Elemental analyses of hypervelocity microparticle impact sites on Interplanetary Dust Experiment sensor surfaces

The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to break down the 0.4 or 1.0 micron thick SIO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle impact sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results were used to classify the particles' origins as 'manmade,' 'natural,' or 'indeterminate.' The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters of these features. Thus far a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF have been analyzed: 36 from tray C-9 (Leading (ram), or East, side), 18 from tray C-3 (Trailing (wake), or West, side), 12 from tray B-12 (North side), 4 from tray D-6 (South side), 3 from tray H-11 (Space end), and 6 from tray G-10 (Earth end). Residue from manmade debris was identified in craters on all trays. (Aluminum oxide particle residues were not detectable on the Al/Si substrates.) These results were consistent with the IDE impact record which showed highly variable long term microparticle impact flux rates on the West, Space and Earth sides of the LDEF which could not be ascribed to astronomical variability of micrometeorite density. The IDE record also showed episodic bursts of microparticle impacts on the East, North, and South sides of the satellite, denoting passage through orbital debris clouds or rings

Applications of mineral chemistry to petrogenesis and exploration in conduit-type Cu-PGE deposits

The mineralogy and mineral chemistry of Fe-Ti oxides, sulfides, and vein-hosted silicates has been used to characterize the petrogenesis of the Eastern Gabbro of the Coldwell Complex, Ontario, to better characterize the processes that generated and modified copper and platinum-group element (PGE) mineralization that it contains, and to develop and test exploration tools in this system. Understanding these processes is critical to an understanding of conduit-type Cu-PGE systems and their exploration potential. Fe-Ti oxides in the Eastern Gabbro exhibit a continuum of mineralogically distinct exsolution textures. Trellis-type intergrowths, which have systematically higher Fe3+ : Fe2+ and multivalent-element concentrations than cloth-type intergrowths, formed through subsolidus oxidation of the latter by a CO2-rich fluid. Variable distribution of cloth- and trellis-type intergrowths in different rock types and mineralized occurrences in the Eastern Gabbro indicate that they experienced different degrees of fluid-induced oxidation. The elements that are typically used for petrogenesis were not affected by subsolidus oxidation as this process only affected the concentration of a few multivalent elements. Accordingly, oxide chemistry indicates that the metabasalt and Layered Series of the Eastern Gabbro crystallized from magmas that experienced little to no magma mixing, with the latter having crystallized from a more evolved magma than the former. The later, mineralized Marathon Series crystallized from mixtures of several physically and compositionally distinct magmas. These features are consistent with formation of the mineralization in the Marathon Series in a magma conduit. The data from the Eastern Gabbro indicate that the chemistry of oxides is not a robust indicator of mineralization because oxide chemistry is the same in mineralized and barren rock, and because mineralization could not be accurately identified using previously-developed petrogenetic tools that use oxide chemistry. An understanding of the processes that generate and modify mineralization can help identify exploration targets in variably mineralized plutons. The compositional similarity between magmatic and hydrothermal chalcopyrite, which occur throughout the Eastern Gabbro, indicate that the latter formed through the local dissolution and re-precipitation of the former. Variations in whole-rock Cu/Pd and sulfide S/Se demonstrates that two dominant processes generated the variable Cu/Pd mineralization in the Eastern Gabbro. First, mineralized zones in different parts of the system were variably contaminated by rocks with low and high S/Se. Second, sulfides in different zones experienced different R factors, which resulted in mineralization with variable PGE grades. The trace-element chemistry of vein minerals in late-stage hydrothermal veins is largely independent of local controls (e.g., host rock, host mineral). Although their chemistry appears to vary with proximity to mineralization, this interpretation is misleading as the same variability is observed with proximity to the footwall contact. Their chemistry is, therefore, not a robust vector for mineralization. Variations in vein density, however, may provide a valuable tool for locating zones of mineralization. This demonstrates the need to assess the sources of metals in vein-hosted minerals prior to the application of their chemistry to mineral exploration

CIRSS vertical data integration, San Bernardino study

The creation and use of a vertically integrated data base, including LANDSAT data, for local planning purposes in a portion of San Bernardino County, California are described. The project illustrates that a vertically integrated approach can benefit local users, can be used to identify and rectify discrepancies in various data sources, and that the LANDSAT component can be effectively used to identify change, perform initial capability/suitability modeling, update existing data, and refine existing data in a geographic information system. Local analyses were developed which produced data of value to planners in the San Bernardino County Planning Department and the San Bernardino National Forest staff

