20,343 research outputs found
Non-contact temperature measurement requirements
The Marshall Space Flight Center is involved with levitation experiments for Spacelab, Space Station, and drop tube/tower operations. These experiments have temperature measurement requirements, that of course must be non-contact in nature. The experiment modules involved are the Acoustic Levitator Furnace (ALF), and the Modular Electromagnetic Levitator (MEL). User requirements of the ALF and drop tube are presented. The center also has temperature measurement needs that are not microgravity experiment oriented, but rather are related to the propulsion system for the STS. This requirement will also be discussed
The effects of room design on computer-supported collaborative learning in a multi-touch classroom.
While research indicates that technology can be useful for supporting learning and collaboration, there is still relatively little uptake or widespread implementation of these technologies in classrooms. In this paper, we explore one aspect of the development of a multi-touch classroom, looking at two different designs of the classroom environment to explore how classroom layout may influence group interaction and learning. Three classes of students working in groups of four were taught in the traditional forward-facing room condition, while three classes worked in a centered room condition. Our results indicate that while the outcomes on tasks were similar across conditions, groups engaged in more talk (but not more off-task talk) in a centered room layout, than in a traditional forward-facing room. These results suggest that the use of technology in the classroom may be influenced by the location of the technology, both in terms of the learning outcomes and the interaction behaviors of students. The findings highlight the importance of considering the learning environment when designing technology to support learning, and ensuring that integration of technology into formal learning environments is done with attention to how the technology may disrupt, or contribute to, the classroom interaction practices
Leaching of an Acetanilide Herbicide, CP55097 in Soil Columns
The leachability of the acetanilide herbicide, CP55097 was determined using a soil column system. This herbicide, which is used as a preemergent against certain grasses and broadleaf weeds, was leached through four different soils (sandy clay, sandy loam, sandy clay loam and clay loam) using the following procedure. Plastic columns consisting of 8 rings (2 in. dia. x 1 in.) were assembled and their bottoms covered with cheesecloth. They were then filled with soil and prewetted with water to attain field capacity. Herbicide concentrations equalling 0, 1, 3, 6 lb/A were pipetted onto the soil surface and 0, 1, 2, 4 in/A of water was applied at an approximate rate of 1 ml/minute. The columns were leached for two days, then disassembled and the soil placed in styrofoam cups. The extent to which CP55097 leached through the soil columns was determined by an oat bioassay (Avena sativa var. Noble). After the soil dried for two days, 10 oat seeds were planted with the hilum end down. The plants were grown at a temperature of approximately 80 F and illuminated with cool white fluorescent light at 300 ft-c on a 15 hour photoperiod cycle. The plants were watered twice a day for a duration of eight days after which the shoots were weighed and the percent germination recorded.
The organic matter and clay content of the soils was found to have a significant effect on the movement of the herbicide. In general, the herbicide moved less in soils with higher organic matter and/or clay content. Of the two, organic matter was more effective in reducing herbicide movement. Only in the low clay-low organic matter sandy loam was the herbicide leached throughout the eight inches of soil.
Statistically at a significance level of 0.05 all factors; soil type, CP55097 concentration, water application and soil depth separately and all interactions thereof significantly affected oat growth. However, the depth of leaching as determined by growth reduction, was not correlated with the concentration of CP55097 applied. Even though increasing concentrations of herbicide did reduce oat growth at specific depths, the maximum depth of observable effect was constant for each initial concentration tested
Design, Testing and Evaluation of Robotic Mechanisms and Systems for Environmental Monitoring and Interaction
Unmanned Aerial Vehicles (UAVs) have significantly lowered the cost of remote aerial data collection. The next generation of UAVs, however, will transform the way that scientists and practitioners interact with the environment. In this thesis, we address the challenges of flying low over water to collect water samples and temperature data. We also develop a system that allows UAVs to ignite prescribed fires. Specifically, this thesis contributes a new peristaltic pump designed for use on a UAV for collecting water samples from up to 3m depth and capable of pumping over 6m above the water. Next, temperature sensors and their deployment on UAVs, which have successfully created a 3D thermal structure map of a lake, contributes to mobile sensors. A sub-surface sampler, the “Waterbug” which can sample from 10m deep and vary buoyancy for longer in-situ analysis contributes to robotics and mobile sensors. Finally, we designed and built an Unmanned Aerial System for Fire Fighting (UAS-FF), which successfully ignited over 150 acres of prescribed fire during two field tests and is the first autonomous robot system for this application.
