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1
Alapää, Pär. „Soil geochemical mapping of manganese in Norrbotten : Delineation of the spatial and statistical distribution of manganese and correlated elements in glacial tills“. Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-111075.
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Information from soil geochemical mapping programmes is useful within a number of different fields including for example mineral exploration and environmental research. The purpose of this thesis was to investigate the relationship between soil metal concentrations and geological factors such as bedrock lithology, structural geology, mineralizations etc. The study used data acquired in association with a nationwide soil geochemical mapping programme conducted by the Geological Survey of Sweden, SGU. These data contained both total element concentrations measured via X-ray fluorescence spectroscopy and acid leached concentrations measured with plasma technique. Basic statistical compilations were made, including classification of element concentrations into percentiles according to SGU standards, calculation of leachability and correlation analyses. Spatial analyses were also done, using GIS-software. The results showed that all investigated elements except zinc had elevated median values for total concentrations in the project area compared to the natural median values. The strongest correlation for total element concentrations was that between iron and cobalt with Spearman ρ=0.88. Furthermore, the results of this study indicated that sampling sites superimposing volcanic rocks contained the highest total concentrations of manganese. The results also suggested that manganese content increased with increasing age of the underlying bedrock. The highest median concentration of 0.80 g/kg was found in Archean rocks. Known mineralizations were often reflected in the form of positive element anomalies in the till geochemistry. The obtained results were also consistent with the average composition of the bedrock. No clear connections with any of the other investigated geological factors could be made.
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Šindelářová, Anna. „Analýza zubů a kostí metodou spektroskopie laserem buzeného plazmatu“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-445149.
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The presented diploma thesis deals with the elemental composition of hard tissues – human and murine jaws studied by laser-induced plasma spectroscopy (LIBS). Samples of human teeth contained a disease called ankylosis and the difference in elemental composition of healthy and diseased tissue was observed to localize ankylosis in the tooth. When evaluating the map of the spatial distribution of phosphorus and calcium, a decrease in the concentration of these elements in the ankylosis infected area was observed. Furthermore, murine jaws containing lead were analyzed. When assessing the spatial distribution of lead in tissue, it was found that lead was incorporated in murine teeth in the enamel at the tip of the incisor and molars. In conclusion, LIBS method achieved good results considering the detection of the elemental distribution of hard tissues. It enables to differentiate parts of the tooth in terms of elemental composition and tissue hardness and also to detect changes in the matrix caused by a disease or bioaccumulation of heavy metals.
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Nabeel, Muhammad. „Diffusion of Elemental Additives during Sintering“. Thesis, KTH, Materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-100702.
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The mechanical properties of components made by PM steels are normally inferior to those made by alternative processes. One of the main reasons is that a large amount of pores are present in sintered components. The other main reason is that the alloying elements, particularly Ni, are not uniformly distributed after conventional sintering procedures. This work is aimed at a better understanding of the influence of alloying additions on mechanical properties and homogeneity of the microstructure. The experimental work has been carried out in two trials. Trial 1 was performed to investigate mechanical properties of Distaloy powders (commercial grades) and second trial to examine influence of alloying additions on homogeneity of microstructure. For trial 1, as-sintered and heat treated specimens were produced by mixing commercial powders with two different carbon levels. Whereas, alloying elements were admixed to base iron powder for producing sintered specimens for trial 2. Mechanical properties including dimensional changes, micro-hardness, tensile strength and impact resistance were measured. Distribution of alloying elements was studied using LOM and SEM-EDS analysis. The results obtained show that additions of alloying elements enhance the mechanical properties. Moreover, interaction of C with Cu and Ni as well as interaction between Cu and Ni have a deceive role in determining final properties of the components. The metallographic investigation indicated that major reasons of heterogeneous microstructure are slow diffusion of Ni in Fe matrix and interaction of other alloying elements with Ni. The results of trial 2 showed that addition of Mo and Cu to Ni-containing PM steels improves the distribution of Ni in Fe matrix. Mo results in improved uniformity of microstructure by lowering the chemical potential of carbon. In Ni and Cu containing alloys, the interaction between Ni and Cu is responsible for enhanced distribution of Ni. However, the improved Ni distribution is achieved at the expense of non-uniform distribution of Cu. In Ni-containing PM steels, improved microstructure homogenization can be attained by increasing Ni-Cu interaction, lowering the surface energy of Ni-Cu liquid and decreasing the chemical potential of carbon.
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Khaleque, Nazrul. „Quantitative elemental and molecular mapping of undemineralised tissue using x-ray microscopy“. Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243822.
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5
Ahari, Homayoun. „Assembly, phase transitions, order and elemental distribution in microporous tin(IV) chalcogenides“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ35095.pdf.
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6
Anderson, Evan Pelzner. „Chuaria, Vendotaenia, and the taphonomy of the Carbonaceous Compression“. Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/72988.
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Carbonaceous Compressions are a widespread preservational style for fossils, yet their taphonomy remains poorly understood. Previous studies focusing on the taphonomy of carbonaceous compressions have primarily looked at exceptionally preserved faunas in plane view. The precious nature of these fossils leaves destructive techniques of analysis out of the question, but these techniques are necessary if the taphonomy of carbonaceous compressions is to be deciphered. This study analyzes Neoproterozoic carbonaceous compressions from the Yangtze Gorges area in order to address this issue. Chuaria fossils from the Jiulongwan, Sixi, and Sifangtan sections of the Doushantuo Formation and Vendotaenia fossils from the Wuhe and Miaohe sections of the Denying Formation are microchemically analyzed in both plane view and cross section in order to gain a greater understanding of the makeup of carbonaceous compressions. Results confirm and elaborate on previous studies. Likely clay coats are detected on some Chuaria specimens, while they are absent on less thermally mature specimens. Evidence for sulfate reduction in association with carbonaceous compressions is found. Sulfur enrichment, rather than clay coats, is found in association with Vendotaenia fossils. These observations lead to the hypothesis that while organic remains require a very precise set of taphonomic conditions in order to be preserved as carbonaceous compressions, there may be more than one set of conditions that allow for preservation. More studies of a greater taxonomic and taphonomic range of carbonaceous compressions are needed, however, if the mechanisms which control this preservational pathway are to be fully understood.Master of Science
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Feldman, Steven B. „Pedogenesis, weathering processes, and elemental distribution along a soil climosequence in the southern Piedmont“. Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-155645/.
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Destun, Krystofer J. „Mapping stream fish distribution and abundance from riparian vegetation“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35882.pdf.
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9
Gerych, Walter. „Versatile Anomaly Detection with Outlier Preserving Distribution Mapping Autoencoders“. Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1345.
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State-of-the-art deep learning methods for outlier detection make the assumption that outliers will appear far away from inlier data in the latent space produced by distribution mapping deep networks. However, this assumption fails in practice,because the divergence penalty adopted for this purpose encourages mapping outliers into the same high-probability regions as inliers. To overcome this shortcoming,we introduce a novel deep learning outlier detection method, called Outlier Preserving Distribution Mapping Autoencoder (OP-DMA), which succeeds to map outliers to low probability regions in the latent space of an autoencoder. For this we leverage the insight that outliers are likely to have a higher reconstruction error than inliers. We thus achieve outlier-preserving distribution mapping through weighting the reconstruction error of individual points by the value of a multivariate Gaussian probability density function evaluated at those points. This weighting implies that outliers will result in an overall penalty if they are mapped to low-probability regions. We show that if the global minimum of our newly proposed loss function is achieved,then our OP-DMA maps inliers to regions with a Mahalanobis distance less than \delta, and outliers to regions past this \delta, \delta being the inverse ChiSquared CDF evaluated at 1−\alpha with \alpha the percentage of outliers in the dataset. We evaluated OP-DMA on 11 benchmark real-world datasets and compared its performance against 7 different state-of-the-art outlier detection methods, including ALOCC and MO-GAAL. Our experiments show that OP-DMA outperforms the state-of-the-art methods on 7 of the datasets, and performs second best on 3 of the remaining 4 datasets, while no other method won on more than 1 dataset.
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Kelly, Dermot James. „Connexin distribution and optical mapping of the mammalian av node“. Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=78393.
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Atrioventricular (AV) nodal conduction and the pathways of propagation through the AV node have remained enigmatic. Histological and immunohistochemical studies have revealed distinct cellular regions within the AV node with varying distribution of specific ion channels. However, to date, there is little information concerning the pattern of localization of the gap junction proteins that mediate intercellular communication. The current immunohistochemical/confocal studies show a non-uniform distribution of three connexin isoforms (Cx 40, Cx 43 and Cx 45) within these cellular regions of the rat AV node with a marked transition from Cx 43 to Cx 40 at the compact node region. In addition, a high resolution mapping system coupled with extracellular recording electrodes was implemented during this study and has allowed for a macroscopic overview of the rabbit AV node. This approach revealed a marked delay in conduction at the area of the compact node. This information in association with the immunohistochemical studies may help to provide further insight into the mechanisms underlying the AV nodal delay.
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Pigott, David Michael. „Mapping the global distribution of zoonoses of public health importance“. Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:962dc1a7-c6c1-4878-ab6f-94dcebf7b1e1.
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Medical cartography can provide valuable insights into the epidemiology and ecology of infectious diseases, providing a quantitative representation of the distribution of these pathogens. Such methods therefore provide a key step in informing public health policy decisions ranging from prioritising sites for further investigation to identifying targets for interventions. By increasing the resolution at which risk is defined, policymakers are provided with an increasingly informed approach for considering next steps as well as evaluating past progress. In spite of their benefits however, global maps of infectious disease are lacking in both quality and comprehensiveness. This thesis sets out to investigate the next steps for medical cartography and details the use of species distribution models in evaluating global distributions of a variety of zoonotic diseases of public health importance. Chapter 2 defines a methodology by which global targets for infectious disease mapping can be quantitatively assessed by comparing the global burden of each disease with the demand from national policymakers, non-governmental organisations and academic communities for global assessments of disease distribution. Chapter 3 introduces the use of boosted regression trees for mapping the distribution of a group of vector-borne diseases identified as being a high priority target, the leishmaniases. Chapter 4 adapts these approaches to consider Ebola virus disease. This technique shows that the West African outbreak was ecologically consistent with past infections and suggests a much wider area of risk than previously considered. Chapter 5 investigates Marburg virus disease and considers the variety of different factors relating to all aspects of the transmission cycle that must be considered in these analyses. Chapters 6 and 7 complete the mapping of the suite of viral haemorrhagic fevers by assessing the distribution of Crimean-Congo haemorrhagic fever and Lassa fever. Finally, Chapter 8 considers the risk that these viral haemorrhagic fevers present to the wider African continent, quantifying potential risk of spillover infections, local outbreaks and more widespread infection. This thesis addresses important information gaps in global knowledge of a number of pathogens of public health importance. In doing so, this work provides a template for considering the global distribution of a number of other zoonotic diseases.
