Browsing by Author "Lee, Jeff"
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Item Analyzing Trends of Land Cover Change in Africa from 2000-2020(2023-08) Ige, Olukayode B.; Wang, Xuantong; Bhattachan, Abinash; Lee, JeffThis research analyzes the trends of land cover changes in Africa from 2000 to 2020. The study utilizes advanced geographic information systems (GIS) and statistical analysis to examine the patterns, drivers, and impacts of land cover change across the continent. The analysis of multi-temporal satellite imagery and data derived from the Copernicus Land Cover dataset enables the generation of accurate land cover change maps for the study period. Spatial and statistical analyses were conducted to quantify the magnitude and spatial distribution of land cover changes and identify hotspots of change. This research investigates the drivers of land cover change, including population growth, agricultural expansion, infrastructure development, and natural resource extraction. Additionally, the study examines the ecological, social, and economic impacts of land cover change, emphasizing the loss of forest cover, habitat fragmentation, biodiversity loss, and effects on local communities. The findings of this research contribute to a better understanding of land cover change dynamics in Africa and provide valuable insights for sustainable land management, biodiversity conservation, and informed decision-making.Item Design of a Jettison System For Space Transit Vehicles(51st International Conference on Environmental Systems, 7/10/2022) Sepka, Steve; Ewert, Michael; Lee, Jeff; Chen, Thomas; Venigalla, ChandrakanthMany options to re-use waste are currently being developed by NASA. These include combustion, compaction, torrefaction, and converting waste materials to an easily stored base polymer for future use. Human exploration missions require large amounts of supplies such as food, clothing and spare parts. A many-month journey to Mars will still result in the generation of a substantial amount of problematic waste products. It is thought that this waste must be discarded to enable a Mars transit mission. The most cost-effective, reliable, and safest method to address this problem may be to simply jettison these materials from the spacecraft. The ability to jettison requires a multi-component integrated system design. Major components include a launcher, airlocks, trash bags, and tracking system. Depending upon mission requirements, a jettison dedicated airlock may be necessary. In other cases, the crew airlock might be all that is needed. This paper will discuss these design issues and give guidance to a pathway forward.Item Development of an Adsorption System for the Trash Compaction Processing System designed for operation in the International Space Station Express Rack(2020 International Conference on Environmental Systems, 2020-07-31) Pace, Gregory; Lee, Jeff; Parodi, Jurek; Richardson, Justine; Trieu, Serena; Young, Janine; Martin, KevinA water recovery system that utilizes adsorption to work with the Trash Compaction Processing System, formerly known as the Heat Melt Compactor, is being designed at NASA Ames Research Center as an option to current state of the art micro-gravity water management systems and contaminant control systems used in space. The adsorption system will be used in conjunction with the International Space Station Vacuum Exhaust system to avoid both the complexities of gas liquid phase separation in micro-gravity and venting of Trash Compaction Processing System effluents to the spacecraft cabin. The adsorption system will allow the water and gaseous effluents generated during the Trash Compaction System operation to be removed in a matter that meets the Vacuum Exhaust System venting rate requirements. The Trash Compaction Processing System is planned to fly as a Technology Demonstration on the International Space Station in the space station EXPRESS Rack facility. This paper describes the trade space that the adsorption system must operate in using the EXPRESS Rack facilities resources including the use of the Space Station Vacuum Exhaust System. Also described in this paper are design solutions to allow the adsorption system to function within the Express Rack and Vacuum Exhaust System Parameters.Item Ionomer-membrane Water Processor (IWP) Engineering Development Unit (EDU) Brine Water Recovery Test Results(45th International Conference on Environmental Systems, 2015-07-12) Kelsey, Laura K.; Pasadilla, Patrick; Fisher, John; Lee, JeffClosing the water loop on long duration spaceflight missions is a key aspect of reducing mission mass and logistics support for orbiting facilities and is a necessity for interplanetary spacecraft. Closing that water loop cannot be achieved without recovery of water from brine. As such, NASA has identified brine processing as an enabling technology for exploring other worlds. Paragon Space Development Corporation is developing the patent-pending Ionomer- membrane Water Processor (IWP) to enable water recovery from urine and brine. Through a NASA SBIR Phase 2 effort, Paragon developed and tested a large-scale IWP Engineering Development Unit (EDU). Testing with urine brine pretreated with the International Space Station (ISS) pretreatment formulation was conducted by both Paragon and NASA Ames Research Center. The IWP EDU successfully recovered over 85% of the water from brine, boosting total water recovery from urine up to 98%. Testing also demonstrated 99% removal of contaminants in brine in a configuration designed for microgravity application.Item Testing “Global Stilling” with ERA-5 Reanalysis Data(2023-12) Rahman, Shaikh Sadiqur; Lee, Jeff; Wang, Xuantong"Global Terrestrial Stilling," a noticeable decrease in wind speeds around the globe, has been reported, with implications for energy generation and other environmental phenomena. The two leading possible causes are increased surface roughness due to land use changes and general climate changes. However, some long-term regional studies show no trend toward decreasing wind speeds. Global wind speed data since 1979 is available in reanalysis datasets. Here, we use ERA5 to map decadal averages of 10m wind speed. From the decadal mean ten meter wind speed map, we got that in