesis, Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-5071.
Testo completo+46720459586
Rose, Clémence. "Nucléation et formation de nouvelles particules à haute altitude". Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22507/document.
Testo completoNew particle formation (NPF) results from a complex sequence of multiple processes and contributes to an important fraction of the total atmospheric aerosol number concentration. After they grow, newly formed particles can act as cloud condensation nuclei (CCN), and thus have indirect effect on the Earth radiative balance through cloud related radiative processes. While NPF has often been observed and studied at low altitudes, the occurrence of the process is poorly documented in the literature for high altitude sites. We report a high annual frequency of the NPF process (64%) at the highest measurement site in the world, Chacaltaya (5240 m, Bolivia), in 2012, with frequent multiple events. At the puy de Dôme station (1465 m, ACTRIS, GAW), the occurrence of NPF in the free troposphere was detected using a unique instrumental setup. A complete analysis of the vertical extension of the NPF process was performed based on airborne measurements conducted above the Mediterranean basin in the frame of the HYMEX project (MISTRALS, September – November 2012). Our observations suggest that NPF could be favored at high altitudes with a probability of occurrence increased by 10 above 1000 m. At these altitudes, NPF could significantly contribute to the production of CCN, since 68% of the analyzed events show particle growth up to CCN sizes at Chacaltaya. The high number of observations recorded in various environments also contributed to improve our knowledge regarding the charge of the nucleated clusters, the identity of the gaseous precursors and the atmospheric parameters influencing the NPF process. This will allow a better parameterization of the NPF process in modelling tools