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Fodrie, Fredrick Joel. „Quantifying nursery habitat value for the California halibut, Paralichthys californicus distribution, elemental fingerprinting and demographic approaches /“. Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3240046.
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Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed January 12, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Praechter, Todd A. „Affect of Emission Controls on the Elemental Concentration and Particle Size of Coal Ash“. University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378196568.
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Risterucci, Paul. „Coupling of electron spectroscopies for high resolution elemental depth distribution profiles in complex architectures of functional materials“. Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0047/document.
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Ce travail de thèse est focalisé sur la détermination, de manière non-destructive, d'interfaces profondément enterrées dans des empilements multi-couches utilisés dans les conditions de technologie réelles au travers d'une méthode innovante basée sur la photoémission avec utilisation de rayons-x de haute énergie (HAXPES) et l'analyse du fond continu inélastique. Au cours de cette thèse, une procédure numérique a été développée pour quantifier la correspondance entre la mesure du fond continu faite par HAXPES et la simulation du fond continu représentative d'une distribution en profondeur donnée. Cette méthode permet de trouver la distribution en profondeur d'un élément grâce à une procédure semi automatisée. Dans un premier temps cette méthode a été testée en étudiant une couche ultra fine de lanthane enterrée à une profondeur >50 nm dans un dispositif de grille métallique high-k. L'influence des paramètres utilisés lors de l'analyse y est étudiée et révèle l'importance principale d'un paramètre en particulier, la section efficace de diffusion inélastique. La combinaison de mesures HAXPES avec l'analyse du fond continu inélastique utilisant cette nouvelle méthode permet d'augmenter la profondeur de sonde jusqu'à un niveau sans précédent. Ainsi l'échantillon peut être sondé jusqu'à 65 nm sous la surface avec une haute sensibilité à une couche nanométrique. Dans un second temps, la méthode précédemment validée d'analyse de fond continu inélastique est combinée avec une étude haute résolution des niveaux de cœur dans un échantillon servant de source dans un transistor à haute mobilité. Les deux analyses sont complémentaires puisqu'elles permettent d'obtenir la distribution en profondeur des éléments ainsi que leur environnement chimique. Le résultat donne une description complète des diffusions élémentaires dans l'échantillon suivant les différentes conditions de recuitThis thesis tackles the challenge of probing in a non-destructive way deeply buried interfaces in multilayer stacks used in technologically-relevant devices with an innovative photoemission method based on Hard X-ray PhotoElectron Spectroscopy (HAXPES) and inelastic background analysis. In this thesis, a numerical procedure has been implemented to quantify the matching between a HAXPES measured inelastic background and a simulated inelastic background that is representative of a given depth distribution of the chemical elements. The method allows retrieving depth distributions at large depths via a semi-automated procedure. First, this method has been tested by studying an ultra-thin layer of lanthanum buried at depth >50 nm in a high-k metal gate sample. The influence of the parameters involved in the analysis is studied unraveling the primary importance of the inelastic scattering cross section. The combination of HAXPES with inelastic background analysis using this novel method maximizes the probing depth to an unprecedented level, allowing to probe the sample up to 65 nm below the surface with a high sensitivity to a nm-thick layer. Second, the previously-checked inelastic background analysis is combined with that of high resolution core-level spectra in the case of the source part of a high electron mobility transistor. The two analyses are complementary as they allow retrieving the elemental depth distribution and the chemical state, respectively. The result gives a complete picture of the elemental intermixing within the sample when it is annealed at various temperatures
Denne afhandling omhandler problemet med at probe dybt begravede grænseflader i multilags stacks, som bruges i teknologisk relevante devices, med en innovativ fotoemissions metode, der er baseret på Hard X-ray PhotoElectron Spectroscopy (HAXPES) og analyse af den uelastiske baggrund. I afhandlingen er en numerisk procedure blevet implementeret til at kvantificere forskellen mellem en HAXPES målt uelastisk baggrund og en modelleret baggrund, som svarer til en given dybdefordeling af atomerne. Metoden muliggør, med en halv-automatisk procedure, at bestemme dybdefordelingen i store dybder. Metoden er først blevet testet ved at studere et ultra-tyndt lag af lanthan, som er begravet i en dybde > 50 nm i en high-k-metal-gate prøve. Indflydelsen af parametrene der ingår i analysen er blevet studeret for at opklare den primære betydning af det anvendte uelastiske spredningstværsnit. Kombinationen af HAXPES med analyse af den uelastiske baggrund og brug af den nye numeriske metode giver en hidtil uset probe-dybde, som giver mulighed for at probe den atomare sammens ætning i op til 65 nm dybde under overfladen og med høj følsomhed af et kun nm tykt lag. Dernæst er den uelastiske baggrundsanalyse blevet kombineret med højopløst core-level spektroskopi for at studere de aktive dele i en høj-elektronmobilitets transistor. De to analyser er komplementære, idet de henholdsvis bestemmer den atomare fordeling og atomernes kemiske bindingstilstand. Resultatet giver et fuldstændigt billede af atomernes omfordeling i prøven når denne opvarmes til forskellige temperaturer
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Wall, Carrie Christy. „Shelf-scale Mapping of Fish Distribution Using Active and Passive Acoustics“. Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4251.
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Fish sound production has been associated with courtship and spawning behavior. Acoustic recordings of fish sounds can be used to identify distribution and behavior. Passive acoustic monitoring (PAM) can record large amounts of acoustic data in a specific area for days to years. These data can be collected in remote locations under potentially unsafe seas throughout a 24-hour period providing datasets unattainable using observer-based methods. However, the instruments must withstand the caustic ocean environment and be retrieved to obtain the recorded data. This can prove difficult due to the risk of PAMs being lost, stolen or damaged, especially in highly active areas. In addition, point-source sound recordings are only one aspect of fish biogeography. Passive acoustic platforms that produce low self-generated noise, have high retrieval rates, and are equipped with a suite of environmental sensors are needed to relate patterns in fish sound production to concurrently collected oceanographic conditions on large, synoptic scales. The association of sound with reproduction further invokes the need for such non-invasive, near-real time datasets that can be used to enhance current management methods limited by survey bias, inaccurate fisher reports, and extensive delays between fisheries data collection and population assessment.
Red grouper (Epinephelus morio) exhibit the distinctive behavior of digging holes and producing a unique sound during courtship. These behaviors can be used to identify red grouper distribution and potential spawning habitat over large spatial scales. The goal of this research was to provide a greater understanding of the temporal and spatial distribution of red grouper sound production and holes on the central West Florida Shelf (WFS) using active sonar and passive acoustic recorders. The technology demonstrated here establishes the necessary methods to map shelf-scale fish sound production. The results of this work could aid resource managers in determining critical spawning times and areas.
Over 403,000 acoustic recordings were made across an approximately 39,000 km2 area on the WFS during periods throughout 2008 to 2011 using stationary passive acoustic recorders and hydrophone-integrated gliders. A custom MySQL database with a portal to MATLAB was developed to catalogue and process the large acoustic dataset stored on a server. Analyses of these data determined the daily, seasonal and spatial patterns of red grouper as well as toadfish and several unconfirmed fish species termed: 100 Hz Pulsing, 6 kHz Sound, 300 Hz FM Harmonic, and 365 Hz Harmonic.
Red grouper sound production was correlated to sunrise and sunset, and was primarily recorded in water 15 to 93 m deep, with increased calling within known hard bottom areas and in Steamboat Lumps Marine Reserve. Analyses of high-resolution multibeam bathymetry collected in a portion of the reserve in 2006 and 2009 allowed detailed documentation and characterization of holes excavated by red grouper. Comparisons of the spatially overlapping datasets suggested holes are constructed and maintained over time, and provided evidence towards an increase in spawning habitat usage. High rates of sound production recorded from stationary recorders and a glider deployment were correlated to high hole density in Steamboat Lumps. This research demonstrates the utility of coupling passive acoustic data with high-resolution bathymetric data to verify the occupation of suspected male territory (holes) and to provide a more complete understanding of effective spawning habitat. Annual peaks in calling (July and August, and November and December) did not correspond to spawning peaks (March - May); however, passive acoustic monitoring was established as an effective tool to identify areas of potential spawning activity by recording the presence of red grouper.
Sounds produced by other species of fish were recorded in the passive acoustic dataset. The distribution of toadfish calls suggests two species (Opsanus beta and O. pardus) were recorded; the latter had not been previously described. The call characteristics and spatial distribution of the four unknown fish-related sounds can be used to help confirm the sources. Long-term PAM studies that provide systematic monitoring can be a valuable assessment tool for all soniferous species. Glider technology, due to a high rate of successful retrieval and low self-generated noise, was proven to be a reliable and relatively inexpensive method to collect fisheries acoustic data in the field. The implementation of regular deployments of hydrophone-integrated gliders and fixed location passive acoustic monitoring stations is suggested to enhance fisheries management.
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Kommana, Karteek. „Implementation of a Geoserver Applicatoin For GIS Data Distribution and Manipulation“. Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-92592.
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Accessibility and Interactivity are keywords of information today and that is equally important in science as anywhere else. When scientists share information it benefits if it is intuitive, informative and simple and does not demand expert skills in complicated formats. This master thesis has the aim to investigate open source software tools to design a web map application that can be used by any institute or NGO to distribute their data over internet. The Java platform to be implemented is the open source OpenLayers which allow users to view and potentially manipulate GIS map data through a web map application. Whatever GIS data made available on the Geoserver (the host site for the application) can be shared to users worldwide. The user can then: add from a list of available data layers, choose background (e.g. Google Earth, Open Street Map, etc.), zoom in and out, pan, change symbols and colors, add their own data on top and start animation (if applicable). The data distributed from the Geoserver can also be viewed and accessed from smartphones whichopens the possibility to make the public part of the larger data gathering task of specific scientific inventories like observations of migrating birds, or whatever indicator a specific scientist is interested in. Data is uploaded to the Geoserver and can then be analyzed and the result is distributed to the public.