Advisers: Carrick Detweiler and Carl Nelso
Leaching of an Acetanilide Herbicide, CP55097 in Soil Columns
The leachability of the acetanilide herbicide, CP55097 was determined using a soil column system. This herbicide, which is used as a preemergent against certain grasses and broadleaf weeds, was leached through four different soils (sandy clay, sandy loam, sandy clay loam and clay loam) using the following procedure. Plastic columns consisting of 8 rings (2 in. dia. x 1 in.) were assembled and their bottoms covered with cheesecloth. They were then filled with soil and prewetted with water to attain field capacity. Herbicide concentrations equalling 0, 1, 3, 6 lb/A were pipetted onto the soil surface and 0, 1, 2, 4 in/A of water was applied at an approximate rate of 1 ml/minute. The columns were leached for two days, then disassembled and the soil placed in styrofoam cups. The extent to which CP55097 leached through the soil columns was determined by an oat bioassay (Avena sativa var. Noble). After the soil dried for two days, 10 oat seeds were planted with the hilum end down. The plants were grown at a temperature of approximately 80 F and illuminated with cool white fluorescent light at 300 ft-c on a 15 hour photoperiod cycle. The plants were watered twice a day for a duration of eight days after which the shoots were weighed and the percent germination recorded.
The organic matter and clay content of the soils was found to have a significant effect on the movement of the herbicide. In general, the herbicide moved less in soils with higher organic matter and/or clay content. Of the two, organic matter was more effective in reducing herbicide movement. Only in the low clay-low organic matter sandy loam was the herbicide leached throughout the eight inches of soil.
Statistically at a significance level of 0.05 all factors; soil type, CP55097 concentration, water application and soil depth separately and all interactions thereof significantly affected oat growth. However, the depth of leaching as determined by growth reduction, was not correlated with the concentration of CP55097 applied. Even though increasing concentrations of herbicide did reduce oat growth at specific depths, the maximum depth of observable effect was constant for each initial concentration tested
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Influence of spatial resolution on diurnal variability during the north American monsoon
Diurnal variability is an important yet poorly understood aspect of the warm-season precipitation regime over southwestern North America. In an effort to improve its understanding, diurnal variability is investigated numerically using the fifth-generation Pennsylvania State University (PSU)-NCAR Mesoscale Model (MM5). The goal herein is to determine the possible influence of spatial resolution on the diurnal cycle. The model is initialized every 48 h using the operational NCEP Eta Model 212 grid (40 km) model analysis. Model simulations are carried out at horizontal resolutions of both 9 and 3 km. Overall, the model reproduces the basic features of the diurnal cycle of rainfall over the core monsoon region of northwestern Mexico and the southwestern United States. In particular, the model captures the diurnal amplitude and phase, with heavier rainfall at high elevations along the Sierra Madre Occidental in the early-afternoon that shifts to lower elevations along the west slopes in the evening. A comparison to observations (gauge and radar data) shows that the high-resolution (3 km) model generates better rainfall distributions on time scales from monthly to hourly than the coarse-resolution (9 km) model, especially along the west slopes of the Sierra Madre Occidental. The model has difficulty with nighttime rainfall along the slopes, over the Gulf of California, and over Arizona. A comparison of surface wind data from three NCAR Integrated Sounding System (ISS) stations and the Quick Scatterometer (QuikSCAT) to the model reveals a low bias in the strength of the Gulf of California low-level jet, even at high resolution. The model results indicate that outflow from convection over northwestern Mexico can modulate the low-level jet, though the extent to which these relationships occur in nature was not investigated. © 2008 American Meteorological Society
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