Miracle-dz/UniFAR-FTUs huggingface dataset:
Forest‐Induced Exponential Growth of Precipitation Along Climatological Wind Streamlines Over the Amazon

The Amazon forests and climatological precipitation patterns in South America are interrelated. A fundamental question is how these patterns depend on the presence of forests. Here we investigate this relationship by studying how precipitation varies with distance from the ocean along wind streamlines linking the Atlantic Ocean to northwestern and southern South America through the Amazon forests. Through a robust observation‐based analysis, we found that precipitation exponentially increases with distance from the ocean along wind streamlines flowing over forests, while it exponentially decreases downwind of the forests. These patterns are consistent with multiple mechanisms through which forests influence the transport of atmospheric moisture and precipitation production over the continent. We propose a conceptual explanation of this forest influence based on the atmospheric water balance. Our results imply that a major consequence of the degradation or loss of forests may be a disruption of these mechanisms, with widespread impacts on continental precipitation.
Was the Laurentide Ice Sheet significantly reduced during Marine Isotope Stage 3?

Accurately reconstructing the paleogeography of the Laurentide Ice Sheet (LIS) during Marine Isotope Stage 3 (MIS 3; ca. 57,000 to ca. 29,000 yr B.P.) is critical for understanding glacial growth toward the Last Glacial Maximum (LGM), refining sea-level histories, and studying the Earth system response to rapid climate change events. Here, we present a geochronological data set useful for testing hypotheses of global sea level and refining ice sheet configuration through this interval. Data (n = 735) span the entire MIS 3 interval and consist of 14C determinations (n = 651), cosmogenic exposure ages (n = 52), and optically stimulated luminescence dates (n = 32). On that basis, we hypothesize that the central region of the LIS underwent a dramatic reduction in ice from ca. 52 to 40 ka. Key to this hypothesis are geological records at sites in the Hudson Bay Lowlands (east central Canada) that suggest a marine incursion and development of terrestrial landscapes. We show that these landscapes are consistent with recently published glacial isostatic adjustment predictions that include widespread deglaciation of the eastern (Labrador) sector of the LIS with ice buildup over the western (Keewatin) sector at 42 ka. Ice growth from this minimum toward the LGM is likely to have been rapid. The agreement between this data set and modeling predictions prompts the reassessment of key Late Pleistocene records, including Heinrich events, loess deposition in the continental United States, and sedimentological records from the Gulf of Mexico.
Clethodim resistance in Lolium rigidum (annual ryegrass) and its management in broadleaf crops

v DECLARATION . vii PUBLICATIONS ARISING FROM THIS THESIS . viii FIGURES PUBLISHED WITH CONSENT FROM COPYRIGHT HOLDERS IN THIS THESIS . x ACKNOWLEDGEMENTS . xi ACRONYMS . xiii . 1 CHAPTER 1 Review of Literature 1.
Delay Stability of Back-Pressure Policies in the Presence of Heavy-Tailed Traffic

We study multihop networks with flow-scheduling constraints, no constraints on simultaneous activation of different links, potentially multiple source-destination routes, and a mix of heavy-tailed and light-tailed traffic. In this setting, we analyze the delay performance of the widely studied class of Back-Pressure scheduling policies, known for their throughput optimality property, using as a performance criterion the notion of delay stability, i.e., whether the expected end-to-end delay in steady state is finite. Our analysis highlights the significance of “bottleneck links,” i.e., links that are allowed to serve the source queues of heavy-tailed flows. The main idea is that traffic that has to pass through bottleneck links experiences large delays under Back-Pressure. By means of simple examples, we provide insights into how the network topology, the routing constraints, and the link capacities may facilitate or hinder the ability of light-tailed flows to avoid bottlenecks. Our delay-stability analysis is greatly simplified by the use of fluid approximations, allowing us to derive analytical results that would have been hard to obtain through purely stochastic arguments. Finally, we show how to achieve the best performance with respect to the delay stability criterion, by using a parameterized version of the Back-Pressure policy.
Friction Surfacing of Aluminium Alloys