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Yatim, Alexandra Katharina Verfasser], Matthias [Akademischer Betreuer] Wuttig und Joachim [Akademischer Betreuer] [Mayer. „Investigation of the elemental distribution in electronic materials for mobile devices / Alexandra Katharina Yatim ; Matthias Wuttig, Joachim Mayer“. Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130403041/34.
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Yatim, Alexandra Katharina [Verfasser], Matthias Akademischer Betreuer] Wuttig und Joachim [Akademischer Betreuer] [Mayer. „Investigation of the elemental distribution in electronic materials for mobile devices / Alexandra Katharina Yatim ; Matthias Wuttig, Joachim Mayer“. Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130403041/34.
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Xing, Liqun 1962. „Marker density, marker distribution and QTL-by-environment interaction in QTL mapping“. Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36734.
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Two studies were conducted on gene mapping analysis. For the first study, genetic simulation experiments were conducted to address the effects of marker density, method of mapping analysis, and gaps in a marker map on the efficiency of QTL detection and the accuracy of QTL parameter estimation. The simulated genome consisted of seven chromosomes with seven or eight segregating QTL affecting the simulated quantitative trait. A set of six randomly segregating QTL outside the test region was consistently used to represent 40% of phenotypic variation. An individual QTL or a linkage block of two QTL on a target chromosome contributed 10% of phenotypic variation. The marker map was either dense (with markers every 4 cM) or sparse (with markers every 20 cM). The gap in the marker map was either 32 cM or 56 cM. Interval mapping and composite interval mapping were used to map QTL on the target chromosome. A dense map provided more power of QTL detection, better accuracy of QTL parameter estimation, and higher false-positive error rates for the target chromosome than a sparse map. Composite interval mapping provided more power of QTL detection, better accuracy of QTL parameter estimation, and lower false-positive error rates than interval mapping. Presence of a large gap in a marker map affected QTL detection and QTL parameter estimation for a QTL inside or near the gap. The use of a dense map with composite interval mapping was the most efficient combination tested in this study. For the second study, a mixed factorial regression model for interval mapping was developed for conducting QTL-by-environment interaction analysis and for providing inferences about QTL that are applicable beyond the environments used in the experiments. Genetic simulation was used to test the model for the power of detecting QTL-by-environment interaction and identifying the types of such interaction as crossover or non-crossover, and for the accuracy of estimating QTL parameters. The model prov
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Xing, Liqun. „Marker density, marker distribution and QTL-by-environment interaction in QTL mapping“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0034/NQ64696.pdf.
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Potter, Marcus Jason. „Parametric analysis of a solid polymer fuel cell using current distribution mapping“. Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/19470.
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During operation of the solid polymer fuel cell (SPFC). its performance is limited by the concentrations of hydrogen and oxygen at the reaction interfaces and in most SPFC designs, the hydration state of the membrane. Since in general, the concentrations of water and the gaseous species vary along the flow channel, the performance is also likely to change along the flow channel. In order to study this phenomenon, a measurement system was developed to map the current distribution across the electrode surface. The current distribution has been measured by dividing one of the current collectors into a number of electrically isolated segments. The current flowing through each of the segments was measured while maintaining a constant potential across the surface of the gas diffusion layer. Two separate segmented current collectors were developed. The first was used to measure the current distribution for an 80 cm2 single cell, and the second was used to investigate the local current densities around a single flow channel. The effects of the feed gas humidities on the spatial current density in the 80 cm2 fuel cell were investigated for two different membrane-electrode configurations. With Nafion 117 as electrolyte and at a cell temperature of 80°C. the membrane was found to dehydrate in the initial portion of the gas flow channel when the relative humidity of both the hydrogen and oxygen feed gases was less than 50%. With a Gore-Select membrane electrode assembly (hydrogen and air. temperature- 60°C). the membrane was sufficiently hydrated at all feed gas humidification conditions. The performance of the cell was found to deteriorate at higher feed gas humidities as a result of the lower partial pressures of the reactant gases. Measurements of the effects of gas pressures, stoichiometries and humidities on the length-wise and width-wise perfonnance around a single flow channel (Gore-Select membrane electrode assembly) are discussed in relation to a gas flow model.
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Scott-Hayward, Lindesay Alexandra Sarah. „Novel methods for species distribution mapping including spatial models in complex regions“. Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4514.
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Species Distribution Modelling (SDM) plays a key role in a number of biological applications: assessment of temporal trends in distribution, environmental impact assessment and spatial conservation planning. From a statistical perspective, this thesis develops two methods for increasing the accuracy and reliability of maps of density surfaces and provides a solution to the problem of how to collate multiple density maps of the same region, obtained from differing sources. From a biological perspective, these statistical methods are used to analyse two marine mammal datasets to produce accurate maps for use in spatial conservation planning and temporal trend assessment. The first new method, Complex Region Spatial Smoother [CReSS; Scott-Hayward et al., 2013], improves smoothing in areas where the real distance an animal must travel (`as the animal swims') between two points may be greater than the straight line distance between them, a problem that occurs in complex domains with coastline or islands. CReSS uses estimates of the geodesic distance between points, model averaging and local radial smoothing. Simulation is used to compare its performance with other traditional and recently-developed smoothing techniques: Thin Plate Splines (TPS, Harder and Desmarais [1972]), Geodesic Low rank TPS (GLTPS; Wang and Ranalli [2007]) and the Soap lm smoother (SOAP; Wood et al. [2008]). GLTPS cannot be used in areas with islands and SOAP can be very hard to parametrise. CReSS outperforms all of the other methods on a range of simulations, based on their fit to the underlying function as measured by mean squared error, particularly for sparse data sets. Smoothing functions need to be flexible when they are used to model density surfaces that are highly heterogeneous, in order to avoid biases due to under- or over-fitting. This issue was addressed using an adaptation of a Spatially Adaptive Local Smoothing Algorithm (SALSA, Walker et al. [2010]) in combination with the CReSS method (CReSS-SALSA2D). Unlike traditional methods, such as Generalised Additive Modelling, the adaptive knot selection approach used in SALSA2D naturally accommodates local changes in the smoothness of the density surface that is being modelled. At the time of writing, there are no other methods available to deal with this issue in topographically complex regions. Simulation results show that CReSS-SALSA2D performs better than CReSS (based on MSE scores), except at very high noise levels where there is an issue with over-fitting. There is an increasing need for a facility to combine multiple density surface maps of individual species in order to make best use of meta-databases, to maintain existing maps, and to extend their geographical coverage. This thesis develops a framework and methods for combining species distribution maps as new information becomes available. The methods use Bayes Theorem to combine density surfaces, taking account of the levels of precision associated with the different sets of estimates, and kernel smoothing to alleviate artefacts that may be created where pairs of surfaces join. The methods were used as part of an algorithm (the Dynamic Cetacean Abundance Predictor) designed for BAE Systems to aid in risk mitigation for naval exercises. Two case studies show the capabilities of CReSS and CReSS-SALSA2D when applied to real ecological data. In the first case study, CReSS was used in a Generalised Estimating Equation framework to identify a candidate Marine Protected Area for the Southern Resident Killer Whale population to the south of San Juan Island, off the Pacific coast of the United States. In the second case study, changes in the spatial and temporal distribution of harbour porpoise and minke whale in north-western European waters over a period of 17 years (1994-2010) were modelled. CReSS and CReSS-SALSA2D performed well in a large, topographically complex study area. Based on simulation results, maps produced using these methods are more accurate than if a traditional GAM-based method is used. The resulting maps identified particularly high densities of both harbour porpoise and minke whale in an area off the west coast of Scotland in 2010, that might be a candidate for inclusion into the Scottish network of Nature Conservation Marine Protected Areas.
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Ytterman, Caroline. „Grundämnes-distribuering och bendensitet : En XRF-undersökning av vikingatida och medeltida lårben från fyra arkeologiska lokaler“. Thesis, Uppsala universitet, Arkeologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-294164.
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This essay focuses on developing non-destructive methods to investigate the relationship between elemental distribution and bone porosity in archaeological bone. The skeletal material, which was analyzed, came from the archaeological sites of Skara (county of Västergötland), Varnhem (county of Västergötland), Sigtuna (county of Uppland) and Kopparsvik (county of Gotland). The essay is based on the results of a previous project, Osteoporosis och osteoarthritis, då och nu (Sten 2012). That project aimed at establishing whether medieval people, buried on the above mentioned archaeological sites, were suffersing from osteoporosis and/or osteoarthritis. This knowledge might help the medical research of today to solve the problem of possibly preventing those bone diseases. The method used was DXA-scanning, which was developed for examine osteoporosis in bone from living people. The result showed that the skeletons from the Skara site had an increased bone mineral density (BMD) compared to the skeletons from the other three sites. This essay investigates why these skeletal remains have a higher BMD and how this affects the results of methods like DXA. In this bachelor project various X-ray instruments were used to analyze the BMD of the skeletal remains. The X-ray pictures were then modified to exhibit high and low density areas in the bone. The elemental distribution of the surface area of the neck of the femur was examined with a μXRF-spectrometer. As a complement to the μXRF-spectrometer a SEM (scanning electron microscope) was used to analyze the elemental distribution of a cross section of the femur neck. Soil samples were collected from Skara and Varnhem and analyzed by using μXRF-spectrometry to find out if there was a correlation between the elemental content of the bone and surrounding soil. The skeletal remains from Skara exhibited increased values of iron and manganese combined with higher bone density. The soil from Skara showed a high level of particularly iron. This could be the reason for the increased BMD of the individuals from Skara when using the DXA-analysis. It is likely that, in each archaeological site, iron and manganese ions have diffused from both ground water and soil into the bones and thus increased the BMD. This is especially notified of the skeletal remains of Skara.
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Schmidt, Thomas Justus, Methap Oezaslan, W. Liu, Maarten Nachtegaal, Anatoly I. Frenkel, B. Rutkowski, Matthias Werheid et al. „Homogeneity and elemental distribution in self-assembled bimetallic Pd–Pt aerogels prepared by a spontaneous one-step gelation process“. Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30258.
