1,786 research outputs found
Eric Breon, Horn
Horn Quintet in E-flat major, K. 407 / Wolfgang Amadeus Mozart; Parable VIII for Solo Horn / Vincent Persichetti; Scherzo Concertante / Václav Nelhybel; From Six Melodies for Horn and Piano / Charles Gounod; Suite for Horn and Piano / Alec Wilde
Traction drive considerations and designs for the next generation
The self-actuating traction drive speed reducer presented in the Journal of Mechanical Design, July 2005, Vol. 127 written by Donald R. Flugrad and Abir Z. Qamhiyah is used as a reference for the basis of second generation designs. The design equations and considerations for gears are presented first as a reference for comparisons made. The work and heat generated by clutches and breaks is presented next as a reference for comparisons made. A comparison between gears and traction drive rollers is elaborated on, which includes the topics of design expertise, heat generated, life considerations, and manufacturing. The design equations developed by Donald R. Flugrad and Abir Z. Qamhiyah are used to develop an equation for the resultant load placed on the roller shaft during steady state in terms of the torque requirements. Three alternative roller designs and equations for the stresses and deflection at the points of interest are developed, where the resultant load calculated for the shaft can be directly inserted into the equations derived. Next, five different second generation traction drive designs are developed that produce that same theoretical efficiency as the single stage self actuating traction drive used as a reference. Each design developed is unique and has not been discussed until now, as well as the intermediate roller pair\u27s directions are demonstrated for each design. Finally, future recommendations, considerations, and continuing development for the self actuating traction drive design are presented, which includes, incorporating elastic rollers, composite roller coatings, and producing efficiency testing results. This includes using the presented different traction drive designs to be incorporated into a user interactive prototype
Christian doctrine as a means of Christian spiritual formation
https://place.asburyseminary.edu/ecommonsatsdissertations/1303/thumbnail.jp
The importance of transport model uncertainties for the estimation of CO2 sources and sinks using satellite measurements
This study presents a synthetic model intercomparison to investigate the importance of transport model errors for estimating the sources and sinks of CO2 using satellite measurements. The experiments were designed for testing the potential performance of the proposed CO2 lidar A-SCOPE, but also apply to other space borne missions that monitor total column CO2. The participating transport models IFS, LMDZ, TM3, and TM5 were run in forward and inverse mode using common a priori CO2 fluxes and initial concentrations. Forward simulations of column averaged CO2 (xCO2) mixing ratios vary between the models by s=0.5 ppm over the continents and s=0.27 ppm over the oceans. Despite the fact that the models agree on average on the sub-ppm level, these modest differences nevertheless lead to significant discrepancies in the inverted fluxes of 0.1 PgC/yr per 106 km2 over land and 0.03 PgC/yr per 106 km2 over the ocean. These transport model induced flux uncertainties exceed the target requirement that was formulated for the A-SCOPE mission of 0.02 PgC/yr per 106 km2, and could also limit the overall performance of other CO2 missions such as GOSAT. A variable, but overall encouraging agreement is found in comparison with FTS measurements at Park Falls, Darwin, Spitsbergen, and Bremen, although systematic differences are found exceeding the 0.5 ppm level. Because of this, our estimate of the impact of transport model uncerainty is likely to be conservative. It is concluded that to make use of the remote sensing technique for quantifying the sources and sinks of CO2 not only requires highly accurate satellite instruments, but also puts stringent requirements on the performance of atmospheric transport models. Improving the accuracy of these models should receive high priority, which calls for a closer collaboration between experts in atmospheric dynamics and tracer transpor
Inverse modeling of CO2 sources and sinks using satellite data: a synthetic inter-comparison of measurement techniques and their performance as a function of space and time