Friction surfacing is a solid state technique that aroused interest, special to process thermo-sensitive materials, since it avoids the melted phase preventing the formation of intermetallics at in interface and the variation of the base material properties due to heat affection. These features make this technology suitable for hardfacing or corrosion protection coatings, as well as for repairing worn parts. The present study analyzed the influence of operating processing parameters in the production of coatings, using AA6082-T6 rods, over AA2024-T3 substrates. A metallurgic and mechanical characterization was carried out revealing a fine equiaxial grained microstructure with enhanced mechanical properties. When compared to the as received rod material, the ultimate tensile strength improved by 25%, while the strain increased by 42% and the wear rate was reduced by 24%.
Contrail Formation: Analysis of Sublimation Mechanisms

We study losses of ice crystals in a persistent, soot‐rich contrail in the wake behind a medium‐sized aircraft at cruise. Constraining a model covering ice nucleation, growth, and sublimation phases with an aircraft data set, we track the sublimation history over 2 min of contrail age and relate ice crystal numbers to the number of soot particles emitted by the aircraft engines. We analyze the observed vertical distribution of ice numbers, estimating an exponential scale height in the range 50–100 m and wake‐averaged ice numbers (1.3–1.7) × 1015 (kg‐fuel)−1 after sublimation, removing 60% of the ice crystals that originally nucleated on emitted soot particles. We define soot emission‐ and ice supersaturation‐dependent contrail depths, affecting estimates of horizontal spreading rates of contrails. Our findings have ramifications for the representation of long‐lived contrails in global models.
Calculation of the Spatial Flooding Intensity with Unit Flood Response Method in the Tangrah Watershed, Iran

Increased flooding in recent years indicates that most parts of the country are subjected to periodic and destructive flood attacks. Therefore, the identification of high-risk areas with potential runoff production within a watershed area is one of the most important measures in flood control and reduction of the damage caused by it. In this study, the quasi-distributional ModClark method was employed to simulate the hydrograph of flooding, and the unit flood response method was applied to determine the intensity of flooding of different areas of the Tangrah watershed, Iran. For this purpose, the ModClark model was first calibrated and verified. Thereafter, the design of rainfall with 50 and 100-year return periods ( ) was extracted at the Tangrah station and the design flood was calculated with the above-mentioned return periods. By combining the curve number layers, slope, precipitation, and flow distance, homogeneous units were obtained in terms of the flood. The effect of each homogeneous unit on the total watershed output was obtained by the removal of each unit and implementation of the rainfall-runoff model. According to the 100-year return runoff production potential, homogeneous units of 116 with a fi (0.54 m 3 / s. km 2 ) were identified as the most effective cell in the Tangrah watershed area, which could be explained by the soil type, vegetation, and other physical factors of these units.
DIET AND SPACE USE OF THE MARTIAL EAGLE ( POLEMAETUS BELLICOSUS ) IN THE MAASAI MARA REGION OF KENYA

OF THESIS DIET AND SPACE USE OF THE MARTIAL EAGLE (POLEMAETUS BELLICOSUS) IN THE MAASAI MARA REGION OF KENYA The martial eagle (Polemaetus bellicosus) is a vulnerable species that is declining throughout large portions of its range. There is an urgent need to improve understanding of this species’ ecology to inform its conservation. I equipped 20 adult martial eagles with global positioning system backpack transmitters to characterize diet and space use of the species in the Maasai Mara region of Kenya. The resulting high-resolution transmitter data sets allowed for the rapid location of kills and provided a means to estimate home range size. From November 2016 to April 2018, 191 kills were identified from 206 kill location visits. Martial eagle diet comprised 26 prey species of which hares (two Lepus species, 17.3%), impala fawns (Aepyceros melampus, 13.6%) and helmeted guineafowl (Numida meleagris, 12%) were the most numerous. Sex-based differences in diet were found, with females selecting for heavier prey items (p < 0.001). The average 95% kernel density estimated home range for the duration-of-transmitter-placement (average of 372 days) was 174.5 ± 83.2 km2, a much larger estimate than previously reported. This study is the most extensive to date on martial eagle diet and spatial ecology in eastern Africa, and the first to show dietary differences between the sexes.
DIAGNOSIS OF SUPERCOOLED LARGE DROP CONDITIONS USING CLOUD WATER CONTENT AND DROP CONCENTRATION