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Multi-metallic aerogels have recently emerged as a novel and promising class of unsupported electrocatalyst materials due to their high catalytic activity and improved durability for various electrochemical reactions. Aerogels can be prepared by a spontaneous one-step gelation process, where the chemical co-reduction of metal precursors and the prompt formation of nanochain-containing hydrogels, as a preliminary stage for the preparation of aerogels, take place. However, detailed knowledge about the homogeneity and chemical distribution of these three-dimensional Pd–Pt aerogels at the nano-scale as well as at the macro-scale is still unclear. Therefore, we used a combination of spectroscopic and microscopic techniques to obtain a better insight into the structure and elemental distribution of the various Pd-rich Pd–Pt aerogels prepared by the spontaneous one-step gelation process. Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy and high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) in combination with energy-dispersive X-ray spectroscopy (EDX) were employed in this work to uncover the structural architecture and chemical composition of the various Pd-rich Pd–Pt aerogels over a broad length range. The Pd80Pt20, Pd60Pt40 and Pd50Pt50 aerogels showed heterogeneity in the chemical distribution of the Pt and Pd atoms inside the macroscopic nanochain-network. The features of mono-metallic clusters were not detected by EXAFS or STEM-EDX, indicating alloyed nanoparticles. However, the local chemical composition of the Pd–Pt alloys strongly varied along the nanochains and thus within a single aerogel. To determine the electrochemically active surface area (ECSA) of the Pd–Pt aerogels for application in electrocatalysis, we used the electrochemical CO stripping method. Due to their high porosity and extended network structure, the resulting values of the ECSA for the Pd–Pt aerogels were higher than that for a commercially available unsupported Pt black catalyst. We show that the Pd–Pt aerogels possess a high utilization of catalytically active centers for electrocatalytic applications based on the nanostructured bimetallic framework. Knowledge about the homogeneity and chemical distribution of the bimetallic aerogels can help to further optimize their preparation by the spontaneous one-step gelation process and to tune their electrocatalytic reactivity.
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Schmidt, Thomas Justus, Methap Oezaslan, W. Liu, Maarten Nachtegaal, Anatoly I. Frenkel, B. Rutkowski, Matthias Werheid et al. „Homogeneity and elemental distribution in self-assembled bimetallic Pd–Pt aerogels prepared by a spontaneous one-step gelation process“. Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-222784.
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Multi-metallic aerogels have recently emerged as a novel and promising class of unsupported electrocatalyst materials due to their high catalytic activity and improved durability for various electrochemical reactions. Aerogels can be prepared by a spontaneous one-step gelation process, where the chemical co-reduction of metal precursors and the prompt formation of nanochain-containing hydrogels, as a preliminary stage for the preparation of aerogels, take place. However, detailed knowledge about the homogeneity and chemical distribution of these three-dimensional Pd–Pt aerogels at the nano-scale as well as at the macro-scale is still unclear. Therefore, we used a combination of spectroscopic and microscopic techniques to obtain a better insight into the structure and elemental distribution of the various Pd-rich Pd–Pt aerogels prepared by the spontaneous one-step gelation process. Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy and high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) in combination with energy-dispersive X-ray spectroscopy (EDX) were employed in this work to uncover the structural architecture and chemical composition of the various Pd-rich Pd–Pt aerogels over a broad length range. The Pd80Pt20, Pd60Pt40 and Pd50Pt50 aerogels showed heterogeneity in the chemical distribution of the Pt and Pd atoms inside the macroscopic nanochain-network. The features of mono-metallic clusters were not detected by EXAFS or STEM-EDX, indicating alloyed nanoparticles. However, the local chemical composition of the Pd–Pt alloys strongly varied along the nanochains and thus within a single aerogel. To determine the electrochemically active surface area (ECSA) of the Pd–Pt aerogels for application in electrocatalysis, we used the electrochemical CO stripping method. Due to their high porosity and extended network structure, the resulting values of the ECSA for the Pd–Pt aerogels were higher than that for a commercially available unsupported Pt black catalyst. We show that the Pd–Pt aerogels possess a high utilization of catalytically active centers for electrocatalytic applications based on the nanostructured bimetallic framework. Knowledge about the homogeneity and chemical distribution of the bimetallic aerogels can help to further optimize their preparation by the spontaneous one-step gelation process and to tune their electrocatalytic reactivity.
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Ozaslan, Mehtap, Wei Liu, Maarten Nachtegaal, Anatoly Frenkel, Bogdan Rutkowski, Matthias Werheid, Anne-Kristin Herrmann et al. „Homogeneity and Elemental Distribution in Self-Assembled Bimetallic Pd-Pt Aerogels prepared by a spontaneous one-step gelation process“. Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-210970.
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Multi-metallic aerogels have recently emerged as a novel and promising class of unsupported electrocatalyst materials due to their high catalytic activity and improved durability for various electrochemical reactions. Aerogels can be prepared by a spontaneous one-step gelation process, where the chemical co-reduction of metal precursors and the prompt formation of the nanochain-consisting hydrogels, as a preliminary stage for the preparation of aerogels take place. However, detailed knowledge about the homogeneity and chemical distribution of these three-dimensional Pd-Pt aerogels at the nano-scale as well as at the macro-scale is still unclear to date.
Therefore, we used a combination of spectroscopic and microscopic techniques to obtain a better insight into the structure and elemental distribution of the various Pd-rich Pd-Pt aerogels prepared by the spontaneous one-step gelation process. Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy and high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) in combination with energy-dispersive X-ray spectroscopy (EDX) were employed in this work to uncover the structural architecture and chemical composition of the various Pd-rich Pd-Pt aerogels over a broad length range. The Pd80Pt20, Pd60Pt40 and Pd50Pt50 aerogels showed heterogeneity in the chemical distribution of the Pt and Pd atoms inside the macroscopic nanochain-network. Features of monometallic clusters were not detected by EXAFS or STEM-EDX, indicating alloyed nanoparticles. However, the local chemical composition of the Pd-Pt alloys strongly varied along the nanochains and thus within a single aerogel. To determine the electrochemically active surface area (ECSA) of the Pd-Pt aerogels for applications in electrocatalysis, we used the electrochemical CO stripping method. Due to high porosity and extended network structure, the resulting values of the ECSA for the Pd-Pt aerogels were higher than that for a commercially available unsupported Pt black catalyst. We show that the Pd-Pt aerogels possess a high utilization of catalytically active centers for electrocatalytic applications based on the nanostructured bimetallic framework.
Knowledge about the homogeneity and chemical distribution of the bimetallic aerogels can help to further optimize their preparation by the spontaneous one-step gelation process and to tune their electrocatalytic reactivity.
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Karavai, Olga. „Mapping local corrosion parameters using SVET and SIET“. Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22052.
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Doutoramento em Ciência e Engenharia de MateriaisLocalized corrosion, i.e., corrosion confined to local regions, is difficult to predict and control. In general, it appears as a result of heterogeneities, either in the metal or in the corrosive environment. One of the phenomenological features of localised corrosion is the development of specific environments close to active sites. In practice, the micro-environment near the metallic surface is different from that of the bulk medium and varies with time and conditions of the system under study. Localized electrochemical techniques based on the use of microelectrodes are well suited for in situ sensing the distribution of potential, current and chemical species in active zones, pores or defects. Most of the published work dealing with microelectrodes in corrosion is mainly exploratory and their use in a regular basis is still rare in corrosion research. This work presents the development and application of microelectrodes as experimental tools capable to assess local electrochemical reactions on metallic substrates immersed in aggressive solutions. Traditional electrochemical techniques used in corrosion research give the average response of the global activity of the whole surface not discriminating local effects and local chemistry. Therefore they are unable per si to properly characterize localized phenomena and the corresponding corrosion, inhibitive mechanisms and, sometimes, even to select the best protection methods. It is important to know local parameters such as pH, micro-galvanic effects, concentration of oxidizing (like O2) and aggressive (like Cl-) species, and formation of surface films. The Scanning Vibrating Electrode Technique (SVET) was used for local measurements of ionic currents in solution. The technique detects the potential distribution in solution associated to ionic currents in solution. For the analysis of the chemical species involved in the corrosion process, electrochemical microsensors were used in SIET (Scanning Ion Selective Electrode Technique) mode. Microelectrodes sensitive to pH, dissolved oxygen and metal cations (namely, Mg2+, Zn2+ and Cu2+) were developed and characterized. Work was also done with microeloectrodes sensitive to Al3+, but with less success. Then, they were used for investigating the reactivity on defects and corrosion inhibition on coated aluminium and magnesium alloys, detecting the micro-distribution of chemical species in solution close to the corroding surface of Zn, Cu and a Zn- Fe galvanic couple specimens. ix Limitations and difficulties exist for the use of these techniques in corrosion research due to the inherent reactivity of corroding metals, with the formation of corrosion products and sharp changes of pH, O2 and ionic strength along the samples surface. In spite of the difficulties, the results presented here demonstrate that the SVET/SIET mapping gives useful information for the quantification of electrochemical processes at the micro-level. The data are of prime importance for the modelling and simulation of corrosion mechanisms, selection of new corrosion inhibitors and development of ‘‘smart” coatings that suppress the corrosion processes.