Image analysis techniques for classification of pulmonary disease in cattle

Histologic analysis of tissue samples is often a critical step in the diagnosis of disease. However, this type of assessment is inherently subjective, and consequently a high degree of variability may occur between results produced by different pathologists. Histologic analysis is also a very time-consuming task for pathologists. Computer-based quantitative analysis of tissue samples shows promise for both reducing the subjectivity of traditional manual tissue assessments, as well as potentially reducing the time required to analyze each sample. The objective of this thesis project was to investigate image processing techniques and to develop software which could be used as a diagnostic aid in pathology assessments of cattle lung tissue samples. The software examines digital images of tissue samples, identifying and highlighting the presence of a set of features that indicate disease, and that can be used to distinguish various pulmonary diseases from one another. The output of the software is a series of segmented images with relevant disease indicators highlighted, and measurements quantifying the occurrence of these features within the tissue samples. Results of the software analysis of a set of 50 cattle lung tissue samples were compared to the detailed manual analysis of these samples by a pathology expert.The combination of image analysis techniques implemented in the thesis software shows potential. Detection of each of the disease indicators is successful to some extent, and in some cases the analysis results are extremely good. There is a large difference in accuracy rates for identification of the set of disease indicators, however, with sensitivity values ranging from a high of 94.8% to a low of 22.6%. This wide variation in result scores is partially due to limitations of the methodology used to determine accuracy

Large-Scale Textured 3D Scene Reconstruction

Die Erstellung dreidimensionaler Umgebungsmodelle ist eine fundamentale Aufgabe im Bereich des maschinellen Sehens. Rekonstruktionen sind für eine Reihe von Anwendungen von Nutzen, wie bei der Vermessung, dem Erhalt von Kulturgütern oder der Erstellung virtueller Welten in der Unterhaltungsindustrie. Im Bereich des automatischen Fahrens helfen sie bei der Bewältigung einer Vielzahl an Herausforderungen. Dazu gehören Lokalisierung, das Annotieren großer Datensätze oder die vollautomatische Erstellung von Simulationsszenarien. Die Herausforderung bei der 3D Rekonstruktion ist die gemeinsame Schätzung von Sensorposen und einem Umgebunsmodell. Redundante und potenziell fehlerbehaftete Messungen verschiedener Sensoren müssen in eine gemeinsame Repräsentation der Welt integriert werden, um ein metrisch und photometrisch korrektes Modell zu erhalten. Gleichzeitig muss die Methode effizient Ressourcen nutzen, um Laufzeiten zu erreichen, welche die praktische Nutzung ermöglichen. In dieser Arbeit stellen wir ein Verfahren zur Rekonstruktion vor, das fähig ist, photorealistische 3D Rekonstruktionen großer Areale zu erstellen, die sich über mehrere Kilometer erstrecken. Entfernungsmessungen aus Laserscannern und Stereokamerasystemen werden zusammen mit Hilfe eines volumetrischen Rekonstruktionsverfahrens fusioniert. Ringschlüsse werden erkannt und als zusätzliche Bedingungen eingebracht, um eine global konsistente Karte zu erhalten. Das resultierende Gitternetz wird aus Kamerabildern texturiert, wobei die einzelnen Beobachtungen mit ihrer Güte gewichtet werden. Für eine nahtlose Erscheinung werden die unbekannten Belichtungszeiten und Parameter des optischen Systems mitgeschätzt und die Bilder entsprechend korrigiert. Wir evaluieren unsere Methode auf synthetischen Daten, realen Sensordaten unseres Versuchsfahrzeugs und öffentlich verfügbaren Datensätzen. Wir zeigen qualitative Ergebnisse großer innerstädtischer Bereiche, sowie quantitative Auswertungen der Fahrzeugtrajektorie und der Rekonstruktionsqualität. Zuletzt präsentieren wir mehrere Anwendungen und zeigen somit den Nutzen unserer Methode für Anwendungen im Bereich des automatischen Fahrens

Detection of humidity-treated aged latent prints using cyanoacrylate fuming and a reflected ultraviolet imaging system (RUVIS)

For the past several decades, challenges in the detection and collection of latent prints exposed to harsh environmental conditions have inspired research in pretreatment methods prior to the application of chemical, physical, or optical-based enhancement techniques. Some of the difficulties associated with processing degraded latent prints are attributed to dehydration, alterations in chemical composition, and physical disturbance of ridge detail. This study seeks to investigate the effectiveness of humidity, cyanoacrylate fuming method (CFM), and a reflected ultraviolet imaging system (RUVIS) on the detection and collection of aged latent palmprints. Prints were exposed to air flow and ultraviolet (UV) light for a period of 0 to 28 days, and subsequently treated with either cool or warm humidity and CFM. RUVIS was then utilized to detect and capture friction ridge detail after each treatment step. Improvements in RUVIS detection between treatments were evaluated based on four response factors: minutiae count, percent print recovery, ridge thickness and contrast. By measuring these factors, each latent print photograph was able to be converted to quantifiable data to facilitate statistical analysis of potential differences or improvements between treatments. The results demonstrate that the application of 80% relative humidity successfully revived aged latent palmprints across all factors. The combined effect of humidity followed v by CFM treatment and RUVIS detection was greatest for minutiae count and ridge thickness, while percent print recovery and contrast demonstrated more modest improvements when compared to control prints. Additionally, cool temperature treatments outperformed warm temperature treatments across all factors except contrast. The data therefore suggest that to achieve print rejuvenation and overall improvements in RUVIS detection, combined cool humidity and CFM is more effective than humidity alone. The data also indicate a potential correlation between temperature treatments and latent print age. Warm humidity combined with CFM appeared to best enhance RUVIS images on fresher prints of a few days to one week old, while cool humidity and CFM appeared to maximally enhance RUVIS images on prints of several weeks old

