10,366 research outputs found

    Method and Apparatus for Removal of Phosphate from Wastewater Streams

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    Church and Dwight uses a phosphate-containing soap in their latex condom manufacturing process in Chesterfield County, VA. The wastewater streams from this process contain a concentration of phosphate that is over the county limit, costing $100,000/yr for non-optimized disposal. C&D has a need for an in-house method of phosphate removal which does not interfere with current manufacturing or wastewater treatment processes. The focus of the project was precipitation methodology as it is the most economically feasible option for these high concentrations of phosphate; more advanced technologies were considered for a potential final polishing step to remove any residual phosphate. The chemistry for the proposed process was developed by Design of Experiment, utilizing multiple independent and dependent variables. Once optimized, pilot trials were performed in order to verify the lab-scale chemistry. The proposed method of phosphate treatment requires a pH adjustment of the wastewater via sulfuric acid, followed by chemical precipitation via PC-1101 (proprietary coagulant). This solid precipitate is then to be collected utilizing a filter press. Optimal laboratory trials consistently reduced the phosphate concentration by \u3e95%, from 2000-3000 ppm (as Phosphorus) to a nominal 50 ppm (as P). This method will reduce the cost of phosphate treatment by about 40%, with room to further reduce cost via long-term optimization of the pH and coagulant ratio.https://scholarscompass.vcu.edu/capstone/1158/thumbnail.jp

    Notes on \u3ci\u3eTaeniogonalos Gundlachii\u3c/i\u3e (Hymenoptera: Trigonalidae) From Wisconsin

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    This is the first report of Taeniogonalos gundlachii (Cresson) (Hymenoptera: Trigonalidae) from Wisconsin and of this hyperparasitoid reared from the initial host Euchaetes egle (Drury) (Lepidoptera: Arctiidae). Data are provided from 30 Malaise trap specimens and from a single reared specimen

    Innovative psychological treatments for depression

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    A number of high-intensity psychosocial interventions have been shown to be as efficacious as and more enduring than medications in the treatment of nonpsychotic depression. Moreover, there have been important advances in the development of strategies to facilitate the selection of the best treatment for a given patient with a depression diagnosis. However, the demand for services is too great to be met by conventional high-intensity approaches alone. Some of the most exciting work in recent years has focused on the development of low-intensity approaches that can benefit many people and do so cost-effectively

    Airborne Four-Dimensional Flight Management in a Time-based Air Traffic Control Environment

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    Advanced Air Traffic Control (ATC) systems are being developed which contain time-based (4D) trajectory predictions of aircraft. Airborne flight management systems (FMS) exist or are being developed with similar 4D trajectory generation capabilities. Differences between the ATC generated profiles and those generated by the airborne 4D FMS may introduce system problems. A simulation experiment was conducted to explore integration of a 4D equipped aircraft into a 4D ATC system. The NASA Langley Transport Systems Research Vehicle cockpit simulator was linked in real time to the NASA Ames Descent Advisor ATC simulation for this effort. Candidate procedures for handling 4D equipped aircraft were devised and traffic scenarios established which required time delays absorbed through speed control alone or in combination with path stretching. Dissimilarities in 4D speed strategies between airborne and ATC generated trajectories were tested in these scenarios. The 4D procedures and FMS operation were well received by airline pilot test subjects, who achieved an arrival accuracy at the metering fix of 2.9 seconds standard deviation time error. The amount and nature of the information transmitted during a time clearance were found to be somewhat of a problem using the voice radio communication channel. Dissimilarities between airborne and ATC-generated speed strategies were found to be a problem when the traffic remained on established routes. It was more efficient for 4D equipped aircraft to fly trajectories with similar, though less fuel efficient, speeds which conform to the ATC strategy. Heavy traffic conditions, where time delays forced off-route path stretching, were found to produce a potential operational benefit of the airborne 4D FMS

    Determination of depth-viewing volumes for stereo three-dimensional graphic displays