A corrosão localizada, i.e., corrosão confinada a locais específicos, é difícil de prever e controlar. Em geral, ocorre como resultado de heterogeneidades tanto no metal como no ambiente corrosivo. Uma das características da corrosão localizada é o desenvolvimento de ambientes específicos junto das zonas activas. Na prática, o micro-ambiente junto da superfície metálica é diferente do do seio da solução, variando com o tempo e com as condições do sistema em estudo. Técnicas electroquímicas localizadas baseadas na utilização de microeléctrodos são convientes para medir a distribuição de potencial, intensidade de corrente e espécies químicas em solução junto de zonas activas, poros ou defeitos. Muito do trabalho que existe publicado sobre microeléctrodos em corrosão refere-se a trabalho exploratório que permanece numa etapa preliminar. A aplicação de microeléctrodos em estudo de corrosão numa base rotineira é ainda rara. Este trabalho apresenta o desenvolvimento e aplicação de microeléctrodos como ferramentas experimentais capazes de aceder a reacções electroquímicas locais em substratos metálicos imersos em soluções agressivas. As técnicas electroquímicas tradicionais usadas no estudo de corrosão dão resposta média do processo global em toda a superfície da amostra sem distinguir efeitos locais e a química local. Não são, portanto, adequadas para a descrição detalhada dos mecanismos de corrosão localizada, de processos de inibição e, por vezes, para a selecção dos métodos de protecção mais adequados. É importante conhecer parâmetros locais, como pH, efeitos micro-galvânicos, concentração de espécies oxidantes (como O2) e agressivas (como Cl-), formação de filmes superficiais. Neste trabalho usou-se a técnica do eléctrodo vibrante de varrimento (SVET) para medições locais de corrente iónica em solução. A técnica detecta a distribuição de potencial em solução, associada à corrente iónica. Para a análise de espécies químicas envolvidas no processo corrosivo, foram usados microsensores electroquímicos no modo SIET (Técnica de Varrimento de Eléctrodo Selectivo de Iões). vii Foram desenvolvidos e caracterizados microeléctrodos sensíveis a pH, oxigénio dissolvido e catiões metálicos (nomeadamente, Mg2+, Zn2+ e Cu2+). Trabalhou-se também no desenvolvimento de microeléctrodos sensíveis a Al3+, embora com menos sucesso. Os microeléctrodos foram utilizados na investigação da corrosão e inibição em defeitos induzidos em revestimentos protectores aplicados sobre ligas de alumínio e de magnésio, e na detecção da micro-distribuição de espécies químicas em solução perto de eléctrodos de zinco, cobre e de um par galvânico Zn-Fe. Este trabalho revela também as limitações e dificuldades na aplicação destas técnicas ao estudo de corrosão devido à inerente reactividade do processo corrosivo, com formação de produtos de corrosão e grandes variações de pH, O2 e força iónica ao longo da superfície de amostra. Apesar das dificuldades, os resultados aqui apresentados demonstram que o mapeamento por SVET/SIET fornece informações muito úteis para a quantificação de processos electroquímicos à micro-escala. Os dados são de primordial importância para a modelação e simulação de mecanismos de corrosão, selecção de novos inibidores de corrosão e desenvolvimento de revestimentos anticorrosivos “inteligentes”.
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Vogiatzakis, Ioannis Nikolaou. „Predicting the distribution of plant communities in the Lefka Ori, Crete, using GIS“. Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366329.
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Qi, Dongmei [Verfasser]. „Isotopic and elemental distribution of copper between Cu-bearing minerals and aqueous fluids : implications of an experimental study / Dongmei Qi“. Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2019. http://d-nb.info/1176105213/34.
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Greenwald, Roby. „Real-time measurement of the water-insoluble aerosol size distribution instrument development and implementation /“. Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-07072005-105355/.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2006.Armistead Russell, Committee Member ; James Mulholland, Committee Member ; Rodney Weber, Committee Member ; Michael H. Bergin, Committee Chair ; Jean-Luc Jaffrezo, Committee Member.
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Neumann, Patrick P. [Verfasser]. „Gas Source Localization and Gas Distribution Mapping with a Micro-Drone / Patrick P. Neumann“. Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1036638340/34.
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Guerra, Loaiza Carlos A. „Mapping the contemporary global distribution limits of malaria using empirical data and expert opinion“. Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496900.
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Machado, Adelina da Conceicao. „Mapping of the distribution of Mycobacterium bovis strains involved in bovine tuberculosis in Mozambique“. Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/98114.
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Thesis (PhD)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Bovine tuberculosis (BTB), caused by bacteria of the Mycobacterium tuberculosis complex is reported to cause economic and public health negative impact in countries where it is prevalent. The control of the disease has been a difficult task worldwide. The main object of this thesis was to use molecular tools to generate useful information to contribute to the design of appropriate BTB control measures in Mozambique. To do so we considered a deep knowledge of the BTB history in Mozambique to be essential. The search was largely based on the reports produced annually by the Veterinary Services and other available information. We found reports of BTB in Mozambique as early as 1940. These cases were mainly identified as a result of post-mortem meat inspection. The higher numbers of cases reported were from 8 locations, namely Maputo, Magude, Vilanculos, Beira, Chimoio, Tete, Quelimane and Nampula, and served as a basis to decide the locations to perform prevalence and molecular epidemiologic studies. Prevalence studies were done in 10 districts selected based on the history of a high number of BTB case reports (intentionally biased towards locations presumably with higher prevalence), a high cattle density, but also to represent districts from the south, centre and north of Mozambique. A representative sample was defined, based on all livestock areas or villages in Massingir and Govuro Districts or by randomly selecting small-scale and commercial herds in 8 districts, specifically Manhiça, Chibuto, Buzi, Gondola, Mutarara, Mogovolas, Angoche and Mecanhelas. Results were obtained from 6983 cattle tested using tuberculin testing. Apparent prevalence varied from 0.98% in Massingir to 39.6% in the Govuro, with prevalence as high as 71.4% in some livestock areas/herds. The analysis of risk factors showed no noteworthy difference with respect to the sex of the animal. Younger age had significantly lower odds of infection compared to the older age class. There was a tendency of cattle from small-scale herds to have lower prevalence when compared to the commercial herds. From the prevalence studies, 187 tissue and 41 milk samples from BTB reactors were collected. Additionally 220 tissue samples were obtained from the Central Veterinary Laboratory routine diagnostic work. Samples were subject to bacteriological culture and a collection of 170 M. bovis isolates were obtained. Eight additional isolates were supplied from another study. All isolates were subjected to molecular typing using spoligotyping, and a sub-sample using MIRU-VNTR and regions of difference (RD) analysis. Fifteen different spoligotype patterns were identified of which 8 were not previously registered in the Mbovis.org database. The pattern SB0961 accounted for 61% of the isolates and was found in all areas of the country investigated. We hypothesize that this was one of the first clones to be introduced in Mozambique. Twenty-nine isolates had the pattern SB0140, which is specific for the European 1 (Eu1) clonal complex. Eleven isolates with this spoligotype were subjected to RD analysis, and all isolates had the Eu1 specific deletion. These were all isolated from cattle from the south of Mozambique and the majority from commercial farms that imported cattle, mainly from South Africa, where the Eu1 clonal complex is common. There were no isolates of the African 1 (Af1) or African 2 (Af2) clonal complexes that are frequent in Central-West Africa and East Africa, respectively. The clones identified from different farms and districts, strongly suggest routes of transmission and/or common source of infection. In conclusion, our results show a potential increase in the prevalence of BTB in Mozambique even taking into consideration i) that the selection of locations in our study was biased towards locations with a history of higher BTB prevalence and ii) the use of a more sensitive technique i.e. the testing in the middle neck region as opposed to the testing in the caudal fold as used in previous studies. Even if no cattle to human transmission was found in studies done in Mozambique so far, the evidence of M. bovis shedding through milk and the lack of correct practices to prevent animal to human transmission (consumption of raw milk), strongly suggests that there is zoonotic risk; a subject that needs to be investigated. The results presented in this work also strengthen the need to reinforce the current regulations that require a negative BTB test result before cattle importation. The same should be enforced for the internal movements, as the frequency of shared genotypes (Spoligotype and MIRU) from cattle originating from different parts of the country strongly suggest intra-contry transmission of BTB.
AFRIKAANSE OPSOMMING: Beestering (BTB), wat veroorsaak word deur bakterieë van die Mycobacterium tuberculosis kompleks, het ‘n negatiewe impak op die ekonomiese en publike gesondheid in lande waar dit voorkom. Die beheer van die siekte is ‘n moeilike taak wêreldwyd. Die hoofdoel van hierdie tesis was om molekulêre toetse te gebruik om nuttige inligting te genereer wat sal bydra tot die ontwikkeling van toepaslike BTB beheermaatrëels in Mosambiek. Om dit te kon doen, was dit noodsaaklik om ‘n indiepte kennies te hê van BTB geskiedenis in Mosambiek. Die soektog was gebaseer op jaarlikse verslae van Veearts Dienste en ander beskikbare inligting. Ons het verslae gevind van BTB in Mosambiek so vroeg as 1940. Hierdie gevalle is hoofsaaklik geïdentifiseer as gevolg van roetine na-doodse inspeksie van vleis. Hoër getalle van sulke gevalle is geïdentifiseer in 8 distrikte, naamlik Maputo, Magude, Vilanculos, Beira, Chimoio, Tete, Quelimane en Nampula; en het gedien as ‘n basis vir die seleksie van studieareas vir die voorkoms studies. Voorkoms studies is uitgevoer in 10 distrikte gekies op grond van die geskiedenis van 'n hoër aantal BTB gevalle in hierdie areas (doelbewus bevooroordeeld teenoor plekke vermoedelik met 'n hoër voorkoms), asook‘n hoë digtheid beeste, maar ook om distrikte in die suide, middel en noorde van Mosambiek te verteenwoordig. ‘n Verteenwoordigende steekproef is geïdentifiseer gebaseer op al die vee-gebiede of dorpe in Massingir and Govuro distrikte óf deur kleinskaalse en kommersiële kuddes lukraak te kies in 8 distrikte, spesifiek Manhica, Chibuto, Busi, Gondola, Mutarara, Mogovolas, Angoche en Mecanhelas. Resultate is verkry deur 6983 beeste te toets met behulp van die tuberkulien vel toets. Skynbare voorkoms het gewissel van 0,98 % in Massingir tot 39,6 % in Govuro, met voorkoms so hoog as 71,4 % in sommige vee gebiede/ kuddes. Die ontleding van risiko faktore het geen noemenswaardige verskil met betrekking tot die geslag van die dier gewys nie. Jonger ouderdom diere het ‘n aansienlike laer kans van infeksie gehad in vergelyking met die ouer ouderdom klas. Daar was 'n neiging van beeste van kleinskaalse kuddes om ‘n laer voorkoms te hê in vergelyking met die kommersiële kuddes. Van die voorkoms studies, is 187 weefsel- en 41 melkmonsters van BTB reaktors ingesamel. ‘n Addisionele 220 weefselmonsters is verkry vanaf die Sentrale Veterinêre Laboratorium se roetine diagnostiese werk. Monsters was onderhewig aan bakteriologiese kweking en 'n versameling van 170 M. bovis isolate is verkry. Agt bykomende isolate is voorsien deur 'n ander studie. Alle isolate was onderhewig aan molekulêre-tipering met behulp van spoligotipering en ‘n subgroep met behulp van MIRU-VNTR en analise van genomies diverse areas. Vyftien verskillende spoligotipering patrone is geïdentifiseer, waarvan 8 nie voorheen in die Mbovis.org databasis geregistreer is nie. Die SB0961 patroon is geïdentifiseer vir 61% van die isolate en gevind in alle dele van die land wat ondersoek was. Ons hipotese is dat hierdie een van die eerste klone was wat voorgestel is in Mosambiek. Nege en twintig isolate het die SB0140 patroon gehad wat spesifiek is aan die Europese 1 (EU1) klonale kompleks. Elf isolate met hierdie spoligotipering patroon is verder geanaliseer om genomies diverse areas te identifiseer, waarvan almal die Eu1 spesifieke delesie getoon het. Hierdie isolate is almal geïsoleer uit beeste van die suide van Mosambiek, asook beeste gevind op kommersiele plase wat hoofsaaklik vanuit Suid Afrika invoer- waar die EU1 klonale kompleks algemeen is. Daar is geen isolate van die Afrikaans 1 (AF1) of Afrikaans 2 (AF2) klonale komplekse nie, dikwels gevind in onderskeidelik Sentraal-Wes-Afrika en Oos- Afrika. Isolate wat in verskillende plase en distrikte geïdentifiser is dui roetes van transmissie en/ of a gemeenskaplike bron van infeksie aan. Ten slotte, ons resultate dui op 'n moontlike toename in die voorkoms van BTB in Mosambiek, selfs met inagneming dat i) die keuse van areas in ons studie is bevooroordeeld teenoor areas met 'n geskiedenis van hoër BTB voorkoms en ii) die gebruik van 'n meer sensitiewe tegniek d.w.s. toetsing in die middel nekgebied i.p.v. toetsing in die stert vou soos gebruik in vorige studies. Selfs al is geen bees-na-mens-oordrag gevind nie, is die bewys van M. bovis oordrag deur melk en die gebrek aan korrekte prosedures om dier-na-mens-oordrag te voorkom (verbruik van nie-gepasturiseerde melk), ‘n sterk bewys van die soönotiese risiko; ‘n onderwerp wat ondersoek moet word. Die resultate van hierdie ondersoek beklemtoon die behoefte om die huidige regulasies wat ‘n negatiewe BTB toetsuitslag vereis voor beeste ingevoer word, te versterk. Dieselfde maatreëls moet ingestel word vir interne beweging van beeste, omdat die frekwensie van gedeelde genotipes (Spoligotipering en MIRU) tussen beeste met oorsprong uit verskillende dele van die land aandui dat interne oordrag van BTB plaasvind.