The hazards associated with icing encounters with supercooled large drops (SLD) have been well documented. Both supercooled drizzle and rain aloft can cause ice to form beyond the protected parts of an aircraft. Such ice can have non-conformal shapes and has been shown to result in increased drag, decreased lift and even loss of control (e.g. Sand et al. 1984; Marwitz et al. 1997; Bernstein et al. 1999). Climatologies of surface observations suggest that most SLD develop via the collision-coalescence process (Bernstein 2000; Cortinas et al. 2004). Maritime air masses have been shown to be particularly conducive to this process, presumably because their clean nature is favorable to the formation of clouds with low drop concentrations. Continental air masses typically contain larger concentrations of cloud condensation nuclei (CCN), so there is a tendency toward clouds that are dominated by small drops (Rasmussen et al. 2002). However, non-classical SLD are commonly observed in continental regimes, both at the surface (as freezing drizzle; Bernstein 2000) and aloft (e.g. Cober et al. 2001). For SLD to form in such an environment, it is suggested that either the liquid water content (LWC) must be large enough or the cloud drop concentration must be small enough so that a collision coalescence process can be effective. As part of several field programs, NCAR meteorologists have directed the NASA Glenn Research Center’s Twin Otter research aircraft into a wide variety of icing situations, many of which included SLD. Through this experience, other field programs, case studies and climatological research, patterns that associate SLD formation with characteristic LWC and drop spectra have begun to emerge. The interplay of some synopticand mesoscale forcing, and clouds with certain temperatures, moisture contents, and thermodynamic structures appears to be important to the amount of water and the drop size ranges produced. In this paper, Twin Otter observations of icing clouds with different combinations of LWC and drop concentration will be related to surface and upper air patterns, as well as to local thermodynamic structure, to assess the mechanisms associated with SLD and non-SLD icing scenarios.
The use of sea ice habitat by female polar bears in the Beaufort Sea

Polar bears (Ursus maritimus) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We explored the use of discrete choice models to describe habitat selection by female polar bears in the Beaufort Sea. Using stepwise procedures we generated resource selection models of habitat use. Sea ice characteristics and ocean depths at known polar bear locations were compared to the same features at randomly selected locations. Models generated for each of four seasons confirmed complexities of habitat use by polar bears and their response to numerous factors. Bears preferred shallow water areas where different ice types intersected. Variation among seasons was reflected mainly in differential selection of total ice concentration, ice stages, floe sizes, and their interactions. Distance to the nearest ice interface was a significant term in models for three seasons. Water depth was selected as a significant term in all seasons, possibly reflecting higher productivity in shallow water areas. Preliminary tests indicate seasonal models can predict polar bear distribution based on prior sea ice charts and bathymetry data.
Scrash: A System for Generating Secure Crash Information

This paper presents Scrash, a system that safeguards user privacy by removing sensitive data from crash reports that are sent to developers after program failures. Remote crash reporting, while of great help to the developer, risks the user's privacy because crash reports may contain sensitive user information such as passwords and credit card numbers. Scrash modifies the source code of C programs to ensure that sensitive data does not appear in a crash report. Scrash adds only a small amount of run-time overhead and requires minimal involvement on the part of the developer.
Document Length Normalization by Statistical Regression