Development of techniques for high-resolution spatially-resolved elemental analysis in materials of interest in luminescence dating

A series of analytical techniques have been developed to characterise the surface distribution of elements in a number of materials of archaeological interest, in support of current and future research in luminescence dating techniques. Under certain circumstances, sample heterogeneity, with respect to naturally occurring radionuclides, may significantly reduce the levels of accuracy associated with experimentally determined luminescence dates. The aim of this thesis is to develop a series of high-resolution, spatially resolved techniques to assess and quantify the degree of matrix (material fabric) radionuclide heterogeneity present in a number of archaeological materials. Digital analysis and mineralogical staining techniques were combined to provide initial data regarding matrix heterogeneity and the distribution patterns of potassium-bearing minerals and in some cases, provided data that were comparable to those derived from SEM-EDX analyses. Alpha autoradiographic techniques using solid state nuclear track detectors (CR-39) were applied initially to map localised differences in surface alpha activity, and were subsequently developed to provide semi-quantitative data about the concentration of alpha emitters present, and by association, the likely concentrations of uranium and thorium. Micro-sampling techniques were developed to produce material for instrumental analysis (ICP-MS and AAS), to provide quantitative information about the concentrations of uranium, thorium and potassium in the areas of interest, highlighted by the application of the aforementioned techniques. The techniques were successfully applied in a number of case studies, providing both quantitative and qualitative information relating to material characteristics with respect to luminescence dating techniques

A Review of Codebook Models in Patch-Based Visual Object Recognition

The codebook model-based approach, while ignoring any structural aspect in vision, nonetheless provides state-of-the-art performances on current datasets. The key role of a visual codebook is to provide a way to map the low-level features into a fixed-length vector in histogram space to which standard classifiers can be directly applied. The discriminative power of such a visual codebook determines the quality of the codebook model, whereas the size of the codebook controls the complexity of the model. Thus, the construction of a codebook is an important step which is usually done by cluster analysis. However, clustering is a process that retains regions of high density in a distribution and it follows that the resulting codebook need not have discriminant properties. This is also recognised as a computational bottleneck of such systems. In our recent work, we proposed a resource-allocating codebook, to constructing a discriminant codebook in a one-pass design procedure that slightly outperforms more traditional approaches at drastically reduced computing times. In this review we survey several approaches that have been proposed over the last decade with their use of feature detectors, descriptors, codebook construction schemes, choice of classifiers in recognising objects, and datasets that were used in evaluating the proposed methods

Application of Multivariate Statistical Methodology to Model Factors Influencing Fate and Transport of Fecal Pollution in Surface Waters

Degraded surface water quality is a growing public health concern. While indicator organisms are frequently used as a surrogate measure of pathogen contamination, poor correlation is often observed between indicators and pathogens. Because of adverse health effects associated with poor water quality, an assessment of the factors influencing the fate and transport of fecal pollution is necessary to identify sources and effectively design and implement Best Management Practices (BMPs) to protect and restore surface water quality. Sinking Creek is listed on the State of Tennessee’s 303D list as impaired due to pathogen contamination. The need to address the listing of this and other water bodies on the 303D list through the Total Maximum Daily Load (TMDL) process has resulted in increased research to find methods that effectively and universally identify sources of fecal pollution. The main objective of this research is to better understand how microbial, chemical, and physical factors influence pathogen fate and transport in Sinking Creek. This increased understanding can be used to improve source identification and remediation. To accomplish this objective, physical, chemical, and microbial water quality parameters were measured and the data were analyzed using multivariate statistical methods to identify those parameters influencing pathogen fate and transport. Physical, chemical, and microbial water and soil properties were also characterized along Sinking Creek to determine their influences on the introduction of fecal pollution to surface water. Results indicate that the 30-day geometric mean of fecal indicator organisms is not representative of true watershed dynamics and that their presence does not correlate with the presence of bacterial, protozoan, or viral pathogens in Sinking Creek. The use of multivariate statistical analyses coupled with a targeted water quality-monitoring program has demonstrated that nonpoint sources of fecal pollution vary spatially and temporally and are related to land use patterns. It is suggested that this data analysis approach can be used to effectively identify nonpoint sources of fecal pollution in surface water