Currently two polar orbiting satellite instruments measure CO<sub>2</sub> concentrations in the Earth's atmosphere, while other missions are planned for the coming years. In the future such instruments might become powerful tools for monitoring changes in the atmospheric CO<sub>2</sub> abundance and to improve our quantitative understanding of the leading processes controlling this. At the moment, however, we are still in an exploratory phase where first experiences are collected and promising new space-based measurement concepts are investigated. This study assesses the potential of some of these concepts to improve CO<sub>2</sub> source and sink estimates obtained from inverse modelling. For this purpose the performance of existing and planned satellite instruments is quantified by synthetic simulations of their ability to reduce the uncertainty of the current source and sink estimates in comparison with the existing ground-based network of sampling sites. Our high resolution inversion of sources and sinks (at 8°x10°) allows us to investigate the variation of instrument performance in space and time and at various temporal and spatial scales. The results of our synthetic tests clearly indicate that the satellite performance increases with increasing sensitivity of the instrument to CO<sub>2</sub> near the Earth's surface, favoring the near infra-red technique. Thermal infrared instruments, on the contrary, reach a better global coverage, because the performance in the near infrared is reduced over the oceans owing to a low surface albedo. Near infra-red sounders can compensate for this by measuring in sun-glint, which will allow accurate measurements over the oceans, at the cost, however, of a lower measurement density. Overall, the sun-glint pointing near infrared instrument is the most promising concept of those tested. We show that the ability of satellite instruments to resolve fluxes at smaller temporal and spatial scales is also related to surface sensitivity. All the satellite instruments performed relatively well over the continents resulting mainly from the larger prior flux uncertainties over land than over the oceans. In addition, the surface networks are rather sparse over land increasing the additional benefit of satellite measurements there. Globally, challenging satellite instrument precisions are needed to compete with the current surface network (about 1ppm for weekly and 8°x10° averaged SCIAMACHY columns). Regionally, however, these requirements relax considerably, increasing to 5ppm for SCIAMACHY over tropical continents. This points not only to an interesting research area using SCIAMACHY data, but also to the fact that satellite requirements should not be quantified by only a single number. The applicability of our synthetic results to real satellite instruments is limited by rather crude representations of instrument and data retrieval related uncertainties. This should receive high priority in future work
Radio Astronomy
Contains reports on four research projects.National Aeronautics and Space Administration (Grant NsG-240-62)National Aeronautics and Space Administration (Grant NsG-419)Lincoln Laboratory (Purchase Order DDL BB-107)U. S. Air Force (Contract AF 19(628)-500)Office of Naval Research (Contract Nonr 3963(02
Flight Servicing of Robotic Refueling Mission 3
The Robotic Refueling Mission 3 (RRM3) payload launched aboard a SpaceX rocket en route to the International Space Station on December 5th, 2018. The Goddard Space Flight Center designed payload carried approximately 50 liters of liquid methane onboard, with a mission to demonstrate long term storage and transfer of the cryogenic fluid in microgravity. Kennedy Space Center (KSC) was tasked to design, fabricate, test, and operate a system equipped to fill an RRM3 dewar with liquid methane prior to launch. Though KSC has a rich history of fueling rockets and payloads, no such operations had previously been accomplished using liquid methane. As such, all of the hardware and processes had to be developed from scratch. The completed ground system design, along with the verification and validation testing will be outlined in this paper. Several challenges that were met and overcome during procurement of the high purity methane are described. In addition, budget restrictions prohibited fueling operations from occurring in traditional processing facilities. The unique and creative solutions which were required to maintain payload cleanliness during cryogenic servicing are also detailed
Radio Astronomy
Contains reports on four research projects.National Aeronautics and Space Administration (Grant NsG-264-62)U. S. Navy (Office of Naval Research) under Contract Nonr-3963(02)-Task 2Lincoln Laboratory, Purchase Order DDL B-00368U. S. NavyU. S. ArmyU. S. Air Force under Air Force Contract AF19(604)-7400National Aeronautics and Space Administration (Grant NsG-250-62)National Aeronautics and Space Administration (Contract NaSr-101
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