The document-length normalization problem has been widely studied in the field of information retrieval. The cosine normalization (Baeza-Yates and Ribeiro-Neto, 1999), the maximum if normalization (Allan et al., 1997) and the byte length normalization (Robertson et al., 1992) are the most commonly used normalization techniques. In (Singhal et al., 1996), authors studied the retrieval probability of documents w.r. t. their size, using different similarity measures. They have shown that none of existing measures retrieve the documents of different lengths with the same probability. We first show here that the document and query sizes are indeed very influent on the similarity score expectation. Therefore, we propose to realize a statistical regression of the similarity scores distribution w. r. t. document and query sizes in order to normalize them. Experimental results appear to indicate that our approach, as well in the field of classical Information Retrieval as when applied to a document clustering process, allows to judge similarities really more fairly.
Applications of CryoSat-2 swath radar altimetry over Icelandic ice caps and Patagonian ice fields

Satellite altimetry has been traditionally used in the past few decades to measure elevation of land ice, quantify changes in ice topography and infer the mass balance of large and remote areas such as the Greenland and Antarctic ice sheets. Radar altimetry is particularly well suited to this task due to its all-weather year-round capability of observing the ice surface. However, monitoring of ice caps and ice fields bodies of ice with areas typically smaller than ∼10,000 km2 has proven more challenging. The large footprint of a conventional radar altimeter and coarse ground track coverage are less suited to observing comparatively small regions with complex topography. Since 2010, the European Space Agency’s CryoSat-2 satellite has been collecting ice elevation measurements over ice caps and ice fields with its novel radar altimeter. CryoSat-2’s smaller intertrack spacing provides higher density of observations compared to previous satellite altimeters. Additionally, it generates more accurate measurements because (i) the footprint size is reduced in the along-track direction by means of synthetic aperture radar processing and (ii) interferometry allows to precisely locate the the across-track angle of arrival of a reflection from the surface. Furthermore, the interferometric capabilities of CryoSat-2 allow for the processing of the delayed surface reflections after the first echo. When applied over a sloping surface, this procedure generates a swath of elevations a few km wide compared to the conventional approach returning a single elevation. In this thesis, swath processing of CryoSat-2 interferometric data is exploited to generate topographic data over ice caps and ice fields. The dense elevation field is then used to compute maps of elevation change rates at sub-kilometer resolution with the aim of quantifying ice volume change and mass balance. A number of algorithms have been developed in this work, partly or entirely, to form a complete processing chain from generating the elevation field to calculating volume and
Hydromechanical Properties of Gas Hydrate‐Bearing Fine Sediments From In Situ Testing

The hydromechanical properties of gas hydrate‐bearing sediment are key in assessing offshore geohazards and the resource potential of gas hydrates. For sandy materials, such properties were proved highly dependent on hydrate content (Sh) as well as on their distribution and morphology. Owing to difficulties in testing gas hydrate‐bearing clayey sediments, the impact of hydrates on the behavior of such materials remains poorly understood. Hence, to provide insight into the characterization of clayey sediments containing hydrate, this study relies on a unique database of in situ acoustic, piezocone, and pore pressure dissipation measurements collected in a high gas flux system offshore Nigeria. Compressional wave velocity measurements were used as means of both detecting and quantifying gas hydrate in marine sediments. The analysis of piezocone data in normalized soil classification charts suggested that contrary to hydrate‐bearing sands, the behavior of gas hydrate‐bearing clays tends to be contractive. Correlations of acoustic and geotechnical data have shown that the stiffness and strength tend to increase with increasing Sh. However, several sediment intervals sharing the same Sh have revealed different features of mechanical behavior; suggesting that stiffness and strength of gas hydrate‐bearing clays are influenced by the distribution/morphology of gas hydrate. Pore pressure dissipation data confirmed the contractive behavior of gas hydrate‐bearing clays and showed that at low hydrate content, the hydraulic diffusivity (Ch) decreases when Sh increases. However, for Sh exceeding 20%, it was shown that an increase of Ch with Sh could be linked to the presence of fractures in the hydrate‐sediment system.
U.S. DOE’s Economic Approaches and Resources for Evaluating the Cost of Implementing Carbon Capture, Utilization, and Storage (CCUS)

