Energy efficient engine flight propulsion system: Aircraft/engine integration evaluation

Results of aircraft/engine integration studies conducted on an advanced flight propulsion system are reported. Economic evaluations of the preliminary design are included and indicate that program goals will be met. Installed sfc, DOC, noise, and emissions were evaluated. Aircraft installation considerations and growth were reviewed

Linear magnetic spring and spring/motor combination

A magnetic spring, or a spring and motor combination, providing a linear spring force characteristic in each direction from a neutral position, in which the spring action may occur for any desired coordinate of a typical orthogonal coordinate system. A set of magnets are disposed, preferably symmetrically about a coordinate axis, poled orthogonally to the desired force direction. A second set of magnets, respectively poled opposite the first set, are arranged on the sprung article. The magnets of one of the sets are spaced a greater distance apart than those of the other, such that an end magnet from each set forms a pair having preferably planar faces parallel to the direction of spring force, the faces being offset so that in a neutral position the outer edge of the closer spaced magnet set is aligned with the inner edge of the greater spaced magnet set. For use as a motor, a coil can be arranged with conductors orthogonal to both the magnet pole directions and the direction of desired spring force, located across from the magnets of one set and fixed with respect to the magnets of the other set. In a cylindrical coordinate system having axial spring force, the magnets are radially poled and motor coils are concentric with the cylinder axis

Report on uncertainty methods

The issue of uncertainty is critical for climate change science and policy. A great deal of research analysis has gone into identifying the scope and character of uncertainty in climate change itself, in how analysts and assessment teams can and should communicate that uncertainty to policy- and decision-makers, and how policy- and decision-makers can then incorporate nowledge about the sources and magnitude of uncertainty in their choices. The primary purpose of this deliverable is to summarize that literature, and to synthesize it in a manner that is useful for the Mediation project, namely in improving the practice of assessing adaptaion needs and options, and in building a useful decision-support platform or system. The report starts with a user-driven focus, summarizing the literatures on both descriptive and normative models of decision-making under uncertainty, in order to identify the most effective and esential information inputs for each of these models. The report then summarizes some of the main guidance documents on communicating uncertanty, prepared for or in use by the Intergovernmental Panel on Climate Change, the United States government, and the Dutch government. Fially, the report synthesizes these previous studies for use in the Mediation project and its users by focusing on three essential characteristics of uncertainty communication: parsimony, personalization, and practicality. It identifies specific strategies for using these three criteria to ensure that assessments for climate adaptation are salient, credible, and legitimate, and thus ultimately construtive inputs into policy- and decision-making

COBE ground segment gyro calibration

Discussed here is the calibration of the scale factors and rate biases for the Cosmic Background Explorer (COBE) spacecraft gyroscopes, with the emphasis on the adaptation for COBE of an algorithm previously developed for the Solar Maximum Mission. Detailed choice of parameters, convergence, verification, and use of the algorithm in an environment where the reference attitudes are determined form the Sun, Earth, and star observations (via the Diffuse Infrared Background Experiment (DIRBE) are considered. Results of some recent experiments are given. These include tests where the gyro rate data are corrected for the effect of the gyro baseplate temperature on the spacecraft electronics

Design of a flight qualified long-life cryocooler

A second generation Stirling cycle cryogenic refrigerator with a linear drive, magnetic bearings, and clearance seals; designed to produce 5 watts of cooling at 65 Kelvin and to meet Space Shuttle mission requirements is described. The first generation refrigerator met all performance specifications, and operated with no failure for over 12,030 hours. Meeting launch requirements necessitated improvements in the electromagnetic bearings, the radial position sensors, and in the structural design of the moving elements. Organic contamination was eliminated by the use of all metal and ceramic construction. Reductions in system input power are attained by an integral magnetic spring/motor for the displacer and by more efficient linear motors and drive electronics

Design and fabrication of a long-life Stirling cycle cooler for space application. Phase 3: Prototype model

