A5035700052- Lightning and Electromagnetic Phenomena
- Fire effects on ecosystems
- Ionosphere and magnetosphere dynamics
- Childhood Cancer Survivors' Quality of Life
- Electrical Fault Detection and Protection
- Palliative Care and End-of-Life Issues
- Earthquake Detection and Analysis
- High voltage insulation and dielectric phenomena
- Atmospheric aerosols and clouds
- Family Support in Illness
- Atmospheric chemistry and aerosols
- Acute Lymphoblastic Leukemia research
- Icing and De-icing Technologies
- Plant Water Relations and Carbon Dynamics
- Aerosol Filtration and Electrostatic Precipitation
- Power Line Communications and Noise
- Seismic Waves and Analysis
- Advanced Optical Sensing Technologies
- Astrophysics and Cosmic Phenomena
- Impact of Light on Environment and Health
- Meteorological Phenomena and Simulations
- Electrostatic Discharge in Electronics
- COVID-19 Clinical Research Studies
- Remote Sensing in Agriculture
- Cognitive Abilities and Testing
University of Oklahoma Health Sciences Center
2014-2025
University of Oklahoma
2012-2024
Oklahoma City University
2019
Wilford Hall Ambulatory Surgical Center
2014
Pennsylvania State University
1996
U.S. National Science Foundation
1984-1986
University of Florida
1977-1984
The University of Texas at Dallas
1974
In this trial, we compared Child Protective Services (CPS) recidivism outcomes between the home-based SafeCare (SC) model for child neglect and comparable services, but without SC modules, parents in CPS system across 2 quality control strategies: coached (C) uncoached implementation. is a behavioral skills training designed neglecting or maltreating parents. The study was conducted scaled-up, statewide implementation setting.Two thousand one hundred seventy-five parents, treated by 219 home...
We present a characterization of Florida lightning return stroke electric and magnetic fields derived from simultaneous measurements the at two separate stations, one station being within 15 km lightning, other either about 50 or 200 lightning. give (1) examples correlated wave forms, (2) typical first subsequent forms over distance range 1.0–200 km, (3) following statistical data which were derived: for field, rise time, initial peak value, ramp starting slope, value 170 μs, ratio μs to...
The field program of the Thunderstorm Electrification and Lightning Experiment (TELEX) took place in central Oklahoma, May–June 2003 2004. It aimed to improve understanding interrelationships among microphysics, kinematics, electrification, lightning a broad spectrum storms, particularly squall lines storms whose electrical structure is inverted from usual vertical polarity. was built around two permanent facilities: KOUN polarimetric radar Oklahoma Mapping Array. In addition, balloon-borne...
We analyzed in detail the electric field variations preceding first return strokes of 80 cloud‐to‐ground lightning flashes nine different storms observed at NASA Kennedy Space Center during summers 1976 and 1977. The are best characterized as having two sections: preliminary stepped leader. stepped‐leader electric‐field change begins a transition period few milliseconds duration marked by characteristic bipolar pulses. durations leaders lie most frequently range 6–20 milliseconds. infer from...
With an X ray detector designed for flight on a free balloon, we obtained sounding of intensity and electric‐field strength in mesoscale convective system (MCS) near Norman, Oklahoma, the spring 1995. The balloon passed through region high electric field strength, at which time increase about 2 orders magnitude occurred, lasting approximately 1 min. returned to background levels lightning flash that reduced measured balloon. This observation suggests production mechanism rays observed is...
We present correlated measurements of the voltage induced on a power line by nearby lightning and vertical electric field intensity from that lightning. Data are given for more than 100 first strokes 200 subsequent with ground strike point located triangulation using network television cameras thunder ranging. Voltages were measured at one end 460 m unenergized distribution which was open-circuited both ends. A neutral wire beneath grounded The time-domain voltaqe waveforms detected recorded...
We present observations of a rocket‐and‐wire triggered lightning flash obtained with high‐speed video cameras recording 5400 and 50000 frames per second (frame times 185 μ s 20 s) time‐synchronized current electric field measurements. Transient leader channels were observed precursor pulses occurring before the development sustained upward positive that initiated initial continuous current. The stepped constant speed 5.6 × 10 4 m −1 over its 100 m. wire destruction occurred discontinuously...
[1] We report observations of two negative polarity gigantic jets sufficiently near very high-frequency (VHF) lightning mapping networks that the associated characteristics and charge transfer could be investigated. In both cases jet-producing flash began as ordinary intracloud with upper level channels attempting to exit cloud, then produced upward jet. Neither had developed ground, confirming major during occurred between cloud ionosphere. The leader progression one event was detected at...
The temporal and spatial development of sprite‐producing lightning flashes is examined with coordinated observations over an asymmetric mesoscale convective system (MCS) on 29 June 2011 near the Oklahoma Lightning Mapping Array (LMA). Sprites produced by a total 26 were observed simultaneously video from Bennett, Colorado Hawley, Texas, enabling triangulation sprites in comparison parent (in particular, negatively charged stepped leaders) three‐dimensional space. In general, prompt within 20...