the 1980s, the average wind speed was 6.29 m/s, and in the 2010s, it was 6.19 m/s. The results show a complicated pattern of small increases (within 5% of zero) and significant increases (10 to 20%) spread out in the equatorial regions. There are also decreases (5 to 10%) in the Polar Regions and parts of southern Asia, Europe, and other places. However, from the 1980s to the 2010s, there was a significant decrease in global wind speed of -2.67%. This trend suggests that wind speeds have decreased over time, with a particularly sharp decline in the past two decades.Item The magic of tourism: A look into the impact of Harry Potter tourism on Edinburgh(2020-12) Webb, Hannah M.; Carter, Perry L.; Lee, Jeff; Mulligan, KevinThe Harry Potter series by J. K. Rowling has profoundly touched the lives of many readers. The series has become a global cultural phenomenon of unimagined proportions. Many of the places in the books and scenes in the movies are based on locations in Edinburgh, the city where Rowling wrote most of the Harry Potter series. These locations in Edinburgh have become places of Harry Potter tourism. Increased tourism can boost an economy, but it can also create issues for the permanent residents of these tourist destinations. During the summer of 2018, fieldwork was conducted in Edinburgh with The Potter Trail walking tours, a tour company that specializes in connecting the fictional places of the books and movies to their real-world counterparts in the city. The aim of this research is to show ways in which Harry Potter tourism has affected Edinburgh by creating and authenticating points of connection. Over a three day period, the team observed eight tours and interviewed 35 tourists. The observations of the tours demonstrate ways in which the study area has been affected by the increased tourism. The analysis of the interviews suggest that visitors take these journeys in order to encounter points of connection which challenge the line between fiction and non-fiction.Item Using drone mounted multispectral cameras to map fossil sites(2020-05) Reinhart, Joshua A.; Lee, Jeff; Carter, Perry L.In this paper the uses of drone mounted multispectral cameras are tested in the field of paleontology with the intent to locate fossils. To test this methodology a map, made of up of many aerial near infrared images, were analyzed based on light returns in the near infrared spectrum (850 nm). Using these returns specific value for the fossils were established and 2 classification techniques were applied (Pixel inspector and interactive supervised classification). The results show that there are many fossils in the study area that can be excavated. A shapefile of all found fossils was created and the best groupings of fossils were selected to be possible fossil sites of which there were 23. These sites were then ranked based on number of possible fossils in a site by the size of the site which helped determine the sites worth excavating. This study shows the benefits of using drone mounted cameras to scout an area prior to a paleontological excavation. Finding a possible fossil site prior to an excavation allows a researcher to focus the bulk of their time and energy on the excavation rather than looking for the fossils on foot.Item Variations of particulate matter and blowing dust in Lubbock, Texas(2020-08) Kelley, Mary C.; Ardon-Dryer, Karin; Lee, Jeff; Stout, JohnParticulate matter (PM) are microscopic solid and liquid particles that are suspended in the atmosphere, separated in to two predominant sizes, PM10 and PM2.5. PM is a hazard to human health and property. In this study, PM2.5 concentrations measured in Lubbock, Texas by the Texas Commission of Environmental Quality (TCEQ) station from 2001 to 2018 were examined for temporal (diurnal, weekly, monthly, seasonal, and annually), meteorological (temperature, relative humidity, wind speed, wind gust, and visibility), and El Niño Southern Oscillation (ENSO) distributions. Majority of the daily average PM2.5 concentrations were below the Environmental Protection Agency (EPA) standard of 35 µg m-3 though there were many high hourly PM2.5 concentrations. No correlation was found between the hourly PM2.5 concentrations and the meteorological parameters. The diurnal distribution showed a bimodal distribution, with morning and evening peaks. April and June had the highest PM2.5 monthly concentrations resulting in spring and summer having the highest seasonal average. Comparing concentrations between ENSO events showed La Niña to have higher PM2.5 concentrations, with maximum concentrations during a weak La Niña. One of the event that contributors to the increasing of atmospheric PM is dust storms. Dust storms are a meteorological phenomenon where high winds loft dust particles into the atmosphere. One of the most important parameters that initiate dust storms is strong wind speeds. These strong winds are caused by synoptic or convective disturbances. This study examines blowing dust days in Lubbock, Texas from 2000 to 2019. To determine a blowing dust day, Meteorological Aerodrome Reports (METARs) from the Lubbock National Weather Service were used. All weather observations associated with dust event (BLDU, DS, DU) were recorded and analyzed to determine diurnal, seasonal, and meteorological patterns. Dust days were separated by meteorological cause (convection vs synoptic) and examined for similarity and differences between the two. Annual dust events did not show any positive or negative trend but did correlate with lower annual precipitation. Comparison of different meteorological parameters between dust days to non-dust days showed that dust days had higher temperatures, higher wind speed, and wind gust, and with lower visibilities and lower relative humidity values. Dust storms days had higher PM2.5 concentrations during La Niña, for both synoptic and convective. Most of the dust storms days were caused by a synoptic disturbance that occurred during the winter months while convective dust storms occurred mostly in June. Synoptic was associated with longer durations compared to the convective events. Convective events were associated with higher temperatures and relative humidity but with lower wind speeds and gusts compared to synoptic dust storm.