Investigation of a moving-model technique for measuring ground effect

A ground-based testing technique is under development for the measurement of dynamic or time-dependent ground effects which may be present during aircraft approach and landing. The technique utilizes a model moving horizontally over an upwardly-inclined ground plane to simulate rate of descent. Results were obtained in the Langley Research Center (LaRC) Vortex Research Facility (VRF) for a generic 60 delta wing and for an F-18 configuration, both with and without thrust reversing, at forward speeds up to 100 ft/sec. These same models and support hardware were also tested in the LaRC 14 by 22 Foot Subsonic Tunnel at identical conditions (but without rate of descent) with and without a moving-belt ground plane to obtain data for comparison

An assessment of ground effects determined by static and dynamic testing techniques

A new testing technique was developed wherein the rate of descent can be included as a parameter in ground effects investigations. This technique simulates the rate of descent by horizontal motion of a model over an inclined ground board in the Langley Vortex Research Facility (VRF) During initial evaluations of the technique, dynamic ground effects data were obtained over the inclined ground board, steady state ground effects data were obtained over a flat portion of the ground board, and the results were compared to conventional static wind tunnel ground effect data both with and without a moving belt ground plane simulation. Initial testing and analysis led to the following conclusions: the moving belt ground plane had little effect on static ground effects for the configurations tested unless thrust reversers were employed; in general, rate-of-descent reduced ground effects to the point that for reversed thrust cases an expected loss of lift due to ground effects was eliminated at approach conditions; and, in general, the steady state results from the VRF matched static results obtained from the wind tunnel once the flow field stabilized over the flat portion of the ground board

The toxic sheep collar for control of sheep-killing coyotes: A progress report

The toxic sheep collar is the most selective method known for killing coyotes that prey on domestic sheep. The concept dates back to the early 1900's and has been studied at the Denver Wildlife Research Center (DWRC) since 1974. Field tests with sodium cyanide (NaCN) in 1975 were unsuccessful due to repellent properties of the toxicant and to the apparent reluctance of coyotes to attack tethered lambs wearing bulky collars. Coyotes attacked one or more tethered, collared lambs in 7 of the 19 test pastures. In all, 14 collared lambs were attacked. Eight of the collars were punctured but no dead coyotes were recovered. A smaller collar containing diphacinone was field tested in 1976. The diphacinone-filled collars were readily accepted by coyotes and lethal to them, but the slow action (5-16 days between dosing and death) of diphacinone made it difficult to assess the effectiveness of these collars under field conditions. Target flocks containing 1 to 12 collared lambs plus uncollared ewes were placed in 15 fenced pastures from which the larger ranch flocks had been removed after repeated coyote predation. One or more collared lambs were attacked in 11 of the 15 tests. An unknown number of coyotes were killed, and in most tests the subsequent incidence of predation was lower than that before the test. Captive coyotes continued to kill sheep for 4 or 5 days after they received a lethal dose of diphacinone; therefore a faster-acting toxicant is needed. This research has shown that problem coyotes can be killed with toxic collars, but further studies are needed to determine the feasibility of this approach compared with traditional means of control. In most tests to date the frequency of coyote predation has been too low and too irregular to permit effective use of the collar; target flocks were in the field for an average of 10 days before being attacked. The known disadvantages of the method include the need to sacrifice live lambs, the human hazards associated with the use of toxicants under field conditions, and the costs of managing target flocks and other sheep in the problem areas

A COMPARISON OF SEQUENTIAL AND INTEGRATED DATA FUSION FOR ESTIMATING HYDROLOGIC PROPERTIES DURING A SYNTHETIC GPR MONITORED INFILTRATION EVENT

Constraining parameters that govern variably saturated flow is important for applications ranging from quantifying water availability for ecosystems to constraining recharge rates and contaminant fluxes to groundwater. In this study I explore the effectiveness of sequential versus integrated data fusion for estimating unsaturated flow parameters using ground penetrating radar (GPR) data. In Sequential Data Fusion (SDF), geophysical imaging is used to create a map of the geophysical properties of the subsurface. These properties are then transformed to hydrologic properties that can be used to constrain an independent hydrologic inverse problem. In contrast, Integrated Data Fusion (IDF) uses the geophysical data to directly constrain hydrologic properties of interest without performing the intermediate geophysical imaging step. The comparison of SDF and IDF is performed for a synthetic study of 2D infiltration into a homogeneous soil from a constant flux point source located at the ground surface. The focus is on results for the estimation of intrinsic permeability (k) from cross- borehole GPR traveltimes collected throughout the duration of the infiltration event. The target permeability (k=7.4x10-12m2) is uniform over the 20 meter by 20 meter area modeled in this study; though the soil is homogeneous, water content is both spatially variable and transient. I use TOUGH2 to simulate infiltration, MATLAB to simulate GPR traveltimes, and PEST to perform the parameter estimation. To quantitatively compare SDF and IDF, I calculate the normalized error in estimated permeability for each method. In my study, I investigated the performance of the data fusion methods under varying survey geometries by changing the antenna spacing. In all cases I have found that IDF significantly outperforms SDF. For large antenna separations (1.7-6.7m) SDF produces an average error in estimated permeability of 73% while IDF errors are only 6%. As ray density is increased for antenna separations of 1.0-1.5m, average estimation error for SDF drops to 72%, but is reduced to only 3% for IDF. Also, SDF estimates are consistently biased lower than the target value, while IDF results are unbiased. My results suggest the IDF is a powerful new approach for hydrologic characterization of the subsurface using geophysical measurements

Comments: Forfeiture of Attorneys\u27 Fees under the Comprehensive Forfeiture Act of 1984: Not What Congress Ordered

In 1984 Congress amended the criminal forfeiture provisions of the RICO and CCE statutes. The Department of Justice has interpreted the amended laws to allow for the restraint and forfeiture of assets transferred by a defendant to defense counsel as compensation for legitimate legal services. This comment explores the legislative history of the amendments, as well as the constitutional and ethical concerns which arise under the Department\u27s interpretation, to conclude that Congress did not intend bona fide attorneys\u27 fees to be subject to the forfeiture provisions of the RICO and CCE statutes

A study of casework with fourteen male patients at the psychosomatic clinic of the Massachusetts Memorial Hospitals from June, 1949 to July, 1951

Thesis (M.S.)--Boston Universit