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Mesa, Christian Requena. „The ecosystem services of the Cerrado trees : modelling, distribution mapping and implications for conservation“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/170195.
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O interesse em valorizar os serviços ecossistêmicos fornecidos pela vegetação natural aumentou em um esforço para mitigar os efeitos da mudança do uso da terra. Nesta linha de pensamento, desenvolvemos um índice para valorar as comunidades de árvores - do ponto de vista antropocêntrico - da savana brasileira (Cerrado). O índice e a cartografia produzida servirão como ferramenta para a priorização da conservação, bem como para revelar como a colonização e a expansão da agricultura tem ocorrido. Para desenvolver o índice, foram produzidas novas camadas ambientais com resolução de 90m; A distribuição das 93 espécies mais comuns foi modelada; e a cartografia da distribuição de cada uso humano das árvores (alimentos, aromáticos, fibras, cosméticos, cortiça, etc., totalizando 20 usos) e um índice de valor total fo desenvolvido. O novo índice de valor, nomenado a Soma de Usos (SoU, Sum of Uses), representa o número esperado de usos para a montagem de espécies potenciais que poderia estar ocorrendo no lugar em condições ideais. O impacto da agricultura foi avaliado pela contabilização da área que foi convertida em lavouras. Nossos resultados indicam fortemente que a colonização humana e a expansão de terras cultivadas eliminaram as árvores de áreas que antes eram melhores prestadores de serviços ambientais. Por outro lado, observamos também que as áreas protegidas no Cerrado estão localizadas onde esperamos encontrar valor marginal para as espécies ótimas. Esses resultados nos levam a pensar que a estratégia de conservação pode estar longe de ser ideal para o maior remanescente arável do mundo.The interest in valuing the ecosystem services provided by the natural vegetation has increased in an effort to mitigate the effects of land use change. In this line of thinking, we developed an index to value the tree communities -from an anthropocentric point of view- of the Brazilian savannah (Cerrado). The index and the cartography produced will serve as a tool for prioritization of conservation, has well as to unveil how colonization and agriculture expansion has taken place. In order to develop the index: new environmental layers at 90m resolution were produced; the most common 93 species’ distribution was modelled; and cartography for each use humans derive from the trees (food, aromatic, fiber, cosmetic, cork, etc., totaling 20 uses) and a total value index were developed. The new index of value, namely the Sum of Uses (SoU), represent the expected number of uses for the potential species assemblage that could be taking place under optimal conditions. The impact of agriculture was assessed by accounting for the area that has been converted to croplands. Our results strongly indicate that human settlement and cropland expansion have cleared the trees of areas that once were better than average ecosystem service providers. On the other hand, we also observe that protected areas in the Cerrado are located where we expect to find marginal value for the optimal communities. These results lead us to think that the conservation strategy might be far from optimal for the largest remaining arable patch in the world.
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Deribe, Kebede. „Mapping the spatial distribution and epidemiology of podoconiosis in Ethiopia : implications for disease control“. Thesis, University of Brighton, 2016. https://research.brighton.ac.uk/en/studentTheses/c3bd5446-7507-4da6-85e7-427778bf59fd.
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In the last ten years, there has been significant progress towards the prevention, control and elimination of podoconiosis as a health problem. There are however gaps in our understanding of the epidemiology and geography of podoconiosis that hinder the planning and scale-up of intervention activities. Therefore, this PhD project aimed to define the current geographical distribution and disease burden of podoconiosis in Ethiopia and investigate underlying risk factors. This thesis adopted two main approaches to understanding distribution: first, historical data were compiled and analysed; second, a nationwide mapping survey was conducted. These data were contextualised through a systematic review of the literature on neglected tropical diseases (NTDs) in Ethiopia. The data were also used to develop elimination targets and endemicity classifications in a Delphi exercise involving a range of international NTD experts.
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Switanek, Matthew B., Peter A. Troch, Christopher L. Castro, Armin Leuprecht, Hsin-I. Chang, Rajarshi Mukherjee und Eleonora M. C. Demaria. „Scaled distribution mapping: a bias correction method that preserves raw climate model projected changes“. COPERNICUS GESELLSCHAFT MBH, 2017. http://hdl.handle.net/10150/624439.
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Commonly used bias correction methods such as quantile mapping (QM) assume the function of error correction values between modeled and observed distributions are stationary or time invariant. This article finds that this function of the error correction values cannot be assumed to be stationary. As a result, QM lacks justification to inflate/deflate various moments of the climate change signal. Previous adaptations of QM, most notably quantile delta mapping (QDM), have been developed that do not rely on this assumption of stationarity. Here, we outline a methodology called scaled distribution mapping (SDM), which is conceptually similar to QDM, but more explicitly accounts for the frequency of rain days and the likelihood of individual events. The SDM method is found to outperform QM, QDM, and detrended QM in its ability to better preserve raw climate model projected changes to meteorological variables such as temperature and precipitation.
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Jones, Jesse Jack. „Effects of Non-homogeneous Population Distribution on Smoothed Maps Produced Using Kernel Density Estimation Methods“. Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699888/.
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Understanding spatial perspectives on the spread and incidence of a disease is invaluable for public health planning and intervention. Choropleth maps are commonly used to provide an abstraction of disease risk across geographic space. These maps are derived from aggregated population counts that are known to be affected by the small numbers problem. Kernel density estimation methods account for this problem by producing risk estimates that are based on aggregations of approximately equal population sizes. However, the process of aggregation often combines data from areas with non-uniform spatial and population characteristics. This thesis presents a new method to aggregate space in ways that are sensitive to their underlying risk factors. Such maps will enable better public health practice and intervention by enhancing our ability to understand the spatial processes that result in disparate health outcomes.
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Presley, DeAnn R. „Genesis and spatial distribution of upland soils in east central Kansas“. Diss., Kansas State University, 2007. http://hdl.handle.net/2097/288.
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Doctor of PhilosophyDepartment of Agronomy
Michel D. Ransom
Upland soils in east central Kansas have a complex genesis, often contain one or more paleosols, and form in multiple parent materials including loess, colluvium, residuum, and alluvium. Quaternary loess/paleosol investigations have largely ignored this region of Kansas, as the total loess thickness on uplands is <2 m thick. In this study, the objectives are to examine the morphology and genesis of the soils of interest and how these characteristics vary within soil profiles, across landscapes, and throughout the current series mapping extent. The series of interest include the Irwin, Konza, Dwight, and Ladysmith soil series. Methods used in this study include field descriptions and sampling, terrain analysis, micromorphological investigations, and laboratory characterization, including silt and clay mineralogy. Accelerator mass spectrometry (AMS) was used for numerical dating and determination of stable carbon isotope values (δ13C) for selected paleosols. Radiocarbon ages ranged from 24,000 to 19,000 yr BP and δ13C values were between -19 and -17 ‰ (PDB), indicating that the paleosols were formed in Gilman Canyon loess or the Severance formation, under a mix of C3 and C4 vegetation. Terrain analysis results illustrated that, in given drainage areas, the soil series were mapped on a wide range of slope positions. Field observations and terrain analysis confirmed no relationships between mollic epipedon thickness, solum thickness, paleosol thickness, or depth to the paleosol with respect to landform. Micromorphological investigations revealed increasing soil development with depth, i.e., the presence of two paleosols beneath the modern soil. Mean particle size and mineralogy vary geographically within individual series. Pedogenic carbonate accumulations and redoximorphic concentrations are common features of the soils of interest, and less common features include sodium and gypsum accumulations, slickensides, and redoximorphic depletions. Results from this study will be provided to the USDA-NRCS for use in future soil survey updates, and will contribute to Quaternary loess/paleosol knowledge in Kansas and the Great Plains.
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Pears, Ben. „The nature, distribution and significance of amended and anthropogenic soils on old arable farms and the elemental analysis of black carbonised particles“. Thesis, University of Stirling, 2009. http://hdl.handle.net/1893/2291.
