Wildland Fire Emission Sampling at Fishlake National Forest, Utah Using an Unmanned Aircraft System.

Emissions from a stand replacement prescribed burn were sampled using an unmanned aircraft system (UAS, or "drone") in Fishlake National Forest, Utah, U.S.A. Sixteen flights over three days in June 2019 provided emission factors for a broad range of compounds including carbon monoxide (CO), carbon dioxide (CO2), nitric oxide (NO), nitrogen oxide (NO2), particulate matter < 2.5 microns in diameter (PM2.5), volatile organic compounds (VOCs) including carbonyls, black carbon, and elemental/organic carbon. To our knowledge, this is the first UAS-based emission sampling for a fire of this magnitude, including both slash pile and crown fires resulting in wildfire-like conditions. The burns consisted of drip torch ignitions as well as ground-mobile and aerial helicopter ignitions of large stands comprising over 1,000 ha, allowing for comparison of same-species emission factors burned under different conditions. The use of a UAS for emission sampling minimizes risk to personnel and equipment, allowing flexibility in sampling location and ensuring capture of representative, fresh smoke constituents. PM2.5 emission factors varied 5-fold and, like most pollutants, varied inversely with combustion efficiency resulting in lower emission factors from the slash piles than the crown fires.

Methodology for characterizing emissions from small (0.5-2 MTD) batch-fed gasification systems using multiple waste compositions.

A compact, containerized gasification system was characterized for air emissions while burning four waste types. A methodology is presented for developing a standardized test waste composition and demonstrated using three military and one civilian waste types. Batch charges of waste were processed through a gasification chamber, afterburner, and wet scrubber. The 0.5-2 metric ton per day (MTD) system was designed for mobile deployment by the military in forward operations but would be applicable to small scale civilian applications. Emissions data from these types of small capacity, cyclically operated systems are lacking, limiting efforts to compare technologies and their environmental performance. Eight tests were conducted in a 7-day period at the Kilauea Military Camp (KMC) in Hawaii. The pollutants characterized were chosen based on their regulatory and health relevance: particulate matter (PM), mercury (Hg), elemental composition, volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Averaged data from 4-hour runs, including startups and shutdowns, indicated that five of the nine EPA-regulated compounds (lead, cadmium, Hg, sulfur dioxide, and hydrogen chloride) were under the emission limits set for Other Solid Waste Incineration Units (OSWI) while four, PCDD/PCDF, PM, nitrogen oxides, and carbon monoxide, were higher. The procedures through which waste compositions were created and emissions were characterized provide a methodology by which differing waste to energy technologies can be compared on an equivalent basis. This system's emissions compare favorably with alternative disposal methods. PM and PCDD/PCDF emission factors were, respectively, over 39 and 9 times lower from this unit than from published data on burning simulated military waste in an air curtain incinerator and in open burn piles ("burn pits").

Field Determination of Multipollutant, Open Area Combustion Source Emission Factors with a Hexacopter Unmanned Aerial Vehicle.

An emission sensor/sampler system was coupled to a National Aeronautics and Space Administration (NASA) hexacopter unmanned aerial vehicle (UAV) to characterize gases and particles in the plumes emitted from open burning of military ordnance. The UAV/sampler was tested at two field sites with test and sampling flights spanning over 16 hours of flight time. The battery-operated UAV was remotely maneuvered into the plumes at distances from the pilot of over 600 m and at altitudes of up to 122 m above ground level. While the flight duration could be affected by sampler payload (3.2 to 4.6 kg) and meteorological conditions, the 57 sampling flights, ranging from 4 to 12 min, were typically terminated when the plume concentrations of CO2 were diluted to near ambient levels. Two sensor/sampler systems, termed "Kolibri," were variously configured to measure particulate matter, metals, chloride, perchlorate, volatile organic compounds, chlorinated dioxins/furans, and nitrogen-based organics for determination of emission factors. Gas sensors were selected based on their applicable concentration range, light weight, freedom from interferents, and response/recovery times. Samplers were designed, constructed, and operated based on U.S. Environmental Protection Agency (EPA) methods and quality control criteria. Results show agreement with published emission factors and good reproducibility (e.g., 26% relative standard deviation for PM2.5). The UAV/Kolibri represents a significant advance in multipollutant emission characterization capabilities for open area sources, safely and effectively making measurements heretofore deemed too hazardous for personnel or beyond the reach of land-based samplers.

Sleep in the surgical intensive care unit: continuous polygraphic recording of sleep in nine patients receiving postoperative care.

Sleep was studied in nine patients for two to four days after major non-cardiac surgery by continuous polygraphic recording of electroencephalogram, electrooculogram, and electromyogram. Presumed optimal conditions for sleep were provided by a concerted effort by staff to offer constant pain relief and reduce environmental disturbance to a minimum. All patients were severely deprived of sleep compared with normal. The mean cumulative sleep time (stage 1 excluded) for the first two nights, daytime sleep included, was less than two hours a night. Stages 3 and 4 and rapid eye movement sleep were severely or completely suppressed. The sustained wakefulness could be attributed to pain and environmental disturbance to only minor degree. Sleep time as estimated by nursing staff was often grossly misjudged and consistently overestimated when compared with the parallel polygraphic recording. The grossly abnormal sleep pattern observed in these patients may suggest some fundamental disarrangement of the sleep-wake regulating mechanism.