Abstract We present new high‐speed video observations of a natural negative stepped leader and subsequent dart‐stepped leader. Observations were made at distance 770 m using camera 10,000 frames per second, microwave‐frequency radio receiver, broadband electric field antenna, an avalanche photodiode array. Lightning breakdown was observed in detail for both the During breakdown, detailed images captured discharge structures near tips. These bear remarkable resemblance to corona streamer zone...
Rural communities are among the most underserved and resource-scarce populations in United States. However, there limited data on COVID-19 outcomes rural America. This study aims to compare hospitalization rates inpatient mortality SARS-CoV-2-infected persons stratified by residential rurality.
For 46 multiple‐stroke flashes in which each stroke ground termination was located using a TV camera network and thunder ranging, 15 (33%) had one or more subsequent return strokes whose initial electric field peak normalized to 100 km greater than the first‐stroke of flash. In 9 these with peaks first followed same channel as stroke; five different ground; flash occurred both channel. The interstroke intervals immediately preceding 13 larger that geometric mean (GM) duration 98 ms, 1.7...
We have analyzed very high frequency lightning mapping observations and remote magnetic field measurements to investigate connections between morphology impulse charge moment change (iCMC) of negative cloud‐to‐ground (CG) strokes with estimated peak currents. Four morphologies are identified for a total 2126 within optimum detection range the North Alabama Lightning Mapping Array, statistical iCMC distributions given each these types. Almost all (>90%) largest moments (greater than −200 C...
Purpose: Cardiovascular risk factors (CVRFs) later in life potentiate for late cardiovascular disease (CVD) from cardiotoxic treatment among survivors. This study evaluated the association of baseline CVRFs and CVD early survivorship period. Methods: analysis included patients ages 0-29 at initial diagnosis reported institutional cancer registry between 2010 2017 (n = 1228). Patients who died within 5 years 168), those not seen oncology clinic 312), with one year 17) were excluded....
From a data base consisting of (1) correlated optical and electric field measurements for 11 natural lightning strokes in Florida, (2) current 32 artificially initiated (triggered) New Mexico, (3) 36 triggered dart leader speed is examined as function the following return stroke initial peak, duration previous interstroke interval (excluding continuing current, if present). Return peaks both Mexico Florida were converted to via field‐current regression equation obtained by Willett et al....
During a balloon flight into and above the stratiform region of mesoscale convective system, we observed three x‐ray pulses while was at an altitude approximately 15 km MSL (atmospheric pressure 130 mb). These were one to two orders magnitude background count rate with peak fluxes between 37 270 (cm²‐s‐sr) −1 durations about second. No significant electric field measured time these pulses.
We used realistic models of upper-atmospheric winds in a three-dimensional acoustic ray-tracing program to calculate how much wind refraction alters transit speed and azimuth arrival for long-distance paths. Transit varied by 20% or more, bearing deviations up ten degrees were found, depending on the season direction waves travel. On average, predicted seasonal trends corresponded osbervations, but calculated standard exceed mean values, making simple corrections useless individual cases....
Characteristics of stroke occurrence are investigated for lightning to ground observed near Tampa, Florida (latitude = 27.4°N, longitude 82.2°W) during three days convective thunderstorm activity in July 1979. Strokes were identified from both wideband (0.2 Hz 1.5 MHz) electric field records and simultaneous video tape recordings a network TV cameras. The average number strokes per flash was 4.0 105 flashes the channels 1.6 78 multiple‐stroke flashes. Interstroke intervals distributed...
A comprehensive study of a three‐stroke lightning flash that struck the 150‐m weather tower at Kennedy Space Center (KSC) was recently reported by Uman et al. (1978). Here we supplement presenting three‐dimensional locations sources VHF (30–50 MHz) radiation generated KSC flash. These were obtained measuring with detection and ranging (LDAR) system difference in time arrival (DTOA) radiated pulses four ground stations then calculating from DTOA data. The data via newly developed...
A lightning flash that struck the 150-meter weather tower at Kennedy Space Center was studied by several research groups using varioul techniques. The had unusually large peak currents and a stepped leader of relatively short duration. charged regions neutralized three return strokes were located within horizontal layer between heights about 6 8 kilometers, where environmental temperatures -10 degrees to -20 C. charge source for first stroke coincided with vertical shaft precipitation...
Balloon‐borne gamma‐ray and electric‐field‐change instruments were launched into a daytime summer thunderstorm to evaluate new experimental design test hypotheses for the production of transient luminous events (TLE) (eg. sprites, blue jets) in mesosphere. While ascending, instrument triggered many times on signals from instrument, recording background at those times. A greater than three‐fold increase flux was observed as balloon descended through anvil where strong electric field suspected...