Abstract The United States Department of Energy and National Energy Technology Laboratory are world leaders in Carbon Capture, Utilization, and Storage (CCUS) research and analysis. They have developed resources and a set of economic tools to evaluate the cost to implement CCUS for each segment of the value chain: capture, transport, and storage. This paper provides a comprehensive review of the economic models and analytical approaches DOE/NETL has developed for assessing the CO2 capture, storage, and transport cost drivers that impact the entire CCUS value chain. Failure to effectively evaluate the economic opportunity for CCUS technology to reduce CO2 emissions would deter wide-spread deployment. DOE’s economic models and resources enable a variety of possible analytical approaches to evaluate the economics associated with deploying CCUS. The resources are open-source so that interested stakeholder groups can apply them to their specific problems, and to enable feedback to improve these models moving forward.
CODING IN-DEPTH SEMI-STRUCTURED INTERVIEWS: PROBLEMS OF UNITIZATION AND INTER-CODER RELIABILITY AND AGREEMENT

Many social science studies are based on coded in-depth semi-structured interview transcripts. But researchers rarely report or discuss coding reliability in this work. Nor is there much literature on the subject for this type of data. This paper presents a procedure for developing coding schemes for such data. It involves standardizing the units of text on which coders work and then improving the coding scheme’s discriminant capability (i.e., reducing coding errors) to an acceptable point as indicated by measures of either inter-coder reliability or inter-coder agreement. This approach is especially useful for situations where a single knowledgeable coder will code all the transcripts once the coding scheme has been established. This approach can also be used with other types of qualitative data and in other circumstances.
SensorFlock: A Mobile System of Networked Micro-Air Vehicles ; CU-CS-1018-06

A SensorFlock composed of bird-sized micro aerial vehicles (MAVs) enables low cost high granularity atmospheric sensing of toxic plume behavior and storm dynamics, and provides a unique three-dimensional vantage for monitoring wildlife and ecological systems. This paper describes a complete implementation of our SensorFlock, spanning the development of our MAV airplane, its avionics, semi-autonomous ﬂight control software, launch system, ﬂock control algorithm, and wireless communication networking between MAVs. We present experimental results from ﬂight tests of ﬂocks of MAVs, and a characterization of wireless RF behavior in air-to-air communication as well as air-to-ground communication.
Determinants of West Nile Virus (WNV) incidence in select regions of Canada : an examination of climate and ecological drivers in British Columbia and Saskatchewan

Background: West Nile Virus (WNV) is a zoonotic arbovirus that has caused signi cant disease in Canada, yet remains rare in British Columbia (BC). WNV is spread between avian reservoirs by Culex mosquitoes, and incidental transmission to humans can occur. Understanding temporal and spatial changes in WNV risk is di cult because of the complexity of the transmission cycle. Nonetheless, public health agencies require decision support in order to guide resource allocation. Understanding the climate and ecological drivers of WNV disease can help with the development of such tools. Methods: Descriptive analyses were used to compare ecological and climate conditions in years with and without WNV transmission in BC from 2009 to 2015. Generalized linear mixed models were used to evaluate associations between WNV incidence in Saskatchewan (2003-2007) and: 1) total irrigated landscape, and 2) avian community structure. Results were combined with a literature review to develop a WNV decision-support tool for BC which was evaluated via a user survey. Results: WNV activity in BC between 2009-2015 was limited to select locations during hot summers when temperatures remained above key temperature thresholds during the ampli cation period. In Saskatchewan, human incidence was positively associated with irrigated landscapes in 2003 but not 2007. Non-passerine species richness and abundance was positively associated with incidence from 2003-2007, and the dilution hypothesis was not supported. Heat was consistently associated with incidence, but other predictors had varying e ects between years and models. The resulting decision support tool contained seven surveillance inputs and three hazard levels. Survey results supported the choice of surveillance inputs and the recommended prevention measures. Discussion: Ecological complexity challenges quantitative risk prediction for WNV and necessitates the use of simpler tools for public health decision support. Public health agencies in low-incidence areas should invest public health resources in improving situational awareness and preparedness instead of risk prediction. The decision support tool created here provides a general estimate of WNV ampli cation as a proxy of WNV hazard. Continued re nement of the tool as more is learned about the ecology of WNV would increase its utility.