The NASA Thunderstorm Overflight Program (TOP): Research in atmospheric electricity from an instrumented U-2 aircraft platform

An overview of the NASA Thunderstorm Overflight Program (TOP) is presented. The various instruments flown on the NASA U-2 aircraft, as well as the ground instrumentation used to collect optical and electronic signature from the lightning events, are discussed. Samples of some of the photographic and electronic signatures are presented. Approximately 6400 electronic data samples of optical pulses were collected and are being analyzed

Luminous electrical phenomena in Huntsville, Alabama, tornadoes on April 3, 1974

Unusual lightning and varicolored luminous phenomena were observed on the evening of April 3, 1974, when severe tornadoes passed through Madison County, Alabama. Photographs and eyewitness accounts of this electrical activity are related to the trajectories of the tornadoes and the damage areas they produced

Light airplane crash tests at three pitch angles

Three similar twin-engine general aviation airplane specimens were crash tested at an impact dynamics research facility at 27 m/sec, a flight path angle of -15 deg, and pitch angles of -15 deg, 0 deg, and 15 deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed

Crash tests of four identical high-wing single-engine airplanes

Four identical four place, high wing, single engine airplane specimens with nominal masses of 1043 kg were crash tested at the Langley Impact Dynamics Research Facility under controlled free flight conditions. These tests were conducted with nominal velocities of 25 m/sec along the flight path angles, ground contact pitch angles, and roll angles. Three of the airplane specimens were crashed on a concrete surface; one was crashed on soil. Crash tests revealed that on a hard landing, the main landing gear absorbed about twice the energy for which the gear was designed but sprang back, tending to tip the airplane up to its nose. On concrete surfaces, the airplane impacted and remained in the impact attitude. On soil, the airplane flipped over on its back. The crash impact on the nose of the airplane, whether on soil or concrete, caused massive structural crushing of the forward fuselage. The liveable volume was maintained in both the hard landing and the nose down specimens but was not maintained in the roll impact and nose down on soil specimens

Light airplane crash tests at impact velocities of 13 and 27 m/sec

Two similar general aviation airplanes were crash tested at the Langley impact dynamics research facility at velocities of 13 and 27 m/sec. Other flight parameters were held constant. The facility, instrumentation, tests specimens, and test method are briefly described. Structural damage and accelerometer data are discussed

Thunderstorm observations from Space Shuttle

Results of the Nighttime/Daytime Optical Survey of Lightning (NOSL) experiments done on the STS-2 and STS-4 flights are covered. During these two flights of the Space Shuttle Columbia, the astronaut teams of J. Engle and R. Truly, and K. Mattingly II and H. Hartsfield took motion pictures of thunderstorms with a 16 mm cine camera. Film taken during daylight showed interesting thunderstorm cloud formations, where individual frames taken tens of seconds apart, when viewed as stereo pairs, provided information on the three-dimensional structure of the cloud systems. Film taken at night showed clouds illuminated by lightning with discharges that propagated horizontally at speeds of up to 10 to the 5th m/sec and extended for distances on the order of 60 km or more

Lightning observations from the Space Shuttle

Motion pictures were taken at night from the space shuttle that show lightning discharges spreading horizontally at speeds of .00001 m/sec for distances over 60 km. Tape recordings were made of the accompanying optical pulses detected with a photocell optical system. The observations show that lightning is often a mesoscale phenomenon that conveys large amounts of electric charge and energy derived from an extensive cloud system into a cloud-to-ground discharge. Several video tape recordings of lightning discharges were obtained on shuttle flights since the termination of the NOSL program. The size and location of the lightning illuminated cloud images is now being analyzed, and comparisons are made with meteorological data concerning the cloud system obtained from the McIDAS

The effects of ultraviolet irradiation on the pigment cells of the PET/Wmr mouse epidermis

Epidermal melanocytes in mammals are known to occur in a variety of shapes, sizes, and colors. The basic melanocyte morphology is dependent upon genetics, but there are a number of environmental factors that can cause modification. In the epidermis of PET/\vrnr mice, the population of rnelanocytes reaches a peak and begins to decline during the first post-natal week, and has disappeared within four weeks. Dispersed among the large, highly DOPA-reactive melanocytes are miniature melanocytes. These miniature melanocytes are weakly DOPA-reactive and appear early in the post-natal period. The miniature melanocyte population is relatively constant and these miniature cells are among the last to disappear. The melanocytes of the epidermis in the PET/Hmr mouse were subjected to 3 different wavelengths of UV irradiation. Melanocyte counts of the experimental animals were compared with similar counts of control, non irradiated animals in the first post-natal week. The evidence indicates that these weakly DOPA-reactive, miniature melanocytes remain in fairly constant numbers during the first postnatal week, although UV irradiation did provoke a very clear increase in the numbers of the larger, highly DOPA-reactive melanocytes. That miniature melanocytes persisted throughout the experimental treatments success that they may represent a separate form of melanocyte

Resistance-in-series modeling in high-shear rotary ultrafiltration

Large volumes of spent oil-in-water emulsions are produced in the metal working (MW) industry. In high-shear rotary ultrafiltration (HSR-UF), disk membranes are rotated at speeds up to 1,750 rpm to generate hydraulic turbulence, which scours the membrane surface. Thus, the pump is required only to provide transmernbrane pressure and a small amount of recirculation.;A parametric waste-specific study was conducted to assess the ability of the resistance-in-series (RIS) permeate flux model to predict pressure-flux data collected in the HSR-UF of a synthetic MW fluid. Experiments were conducted using a pilot-scale HSR-UF system with a 0.11 mum average-pore size membrane at a single temperature operating temperature of 110°F. Experiments were conducted at discrete membrane rotational speed/MW fluid concentration combinations over an applied pressure range of 103 to 517 kPa (15 to 75 psig), membrane rotational speeds of 1,150 to 1,750 rpm, and synthetic MW fluid concentrations of 5 to 40% MW fluid.;The RIS model was modified to include membrane rotational speed and oil concentration terms in order to predict the permeate flux at any given transmembrane pressure, rotational speed, and oil concentration. (Abstract shortened by UMI.)