A second-generation, Stirling-cycle cryocooler (cryogenic refrigerator) for space applications, with a cooling capacity of 5 watts at 65 K, was recently completed. The refrigerator, called the Prototype Model, was designed with a goal of 5 year life with no degradation in cooling performance. The free displacer and free piston of the refrigerator are driven directly by moving-magnet linear motors with the moving elements supported by active magnetic bearings. The use of clearance seals and the absence of outgassing material in the working volume of the refrigerator enable long-life operation with no deterioration in performance. Fiber-optic sensors detect the radial position of the shafts and provide a control signal for the magnetic bearings. The frequency, phase, stroke, and offset of the compressor and expander are controlled by signals from precision linear position sensors (LVDTs). The vibration generated by the compressor and expander is cancelled by an active counter balance which also uses a moving-magnet linear motor and magnetic bearings. The driving signal for the counter balance is derived from the compressor and expander position sensors which have wide bandwidth for suppression of harmonic vibrations. The efficiency of the three active members, which operate in a resonant mode, is enhanced by a magnetic spring in the expander and by gas springs in the compressor and counterbalance. The cooling was achieved with a total motor input power of 139 watts. The magnetic-bearing stiffness was significantly increased from the first-generation cooler to accommodate shuttle launch vibrations

The Social Dimensions of Adaptation to Climate Change in Mozambique

The purpose of the Economics of Adaptation to Climate Change (EACC) study is to better understand and estimate the true costs of adapting to climate change in less developed countries. The study is made up of three components. At a global level, there is an analysis of costs across different economic sectors. At a country level, there is an economic component and a social component, taking place in a set of representative case study countries. Mozambique is one of these countries. The economic component of the Mozambique country study has the objective of identifying a set of robust adaptation options for the country, then comparing the direct costs and benefits of those options. To calculate the costs, the team has utilized a computable general equilibrium method. This method is data intensive, it requires a good model of the national economy, but can generate an estimate of the costs of targeted government interventions, in terms of reduced overall economic growth, once those effects have trickled through the labor and capital markets and the economy has returned to equilibrium. The economic team considered a range of adaptation options, which were gathered from the literature and from interactions with national level policy makers and other stakeholders

Visual Responses of Adult Asian Citrus Psyllid (Hemiptera: Liviidae) to Colored Sticky Traps on Citrus Trees

The effects of five differently-colored sticky traps in capturing adult Diaphorina citri were evaluated in citrus orchards. Trap catches of D. citri were monitored fortnightly on blue, green, red, white and yellow sticky cards placed on three citrus varieties during D. citri active flight period from April to July in south Texas. Evaluation of mean trap catches of each color by repeated measures analysis of variance produced three separate groups: yellow traps caught significantly more D. citri adults than the other four traps; red and green traps caught significantly more D. citri than blue and white traps, which were not significantly different. Although the number of adult psyllid captured on all trap types significantly increased with time during the trapping period, the performance of traps did not change with time. Trap catches were also significantly influenced by the citrus species; traps placed on lemon trees captured more D. citri than those placed on sweet orange and grapefruit, suggesting that plant preference exhibited by D. citri may influence the performance of traps. The ratio of trap reflectance between the 680 to 700 nm and the 450 nm was significantly correlated with total trap catches in all host species studied. Thus, this index was a good indicator of the attractiveness of adult D. citri to colored traps. Additionally, we compared the reflectance values of young versus mature flush shoots of the three host plants used in this study as related to densities of D. citri recorded in colored traps. We discussed the importance of visual cues in the host finding behavior of adult D. citri

Resolving Instructor Challenges in the Online Classroom

The rapid growth of online education has led to expanded opportunities for students while introducing instructors to new teaching challenges inherent to virtual learning environments. The practical responsibilities, once confined to the traditional classroom, such as handling student records, class size, teaching assistants, and instructional material now require a new mind set as well as sufficient technical knowledge. The online instructor faces additional opportunities and challenges once the class is online and students have enrolled. How to merge the best of the traditional classroom including teaching and practical responsibilities with the best of an online teaching opportunity become paramount to the online instructor. These issues and corresponding suggestions for the online instructor will be discussed in this paper