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    Real-world, 3-D, pictorial displays incorporating true depth cues via stereopsis techniques offer a potential means of displaying complex information in a natural way to prevent loss of situational awareness and provide increases in pilot/vehicle performance in advanced flight display concepts. Optimal use of stereopsis requires an understanding of the depth viewing volume available to the display designer. Suggested guidelines are presented for the depth viewing volume from an empirical determination of the effective region of stereopsis cueing (at several viewer-CRT screen distances) for a time multiplexed stereopsis display system. The results provide the display designer with information that will allow more effective placement of depth information to enable the full exploitation of stereopsis cueing. Increasing viewer-CRT screen distances provides increasing amounts of usable depth, but with decreasing fields-of-view. A stereopsis hardware system that permits an increased viewer-screen distance by incorporating larger screen sizes or collimation optics to maintain the field-of-view at required levels would provide a much larger stereo depth-viewing volume

    Preliminary geologic mapping near the Nilosyrtis Mensae, Mars

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    Virtually the entire map area is mantled by an irregular deposit of material that is apparently fine-grained and erodible. It is also extremely young, as there is not a single crater larger than 1 km in the map area that was emplaced atop the mantle. Knobs abound in the study area; many are presumably caused by the mantling of pre-existing topography. In many cases the older knob of the core is exposed. Many such knob cores are surrounded by small scarplets; it is not yet clear whether the scarplets are the eroded edges of mantle beds that at one time draped over the knob core and have been subsequently exposed by erosion, or whether they are eroded versions of lobate debris aprons. Many craters in the study area contain concentric crater fill, which may indicate downslope movement of volatile-rich materials or repeated cycles of aeolian gradation

    Piloted simulation of an air-ground profile negotiation process in a time-based Air Traffic Control environment

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    Historically, development of airborne flight management systems (FMS) and ground-based air traffic control (ATC) systems has tended to focus on different objectives with little consideration for operational integration. A joint program, between NASA's Ames Research Center (Ames) and Langley Research Center (Langley), is underway to investigate the issues of, and develop systems for, the integration of ATC and airborne automation systems. A simulation study was conducted to evaluate a profile negotiation process (PNP) between the Center/TRACON Automation System (CTAS) and an aircraft equipped with a four-dimensional flight management system (4D FMS). Prototype procedures were developed to support the functional implementation of this process. The PNP was designed to provide an arrival trajectory solution which satisfies the separation requirements of ATC while remaining as close as possible to the aircraft's preferred trajectory. Results from the experiment indicate the potential for successful incorporation of aircraft-preferred arrival trajectories in the CTAS automation environment. Fuel savings on the order of 2 percent to 8 percent, compared to fuel required for the baseline CTAS arrival speed strategy, were achieved in the test scenarios. The data link procedures and clearances developed for this experiment, while providing the necessary functionality, were found to be operationally unacceptable to the pilots. In particular, additional pilot control and understanding of the proposed aircraft-preferred trajectory, and a simplified clearance procedure were cited as necessary for operational implementation of the concept

    Computational algorithms for increased control of depth-viewing volume for stereo three-dimensional graphic displays

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    Three-dimensional pictorial displays incorporating depth cues by means of stereopsis offer a potential means of presenting information in a natural way to enhance situational awareness and improve operator performance. Conventional computational techniques rely on asymptotic projection transformations and symmetric clipping to produce the stereo display. Implementation of two new computational techniques, as asymmetric clipping algorithm and piecewise linear projection transformation, provides the display designer with more control and better utilization of the effective depth-viewing volume to allow full exploitation of stereopsis cuing. Asymmetric clipping increases the perceived field of view (FOV) for the stereopsis region. The total horizontal FOV provided by the asymmetric clipping algorithm is greater throughout the scene viewing envelope than that of the symmetric algorithm. The new piecewise linear projection transformation allows the designer to creatively partition the depth-viewing volume, with freedom to place depth cuing at the various scene distances at which emphasis is desired
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