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Ever since the development of farming humans have been implicitly linked with the landscape. Influences include the manipulation of natural environments by woodland clearance, field developments and animal husbandry. Development can also be determined by the identification and distribution of soils developed and modified by the addition of organic and inorganic components. Anthropogenic or amended soils have been identified in many forms across north west Europe that retain distinctive physical and chemical indications of historical agrarian and settlement history. This thesis researched the on-site distribution of anthropogenic and amended soils across different landuse areas and identified and quantified a range of black carbonised particles in order to investigate their role in the soils ability to retain high elemental concentrations of manuring and elements associated with domestic activity and industrial processes. Three sites in contrasting environments were chosen for analysis; in Fair Isle, the Netherlands and Ireland on the basis of an excellent agararian and settlement history and previous analysis of anthropogenic soils. The fieldwork results showed extremly deep plaggen soils in the Netherlands but considerably shallower horizons of amended arable soils on Fair Isle and in Ireland contrary to previous analysis. There was however, clear evidence of a reduction in anthropogenic and amended soils with increased distance from the farm centres as a result of less manuring. The soil pH, organic matter, particle size, magnetic susceptibility and bulk elemental analysis results showed unexpected increases in the amended soils of Fair Isle and Ireland and reflected a similar manuring process. In the Netherlands the deep plaggen soils had very low results reflecting modern arable farming. The micromorphology results illustrated distinctive characteristics associated with localised manuring techniques. On Fair Isle and in Ireland the main organic manuring material was peat and burnt peat, whereas in the Netherlands the plaggen soils were predominantly composed of meadowland and heathland turf. At all three sites there was a large number of black carbonised and black amorphous inclusions and point counting and image analysis results showed a decrease with depth and distance from settlement nucleii mirroring the fieldwork observations. The elemental analysis conducted has proved to be an extremly useful tool for the identification of various forms of black carbon and for identifying the provenance of high elemental concentrations. The oxygen:carbon ratios confirmed the origins of organic components used in the development of the amended and anthropogenic soils and the elemental analysis showed that at each site over 80% of visually unidentifiable amorphous black carbon particles were heavily decomposed carbonised inclusions. Overall the elemental concentrations within the black carbonised particles was very low but this reflected the elemental results found in the bulk soils and the inclusions contained higher concentrations of P, Ca, K, Fe and Al and considerably lower concentrations of elements associated with domestic activity or industry Zn, Cu, Ba, Cr, As and Pb.
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Skjønsfjell, Eirik Torbjørn Bakken. „Mapping Orientation Distribution of Talc Particles in Polypropylene by Small-Angle X-ray Scattering Tomography“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23619.
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Small-angle X-ray scattering tomography has for the first time been used toinvestigate the spatially resolved orientation distribution of talc particles in asample of injection molded isotactic polypropylene, where the particles had apreferred orientation along the axis of the injection. The scattering patternsin the direction perpendicular to the rotation axis of the tomography scanwere used to retrieve the orientation distribution in a 2D cross section of thesample.Two different methods are presented, one using a numerical approach ofsimulated annealing and one method using a linear set of equations to findthe distances the X-ray beam travels through the different orientation regions.The method of simulated annealing showed little to no promise inretrieving the orientation distribution while the method using a linear setof equations is successful at retrieving the main features of the orientationdistribution. The resolution is however not yet good enough to distinguishfine details inside the sample.It is believed that with further work on the model used and additional constraintson the reconstruction algorithm higher precision in the retrievedorientation distribution can be achieved.
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Nguyen, Thi Hong Diep, Glino Gallardo Wenresti, Kumar Tripathi Nitin und Hoang Minh Truong. „Cobia cage culture distribution mapping and carrying capacity assessment in Phu Quoc, Kien Giang province“. Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-126816.
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Cobia fish cage is the most popular marine culture species raised in Phu Quoc Island, Vietnam. For its sustainable development, there is a need to determine the carrying capacity to avoid nega-tive marine environmental impact in the future. This study was carried out to collect water samples each two months at the lowest and highest tides at four points around the farming area in Rach Vem, Phu Quoc Island, Kien Giang Province from February to October 2011. Water quality in cobia cage culture was surveyed to assess the environmental status of coastal aquaculture areas including seven parameters such as DO, COD, BOD, TSS, TN, TP and Chlorophyll-a. These parameters are suitable to rear cobia fish cage in this area. Nitrogen and phosphorus are considered as the principal nutrients produced by the cobia fish farm and affecting water environment. This study found that the carrying capacity for fish cage farming in the area is 290.96 to 727.81 tons (based on total nitrogen) and 428.64 to 1,383.88 tons (based on total phosphorus) from February to Au-gust 2011. The maximum number of cobia cages should be, based on total nitrogen, from 64 to 266 and, based on total phosphorus, from 94 to 253. Moreover, this study examined the possibility of remote sensing and geographic information system (GIS) technique based on Object-based Image Analysis (OBIA) method by THEOS imagery for mapping of cage culture facilities and detect the location for cobia cage culture in study areaCá bớp nuôi lồng bè là một trong những loài cá nuôi phổ biến khu vực ven biển Phú Quốc, Việt nam. Nhằm phát triển bền vững vùng ven biển, đề tài thực hiện đã xác định và đánh giá hiện trạng môi trường nước và sức tải môi trường của nghề nuôi cá bớp lồng bè ở đảo Phú Quốc. Nghiên cứu này được thực hiện thông qua việc thu mẫu môi trường nước mỗi 2 tháng theo mức nước triều cao nhất và thấp nhất tại 4 điểm quanh khu vực nuôi tại ấp Rạch Vẹm, huyện Phú Quốc, tỉnh Kiên Giang từ tháng 02-10/2011. Chất lượng nước khu vực nuôi thủy sản cũng được khảo sát với 7 chỉ tiêu gồm DO, COD, BOD, TSS, TN, TP, Chlorophyll-a. Các thông số chất lượng môi trường này phù hợp nuôi cá bớp tại khu vực nghiên cứu dựa trên tiêu chuẩn chất lượng môi trường. Trong nghiên cứu này, đạm và lân là 2 thông số được sử dụng để tính toán sức tải môi trường. Sức tải môi trường được tính toán cho khu vực nuôi cá bớp dao động khoảng từ 290.96 tấn đến 727.81 tấn (tính trên hàm lượng đạm tổng số) và từ 428,64 tấn đến 1.383,88 tấn (tính trên hàm lượng lân tổng số) trong thời gian từ tháng 2 đến tháng 10 năm 2011. Số lượng tối đa lồng bè nuôi cá bớp khoảng từ 64 đến 266 (đạm tổng số) và từ 94 đến 253 (lân tổng số) dựa vào phân tích hồi quy tương quan. Bên cạnh đó, công nghệ viễn thám và hệ thống thông tin địa lý (GIS) đã được ứng dụng bằng cách sử dụng ảnh THEOS để xác định vị trí và phân bố không gian khu vực nuôi cá lồng bè dựa trên phương pháp phân tích đối tượng theo hướng (OBIA)
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Reeve, Kelsie Ann. „Wintertime factors affecting contaminant distribution in farrowing barns“. Thesis, University of Iowa, 2012. https://ir.uiowa.edu/etd/3371.
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Respirable dust, carbon dioxide, ammonia, hydrogen sulfide, and carbon monoxide concentrations were measured using fixed-area monitoring and contaminant mapping in a 19–crate farrowing room during the winter. Direct–reading instruments were used with fixed–area stations and contaminant mapping to evaluate concentrations during five days over a period of a three–week farrowing cycle. Concentrations were evaluated to determine the effect of the pit ventilation on contaminant concentrations, a change in concentration occurred over a sample day, and to determine if three data collection methods produce different daily respirable dust concentrations.
Pit ventilation did have a significant effect on contaminant concentration in a farrowing barn during winter. Compared to when the pit fan was on, mean area contaminant concentration, with the exception of CO, was significantly higher when the pit fan was turned off (p<0.001). Mean respirable dust concentration was 79% higher, CO2 concentration was 35% higher, NH3 increased from 0.03 ppm to 10.8 ppm, and H2S concentrations increased from 0.03 ppm to 0.67 ppm. A significant change in area respirable dust (p<0.001) and CO2 (p<0.001) mean concentrations occurred over time throughout the course of a sample day. Mean area respirable dust concentrations were highest in the beginning of the sample day and decreased by 77 % (pit fan off) to 87% (pit fan on) over a five–hour sample period. Higher concentrations were likely attributed to the feeding period that occurred early in the day. When the pit fan was turned off, mean area CO2 concentrations increased by 24% by the end of the sample day due to the inefficient ventilation and the constant production of CO2 generated by the swine. Finally, comparing the three data collection methods produced similar results concerning the ranking of the daily mean concentrations of respirable dust; however, differences were seen in the magnitude of the daily average respirable dust concentrations across the three data collection methods, which might lead to different interpretations of risk. To ensure risk is not underestimated, multiple fixed–area monitors are recommended to characterize room concentrations.
Throughout the study, contaminant concentration did not exceed regulatory or international consensus standards; however, recommended agricultural health limits suggested in the literature were exceeded for respirable dust, CO2, and NH3. These findings indicate the need to consider personal exposures to those working in farrowing barns and control options to reduce these contaminant concentrations in production facilities.
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Reggente, Matteo. „Statistical gas distribution modelling for mobile robot applications“. Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-37896.
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In this dissertation, we present and evaluate algorithms for statistical gas distribution modelling in mobile robot applications. We derive a representation of the gas distribution in natural environments using gas measurements collected with mobile robots. The algorithms fuse different sensors readings (gas, wind and location) to create 2D or 3D maps. Throughout this thesis, the Kernel DM+V algorithm plays a central role in modelling the gas distribution. The key idea is the spatial extrapolation of the gas measurement using a Gaussian kernel. The algorithm produces four maps: the weight map shows the density of the measurements; the confidence map shows areas in which the model is considered being trustful; the mean map represents the modelled gas distribution; the variance map represents the spatial structure of the variance of the mean estimate. The Kernel DM+V/W algorithm incorporates wind measurements in the computation of the models by modifying the shape of the Gaussian kernel according to the local wind direction and magnitude. The Kernel 3D-DM+V/W algorithm extends the previous algorithm to the third dimension using a tri-variate Gaussian kernel. Ground-truth evaluation is a critical issue for gas distribution modelling with mobile platforms. We propose two methods to evaluate gas distribution models. Firstly, we create a ground-truth gas distribution using a simulation environment, and we compare the models with this ground-truth gas distribution. Secondly, considering that a good model should explain the measurements and accurately predicts new ones, we evaluate the models according to their ability in inferring unseen gas concentrations. We evaluate the algorithms carrying out experiments in different environments. We start with a simulated environment and we end in urban applications, in which we integrated gas sensors on robots designed for urban hygiene. We found that typically the models that comprise wind information outperform the models that do not include the wind data.
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Eisfelder, Christina. „Modelling Net Primary Productivity and Above-Ground Biomass for Mapping of Spatial Biomass Distribution in Kazakhstan“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-119964.
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Biomass is an important ecological variable for understanding the responses of vegetation to the currently observed global change. The impact of changes in vegetation biomass on the global ecosystem is also of high relevance. The vegetation in the arid and semi-arid environments of Kazakhstan is expected to be affected particularly strongly by future climate change. Therefore, it is of great interest to observe large-scale vegetation dynamics and biomass distribution in Kazakhstan.
At the beginning of this dissertation, previous research activities and remote-sensing-based methods for biomass estimation in semi-arid regions have been comprehensively reviewed for the first time. The review revealed that the biggest challenge is the transferability of methods in time and space. Empirical approaches, which are predominantly applied, proved to be hardly transferable. Remote-sensing-based Net Primary Productivity (NPP) models, on the other hand, allow for regional to continental modelling of NPP time-series and are potentially transferable to new regions.
This thesis thus deals with modelling and analysis of NPP time-series for Kazakhstan and presents a methodological concept for derivation of above-ground biomass estimates based on NPP data. For validation of the results, biomass field data were collected in three study areas in Kazakhstan. For the selection of an appropriate model, two remote-sensing-based NPP models were applied to a study area in Central Kazakhstan. The first is the Regional Biomass Model (RBM). The second is the Biosphere Energy Transfer Hydrology Model (BETHY/DLR). Both models were applied to Kazakhstan for the first time in this dissertation. Differences in the modelling approaches, intermediate products, and calculated NPP, as well as their temporal characteristics were analysed and discussed.
The model BETHY/DLR was then used to calculate NPP for Kazakhstan for 2003–2011. The results were analysed regarding spatial, intra-annual, and inter-annual variations. In addition, the correlation between NPP and meteorological parameters was analysed. In the last part of this dissertation, a methodological concept for derivation of above-ground biomass estimates of natural vegetation from NPP time-series has been developed. The concept is based on the NPP time-series, information about fractional cover of herbaceous and woody vegetation, and plants’ relative growth rates (RGRs). It has been the first time that these parameters are combined for biomass estimation in semi-arid regions. The developed approach was finally applied to estimate biomass for the three study areas in Kazakhstan and validated with field data.
The results of this dissertation provide information about the vegetation dynamics in Kazakhstan for 2003–2011. This is valuable information for a sustainable land management and the identification of regions that are potentially affected by a changing climate. Furthermore, a methodological concept for the estimation of biomass based on NPP time-series is presented. The developed method is potentially transferable. Providing that the required information regarding vegetation distribution and fractional cover is available, the method will allow for repeated and large-area biomass estimation for natural vegetation in Kazakhstan and other semi-arid environments.
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Stedman, Jacqueline D. „Regional distribution of elemental concentrations in brain tissue of #normal' ageing and sporadic Alzheimer's disease subjects as determined by PIXE, RBS and INA analyses“. Thesis, University of Surrey, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318698.
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Holmqvist, Niclas. „HANDHELD LIDAR ODOMETRY ESTIMATION AND MAPPING SYSTEM“. Thesis, Mälardalens högskola, Inbyggda system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-41137.
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Ego-motion sensors are commonly used for pose estimation in Simultaneous Localization And Mapping (SLAM) algorithms. Inertial Measurement Units (IMUs) are popular sensors but suffer from integration drift over longer time scales. To remedy the drift they are often used in combination with additional sensors, such as a LiDAR. Pose estimation is used when scans, produced by these additional sensors, are being matched. The matching of scans can be computationally heavy as one scan can contain millions of data points. Methods exist to simplify the problem of finding the relative pose between sensor data, such as the Normal Distribution Transform SLAM algorithm. The algorithm separates the point cloud data into a voxelgrid and represent each voxel as a normal distribution, effectively decreasing the amount of data points. Registration is based on a function which converges to a minimum. Sub-optimal conditions can cause the function to converge at a local minimum. To remedy this problem this thesis explores the benefits of combining IMU sensor data to estimate the pose to be used in the NDT SLAM algorithm.
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Beasley, Daniel. „3D quantitative elemental mapping of biological tissues using proton induced X-ray emission tomography (PIXE-T) and on/off-axis scanning transmission ion microscopy tomography (STIM-T)“. Thesis, University of Surrey, 2006. http://epubs.surrey.ac.uk/843466/.
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A novel experimental set-up was installed at the University of Surrey Ion Beam Centre for the purpose of producing 3D quantitative elemental maps of biological samples by combining simultaneous Proton Induced X-Ray Emission Tomography (PIXE- T), on/off-Axis Scanning Transmission Ion Microscopy-Tomography (STIM-T) and Rutherford Backscatter Spectrometry (RBS). A tomographic sample holder was designed and built and a scattering system developed for On/Off-Axis STIM. 2D PIXE and off-STIM analysis of leukocytes was performed to complement concurrent research and to identify problems with the very recently installed proton microbeam at the Ion Beam Centre. The other major aim was to see if a leukocyte would be a suitable sample for tomographic analysis and to study the damage induced by the beam on biological samples. Instrumental Neutron Activation Analysis (INAA) was performed on hair samples collected from MSc students at the University of Surrey and a database compiled of all elemental analysis of hair performed at the University. This complemented the tomographic analysis performed on a section of a strand of hair. Si, S, Cl, K, Ca, Fe and Zn were mapped using simultaneous PIXE-T, On/Off- Axis STIM-T and RBS.
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Rice, John B. Jr. „Spatial and Temporal Landslide Distribution and Hazard Evaluation Analyzed by Photogeologic Mapping and Relative-Dating Techniques, Salt River Range, Wyoming“. DigitalCommons@USU, 1987. https://digitalcommons.usu.edu/etd/6553.
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The distribution of landslide type and age was analyzed to determine the causes and timing of landsliding, and to assess landslide hazards in the study area. 1173 landslides and zones of landsliding were mapped on 1:15,840 scale air photos and designated by their style of movement and age. Slides were assigned to one of four age classes based on their degree of m orphologic modification visible on air photos. Relative dating (RD) methods previously applied to glacial deposits were used to refine and calibrate the age classification.
Eleven RD para meters were measured on 21 rockslide and 19 glacial deposits. Cluster analyses were run on the RD data set. Slides assigned to Age-Classes 4, 3+, and 2 tend to cluster with probable Pinedale, early Holocene, and Neoglacial-age moraines respectively. Cluster analyses indicate poor age resolution by the RD method from approximately early Altithermal to early Neoglacial time. Landslide age cannot be resolved in this study to a finer degree by the RD method than by the morphologic (air -photo) method. However, cluster analyses generally confirm age assignments and absolute age estimates of the four landslide age classes, despite limitations of the RD method such as boulder spalling, and variations in lithology, deposit type, and elevation/climate between sampled deposits.
The temporal distribution of landslides indicates that mass movements may have occurred rather uniformly throughout Holocene time, with slightly higher rates of sliding during post-Altithermal time due to climatic effects associated with Neoglacial advances.
Spatial analyses indicate that landslides cover 73% of the Cretaceous section. Development, such as logging and road construction, could trigger landsliding in the Cretaceous section.
Landslides account for 15% and 10% of the outcrop areas of the Paleozoic and Triassic-Jurassic sections respectively. Debris flows and slump-earth flows dominate sliding in both sections, with minor numbers of rockslides present. Debris flows pose the greatest hazard in both sections. Fine-grained stratigraphic units have the highest landslide densities in both sections. The previous event locations define areas most susceptible to future sliding.
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Realmuto, Vincent James 1958. „Mapping the distribution of wet soils through the use of reflectance modeling : Dragoon Mountains, Cochise County, Arizona“. Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/191155.
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Soils darken upon wetting due to changes in the scattering properties of the individual soil particles. The objective of this research was to develop a procedure to map the distribution of wet soils using the radiance measurements acquired by a spaceborne imaging scanner. The soil-mapping procedure was designed for use in the regional exploration for ground water resources. The soil-mapping procedure was based upon the detection of reflectance changes in a comparison of Landsat 5 Thematic Mapper (TM) scenes acquired before and after a rain. The Stronghold watershed, which is situated on the western slopes of the Dragoon Mountains, Cochise County, Arizona, was chosen as the test site for the soil-mapping procedure. TM scenes depicting the watershed on 7 June 1985 and 14 November 1985 were used in the change-detection analysis. The region was dry at the time of the June overpass, the November overpass occurred two days after a rain. The recovery of reflectance from radiance requires knowledge of 1) the orientation of the surface relative to the sun and the satellite, 2) the exoatmospheric solar irradiance, 3) the atmospheric optical depth, and 4) the atmospheric path radiance. The orientation of the surface elements were defined through the use of a digital elevation model of the Stronghold watershed. The solar irradiance and atmospheric optical depth were obtained from the literature; the atmospheric path radiance was estimated from shadowed areas depicted in the images. Temporal changes in reflectance were detected by subtracting the November reflectance estimates from those recovered from the June radiance measurements. Changes significant at the 0.05 level were identified through use of the Student-t test. The identical significance level was used to identify temporal changes in the Perpendicular Vegetation Index, or PVI. A surface element was classified as an anomaly if there was a significant temporal change in reflectance with no attendant change in PVI. Field checks of the anomalies proved that wet soils could be mapped via the remote detection of changes in their reflectance. The majority of the false anomalies could be attributed to the disparity between the spatial resolutions of the radiance measurements and the topographic data.
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Baigas, Phillip E. „Winter habitat selection, winter diet, and seasonal distribution mapping of moose (Alces alces shirasi) in southeastern Wyoming“. Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1797714121&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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